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android / platform / external / qt / 9adc00701674d3638e8a2d68e450a6b1a66f0294 / . / Mac-4.7.4 / src / declarative / graphicsitems / qdeclarativelistview.cpp
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/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtDeclarative module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** This file may be used under the terms of the GNU Lesser General Public
** License version 2.1 as published by the Free Software Foundation and
** appearing in the file LICENSE.LGPL included in the packaging of this
** file. Please review the following information to ensure the GNU Lesser
** General Public License version 2.1 requirements will be met:
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of this
** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
** http://www.gnu.org/copyleft/gpl.html.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "private/qdeclarativelistview_p.h"
#include "private/qdeclarativeflickable_p_p.h"
#include "private/qdeclarativevisualitemmodel_p.h"
#include "private/qdeclarativesmoothedanimation_p_p.h"
#include <qdeclarativeexpression.h>
#include <qdeclarativeengine.h>
#include <qdeclarativeguard_p.h>
#include <qdeclarativeinfo.h>
#include <qlistmodelinterface_p.h>
#include <qmath.h>
#include <QKeyEvent>
#include "qplatformdefs.h"
QT_BEGIN_NAMESPACE
#ifndef QML_FLICK_SNAPONETHRESHOLD
#define QML_FLICK_SNAPONETHRESHOLD 30
#endif
void QDeclarativeViewSection::setProperty(const QString &property)
{
if (property != m_property) {
m_property = property;
emit propertyChanged();
}
}
void QDeclarativeViewSection::setCriteria(QDeclarativeViewSection::SectionCriteria criteria)
{
if (criteria != m_criteria) {
m_criteria = criteria;
emit criteriaChanged();
}
}
void QDeclarativeViewSection::setDelegate(QDeclarativeComponent *delegate)
{
if (delegate != m_delegate) {
m_delegate = delegate;
emit delegateChanged();
}
}
QString QDeclarativeViewSection::sectionString(const QString &value)
{
if (m_criteria == FirstCharacter)
return value.isEmpty() ? QString() : value.at(0);
else
return value;
}
//----------------------------------------------------------------------------
class FxListItem
{
public:
FxListItem(QDeclarativeItem *i, QDeclarativeListView *v) : item(i), section(0), view(v) {
attached = static_cast<QDeclarativeListViewAttached*>(qmlAttachedPropertiesObject<QDeclarativeListView>(item));
if (attached)
attached->setView(view);
}
~FxListItem() {}
qreal position() const {
if (section) {
if (view->orientation() == QDeclarativeListView::Vertical)
return section->y();
else
return (view->effectiveLayoutDirection() == Qt::RightToLeft ? -section->width()-section->x() : section->x());
} else {
return itemPosition();
}
}
qreal itemPosition() const {
if (view->orientation() == QDeclarativeListView::Vertical)
return item->y();
else
return (view->effectiveLayoutDirection() == Qt::RightToLeft ? -item->width()-item->x() : item->x());
}
qreal size() const {
if (section)
return (view->orientation() == QDeclarativeListView::Vertical ? item->height()+section->height() : item->width()+section->width());
else
return (view->orientation() == QDeclarativeListView::Vertical ? item->height() : item->width());
}
qreal itemSize() const {
return (view->orientation() == QDeclarativeListView::Vertical ? item->height() : item->width());
}
qreal sectionSize() const {
if (section)
return (view->orientation() == QDeclarativeListView::Vertical ? section->height() : section->width());
return 0.0;
}
qreal endPosition() const {
if (view->orientation() == QDeclarativeListView::Vertical) {
return item->y() + (item->height() >= 1.0 ? item->height() : 1) - 1;
} else {
return (view->effectiveLayoutDirection() == Qt::RightToLeft
? -item->width()-item->x() + (item->width() >= 1.0 ? item->width() : 1)
: item->x() + (item->width() >= 1.0 ? item->width() : 1)) - 1;
}
}
void setPosition(qreal pos) {
if (view->orientation() == QDeclarativeListView::Vertical) {
if (section) {
section->setY(pos);
pos += section->height();
}
item->setY(pos);
} else {
if (view->effectiveLayoutDirection() == Qt::RightToLeft) {
if (section) {
section->setX(-section->width()-pos);
pos += section->width();
}
item->setX(-item->width()-pos);
} else {
if (section) {
section->setX(pos);
pos += section->width();
}
item->setX(pos);
}
}
}
void setSize(qreal size) {
if (view->orientation() == QDeclarativeListView::Vertical)
item->setHeight(size);
else
item->setWidth(size);
}
bool contains(qreal x, qreal y) const {
return (x >= item->x() && x < item->x() + item->width() &&
y >= item->y() && y < item->y() + item->height());
}
QDeclarativeItem *item;
QDeclarativeItem *section;
QDeclarativeListView *view;
QDeclarativeListViewAttached *attached;
int index;
};
//----------------------------------------------------------------------------
class QDeclarativeListViewPrivate : public QDeclarativeFlickablePrivate
{
Q_DECLARE_PUBLIC(QDeclarativeListView)
public:
QDeclarativeListViewPrivate()
: currentItem(0), orient(QDeclarativeListView::Vertical), layoutDirection(Qt::LeftToRight)
, visiblePos(0), visibleIndex(0)
, averageSize(100.0), currentIndex(-1), requestedIndex(-1)
, itemCount(0), highlightRangeStart(0), highlightRangeEnd(0)
, highlightRangeStartValid(false), highlightRangeEndValid(false)
, highlightComponent(0), highlight(0), trackedItem(0)
, moveReason(Other), buffer(0), highlightPosAnimator(0), highlightSizeAnimator(0)
, sectionCriteria(0), spacing(0.0)
, highlightMoveSpeed(400), highlightMoveDuration(-1)
, highlightResizeSpeed(400), highlightResizeDuration(-1), highlightRange(QDeclarativeListView::NoHighlightRange)
, snapMode(QDeclarativeListView::NoSnap), overshootDist(0.0)
, footerComponent(0), footer(0), headerComponent(0), header(0)
, bufferMode(BufferBefore | BufferAfter)
, ownModel(false), wrap(false), autoHighlight(true), haveHighlightRange(false)
, correctFlick(false), inFlickCorrection(false), lazyRelease(false)
, deferredRelease(false), layoutScheduled(false), currentIndexCleared(false)
, inViewportMoved(false)
, minExtentDirty(true), maxExtentDirty(true)
{}
void init();
void clear();
FxListItem *createItem(int modelIndex);
void releaseItem(FxListItem *item);
FxListItem *visibleItem(int modelIndex) const {
if (modelIndex >= visibleIndex && modelIndex < visibleIndex + visibleItems.count()) {
for (int i = modelIndex - visibleIndex; i < visibleItems.count(); ++i) {
FxListItem *item = visibleItems.at(i);
if (item->index == modelIndex)
return item;
}
}
return 0;
}
FxListItem *firstVisibleItem() const {
const qreal pos = isRightToLeft() ? -position()-size() : position();
for (int i = 0; i < visibleItems.count(); ++i) {
FxListItem *item = visibleItems.at(i);
if (item->index != -1 && item->endPosition() > pos)
return item;
}
return visibleItems.count() ? visibleItems.first() : 0;
}
// Returns the item before modelIndex, if created.
// May return an item marked for removal.
FxListItem *itemBefore(int modelIndex) const {
if (modelIndex < visibleIndex)
return 0;
int idx = 1;
int lastIndex = -1;
while (idx < visibleItems.count()) {
FxListItem *item = visibleItems.at(idx);
if (item->index != -1)
lastIndex = item->index;
if (item->index == modelIndex)
return visibleItems.at(idx-1);
++idx;
}
if (lastIndex == modelIndex-1)
return visibleItems.last();
return 0;
}
void regenerate() {
Q_Q(QDeclarativeListView);
if (q->isComponentComplete()) {
if (header) {
if (q->scene())
q->scene()->removeItem(header->item);
header->item->deleteLater();
delete header;
header = 0;
}
if (footer) {
if (q->scene())
q->scene()->removeItem(footer->item);
footer->item->deleteLater();
delete footer;
footer = 0;
}
updateHeader();
updateFooter();
clear();
setPosition(0);
q->refill();
updateCurrent(currentIndex);
}
}
void mirrorChange() {
Q_Q(QDeclarativeListView);
regenerate();
}
bool isRightToLeft() const {
Q_Q(const QDeclarativeListView);
return orient == QDeclarativeListView::Horizontal && q->effectiveLayoutDirection() == Qt::RightToLeft;
}
qreal position() const {
Q_Q(const QDeclarativeListView);
return orient == QDeclarativeListView::Vertical ? q->contentY() : q->contentX();
}
void setPosition(qreal pos) {
Q_Q(QDeclarativeListView);
if (orient == QDeclarativeListView::Vertical) {
q->QDeclarativeFlickable::setContentY(pos);
} else {
if (isRightToLeft())
q->QDeclarativeFlickable::setContentX(-pos-size());
else
q->QDeclarativeFlickable::setContentX(pos);
}
}
qreal size() const {
Q_Q(const QDeclarativeListView);
return orient == QDeclarativeListView::Vertical ? q->height() : q->width();
}
qreal originPosition() const {
qreal pos = 0;
if (!visibleItems.isEmpty()) {
pos = (*visibleItems.constBegin())->position();
if (visibleIndex > 0)
pos -= visibleIndex * (averageSize + spacing);
}
return pos;
}
qreal lastPosition() const {
qreal pos = 0;
if (!visibleItems.isEmpty()) {
int invisibleCount = visibleItems.count() - visibleIndex;
for (int i = visibleItems.count()-1; i >= 0; --i) {
if (visibleItems.at(i)->index != -1) {
invisibleCount = model->count() - visibleItems.at(i)->index - 1;
break;
}
}
pos = (*(--visibleItems.constEnd()))->endPosition() + invisibleCount * (averageSize + spacing);
} else if (model && model->count()) {
pos = model->count() * averageSize + (model->count()-1) * spacing;
}
return pos;
}
qreal startPosition() const {
return isRightToLeft() ? -lastPosition()-1 : originPosition();
}
qreal endPosition() const {
return isRightToLeft() ? -originPosition()-1 : lastPosition();
}
qreal positionAt(int modelIndex) const {
if (FxListItem *item = visibleItem(modelIndex))
return item->position();
if (!visibleItems.isEmpty()) {
if (modelIndex < visibleIndex) {
int count = visibleIndex - modelIndex;
qreal cs = 0;
if (modelIndex == currentIndex && currentItem) {
cs = currentItem->size() + spacing;
--count;
}
return (*visibleItems.constBegin())->position() - count * (averageSize + spacing) - cs;
} else {
int idx = visibleItems.count() - 1;
while (idx >= 0 && visibleItems.at(idx)->index == -1)
--idx;
if (idx < 0)
idx = visibleIndex;
else
idx = visibleItems.at(idx)->index;
int count = modelIndex - idx - 1;
return (*(--visibleItems.constEnd()))->endPosition() + spacing + count * (averageSize + spacing) + 1;
}
}
return 0;
}
qreal endPositionAt(int modelIndex) const {
if (FxListItem *item = visibleItem(modelIndex))
return item->endPosition();
if (!visibleItems.isEmpty()) {
if (modelIndex < visibleIndex) {
int count = visibleIndex - modelIndex;
return (*visibleItems.constBegin())->position() - (count - 1) * (averageSize + spacing) - spacing - 1;
} else {
int idx = visibleItems.count() - 1;
while (idx >= 0 && visibleItems.at(idx)->index == -1)
--idx;
if (idx < 0)
idx = visibleIndex;
else
idx = visibleItems.at(idx)->index;
int count = modelIndex - idx - 1;
return (*(--visibleItems.constEnd()))->endPosition() + count * (averageSize + spacing);
}
}
return 0;
}
QString sectionAt(int modelIndex) {
if (FxListItem *item = visibleItem(modelIndex))
return item->attached->section();
QString section;
if (sectionCriteria) {
QString propValue = model->stringValue(modelIndex, sectionCriteria->property());
section = sectionCriteria->sectionString(propValue);
}
return section;
}
bool isValid() const {
return model && model->count() && model->isValid();
}
qreal snapPosAt(qreal pos) {
if (FxListItem *snapItem = snapItemAt(pos))
return snapItem->position();
if (visibleItems.count()) {
qreal firstPos = visibleItems.first()->position();
qreal endPos = visibleItems.last()->position();
if (pos < firstPos) {
return firstPos - qRound((firstPos - pos) / averageSize) * averageSize;
} else if (pos > endPos)
return endPos + qRound((pos - endPos) / averageSize) * averageSize;
}
return qRound((pos - originPosition()) / averageSize) * averageSize + originPosition();
}
FxListItem *snapItemAt(qreal pos) {
FxListItem *snapItem = 0;
for (int i = 0; i < visibleItems.count(); ++i) {
FxListItem *item = visibleItems[i];
if (item->index == -1)
continue;
qreal itemTop = item->position();
if (highlight && itemTop >= pos && item->endPosition() <= pos + highlight->size() - 1)
return item;
if (itemTop+item->size()/2 >= pos && itemTop-item->size()/2 < pos)
snapItem = item;
}
return snapItem;
}
int lastVisibleIndex() const {
int lastIndex = -1;
for (int i = visibleItems.count()-1; i >= 0; --i) {
FxListItem *listItem = visibleItems.at(i);
if (listItem->index != -1) {
lastIndex = listItem->index;
break;
}
}
return lastIndex;
}
// map a model index to visibleItems index.
int mapFromModel(int modelIndex) const {
if (modelIndex < visibleIndex || modelIndex >= visibleIndex + visibleItems.count())
return -1;
for (int i = 0; i < visibleItems.count(); ++i) {
FxListItem *listItem = visibleItems.at(i);
if (listItem->index == modelIndex)
return i;
if (listItem->index > modelIndex)
return -1;
}
return -1; // Not in visibleList
}
void updateViewport() {
Q_Q(QDeclarativeListView);
if (orient == QDeclarativeListView::Vertical) {
q->setContentHeight(endPosition() - startPosition() + 1);
} else {
q->setContentWidth(endPosition() - startPosition() + 1);
}
}
void itemGeometryChanged(QDeclarativeItem *item, const QRectF &newGeometry, const QRectF &oldGeometry) {
Q_Q(QDeclarativeListView);
QDeclarativeFlickablePrivate::itemGeometryChanged(item, newGeometry, oldGeometry);
if (!q->isComponentComplete())
return;
if (item != contentItem && (!highlight || item != highlight->item)) {
if ((orient == QDeclarativeListView::Vertical && newGeometry.height() != oldGeometry.height())
|| (orient == QDeclarativeListView::Horizontal && newGeometry.width() != oldGeometry.width())) {
scheduleLayout();
}
}
if ((header && header->item == item) || (footer && footer->item == item)) {
if (header)
updateHeader();
if (footer)
updateFooter();
}
if (currentItem && currentItem->item == item)
updateHighlight();
if (trackedItem && trackedItem->item == item)
q->trackedPositionChanged();
}
// for debugging only
void checkVisible() const {
int skip = 0;
for (int i = 0; i < visibleItems.count(); ++i) {
FxListItem *listItem = visibleItems.at(i);
if (listItem->index == -1) {
++skip;
} else if (listItem->index != visibleIndex + i - skip) {
qFatal("index %d %d %d", visibleIndex, i, listItem->index);
}
}
}
void refill(qreal from, qreal to, bool doBuffer = false);
void scheduleLayout();
void layout();
void updateUnrequestedIndexes();
void updateUnrequestedPositions();
void updateTrackedItem();
void createHighlight();
void updateHighlight();
void createSection(FxListItem *);
void updateSections();
void updateCurrentSection();
void updateCurrent(int);
void updateAverage();
void updateHeader();
void updateFooter();
void fixupPosition();
void positionViewAtIndex(int index, int mode);
virtual void fixup(AxisData &data, qreal minExtent, qreal maxExtent);
virtual void flick(QDeclarativeFlickablePrivate::AxisData &data, qreal minExtent, qreal maxExtent, qreal vSize,
QDeclarativeTimeLineCallback::Callback fixupCallback, qreal velocity);
QDeclarativeGuard<QDeclarativeVisualModel> model;
QVariant modelVariant;
QList<FxListItem*> visibleItems;
QHash<QDeclarativeItem*,int> unrequestedItems;
FxListItem *currentItem;
QDeclarativeListView::Orientation orient;
Qt::LayoutDirection layoutDirection;
qreal visiblePos;
int visibleIndex;
qreal averageSize;
int currentIndex;
int requestedIndex;
int itemCount;
qreal highlightRangeStart;
qreal highlightRangeEnd;
bool highlightRangeStartValid;
bool highlightRangeEndValid;
QDeclarativeComponent *highlightComponent;
FxListItem *highlight;
FxListItem *trackedItem;
enum MovementReason { Other, SetIndex, Mouse };
MovementReason moveReason;
int buffer;
QSmoothedAnimation *highlightPosAnimator;
QSmoothedAnimation *highlightSizeAnimator;
QDeclarativeViewSection *sectionCriteria;
QString currentSection;
static const int sectionCacheSize = 4;
QDeclarativeItem *sectionCache[sectionCacheSize];
qreal spacing;
qreal highlightMoveSpeed;
int highlightMoveDuration;
qreal highlightResizeSpeed;
int highlightResizeDuration;
QDeclarativeListView::HighlightRangeMode highlightRange;
QDeclarativeListView::SnapMode snapMode;
qreal overshootDist;
QDeclarativeComponent *footerComponent;
FxListItem *footer;
QDeclarativeComponent *headerComponent;
FxListItem *header;
enum BufferMode { NoBuffer = 0x00, BufferBefore = 0x01, BufferAfter = 0x02 };
int bufferMode;
mutable qreal minExtent;
mutable qreal maxExtent;
bool ownModel : 1;
bool wrap : 1;
bool autoHighlight : 1;
bool haveHighlightRange : 1;
bool correctFlick : 1;
bool inFlickCorrection : 1;
bool lazyRelease : 1;
bool deferredRelease : 1;
bool layoutScheduled : 1;
bool currentIndexCleared : 1;
bool inViewportMoved : 1;
mutable bool minExtentDirty : 1;
mutable bool maxExtentDirty : 1;
};
void QDeclarativeListViewPrivate::init()
{
Q_Q(QDeclarativeListView);
q->setFlag(QGraphicsItem::ItemIsFocusScope);
addItemChangeListener(this, Geometry);
QObject::connect(q, SIGNAL(movementEnded()), q, SLOT(animStopped()));
q->setFlickableDirection(QDeclarativeFlickable::VerticalFlick);
::memset(sectionCache, 0, sizeof(QDeclarativeItem*) * sectionCacheSize);
}
void QDeclarativeListViewPrivate::clear()
{
timeline.clear();
for (int i = 0; i < visibleItems.count(); ++i)
releaseItem(visibleItems.at(i));
visibleItems.clear();
for (int i = 0; i < sectionCacheSize; ++i) {
delete sectionCache[i];
sectionCache[i] = 0;
}
visiblePos = header ? header->size() : 0;
visibleIndex = 0;
releaseItem(currentItem);
currentItem = 0;
createHighlight();
trackedItem = 0;
minExtentDirty = true;
maxExtentDirty = true;
itemCount = 0;
}
FxListItem *QDeclarativeListViewPrivate::createItem(int modelIndex)
{
Q_Q(QDeclarativeListView);
// create object
requestedIndex = modelIndex;
FxListItem *listItem = 0;
if (QDeclarativeItem *item = model->item(modelIndex, false)) {
listItem = new FxListItem(item, q);
listItem->index = modelIndex;
// initialise attached properties
if (sectionCriteria) {
QString propValue = model->stringValue(modelIndex, sectionCriteria->property());
listItem->attached->m_section = sectionCriteria->sectionString(propValue);
if (modelIndex > 0) {
if (FxListItem *item = itemBefore(modelIndex))
listItem->attached->m_prevSection = item->attached->section();
else
listItem->attached->m_prevSection = sectionAt(modelIndex-1);
}
if (modelIndex < model->count()-1) {
if (FxListItem *item = visibleItem(modelIndex+1))
listItem->attached->m_nextSection = item->attached->section();
else
listItem->attached->m_nextSection = sectionAt(modelIndex+1);
}
}
if (model->completePending()) {
// complete
listItem->item->setZValue(1);
listItem->item->setParentItem(q->contentItem());
model->completeItem();
} else {
listItem->item->setParentItem(q->contentItem());
}
QDeclarativeItemPrivate *itemPrivate = static_cast<QDeclarativeItemPrivate*>(QGraphicsItemPrivate::get(item));
itemPrivate->addItemChangeListener(this, QDeclarativeItemPrivate::Geometry);
if (sectionCriteria && sectionCriteria->delegate()) {
if (listItem->attached->m_prevSection != listItem->attached->m_section)
createSection(listItem);
}
unrequestedItems.remove(listItem->item);
}
requestedIndex = -1;
return listItem;
}
void QDeclarativeListViewPrivate::releaseItem(FxListItem *item)
{
Q_Q(QDeclarativeListView);
if (!item || !model)
return;
if (trackedItem == item)
trackedItem = 0;
QDeclarativeItemPrivate *itemPrivate = static_cast<QDeclarativeItemPrivate*>(QGraphicsItemPrivate::get(item->item));
itemPrivate->removeItemChangeListener(this, QDeclarativeItemPrivate::Geometry);
if (model->release(item->item) == 0) {
// item was not destroyed, and we no longer reference it.
unrequestedItems.insert(item->item, model->indexOf(item->item, q));
}
if (item->section) {
int i = 0;
do {
if (!sectionCache[i]) {
sectionCache[i] = item->section;
sectionCache[i]->setVisible(false);
item->section = 0;
break;
}
++i;
} while (i < sectionCacheSize);
delete item->section;
}
delete item;
}
void QDeclarativeListViewPrivate::refill(qreal from, qreal to, bool doBuffer)
{
Q_Q(QDeclarativeListView);
if (!isValid() || !q->isComponentComplete())
return;
itemCount = model->count();
qreal bufferFrom = from - buffer;
qreal bufferTo = to + buffer;
qreal fillFrom = from;
qreal fillTo = to;
if (doBuffer && (bufferMode & BufferAfter))
fillTo = bufferTo;
if (doBuffer && (bufferMode & BufferBefore))
fillFrom = bufferFrom;
bool haveValidItems = false;
int modelIndex = visibleIndex;
qreal itemEnd = visiblePos-1;
if (!visibleItems.isEmpty()) {
visiblePos = (*visibleItems.constBegin())->position();
itemEnd = (*(--visibleItems.constEnd()))->endPosition() + spacing;
int i = visibleItems.count() - 1;
while (i > 0 && visibleItems.at(i)->index == -1)
--i;
if (visibleItems.at(i)->index != -1) {
haveValidItems = true;
modelIndex = visibleItems.at(i)->index + 1;
}
}
if (haveValidItems && (fillFrom > itemEnd+averageSize+spacing
|| fillTo < visiblePos - averageSize - spacing)) {
// We've jumped more than a page. Estimate which items are now
// visible and fill from there.
int count = (fillFrom - itemEnd) / (averageSize + spacing);
for (int i = 0; i < visibleItems.count(); ++i)
releaseItem(visibleItems.at(i));
visibleItems.clear();
modelIndex += count;
if (modelIndex >= model->count()) {
count -= modelIndex - model->count() + 1;
modelIndex = model->count() - 1;
} else if (modelIndex < 0) {
count -= modelIndex;
modelIndex = 0;
}
visibleIndex = modelIndex;
visiblePos = itemEnd + count * (averageSize + spacing) + 1;
itemEnd = visiblePos-1;
}
bool changed = false;
FxListItem *item = 0;
qreal pos = itemEnd + 1;
while (modelIndex < model->count() && pos <= fillTo) {
// qDebug() << "refill: append item" << modelIndex << "pos" << pos;
if (!(item = createItem(modelIndex)))
break;
item->setPosition(pos);
pos += item->size() + spacing;
visibleItems.append(item);
++modelIndex;
changed = true;
if (doBuffer) // never buffer more than one item per frame
break;
}
while (visibleIndex > 0 && visibleIndex <= model->count() && visiblePos-1 >= fillFrom) {
// qDebug() << "refill: prepend item" << visibleIndex-1 << "current top pos" << visiblePos;
if (!(item = createItem(visibleIndex-1)))
break;
--visibleIndex;
visiblePos -= item->size() + spacing;
item->setPosition(visiblePos);
visibleItems.prepend(item);
changed = true;
if (doBuffer) // never buffer more than one item per frame
break;
}
if (!lazyRelease || !changed || deferredRelease) { // avoid destroying items in the same frame that we create
while (visibleItems.count() > 1 && (item = visibleItems.first()) && item->endPosition() < bufferFrom) {
if (item->attached->delayRemove())
break;
// qDebug() << "refill: remove first" << visibleIndex << "top end pos" << item->endPosition();
if (item->index != -1)
visibleIndex++;
visibleItems.removeFirst();
releaseItem(item);
changed = true;
}
while (visibleItems.count() > 1 && (item = visibleItems.last()) && item->position() > bufferTo) {
if (item->attached->delayRemove())
break;
// qDebug() << "refill: remove last" << visibleIndex+visibleItems.count()-1 << item->position();
visibleItems.removeLast();
releaseItem(item);
changed = true;
}
deferredRelease = false;
} else {
deferredRelease = true;
}
if (changed) {
minExtentDirty = true;
maxExtentDirty = true;
if (visibleItems.count())
visiblePos = (*visibleItems.constBegin())->position();
updateAverage();
if (currentIndex >= 0 && currentItem && !visibleItem(currentIndex)) {
currentItem->setPosition(positionAt(currentIndex));
updateHighlight();
}
if (sectionCriteria)
updateCurrentSection();
if (header)
updateHeader();
if (footer)
updateFooter();
updateViewport();
updateUnrequestedPositions();
} else if (!doBuffer && buffer && bufferMode != NoBuffer) {
refill(from, to, true);
}
lazyRelease = false;
}
void QDeclarativeListViewPrivate::scheduleLayout()
{
Q_Q(QDeclarativeListView);
if (!layoutScheduled) {
layoutScheduled = true;
QCoreApplication::postEvent(q, new QEvent(QEvent::User), Qt::HighEventPriority);
}
}
void QDeclarativeListViewPrivate::layout()
{
Q_Q(QDeclarativeListView);
layoutScheduled = false;
if (!isValid() && !visibleItems.count()) {
clear();
setPosition(0);
return;
}
if (!visibleItems.isEmpty()) {
bool fixedCurrent = currentItem && visibleItems.first()->item == currentItem->item;
qreal sum = visibleItems.first()->size();
qreal pos = visibleItems.first()->position() + visibleItems.first()->size() + spacing;
for (int i=1; i < visibleItems.count(); ++i) {
FxListItem *item = visibleItems.at(i);
item->setPosition(pos);
pos += item->size() + spacing;
sum += item->size();
fixedCurrent = fixedCurrent || (currentItem && item->item == currentItem->item);
}
averageSize = qRound(sum / visibleItems.count());
// move current item if it is not a visible item.
if (currentIndex >= 0 && currentItem && !fixedCurrent)
currentItem->setPosition(positionAt(currentIndex));
}
q->refill();
minExtentDirty = true;
maxExtentDirty = true;
updateHighlight();
if (!q->isMoving() && !q->isFlicking()) {
fixupPosition();
q->refill();
}
if (header)
updateHeader();
if (footer)
updateFooter();
updateViewport();
}
void QDeclarativeListViewPrivate::updateUnrequestedIndexes()
{
Q_Q(QDeclarativeListView);
QHash<QDeclarativeItem*,int>::iterator it;
for (it = unrequestedItems.begin(); it != unrequestedItems.end(); ++it)
*it = model->indexOf(it.key(), q);
}
void QDeclarativeListViewPrivate::updateUnrequestedPositions()
{
Q_Q(QDeclarativeListView);
if (unrequestedItems.count()) {
qreal pos = position();
QHash<QDeclarativeItem*,int>::const_iterator it;
for (it = unrequestedItems.begin(); it != unrequestedItems.end(); ++it) {
QDeclarativeItem *item = it.key();
if (orient == QDeclarativeListView::Vertical) {
if (item->y() + item->height() > pos && item->y() < pos + q->height())
item->setY(positionAt(*it));
} else {
if (item->x() + item->width() > pos && item->x() < pos + q->width()) {
if (isRightToLeft())
item->setX(-positionAt(*it)-item->width());
else
item->setX(positionAt(*it));
}
}
}
}
}
void QDeclarativeListViewPrivate::updateTrackedItem()
{
Q_Q(QDeclarativeListView);
FxListItem *item = currentItem;
if (highlight)
item = highlight;
trackedItem = item;
if (trackedItem)
q->trackedPositionChanged();
}
void QDeclarativeListViewPrivate::createHighlight()
{
Q_Q(QDeclarativeListView);
bool changed = false;
if (highlight) {
if (trackedItem == highlight)
trackedItem = 0;
delete highlight->item;
delete highlight;
highlight = 0;
delete highlightPosAnimator;
delete highlightSizeAnimator;
highlightPosAnimator = 0;
highlightSizeAnimator = 0;
changed = true;
}
if (currentItem) {
QDeclarativeItem *item = 0;
if (highlightComponent) {
QDeclarativeContext *highlightContext = new QDeclarativeContext(qmlContext(q));
QObject *nobj = highlightComponent->create(highlightContext);
if (nobj) {
QDeclarative_setParent_noEvent(highlightContext, nobj);
item = qobject_cast<QDeclarativeItem *>(nobj);
if (!item)
delete nobj;
} else {
delete highlightContext;
}
} else {
item = new QDeclarativeItem;
}
if (item) {
QDeclarative_setParent_noEvent(item, q->contentItem());
item->setParentItem(q->contentItem());
highlight = new FxListItem(item, q);
if (currentItem && autoHighlight) {
if (orient == QDeclarativeListView::Vertical) {
highlight->item->setHeight(currentItem->item->height());
} else {
highlight->item->setWidth(currentItem->item->width());
}
highlight->setPosition(currentItem->itemPosition());
}
QDeclarativeItemPrivate *itemPrivate = static_cast<QDeclarativeItemPrivate*>(QGraphicsItemPrivate::get(item));
itemPrivate->addItemChangeListener(this, QDeclarativeItemPrivate::Geometry);
const QLatin1String posProp(orient == QDeclarativeListView::Vertical ? "y" : "x");
highlightPosAnimator = new QSmoothedAnimation(q);
highlightPosAnimator->target = QDeclarativeProperty(highlight->item, posProp);
highlightPosAnimator->velocity = highlightMoveSpeed;
highlightPosAnimator->userDuration = highlightMoveDuration;
const QLatin1String sizeProp(orient == QDeclarativeListView::Vertical ? "height" : "width");
highlightSizeAnimator = new QSmoothedAnimation(q);
highlightSizeAnimator->velocity = highlightResizeSpeed;
highlightSizeAnimator->userDuration = highlightResizeDuration;
highlightSizeAnimator->target = QDeclarativeProperty(highlight->item, sizeProp);
if (autoHighlight) {
highlightPosAnimator->restart();
highlightSizeAnimator->restart();
}
changed = true;
}
}
if (changed)
emit q->highlightItemChanged();
}
void QDeclarativeListViewPrivate::updateHighlight()
{
if ((!currentItem && highlight) || (currentItem && !highlight))
createHighlight();
if (currentItem && autoHighlight && highlight && !hData.moving && !vData.moving) {
// auto-update highlight
highlightPosAnimator->to = isRightToLeft()
? -currentItem->itemPosition()-currentItem->itemSize()
: currentItem->itemPosition();
highlightSizeAnimator->to = currentItem->itemSize();
if (orient == QDeclarativeListView::Vertical) {
if (highlight->item->width() == 0)
highlight->item->setWidth(currentItem->item->width());
} else {
if (highlight->item->height() == 0)
highlight->item->setHeight(currentItem->item->height());
}
highlightPosAnimator->restart();
highlightSizeAnimator->restart();
}
updateTrackedItem();
}
void QDeclarativeListViewPrivate::createSection(FxListItem *listItem)
{
Q_Q(QDeclarativeListView);
if (!sectionCriteria || !sectionCriteria->delegate())
return;
if (listItem->attached->m_prevSection != listItem->attached->m_section) {
if (!listItem->section) {
qreal pos = listItem->position();
int i = sectionCacheSize-1;
while (i >= 0 && !sectionCache[i])
--i;
if (i >= 0) {
listItem->section = sectionCache[i];
sectionCache[i] = 0;
listItem->section->setVisible(true);
QDeclarativeContext *context = QDeclarativeEngine::contextForObject(listItem->section)->parentContext();
context->setContextProperty(QLatin1String("section"), listItem->attached->m_section);
} else {
QDeclarativeContext *context = new QDeclarativeContext(qmlContext(q));
context->setContextProperty(QLatin1String("section"), listItem->attached->m_section);
QObject *nobj = sectionCriteria->delegate()->beginCreate(context);
if (nobj) {
QDeclarative_setParent_noEvent(context, nobj);
listItem->section = qobject_cast<QDeclarativeItem *>(nobj);
if (!listItem->section) {
delete nobj;
} else {
listItem->section->setZValue(1);
QDeclarative_setParent_noEvent(listItem->section, q->contentItem());
listItem->section->setParentItem(q->contentItem());
}
} else {
delete context;
}
sectionCriteria->delegate()->completeCreate();
}
listItem->setPosition(pos);
} else {
QDeclarativeContext *context = QDeclarativeEngine::contextForObject(listItem->section)->parentContext();
context->setContextProperty(QLatin1String("section"), listItem->attached->m_section);
}
} else if (listItem->section) {
qreal pos = listItem->position();
int i = 0;
do {
if (!sectionCache[i]) {
sectionCache[i] = listItem->section;
sectionCache[i]->setVisible(false);
listItem->section = 0;
return;
}
++i;
} while (i < sectionCacheSize);
delete listItem->section;
listItem->section = 0;
listItem->setPosition(pos);
}
}
void QDeclarativeListViewPrivate::updateSections()
{
if (sectionCriteria && !visibleItems.isEmpty()) {
QString prevSection;
if (visibleIndex > 0)
prevSection = sectionAt(visibleIndex-1);
QDeclarativeListViewAttached *prevAtt = 0;
int idx = -1;
for (int i = 0; i < visibleItems.count(); ++i) {
QDeclarativeListViewAttached *attached = visibleItems.at(i)->attached;
attached->setPrevSection(prevSection);
if (visibleItems.at(i)->index != -1) {
QString propValue = model->stringValue(visibleItems.at(i)->index, sectionCriteria->property());
attached->setSection(sectionCriteria->sectionString(propValue));
idx = visibleItems.at(i)->index;
}
createSection(visibleItems.at(i));
if (prevAtt)
prevAtt->setNextSection(attached->section());
prevSection = attached->section();
prevAtt = attached;
}
if (prevAtt) {
if (idx > 0 && idx < model->count()-1)
prevAtt->setNextSection(sectionAt(idx+1));
else
prevAtt->setNextSection(QString());
}
}
}
void QDeclarativeListViewPrivate::updateCurrentSection()
{
Q_Q(QDeclarativeListView);
if (!sectionCriteria || visibleItems.isEmpty()) {
if (!currentSection.isEmpty()) {
currentSection.clear();
emit q->currentSectionChanged();
}
return;
}
int index = 0;
while (index < visibleItems.count() && visibleItems.at(index)->endPosition() < position())
++index;
QString newSection = currentSection;
if (index < visibleItems.count())
newSection = visibleItems.at(index)->attached->section();
else
newSection = visibleItems.first()->attached->section();
if (newSection != currentSection) {
currentSection = newSection;
emit q->currentSectionChanged();
}
}
void QDeclarativeListViewPrivate::updateCurrent(int modelIndex)
{
Q_Q(QDeclarativeListView);
if (!q->isComponentComplete() || !isValid() || modelIndex < 0 || modelIndex >= model->count()) {
if (currentItem) {
currentItem->attached->setIsCurrentItem(false);
releaseItem(currentItem);
currentItem = 0;
currentIndex = modelIndex;
emit q->currentIndexChanged();
updateHighlight();
} else if (currentIndex != modelIndex) {
currentIndex = modelIndex;
emit q->currentIndexChanged();
}
return;
}
if (currentItem && currentIndex == modelIndex) {
updateHighlight();
return;
}
FxListItem *oldCurrentItem = currentItem;
currentIndex = modelIndex;
currentItem = createItem(modelIndex);
if (oldCurrentItem && (!currentItem || oldCurrentItem->item != currentItem->item))
oldCurrentItem->attached->setIsCurrentItem(false);
if (currentItem) {
if (modelIndex == visibleIndex - 1 && visibleItems.count()) {
// We can calculate exact postion in this case
currentItem->setPosition(visibleItems.first()->position() - currentItem->size() - spacing);
} else {
// Create current item now and position as best we can.
// Its position will be corrected when it becomes visible.
currentItem->setPosition(positionAt(modelIndex));
}
currentItem->item->setFocus(true);
currentItem->attached->setIsCurrentItem(true);
// Avoid showing section delegate twice. We still need the section heading so that
// currentItem positioning works correctly.
// This is slightly sub-optimal, but section heading caching minimizes the impact.
if (currentItem->section)
currentItem->section->setVisible(false);
if (visibleItems.isEmpty())
averageSize = currentItem->size();
}
updateHighlight();
emit q->currentIndexChanged();
// Release the old current item
releaseItem(oldCurrentItem);
}
void QDeclarativeListViewPrivate::updateAverage()
{
if (!visibleItems.count())
return;
qreal sum = 0.0;
for (int i = 0; i < visibleItems.count(); ++i)
sum += visibleItems.at(i)->size();
averageSize = qRound(sum / visibleItems.count());
}
void QDeclarativeListViewPrivate::updateFooter()
{
Q_Q(QDeclarativeListView);
if (!footer && footerComponent) {
QDeclarativeItem *item = 0;
QDeclarativeContext *context = new QDeclarativeContext(qmlContext(q));
QObject *nobj = footerComponent->create(context);
if (nobj) {
QDeclarative_setParent_noEvent(context, nobj);
item = qobject_cast<QDeclarativeItem *>(nobj);
if (!item)
delete nobj;
} else {
delete context;
}
if (item) {
QDeclarative_setParent_noEvent(item, q->contentItem());
item->setParentItem(q->contentItem());
item->setZValue(1);
QDeclarativeItemPrivate *itemPrivate = static_cast<QDeclarativeItemPrivate*>(QGraphicsItemPrivate::get(item));
itemPrivate->addItemChangeListener(this, QDeclarativeItemPrivate::Geometry);
footer = new FxListItem(item, q);
}
}
if (footer) {
if (visibleItems.count()) {
qreal endPos = lastPosition() + 1;
if (lastVisibleIndex() == model->count()-1) {
footer->setPosition(endPos);
} else {
qreal visiblePos = position() + q->height();
if (endPos <= visiblePos || footer->position() < endPos)
footer->setPosition(endPos);
}
} else {
footer->setPosition(visiblePos);
}
}
}
void QDeclarativeListViewPrivate::updateHeader()
{
Q_Q(QDeclarativeListView);
if (!header && headerComponent) {
QDeclarativeItem *item = 0;
QDeclarativeContext *context = new QDeclarativeContext(qmlContext(q));
QObject *nobj = headerComponent->create(context);
if (nobj) {
QDeclarative_setParent_noEvent(context, nobj);
item = qobject_cast<QDeclarativeItem *>(nobj);
if (!item)
delete nobj;
} else {
delete context;
}
if (item) {
QDeclarative_setParent_noEvent(item, q->contentItem());
item->setParentItem(q->contentItem());
item->setZValue(1);
QDeclarativeItemPrivate *itemPrivate = static_cast<QDeclarativeItemPrivate*>(QGraphicsItemPrivate::get(item));
itemPrivate->addItemChangeListener(this, QDeclarativeItemPrivate::Geometry);
header = new FxListItem(item, q);
}
}
if (header) {
if (visibleItems.count()) {
qreal startPos = originPosition();
if (visibleIndex == 0) {
header->setPosition(startPos - header->size());
} else {
if (position() <= startPos || header->position() > startPos - header->size())
header->setPosition(startPos - header->size());
}
} else {
if (itemCount == 0)
visiblePos = header->size();
header->setPosition(0);
}
}
}
void QDeclarativeListViewPrivate::fixupPosition()
{
if ((haveHighlightRange && highlightRange == QDeclarativeListView::StrictlyEnforceRange)
|| snapMode != QDeclarativeListView::NoSnap)
moveReason = Other;
if (orient == QDeclarativeListView::Vertical)
fixupY();
else
fixupX();
}
void QDeclarativeListViewPrivate::fixup(AxisData &data, qreal minExtent, qreal maxExtent)
{
if ((orient == QDeclarativeListView::Horizontal && &data == &vData)
|| (orient == QDeclarativeListView::Vertical && &data == &hData))
return;
correctFlick = false;
fixupMode = moveReason == Mouse ? fixupMode : Immediate;
qreal highlightStart;
qreal highlightEnd;
qreal viewPos;
if (isRightToLeft()) {
// Handle Right-To-Left exceptions
viewPos = -position()-size();
highlightStart = highlightRangeStartValid ? size() - highlightRangeEnd : highlightRangeStart;
highlightEnd = highlightRangeEndValid ? size() - highlightRangeStart : highlightRangeEnd;
} else {
viewPos = position();
highlightStart = highlightRangeStart;
highlightEnd = highlightRangeEnd;
}
if (snapMode != QDeclarativeListView::NoSnap && moveReason != QDeclarativeListViewPrivate::SetIndex) {
qreal tempPosition = isRightToLeft() ? -position()-size() : position();
if (snapMode == QDeclarativeListView::SnapOneItem && moveReason == Mouse) {
// if we've been dragged < averageSize/2 then bias towards the next item
qreal dist = data.move.value() - (data.pressPos - data.dragStartOffset);
qreal bias = 0;
if (data.velocity > 0 && dist > QML_FLICK_SNAPONETHRESHOLD && dist < averageSize/2)
bias = averageSize/2;
else if (data.velocity < 0 && dist < -QML_FLICK_SNAPONETHRESHOLD && dist > -averageSize/2)
bias = -averageSize/2;
if (isRightToLeft())
bias = -bias;
tempPosition -= bias;
}
FxListItem *topItem = snapItemAt(tempPosition+highlightStart);
FxListItem *bottomItem = snapItemAt(tempPosition+highlightEnd);
qreal pos;
bool isInBounds = -position() > maxExtent && -position() < minExtent;
if (topItem && isInBounds) {
if (topItem->index == 0 && header && tempPosition+highlightStart < header->position()+header->size()/2) {
pos = isRightToLeft() ? - header->position() + highlightStart - size() : header->position() - highlightStart;
} else {
if (isRightToLeft())
pos = qMax(qMin(-topItem->position() + highlightStart - size(), -maxExtent), -minExtent);
else
pos = qMax(qMin(topItem->position() - highlightStart, -maxExtent), -minExtent);
}
} else if (bottomItem && isInBounds) {
if (isRightToLeft())
pos = qMax(qMin(-bottomItem->position() + highlightEnd - size(), -maxExtent), -minExtent);
else
pos = qMax(qMin(bottomItem->position() - highlightEnd, -maxExtent), -minExtent);
} else {
QDeclarativeFlickablePrivate::fixup(data, minExtent, maxExtent);
return;
}
qreal dist = qAbs(data.move + pos);
if (dist > 0) {
timeline.reset(data.move);
if (fixupMode != Immediate) {
timeline.move(data.move, -pos, QEasingCurve(QEasingCurve::InOutQuad), fixupDuration/2);
data.fixingUp = true;
} else {
timeline.set(data.move, -pos);
}
vTime = timeline.time();
}
} else if (currentItem && haveHighlightRange && highlightRange == QDeclarativeListView::StrictlyEnforceRange
&& moveReason != QDeclarativeListViewPrivate::SetIndex) {
updateHighlight();
qreal pos = currentItem->itemPosition();
if (viewPos < pos + currentItem->itemSize() - highlightEnd)
viewPos = pos + currentItem->itemSize() - highlightEnd;
if (viewPos > pos - highlightStart)
viewPos = pos - highlightStart;
if (isRightToLeft())
viewPos = -viewPos-size();
timeline.reset(data.move);
if (viewPos != position()) {
if (fixupMode != Immediate) {
timeline.move(data.move, -viewPos, QEasingCurve(QEasingCurve::InOutQuad), fixupDuration/2);
data.fixingUp = true;
} else {
timeline.set(data.move, -viewPos);
}
}
vTime = timeline.time();
} else {
QDeclarativeFlickablePrivate::fixup(data, minExtent, maxExtent);
}
data.inOvershoot = false;
fixupMode = Normal;
}
void QDeclarativeListViewPrivate::flick(AxisData &data, qreal minExtent, qreal maxExtent, qreal vSize,
QDeclarativeTimeLineCallback::Callback fixupCallback, qreal velocity)
{
Q_Q(QDeclarativeListView);
data.fixingUp = false;
moveReason = Mouse;
if ((!haveHighlightRange || highlightRange != QDeclarativeListView::StrictlyEnforceRange) && snapMode == QDeclarativeListView::NoSnap) {
correctFlick = true;
QDeclarativeFlickablePrivate::flick(data, minExtent, maxExtent, vSize, fixupCallback, velocity);
return;
}
qreal maxDistance = 0;
qreal dataValue = isRightToLeft() ? -data.move.value()+size() : data.move.value();
qreal highlightStart = isRightToLeft() && highlightRangeStartValid ? size()-highlightRangeEnd : highlightRangeStart;
// -ve velocity means list is moving up/left
if (velocity > 0) {
if (data.move.value() < minExtent) {
if (snapMode == QDeclarativeListView::SnapOneItem && !hData.flicking && !vData.flicking) {
// if we've been dragged < averageSize/2 then bias towards the next item
qreal dist = data.move.value() - (data.pressPos - data.dragStartOffset);
qreal bias = dist < averageSize/2 ? averageSize/2 : 0;
if (isRightToLeft())
bias = -bias;
data.flickTarget = -snapPosAt(-(dataValue - highlightStart) - bias) + highlightStart;
maxDistance = qAbs(data.flickTarget - data.move.value());
velocity = maxVelocity;
} else {
maxDistance = qAbs(minExtent - data.move.value());
}
}
if (snapMode == QDeclarativeListView::NoSnap && highlightRange != QDeclarativeListView::StrictlyEnforceRange)
data.flickTarget = minExtent;
} else {
if (data.move.value() > maxExtent) {
if (snapMode == QDeclarativeListView::SnapOneItem && !hData.flicking && !vData.flicking) {
// if we've been dragged < averageSize/2 then bias towards the next item
qreal dist = data.move.value() - (data.pressPos - data.dragStartOffset);
qreal bias = -dist < averageSize/2 ? averageSize/2 : 0;
if (isRightToLeft())
bias = -bias;
data.flickTarget = -snapPosAt(-(dataValue - highlightStart) + bias) + highlightStart;
maxDistance = qAbs(data.flickTarget - data.move.value());
velocity = -maxVelocity;
} else {
maxDistance = qAbs(maxExtent - data.move.value());
}
}
if (snapMode == QDeclarativeListView::NoSnap && highlightRange != QDeclarativeListView::StrictlyEnforceRange)
data.flickTarget = maxExtent;
}
bool overShoot = boundsBehavior == QDeclarativeFlickable::DragAndOvershootBounds;
if (maxDistance > 0 || overShoot) {
// These modes require the list to stop exactly on an item boundary.
// The initial flick will estimate the boundary to stop on.
// Since list items can have variable sizes, the boundary will be
// reevaluated and adjusted as we approach the boundary.
qreal v = velocity;
if (maxVelocity != -1 && maxVelocity < qAbs(v)) {
if (v < 0)
v = -maxVelocity;
else
v = maxVelocity;
}
if (!hData.flicking && !vData.flicking) {
// the initial flick - estimate boundary
qreal accel = deceleration;
qreal v2 = v * v;
overshootDist = 0.0;
// + averageSize/4 to encourage moving at least one item in the flick direction
qreal dist = v2 / (accel * 2.0) + averageSize/4;
if (maxDistance > 0)
dist = qMin(dist, maxDistance);
if (v > 0)
dist = -dist;
if ((maxDistance > 0.0 && v2 / (2.0f * maxDistance) < accel) || snapMode == QDeclarativeListView::SnapOneItem) {
if (snapMode != QDeclarativeListView::SnapOneItem) {
qreal distTemp = isRightToLeft() ? -dist : dist;
data.flickTarget = -snapPosAt(-(dataValue - highlightStart) + distTemp) + highlightStart;
}
data.flickTarget = isRightToLeft() ? -data.flickTarget+size() : data.flickTarget;
if (overShoot) {
if (data.flickTarget >= minExtent) {
overshootDist = overShootDistance(vSize);
data.flickTarget += overshootDist;
} else if (data.flickTarget <= maxExtent) {
overshootDist = overShootDistance(vSize);
data.flickTarget -= overshootDist;
}
}
qreal adjDist = -data.flickTarget + data.move.value();
if (qAbs(adjDist) > qAbs(dist)) {
// Prevent painfully slow flicking - adjust velocity to suit flickDeceleration
qreal adjv2 = accel * 2.0f * qAbs(adjDist);
if (adjv2 > v2) {
v2 = adjv2;
v = qSqrt(v2);
if (dist > 0)
v = -v;
}
}
dist = adjDist;
accel = v2 / (2.0f * qAbs(dist));
} else if (overShoot) {
data.flickTarget = data.move.value() - dist;
if (data.flickTarget >= minExtent) {
overshootDist = overShootDistance(vSize);
data.flickTarget += overshootDist;
} else if (data.flickTarget <= maxExtent) {
overshootDist = overShootDistance(vSize);
data.flickTarget -= overshootDist;
}
}
timeline.reset(data.move);
timeline.accel(data.move, v, accel, maxDistance + overshootDist);
timeline.callback(QDeclarativeTimeLineCallback(&data.move, fixupCallback, this));
if (!hData.flicking && q->xflick()) {
hData.flicking = true;
emit q->flickingChanged();
emit q->flickingHorizontallyChanged();
emit q->flickStarted();
}
if (!vData.flicking && q->yflick()) {
vData.flicking = true;
emit q->flickingChanged();
emit q->flickingVerticallyChanged();
emit q->flickStarted();
}
correctFlick = true;
} else {
// reevaluate the target boundary.
qreal newtarget = data.flickTarget;
if (snapMode != QDeclarativeListView::NoSnap || highlightRange == QDeclarativeListView::StrictlyEnforceRange) {
qreal tempFlickTarget = isRightToLeft() ? -data.flickTarget+size() : data.flickTarget;
newtarget = -snapPosAt(-(tempFlickTarget - highlightStart)) + highlightStart;
newtarget = isRightToLeft() ? -newtarget+size() : newtarget;
}
if (velocity < 0 && newtarget <= maxExtent)
newtarget = maxExtent - overshootDist;
else if (velocity > 0 && newtarget >= minExtent)
newtarget = minExtent + overshootDist;
if (newtarget == data.flickTarget) { // boundary unchanged - nothing to do
if (qAbs(velocity) < MinimumFlickVelocity)
correctFlick = false;
return;
}
data.flickTarget = newtarget;
qreal dist = -newtarget + data.move.value();
if ((v < 0 && dist < 0) || (v > 0 && dist > 0)) {
correctFlick = false;
timeline.reset(data.move);
fixup(data, minExtent, maxExtent);
return;
}
timeline.reset(data.move);
timeline.accelDistance(data.move, v, -dist);
timeline.callback(QDeclarativeTimeLineCallback(&data.move, fixupCallback, this));
}
} else {
correctFlick = false;
timeline.reset(data.move);
fixup(data, minExtent, maxExtent);
}
}
//----------------------------------------------------------------------------
/*!
\qmlclass ListView QDeclarativeListView
\ingroup qml-view-elements
\since 4.7
\inherits Flickable
\brief The ListView item provides a list view of items provided by a model.
A ListView displays data from models created from built-in QML elements like ListModel
and XmlListModel, or custom model classes defined in C++ that inherit from
QAbstractListModel.
A ListView has a \l model, which defines the data to be displayed, and
a \l delegate, which defines how the data should be displayed. Items in a
ListView are laid out horizontally or vertically. List views are inherently
flickable because ListView inherits from \l Flickable.
\section1 Example Usage
The following example shows the definition of a simple list model defined
in a file called \c ContactModel.qml:
\snippet doc/src/snippets/declarative/listview/ContactModel.qml 0
Another component can display this model data in a ListView, like this:
\snippet doc/src/snippets/declarative/listview/listview.qml import
\codeline
\snippet doc/src/snippets/declarative/listview/listview.qml classdocs simple
\image listview-simple.png
Here, the ListView creates a \c ContactModel component for its model, and a \l Text element
for its delegate. The view will create a new \l Text component for each item in the model. Notice
the delegate is able to access the model's \c name and \c number data directly.
An improved list view is shown below. The delegate is visually improved and is moved
into a separate \c contactDelegate component.
\snippet doc/src/snippets/declarative/listview/listview.qml classdocs advanced
\image listview-highlight.png
The currently selected item is highlighted with a blue \l Rectangle using the \l highlight property,
and \c focus is set to \c true to enable keyboard navigation for the list view.
The list view itself is a focus scope (see \l{qmlfocus#Acquiring Focus and Focus Scopes}{the focus documentation page} for more details).
Delegates are instantiated as needed and may be destroyed at any time.
State should \e never be stored in a delegate.
ListView attaches a number of properties to the root item of the delegate, for example
\c {ListView.isCurrentItem}. In the following example, the root delegate item can access
this attached property directly as \c ListView.isCurrentItem, while the child
\c contactInfo object must refer to this property as \c wrapper.ListView.isCurrentItem.
\snippet doc/src/snippets/declarative/listview/listview.qml isCurrentItem
\note Views do not enable \e clip automatically. If the view
is not clipped by another item or the screen, it will be necessary
to set \e {clip: true} in order to have the out of view items clipped
nicely.
\sa {QML Data Models}, GridView, {declarative/modelviews/listview}{ListView examples}
*/
QDeclarativeListView::QDeclarativeListView(QDeclarativeItem *parent)
: QDeclarativeFlickable(*(new QDeclarativeListViewPrivate), parent)
{
Q_D(QDeclarativeListView);
d->init();
}
QDeclarativeListView::~QDeclarativeListView()
{
Q_D(QDeclarativeListView);
d->clear();
if (d->ownModel)
delete d->model;
delete d->header;
delete d->footer;
}
/*!
\qmlattachedproperty bool ListView::isCurrentItem
This attached property is true if this delegate is the current item; otherwise false.
It is attached to each instance of the delegate.
This property may be used to adjust the appearance of the current item, for example:
\snippet doc/src/snippets/declarative/listview/listview.qml isCurrentItem
*/
/*!
\qmlattachedproperty ListView ListView::view
This attached property holds the view that manages this delegate instance.
It is attached to each instance of the delegate.
*/
/*!
\qmlattachedproperty string ListView::previousSection
This attached property holds the section of the previous element.
It is attached to each instance of the delegate.
The section is evaluated using the \l {ListView::section.property}{section} properties.
*/
/*!
\qmlattachedproperty string ListView::nextSection
This attached property holds the section of the next element.
It is attached to each instance of the delegate.
The section is evaluated using the \l {ListView::section.property}{section} properties.
*/
/*!
\qmlattachedproperty string ListView::section
This attached property holds the section of this element.
It is attached to each instance of the delegate.
The section is evaluated using the \l {ListView::section.property}{section} properties.
*/
/*!
\qmlattachedproperty bool ListView::delayRemove
This attached property holds whether the delegate may be destroyed.
It is attached to each instance of the delegate.
It is sometimes necessary to delay the destruction of an item
until an animation completes.
The example delegate below ensures that the animation completes before
the item is removed from the list.
\snippet doc/src/snippets/declarative/listview/listview.qml delayRemove
*/
/*!
\qmlattachedsignal ListView::onAdd()
This attached handler is called immediately after an item is added to the view.
*/
/*!
\qmlattachedsignal ListView::onRemove()
This attached handler is called immediately before an item is removed from the view.
*/
/*!
\qmlproperty model ListView::model
This property holds the model providing data for the list.
The model provides the set of data that is used to create the items
in the view. Models can be created directly in QML using \l ListModel, \l XmlListModel
or \l VisualItemModel, or provided by C++ model classes. If a C++ model class is
used, it must be a subclass of \l QAbstractItemModel or a simple list.
\sa {qmlmodels}{Data Models}
*/
QVariant QDeclarativeListView::model() const
{
Q_D(const QDeclarativeListView);
return d->modelVariant;
}
void QDeclarativeListView::setModel(const QVariant &model)
{
Q_D(QDeclarativeListView);
if (d->modelVariant == model)
return;
if (d->model) {
disconnect(d->model, SIGNAL(itemsInserted(int,int)), this, SLOT(itemsInserted(int,int)));
disconnect(d->model, SIGNAL(itemsRemoved(int,int)), this, SLOT(itemsRemoved(int,int)));
disconnect(d->model, SIGNAL(itemsMoved(int,int,int)), this, SLOT(itemsMoved(int,int,int)));
disconnect(d->model, SIGNAL(itemsChanged(int,int)), this, SLOT(itemsChanged(int,int)));
disconnect(d->model, SIGNAL(modelReset()), this, SLOT(modelReset()));
disconnect(d->model, SIGNAL(createdItem(int,QDeclarativeItem*)), this, SLOT(createdItem(int,QDeclarativeItem*)));
disconnect(d->model, SIGNAL(destroyingItem(QDeclarativeItem*)), this, SLOT(destroyingItem(QDeclarativeItem*)));
}
d->clear();
QDeclarativeVisualModel *oldModel = d->model;
d->model = 0;
d->setPosition(0);
d->modelVariant = model;
QObject *object = qvariant_cast<QObject*>(model);
QDeclarativeVisualModel *vim = 0;
if (object && (vim = qobject_cast<QDeclarativeVisualModel *>(object))) {
if (d->ownModel) {
delete oldModel;
d->ownModel = false;
}
d->model = vim;
} else {
if (!d->ownModel) {
d->model = new QDeclarativeVisualDataModel(qmlContext(this), this);
d->ownModel = true;
} else {
d->model = oldModel;
}
if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model))
dataModel->setModel(model);
}
if (d->model) {
d->bufferMode = QDeclarativeListViewPrivate::BufferBefore | QDeclarativeListViewPrivate::BufferAfter;
if (isComponentComplete()) {
updateSections();
refill();
if ((d->currentIndex >= d->model->count() || d->currentIndex < 0) && !d->currentIndexCleared) {
setCurrentIndex(0);
} else {
d->moveReason = QDeclarativeListViewPrivate::SetIndex;
d->updateCurrent(d->currentIndex);
if (d->highlight && d->currentItem) {
if (d->autoHighlight)
d->highlight->setPosition(d->currentItem->position());
d->updateTrackedItem();
}
}
d->updateViewport();
}
connect(d->model, SIGNAL(itemsInserted(int,int)), this, SLOT(itemsInserted(int,int)));
connect(d->model, SIGNAL(itemsRemoved(int,int)), this, SLOT(itemsRemoved(int,int)));
connect(d->model, SIGNAL(itemsMoved(int,int,int)), this, SLOT(itemsMoved(int,int,int)));
connect(d->model, SIGNAL(itemsChanged(int,int)), this, SLOT(itemsChanged(int,int)));
connect(d->model, SIGNAL(modelReset()), this, SLOT(modelReset()));
connect(d->model, SIGNAL(createdItem(int,QDeclarativeItem*)), this, SLOT(createdItem(int,QDeclarativeItem*)));
connect(d->model, SIGNAL(destroyingItem(QDeclarativeItem*)), this, SLOT(destroyingItem(QDeclarativeItem*)));
emit countChanged();
}
emit modelChanged();
}
/*!
\qmlproperty Component ListView::delegate
The delegate provides a template defining each item instantiated by the view.
The index is exposed as an accessible \c index property. Properties of the
model are also available depending upon the type of \l {qmlmodels}{Data Model}.
The number of elements in the delegate has a direct effect on the
flicking performance of the view. If at all possible, place functionality
that is not needed for the normal display of the delegate in a \l Loader which
can load additional elements when needed.
The ListView will lay out the items based on the size of the root item
in the delegate.
It is recommended that the delagate's size be a whole number to avoid sub-pixel
alignment of items.
\note Delegates are instantiated as needed and may be destroyed at any time.
State should \e never be stored in a delegate.
*/
QDeclarativeComponent *QDeclarativeListView::delegate() const
{
Q_D(const QDeclarativeListView);
if (d->model) {
if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model))
return dataModel->delegate();
}
return 0;
}
void QDeclarativeListView::setDelegate(QDeclarativeComponent *delegate)
{
Q_D(QDeclarativeListView);
if (delegate == this->delegate())
return;
if (!d->ownModel) {
d->model = new QDeclarativeVisualDataModel(qmlContext(this));
d->ownModel = true;
}
if (QDeclarativeVisualDataModel *dataModel = qobject_cast<QDeclarativeVisualDataModel*>(d->model)) {
int oldCount = dataModel->count();
dataModel->setDelegate(delegate);
if (isComponentComplete()) {
for (int i = 0; i < d->visibleItems.count(); ++i)
d->releaseItem(d->visibleItems.at(i));
d->visibleItems.clear();
d->releaseItem(d->currentItem);
d->currentItem = 0;
updateSections();
refill();
d->moveReason = QDeclarativeListViewPrivate::SetIndex;
d->updateCurrent(d->currentIndex);
if (d->highlight && d->currentItem) {
if (d->autoHighlight)
d->highlight->setPosition(d->currentItem->position());
d->updateTrackedItem();
}
d->updateViewport();
}
if (oldCount != dataModel->count())
emit countChanged();
}
emit delegateChanged();
}
/*!
\qmlproperty int ListView::currentIndex
\qmlproperty Item ListView::currentItem
The \c currentIndex property holds the index of the current item, and
\c currentItem holds the current item. Setting the currentIndex to -1
will clear the highlight and set currentItem to null.
If highlightFollowsCurrentItem is \c true, setting either of these
properties will smoothly scroll the ListView so that the current
item becomes visible.
Note that the position of the current item
may only be approximate until it becomes visible in the view.
*/
int QDeclarativeListView::currentIndex() const
{
Q_D(const QDeclarativeListView);
return d->currentIndex;
}
void QDeclarativeListView::setCurrentIndex(int index)
{
Q_D(QDeclarativeListView);
if (d->requestedIndex >= 0) // currently creating item
return;
d->currentIndexCleared = (index == -1);
if (index == d->currentIndex)
return;
if (isComponentComplete() && d->isValid()) {
if (d->layoutScheduled)
d->layout();
d->moveReason = QDeclarativeListViewPrivate::SetIndex;
d->updateCurrent(index);
} else if (d->currentIndex != index) {
d->currentIndex = index;
emit currentIndexChanged();
}
}
QDeclarativeItem *QDeclarativeListView::currentItem()
{
Q_D(QDeclarativeListView);
if (!d->currentItem)
return 0;
return d->currentItem->item;
}
/*!
\qmlproperty Item ListView::highlightItem
This holds the highlight item created from the \l highlight component.
The \c highlightItem is managed by the view unless
\l highlightFollowsCurrentItem is set to false.
\sa highlight, highlightFollowsCurrentItem
*/
QDeclarativeItem *QDeclarativeListView::highlightItem()
{
Q_D(QDeclarativeListView);
if (!d->highlight)
return 0;
return d->highlight->item;
}
/*!
\qmlproperty int ListView::count
This property holds the number of items in the view.
*/
int QDeclarativeListView::count() const
{
Q_D(const QDeclarativeListView);
if (d->model)
return d->model->count();
return 0;
}
/*!
\qmlproperty Component ListView::highlight
This property holds the component to use as the highlight.
An instance of the highlight component is created for each list.
The geometry of the resulting component instance is managed by the list
so as to stay with the current item, unless the highlightFollowsCurrentItem
property is false.
\sa highlightItem, highlightFollowsCurrentItem, {declarative/modelviews/listview}{ListView examples}
*/
QDeclarativeComponent *QDeclarativeListView::highlight() const
{
Q_D(const QDeclarativeListView);
return d->highlightComponent;
}
void QDeclarativeListView::setHighlight(QDeclarativeComponent *highlight)
{
Q_D(QDeclarativeListView);
if (highlight != d->highlightComponent) {
d->highlightComponent = highlight;
d->createHighlight();
if (d->currentItem)
d->updateHighlight();
emit highlightChanged();
}
}
/*!
\qmlproperty bool ListView::highlightFollowsCurrentItem
This property holds whether the highlight is managed by the view.
If this property is true (the default value), the highlight is moved smoothly
to follow the current item. Otherwise, the
highlight is not moved by the view, and any movement must be implemented
by the highlight.
Here is a highlight with its motion defined by a \l {SpringAnimation} item:
\snippet doc/src/snippets/declarative/listview/listview.qml highlightFollowsCurrentItem
Note that the highlight animation also affects the way that the view
is scrolled. This is because the view moves to maintain the
highlight within the preferred highlight range (or visible viewport).
\sa highlight, highlightMoveSpeed
*/
bool QDeclarativeListView::highlightFollowsCurrentItem() const
{
Q_D(const QDeclarativeListView);
return d->autoHighlight;
}
void QDeclarativeListView::setHighlightFollowsCurrentItem(bool autoHighlight)
{
Q_D(QDeclarativeListView);
if (d->autoHighlight != autoHighlight) {
d->autoHighlight = autoHighlight;
if (autoHighlight) {
d->updateHighlight();
} else {
if (d->highlightPosAnimator)
d->highlightPosAnimator->stop();
if (d->highlightSizeAnimator)
d->highlightSizeAnimator->stop();
}
emit highlightFollowsCurrentItemChanged();
}
}
//###Possibly rename these properties, since they are very useful even without a highlight?
/*!
\qmlproperty real ListView::preferredHighlightBegin
\qmlproperty real ListView::preferredHighlightEnd
\qmlproperty enumeration ListView::highlightRangeMode
These properties define the preferred range of the highlight (for the current item)
within the view. The \c preferredHighlightBegin value must be less than the
\c preferredHighlightEnd value.
These properties affect the position of the current item when the list is scrolled.
For example, if the currently selected item should stay in the middle of the
list when the view is scrolled, set the \c preferredHighlightBegin and
\c preferredHighlightEnd values to the top and bottom coordinates of where the middle
item would be. If the \c currentItem is changed programmatically, the list will
automatically scroll so that the current item is in the middle of the view.
Furthermore, the behavior of the current item index will occur whether or not a
highlight exists.
Valid values for \c highlightRangeMode are:
\list
\o ListView.ApplyRange - the view attempts to maintain the highlight within the range.
However, the highlight can move outside of the range at the ends of the list or due
to mouse interaction.
\o ListView.StrictlyEnforceRange - the highlight never moves outside of the range.
The current item changes if a keyboard or mouse action would cause the highlight to move
outside of the range.
\o ListView.NoHighlightRange - this is the default value.
\endlist
*/
qreal QDeclarativeListView::preferredHighlightBegin() const
{
Q_D(const QDeclarativeListView);
return d->highlightRangeStart;
}
void QDeclarativeListView::setPreferredHighlightBegin(qreal start)
{
Q_D(QDeclarativeListView);
d->highlightRangeStartValid = true;
if (d->highlightRangeStart == start)
return;
d->highlightRangeStart = start;
d->haveHighlightRange = d->highlightRange != NoHighlightRange && d->highlightRangeStart <= d->highlightRangeEnd;
emit preferredHighlightBeginChanged();
}
void QDeclarativeListView::resetPreferredHighlightBegin()
{
Q_D(QDeclarativeListView);
d->highlightRangeStartValid = false;
if (d->highlightRangeStart == 0)
return;
d->highlightRangeStart = 0;
emit preferredHighlightBeginChanged();
}
qreal QDeclarativeListView::preferredHighlightEnd() const
{
Q_D(const QDeclarativeListView);
return d->highlightRangeEnd;
}
void QDeclarativeListView::setPreferredHighlightEnd(qreal end)
{
Q_D(QDeclarativeListView);
d->highlightRangeEndValid = true;
if (d->highlightRangeEnd == end)
return;
d->highlightRangeEnd = end;
d->haveHighlightRange = d->highlightRange != NoHighlightRange && d->highlightRangeStart <= d->highlightRangeEnd;
emit preferredHighlightEndChanged();
}
void QDeclarativeListView::resetPreferredHighlightEnd()
{
Q_D(QDeclarativeListView);
d->highlightRangeEndValid = false;
if (d->highlightRangeEnd == 0)
return;
d->highlightRangeEnd = 0;
emit preferredHighlightEndChanged();
}
QDeclarativeListView::HighlightRangeMode QDeclarativeListView::highlightRangeMode() const
{
Q_D(const QDeclarativeListView);
return d->highlightRange;
}
void QDeclarativeListView::setHighlightRangeMode(HighlightRangeMode mode)
{
Q_D(QDeclarativeListView);
if (d->highlightRange == mode)
return;
d->highlightRange = mode;
d->haveHighlightRange = d->highlightRange != NoHighlightRange && d->highlightRangeStart <= d->highlightRangeEnd;
emit highlightRangeModeChanged();
}
/*!
\qmlproperty real ListView::spacing
This property holds the spacing between items.
The default value is 0.
*/
qreal QDeclarativeListView::spacing() const
{
Q_D(const QDeclarativeListView);
return d->spacing;
}
void QDeclarativeListView::setSpacing(qreal spacing)
{
Q_D(QDeclarativeListView);
if (spacing != d->spacing) {
d->spacing = spacing;
d->layout();
emit spacingChanged();
}
}
/*!
\qmlproperty enumeration ListView::orientation
This property holds the orientation of the list.
Possible values:
\list
\o ListView.Horizontal - Items are laid out horizontally
\o ListView.Vertical (default) - Items are laid out vertically
\endlist
\table
\row
\o Horizontal orientation:
\image ListViewHorizontal.png
\row
\o Vertical orientation:
\image listview-highlight.png
\endtable
*/
QDeclarativeListView::Orientation QDeclarativeListView::orientation() const
{
Q_D(const QDeclarativeListView);
return d->orient;
}
void QDeclarativeListView::setOrientation(QDeclarativeListView::Orientation orientation)
{
Q_D(QDeclarativeListView);
if (d->orient != orientation) {
d->orient = orientation;
if (d->orient == QDeclarativeListView::Vertical) {
setContentWidth(-1);
setFlickableDirection(VerticalFlick);
setContentX(0);
} else {
setContentHeight(-1);
setFlickableDirection(HorizontalFlick);
setContentY(0);
}
d->regenerate();
emit orientationChanged();
}
}
/*!
\qmlproperty enumeration ListView::layoutDirection
This property holds the layout direction of the horizontal list.
Possible values:
\list
\o Qt.LeftToRight (default) - Items will be laid out from left to right.
\o Qt.RightToLeft - Items will be laid out from right to let.
\endlist
When using the attached property \l {LayoutMirroring::enabled} for locale layouts,
the layout direction of the horizontal list will be mirrored. However, the actual property
\c layoutDirection will remain unchanged. You can use the property
\l {LayoutMirroring::enabled} to determine whether the direction has been mirrored.
\sa {LayoutMirroring}{LayoutMirroring}
*/
Qt::LayoutDirection QDeclarativeListView::layoutDirection() const
{
Q_D(const QDeclarativeListView);
return d->layoutDirection;
}
void QDeclarativeListView::setLayoutDirection(Qt::LayoutDirection layoutDirection)
{
Q_D(QDeclarativeListView);
if (d->layoutDirection != layoutDirection) {
d->layoutDirection = layoutDirection;
d->regenerate();
emit layoutDirectionChanged();
}
}
Qt::LayoutDirection QDeclarativeListView::effectiveLayoutDirection() const
{
Q_D(const QDeclarativeListView);
if (d->effectiveLayoutMirror)
return d->layoutDirection == Qt::RightToLeft ? Qt::LeftToRight : Qt::RightToLeft;
else
return d->layoutDirection;
}
/*!
\qmlproperty bool ListView::keyNavigationWraps
This property holds whether the list wraps key navigation.
If this is true, key navigation that would move the current item selection
past the end of the list instead wraps around and moves the selection to
the start of the list, and vice-versa.
By default, key navigation is not wrapped.
*/
bool QDeclarativeListView::isWrapEnabled() const
{
Q_D(const QDeclarativeListView);
return d->wrap;
}
void QDeclarativeListView::setWrapEnabled(bool wrap)
{
Q_D(QDeclarativeListView);
if (d->wrap == wrap)
return;
d->wrap = wrap;
emit keyNavigationWrapsChanged();
}
/*!
\qmlproperty int ListView::cacheBuffer
This property determines whether delegates are retained outside the
visible area of the view.
If this value is non-zero, the view keeps as many delegates
instantiated as it can fit within the buffer specified. For example,
if in a vertical view the delegate is 20 pixels high and \c cacheBuffer is
set to 40, then up to 2 delegates above and 2 delegates below the visible
area may be retained.
Note that cacheBuffer is not a pixel buffer - it only maintains additional
instantiated delegates.
Setting this value can improve the smoothness of scrolling behavior at the expense
of additional memory usage. It is not a substitute for creating efficient
delegates; the fewer elements in a delegate, the faster a view can be
scrolled.
*/
int QDeclarativeListView::cacheBuffer() const
{
Q_D(const QDeclarativeListView);
return d->buffer;
}
void QDeclarativeListView::setCacheBuffer(int b)
{
Q_D(QDeclarativeListView);
if (d->buffer != b) {
d->buffer = b;
if (isComponentComplete()) {
d->bufferMode = QDeclarativeListViewPrivate::BufferBefore | QDeclarativeListViewPrivate::BufferAfter;
refill();
}
emit cacheBufferChanged();
}
}
/*!
\qmlproperty string ListView::section.property
\qmlproperty enumeration ListView::section.criteria
\qmlproperty Component ListView::section.delegate
These properties hold the expression to be evaluated for the \l section attached property.
The \l section attached property enables a ListView to be visually
separated into different parts. These properties determine how sections
are created.
\c section.property holds the name of the property that is the basis
of each section.
\c section.criteria holds the criteria for forming each section based on
\c section.property. This value can be one of:
\list
\o ViewSection.FullString (default) - sections are created based on the
\c section.property value.
\o ViewSection.FirstCharacter - sections are created based on the first
character of the \c section.property value (for example, 'A', 'B', 'C'
sections, etc. for an address book)
\endlist
\c section.delegate holds the delegate component for each section.
Each item in the list has attached properties named \c ListView.section,
\c ListView.previousSection and \c ListView.nextSection. These may be
used to place a section header for related items.
For example, here is a ListView that displays a list of animals, separated
into sections. Each item in the ListView is placed in a different section
depending on the "size" property of the model item. The \c sectionHeading
delegate component provides the light blue bar that marks the beginning of
each section.
\snippet examples/declarative/modelviews/listview/sections.qml 0
\image qml-listview-sections-example.png
\note Adding sections to a ListView does not automatically re-order the
list items by the section criteria.
If the model is not ordered by section, then it is possible that
the sections created will not be unique; each boundary between
differing sections will result in a section header being created
even if that section exists elsewhere.
\sa {declarative/modelviews/listview}{ListView examples}
*/
QDeclarativeViewSection *QDeclarativeListView::sectionCriteria()
{
Q_D(QDeclarativeListView);
if (!d->sectionCriteria) {
d->sectionCriteria = new QDeclarativeViewSection(this);
connect(d->sectionCriteria, SIGNAL(propertyChanged()), this, SLOT(updateSections()));
}
return d->sectionCriteria;
}
/*!
\qmlproperty string ListView::currentSection
This property holds the section that is currently at the beginning of the view.
*/
QString QDeclarativeListView::currentSection() const
{
Q_D(const QDeclarativeListView);
return d->currentSection;
}
/*!
\qmlproperty real ListView::highlightMoveSpeed
\qmlproperty int ListView::highlightMoveDuration
\qmlproperty real ListView::highlightResizeSpeed
\qmlproperty int ListView::highlightResizeDuration
These properties hold the move and resize animation speed of the highlight delegate.
\l highlightFollowsCurrentItem must be true for these properties
to have effect.
The default value for the speed properties is 400 pixels/second.
The default value for the duration properties is -1, i.e. the
highlight will take as much time as necessary to move at the set speed.
These properties have the same characteristics as a SmoothedAnimation.
\sa highlightFollowsCurrentItem
*/
qreal QDeclarativeListView::highlightMoveSpeed() const
{
Q_D(const QDeclarativeListView);\
return d->highlightMoveSpeed;
}
void QDeclarativeListView::setHighlightMoveSpeed(qreal speed)
{
Q_D(QDeclarativeListView);\
if (d->highlightMoveSpeed != speed) {
d->highlightMoveSpeed = speed;
if (d->highlightPosAnimator)
d->highlightPosAnimator->velocity = d->highlightMoveSpeed;
emit highlightMoveSpeedChanged();
}
}
int QDeclarativeListView::highlightMoveDuration() const
{
Q_D(const QDeclarativeListView);
return d->highlightMoveDuration;
}
void QDeclarativeListView::setHighlightMoveDuration(int duration)
{
Q_D(QDeclarativeListView);\
if (d->highlightMoveDuration != duration) {
d->highlightMoveDuration = duration;
if (d->highlightPosAnimator)
d->highlightPosAnimator->userDuration = d->highlightMoveDuration;
emit highlightMoveDurationChanged();
}
}
qreal QDeclarativeListView::highlightResizeSpeed() const
{
Q_D(const QDeclarativeListView);\
return d->highlightResizeSpeed;
}
void QDeclarativeListView::setHighlightResizeSpeed(qreal speed)
{
Q_D(QDeclarativeListView);\
if (d->highlightResizeSpeed != speed) {
d->highlightResizeSpeed = speed;
if (d->highlightSizeAnimator)
d->highlightSizeAnimator->velocity = d->highlightResizeSpeed;
emit highlightResizeSpeedChanged();
}
}
int QDeclarativeListView::highlightResizeDuration() const
{
Q_D(const QDeclarativeListView);
return d->highlightResizeDuration;
}
void QDeclarativeListView::setHighlightResizeDuration(int duration)
{
Q_D(QDeclarativeListView);\
if (d->highlightResizeDuration != duration) {
d->highlightResizeDuration = duration;
if (d->highlightSizeAnimator)
d->highlightSizeAnimator->userDuration = d->highlightResizeDuration;
emit highlightResizeDurationChanged();
}
}
/*!
\qmlproperty enumeration ListView::snapMode
This property determines how the view scrolling will settle following a drag or flick.
The possible values are:
\list
\o ListView.NoSnap (default) - the view stops anywhere within the visible area.
\o ListView.SnapToItem - the view settles with an item aligned with the start of
the view.
\o ListView.SnapOneItem - the view settles no more than one item away from the first
visible item at the time the mouse button is released. This mode is particularly
useful for moving one page at a time.
\endlist
\c snapMode does not affect the \l currentIndex. To update the
\l currentIndex as the list is moved, set \l highlightRangeMode
to \c ListView.StrictlyEnforceRange.
\sa highlightRangeMode
*/
QDeclarativeListView::SnapMode QDeclarativeListView::snapMode() const
{
Q_D(const QDeclarativeListView);
return d->snapMode;
}
void QDeclarativeListView::setSnapMode(SnapMode mode)
{
Q_D(QDeclarativeListView);
if (d->snapMode != mode) {
d->snapMode = mode;
emit snapModeChanged();
}
}
/*!
\qmlproperty Component ListView::footer
This property holds the component to use as the footer.
An instance of the footer component is created for each view. The
footer is positioned at the end of the view, after any items.
\sa header
*/
QDeclarativeComponent *QDeclarativeListView::footer() const
{
Q_D(const QDeclarativeListView);
return d->footerComponent;
}
void QDeclarativeListView::setFooter(QDeclarativeComponent *footer)
{
Q_D(QDeclarativeListView);
if (d->footerComponent != footer) {
if (d->footer) {
if (scene())
scene()->removeItem(d->footer->item);
d->footer->item->deleteLater();
delete d->footer;
d->footer = 0;
}
d->footerComponent = footer;
d->minExtentDirty = true;
d->maxExtentDirty = true;
if (isComponentComplete()) {
d->updateFooter();
d->updateViewport();
d->fixupPosition();
}
emit footerChanged();
}
}
/*!
\qmlproperty Component ListView::header
This property holds the component to use as the header.
An instance of the header component is created for each view. The
header is positioned at the beginning of the view, before any items.
\sa footer
*/
QDeclarativeComponent *QDeclarativeListView::header() const
{
Q_D(const QDeclarativeListView);
return d->headerComponent;
}
void QDeclarativeListView::setHeader(QDeclarativeComponent *header)
{
Q_D(QDeclarativeListView);
if (d->headerComponent != header) {
if (d->header) {
if (scene())
scene()->removeItem(d->header->item);
d->header->item->deleteLater();
delete d->header;
d->header = 0;
}
d->headerComponent = header;
d->minExtentDirty = true;
d->maxExtentDirty = true;
if (isComponentComplete()) {
d->updateHeader();
d->updateFooter();
d->updateViewport();
d->fixupPosition();
}
emit headerChanged();
}
}
void QDeclarativeListView::setContentX(qreal pos)
{
Q_D(QDeclarativeListView);
// Positioning the view manually should override any current movement state
d->moveReason = QDeclarativeListViewPrivate::Other;
QDeclarativeFlickable::setContentX(pos);
}
void QDeclarativeListView::setContentY(qreal pos)
{
Q_D(QDeclarativeListView);
// Positioning the view manually should override any current movement state
d->moveReason = QDeclarativeListViewPrivate::Other;
QDeclarativeFlickable::setContentY(pos);
}
bool QDeclarativeListView::event(QEvent *event)
{
Q_D(QDeclarativeListView);
if (event->type() == QEvent::User) {
if (d->layoutScheduled)
d->layout();
return true;
}
return QDeclarativeFlickable::event(event);
}
void QDeclarativeListView::viewportMoved()
{
Q_D(QDeclarativeListView);
QDeclarativeFlickable::viewportMoved();
if (!d->itemCount)
return;
// Recursion can occur due to refill changing the content size.
if (d->inViewportMoved)
return;
d->inViewportMoved = true;
d->lazyRelease = true;
refill();
if (d->hData.flicking || d->vData.flicking || d->hData.moving || d->vData.moving)
d->moveReason = QDeclarativeListViewPrivate::Mouse;
if (d->moveReason != QDeclarativeListViewPrivate::SetIndex) {
if (d->haveHighlightRange && d->highlightRange == StrictlyEnforceRange && d->highlight) {
// reposition highlight
qreal pos = d->highlight->position();
qreal viewPos;
qreal highlightStart;
qreal highlightEnd;
if (d->isRightToLeft()) {
// Handle Right-To-Left exceptions
viewPos = -d->position()-d->size();
highlightStart = d->highlightRangeStartValid ? d->size()-d->highlightRangeEnd : d->highlightRangeStart;
highlightEnd = d->highlightRangeEndValid ? d->size()-d->highlightRangeStart : d->highlightRangeEnd;
} else {
viewPos = d->position();
highlightStart = d->highlightRangeStart;
highlightEnd = d->highlightRangeEnd;
}
if (pos > viewPos + highlightEnd - d->highlight->size())
pos = viewPos + highlightEnd - d->highlight->size();
if (pos < viewPos + highlightStart)
pos = viewPos + highlightStart;
d->highlightPosAnimator->stop();
d->highlight->setPosition(qRound(pos));
// update current index
if (FxListItem *snapItem = d->snapItemAt(d->highlight->position())) {
if (snapItem->index >= 0 && snapItem->index != d->currentIndex)
d->updateCurrent(snapItem->index);
}
}
}
if ((d->hData.flicking || d->vData.flicking) && d->correctFlick && !d->inFlickCorrection) {
d->inFlickCorrection = true;
// Near an end and it seems that the extent has changed?
// Recalculate the flick so that we don't end up in an odd position.
if (yflick() && !d->vData.inOvershoot) {
if (d->vData.velocity > 0) {
const qreal minY = minYExtent();
if ((minY - d->vData.move.value() < height()/2 || d->vData.flickTarget - d->vData.move.value() < height()/2)
&& minY != d->vData.flickTarget)
d->flickY(-d->vData.smoothVelocity.value());
d->bufferMode = QDeclarativeListViewPrivate::BufferBefore;
} else if (d->vData.velocity < 0) {
const qreal maxY = maxYExtent();
if ((d->vData.move.value() - maxY < height()/2 || d->vData.move.value() - d->vData.flickTarget < height()/2)
&& maxY != d->vData.flickTarget)
d->flickY(-d->vData.smoothVelocity.value());
d->bufferMode = QDeclarativeListViewPrivate::BufferAfter;
}
}
if (xflick() && !d->hData.inOvershoot) {
if (d->hData.velocity > 0) {
const qreal minX = minXExtent();
if ((minX - d->hData.move.value() < width()/2 || d->hData.flickTarget - d->hData.move.value() < width()/2)
&& minX != d->hData.flickTarget)
d->flickX(-d->hData.smoothVelocity.value());
d->bufferMode = d->isRightToLeft()
? QDeclarativeListViewPrivate::BufferAfter : QDeclarativeListViewPrivate::BufferBefore;
} else if (d->hData.velocity < 0) {
const qreal maxX = maxXExtent();
if ((d->hData.move.value() - maxX < width()/2 || d->hData.move.value() - d->hData.flickTarget < width()/2)
&& maxX != d->hData.flickTarget)
d->flickX(-d->hData.smoothVelocity.value());
d->bufferMode = d->isRightToLeft()
? QDeclarativeListViewPrivate::BufferBefore : QDeclarativeListViewPrivate::BufferAfter;
}
}
d->inFlickCorrection = false;
}
d->inViewportMoved = false;
}
qreal QDeclarativeListView::minYExtent() const
{
Q_D(const QDeclarativeListView);
if (d->orient == QDeclarativeListView::Horizontal)
return QDeclarativeFlickable::minYExtent();
if (d->minExtentDirty) {
d->minExtent = -d->startPosition();
if (d->header && d->visibleItems.count())
d->minExtent += d->header->size();
if (d->haveHighlightRange && d->highlightRange == StrictlyEnforceRange) {
d->minExtent += d->highlightRangeStart;
if (d->sectionCriteria) {
if (d->visibleItem(0))
d->minExtent -= d->visibleItem(0)->sectionSize();
}
d->minExtent = qMax(d->minExtent, -(d->endPositionAt(0) - d->highlightRangeEnd + 1));
}
d->minExtentDirty = false;
}
return d->minExtent;
}
qreal QDeclarativeListView::maxYExtent() const
{
Q_D(const QDeclarativeListView);
if (d->orient == QDeclarativeListView::Horizontal)
return height();
if (d->maxExtentDirty) {
if (!d->model || !d->model->count()) {
d->maxExtent = d->header ? -d->header->size() : 0;
d->maxExtent += height();
} else if (d->haveHighlightRange && d->highlightRange == StrictlyEnforceRange) {
d->maxExtent = -(d->positionAt(d->model->count()-1) - d->highlightRangeStart);
if (d->highlightRangeEnd != d->highlightRangeStart)
d->maxExtent = qMin(d->maxExtent, -(d->endPosition() - d->highlightRangeEnd + 1));
} else {
d->maxExtent = -(d->endPosition() - height() + 1);
}
if (d->footer)
d->maxExtent -= d->footer->size();
qreal minY = minYExtent();
if (d->maxExtent > minY)
d->maxExtent = minY;
d->maxExtentDirty = false;
}
return d->maxExtent;
}
qreal QDeclarativeListView::minXExtent() const
{
Q_D(const QDeclarativeListView);
if (d->orient == QDeclarativeListView::Vertical)
return QDeclarativeFlickable::minXExtent();
if (d->minExtentDirty) {
d->minExtent = -d->startPosition();
qreal highlightStart;
qreal highlightEnd;
qreal endPositionFirstItem = 0;
if (d->isRightToLeft()) {
if (d->model && d->model->count())
endPositionFirstItem = d->positionAt(d->model->count()-1);
else if (d->header)
d->minExtent += d->header->size();
highlightStart = d->highlightRangeStartValid
? d->highlightRangeStart - (d->lastPosition()-endPositionFirstItem)
: d->size() - (d->lastPosition()-endPositionFirstItem);
highlightEnd = d->highlightRangeEndValid ? d->highlightRangeEnd : d->size();
if (d->footer)
d->minExtent += d->footer->size();
qreal maxX = maxXExtent();
if (d->minExtent < maxX)
d->minExtent = maxX;
} else {
endPositionFirstItem = d->endPositionAt(0);
highlightStart = d->highlightRangeStart;
highlightEnd = d->highlightRangeEnd;
if (d->header && d->visibleItems.count())
d->minExtent += d->header->size();
}
if (d->haveHighlightRange && d->highlightRange == StrictlyEnforceRange) {
d->minExtent += highlightStart;
d->minExtent = qMax(d->minExtent, -(endPositionFirstItem - highlightEnd + 1));
}
d->minExtentDirty = false;
}
return d->minExtent;
}
qreal QDeclarativeListView::maxXExtent() const
{
Q_D(const QDeclarativeListView);
if (d->orient == QDeclarativeListView::Vertical)
return width();
if (d->maxExtentDirty) {
qreal highlightStart;
qreal highlightEnd;
qreal lastItemPosition = 0;
d->maxExtent = 0;
if (d->isRightToLeft()) {
highlightStart = d->highlightRangeStartValid ? d->highlightRangeEnd : d->size();
highlightEnd = d->highlightRangeEndValid ? d->highlightRangeStart : d->size();
lastItemPosition = d->endPosition();
} else {
highlightStart = d->highlightRangeStart;
highlightEnd = d->highlightRangeEnd;
if (d->model && d->model->count())
lastItemPosition = d->positionAt(d->model->count()-1);
}
if (!d->model || !d->model->count()) {
if (!d->isRightToLeft())
d->maxExtent = d->header ? -d->header->size() : 0;
d->maxExtent += width();
} else if (d->haveHighlightRange && d->highlightRange == StrictlyEnforceRange) {
d->maxExtent = -(lastItemPosition - highlightStart);
if (highlightEnd != highlightStart) {
d->maxExtent = d->isRightToLeft()
? qMax(d->maxExtent, -(d->endPosition() - highlightEnd + 1))
: qMin(d->maxExtent, -(d->endPosition() - highlightEnd + 1));
}
} else {
d->maxExtent = -(d->endPosition() - width() + 1);
}
if (d->isRightToLeft()) {
if (d->header && d->visibleItems.count())
d->maxExtent -= d->header->size();
} else {
if (d->footer)
d->maxExtent -= d->footer->size();
qreal minX = minXExtent();
if (d->maxExtent > minX)
d->maxExtent = minX;
}
d->maxExtentDirty = false;
}
return d->maxExtent;
}
void QDeclarativeListView::keyPressEvent(QKeyEvent *event)
{
Q_D(QDeclarativeListView);
keyPressPreHandler(event);
if (event->isAccepted())
return;
if (d->model && d->model->count() && d->interactive) {
if ((d->orient == QDeclarativeListView::Horizontal && !d->isRightToLeft() && event->key() == Qt::Key_Left)
|| (d->orient == QDeclarativeListView::Horizontal && d->isRightToLeft() && event->key() == Qt::Key_Right)
|| (d->orient == QDeclarativeListView::Vertical && event->key() == Qt::Key_Up)) {
if (currentIndex() > 0 || (d->wrap && !event->isAutoRepeat())) {
decrementCurrentIndex();
event->accept();
return;
} else if (d->wrap) {
event->accept();
return;
}
} else if ((d->orient == QDeclarativeListView::Horizontal && !d->isRightToLeft() && event->key() == Qt::Key_Right)
|| (d->orient == QDeclarativeListView::Horizontal && d->isRightToLeft() && event->key() == Qt::Key_Left)
|| (d->orient == QDeclarativeListView::Vertical && event->key() == Qt::Key_Down)) {
if (currentIndex() < d->model->count() - 1 || (d->wrap && !event->isAutoRepeat())) {
incrementCurrentIndex();
event->accept();
return;
} else if (d->wrap) {
event->accept();
return;
}
}
}
event->ignore();
QDeclarativeFlickable::keyPressEvent(event);
}
void QDeclarativeListView::geometryChanged(const QRectF &newGeometry,
const QRectF &oldGeometry)
{
Q_D(QDeclarativeListView);
d->maxExtentDirty = true;
d->minExtentDirty = true;
if (d->isRightToLeft() && d->orient == Qt::Horizontal) {
// maintain position relative to the right edge
int dx = newGeometry.width() - oldGeometry.width();
setContentX(contentX() - dx);
}
QDeclarativeFlickable::geometryChanged(newGeometry, oldGeometry);
}
/*!
\qmlmethod ListView::incrementCurrentIndex()
Increments the current index. The current index will wrap
if keyNavigationWraps is true and it is currently at the end.
This method has no effect if the \l count is zero.
\bold Note: methods should only be called after the Component has completed.
*/
void QDeclarativeListView::incrementCurrentIndex()
{
Q_D(QDeclarativeListView);
int count = d->model ? d->model->count() : 0;
if (count && (currentIndex() < count - 1 || d->wrap)) {
d->moveReason = QDeclarativeListViewPrivate::SetIndex;
int index = currentIndex()+1;
setCurrentIndex((index >= 0 && index < count) ? index : 0);
}
}
/*!
\qmlmethod ListView::decrementCurrentIndex()
Decrements the current index. The current index will wrap
if keyNavigationWraps is true and it is currently at the beginning.
This method has no effect if the \l count is zero.
\bold Note: methods should only be called after the Component has completed.
*/
void QDeclarativeListView::decrementCurrentIndex()
{
Q_D(QDeclarativeListView);
int count = d->model ? d->model->count() : 0;
if (count && (currentIndex() > 0 || d->wrap)) {
d->moveReason = QDeclarativeListViewPrivate::SetIndex;
int index = currentIndex()-1;
setCurrentIndex((index >= 0 && index < count) ? index : count-1);
}
}
void QDeclarativeListViewPrivate::positionViewAtIndex(int index, int mode)
{
Q_Q(QDeclarativeListView);
if (!isValid())
return;
if (mode < QDeclarativeListView::Beginning || mode > QDeclarativeListView::Contain)
return;
int idx = qMax(qMin(index, model->count()-1), 0);
if (layoutScheduled)
layout();
qreal pos = isRightToLeft() ? -position() - size() : position();
FxListItem *item = visibleItem(idx);
qreal maxExtent;
if (orient == QDeclarativeListView::Vertical)
maxExtent = -q->maxYExtent();
else
maxExtent = isRightToLeft() ? q->minXExtent()-size(): -q->maxXExtent();
if (!item) {
int itemPos = positionAt(idx);
// save the currently visible items in case any of them end up visible again
QList<FxListItem*> oldVisible = visibleItems;
visibleItems.clear();
visiblePos = itemPos;
visibleIndex = idx;
setPosition(qMin(qreal(itemPos), maxExtent));
// now release the reference to all the old visible items.
for (int i = 0; i < oldVisible.count(); ++i)
releaseItem(oldVisible.at(i));
item = visibleItem(idx);
}
if (item) {
const qreal itemPos = item->position();
switch (mode) {
case QDeclarativeListView::Beginning:
pos = itemPos;
if (index < 0 && header)
pos -= header->size();
break;
case QDeclarativeListView::Center:
pos = itemPos - (size() - item->size())/2;
break;
case QDeclarativeListView::End:
pos = itemPos - size() + item->size();
if (index >= model->count() && footer)
pos += footer->size();
break;
case QDeclarativeListView::Visible:
if (itemPos > pos + size())
pos = itemPos - size() + item->size();
else if (item->endPosition() < pos)
pos = itemPos;
break;
case QDeclarativeListView::Contain:
if (item->endPosition() > pos + size())
pos = itemPos - size() + item->size();
if (itemPos < pos)
pos = itemPos;
}
pos = qMin(pos, maxExtent);
qreal minExtent;
if (orient == QDeclarativeListView::Vertical) {
minExtent = -q->minYExtent();
} else {
minExtent = isRightToLeft() ? q->maxXExtent()-size(): -q->minXExtent();
}
pos = qMax(pos, minExtent);
moveReason = QDeclarativeListViewPrivate::Other;
q->cancelFlick();
setPosition(pos);
if (highlight) {
if (autoHighlight) {
highlight->setPosition(currentItem->itemPosition());
highlight->setSize(currentItem->itemSize());
}
updateHighlight();
}
}
fixupPosition();
}
/*!
\qmlmethod ListView::positionViewAtIndex(int index, PositionMode mode)
Positions the view such that the \a index is at the position specified by
\a mode:
\list
\o ListView.Beginning - position item at the top (or left for horizontal orientation) of the view.
\o ListView.Center - position item in the center of the view.
\o ListView.End - position item at bottom (or right for horizontal orientation) of the view.
\o ListView.Visible - if any part of the item is visible then take no action, otherwise
bring the item into view.
\o ListView.Contain - ensure the entire item is visible. If the item is larger than
the view the item is positioned at the top (or left for horizontal orientation) of the view.
\endlist
If positioning the view at \a index would cause empty space to be displayed at
the beginning or end of the view, the view will be positioned at the boundary.
It is not recommended to use \l {Flickable::}{contentX} or \l {Flickable::}{contentY} to position the view
at a particular index. This is unreliable since removing items from the start
of the list does not cause all other items to be repositioned, and because
the actual start of the view can vary based on the size of the delegates.
The correct way to bring an item into view is with \c positionViewAtIndex.
\bold Note: methods should only be called after the Component has completed. To position
the view at startup, this method should be called by Component.onCompleted. For
example, to position the view at the end:
\code
Component.onCompleted: positionViewAtIndex(count - 1, ListView.Beginning)
\endcode
*/
void QDeclarativeListView::positionViewAtIndex(int index, int mode)
{
Q_D(QDeclarativeListView);
if (!d->isValid() || index < 0 || index >= d->model->count())
return;
d->positionViewAtIndex(index, mode);
}
/*!
\qmlmethod ListView::positionViewAtBeginning()
\qmlmethod ListView::positionViewAtEnd()
\since QtQuick 1.1
Positions the view at the beginning or end, taking into account any header or footer.
It is not recommended to use \l {Flickable::}{contentX} or \l {Flickable::}{contentY} to position the view
at a particular index. This is unreliable since removing items from the start
of the list does not cause all other items to be repositioned, and because
the actual start of the view can vary based on the size of the delegates.
\bold Note: methods should only be called after the Component has completed. To position
the view at startup, this method should be called by Component.onCompleted. For
example, to position the view at the end on startup:
\code
Component.onCompleted: positionViewAtEnd()
\endcode
*/
void QDeclarativeListView::positionViewAtBeginning()
{
Q_D(QDeclarativeListView);
if (!d->isValid())
return;
d->positionViewAtIndex(-1, Beginning);
}
void QDeclarativeListView::positionViewAtEnd()
{
Q_D(QDeclarativeListView);
if (!d->isValid())
return;
d->positionViewAtIndex(d->model->count(), End);
}
/*!
\qmlmethod int ListView::indexAt(int x, int y)
Returns the index of the visible item containing the point \a x, \a y in content
coordinates. If there is no item at the point specified, or the item is
not visible -1 is returned.
If the item is outside the visible area, -1 is returned, regardless of
whether an item will exist at that point when scrolled into view.
\bold Note: methods should only be called after the Component has completed.
*/
int QDeclarativeListView::indexAt(qreal x, qreal y) const
{
Q_D(const QDeclarativeListView);
for (int i = 0; i < d->visibleItems.count(); ++i) {
const FxListItem *listItem = d->visibleItems.at(i);
if(listItem->contains(x, y))
return listItem->index;
}
return -1;
}
void QDeclarativeListView::componentComplete()
{
Q_D(QDeclarativeListView);
QDeclarativeFlickable::componentComplete();
updateSections();
d->updateHeader();
d->updateFooter();
if (d->isValid()) {
refill();
d->moveReason = QDeclarativeListViewPrivate::SetIndex;
if (d->currentIndex < 0 && !d->currentIndexCleared)
d->updateCurrent(0);
else
d->updateCurrent(d->currentIndex);
if (d->highlight && d->currentItem) {
if (d->autoHighlight)
d->highlight->setPosition(d->currentItem->position());
d->updateTrackedItem();
}
d->moveReason = QDeclarativeListViewPrivate::Other;
d->fixupPosition();
}
}
void QDeclarativeListView::updateSections()
{
Q_D(QDeclarativeListView);
if (isComponentComplete() && d->model) {
QList<QByteArray> roles;
if (d->sectionCriteria && !d->sectionCriteria->property().isEmpty())
roles << d->sectionCriteria->property().toUtf8();
d->model->setWatchedRoles(roles);
d->updateSections();
if (d->itemCount)
d->layout();
}
}
void QDeclarativeListView::refill()
{
Q_D(QDeclarativeListView);
if (d->isRightToLeft())
d->refill(-d->position()-d->size()+1, -d->position());
else
d->refill(d->position(), d->position()+d->size()-1);
}
void QDeclarativeListView::trackedPositionChanged()
{
Q_D(QDeclarativeListView);
if (!d->trackedItem || !d->currentItem)
return;
if (d->moveReason == QDeclarativeListViewPrivate::SetIndex) {
qreal trackedPos = qCeil(d->trackedItem->position());
qreal trackedSize = d->trackedItem->size();
if (d->trackedItem != d->currentItem) {
trackedPos -= d->currentItem->sectionSize();
trackedSize += d->currentItem->sectionSize();
}
qreal viewPos;
qreal highlightStart;
qreal highlightEnd;
if (d->isRightToLeft()) {
viewPos = -d->position()-d->size();
highlightStart = d->highlightRangeStartValid ? d->size()-d->highlightRangeEnd : d->highlightRangeStart;
highlightEnd = d->highlightRangeEndValid ? d->size()-d->highlightRangeStart : d->highlightRangeEnd;
} else {
viewPos = d->position();
highlightStart = d->highlightRangeStart;
highlightEnd = d->highlightRangeEnd;
}
qreal pos = viewPos;
if (d->haveHighlightRange) {
if (d->highlightRange == StrictlyEnforceRange) {
if (trackedPos > pos + highlightEnd - d->trackedItem->size())
pos = trackedPos - highlightEnd + d->trackedItem->size();
if (trackedPos < pos + highlightStart)
pos = trackedPos - highlightStart;
} else {
if (trackedPos < d->startPosition() + highlightStart) {
pos = d->startPosition();
} else if (d->trackedItem->endPosition() > d->endPosition() - d->size() + highlightEnd) {
pos = d->endPosition() - d->size() + 1;
if (pos < d->startPosition())
pos = d->startPosition();
} else {
if (trackedPos < viewPos + highlightStart) {
pos = trackedPos - highlightStart;
} else if (trackedPos > viewPos + highlightEnd - trackedSize) {
pos = trackedPos - highlightEnd + trackedSize;
}
}
}
} else {
if (trackedPos < viewPos && d->currentItem->position() < viewPos) {
pos = d->currentItem->position() < trackedPos ? trackedPos : d->currentItem->position();
} else if (d->trackedItem->endPosition() >= viewPos + d->size()
&& d->currentItem->endPosition() >= viewPos + d->size()) {
if (d->trackedItem->endPosition() <= d->currentItem->endPosition()) {
pos = d->trackedItem->endPosition() - d->size() + 1;
if (trackedSize > d->size())
pos = trackedPos;
} else {
pos = d->currentItem->endPosition() - d->size() + 1;
if (d->currentItem->size() > d->size())
pos = d->currentItem->position();
}
}
}
if (viewPos != pos) {
cancelFlick();
d->calcVelocity = true;
d->setPosition(pos);
d->calcVelocity = false;
}
}
}
void QDeclarativeListView::itemsInserted(int modelIndex, int count)
{
Q_D(QDeclarativeListView);
if (!isComponentComplete())
return;
d->updateUnrequestedIndexes();
d->moveReason = QDeclarativeListViewPrivate::Other;
qreal tempPos = d->isRightToLeft() ? -d->position()-d->size() : d->position();
int index = d->visibleItems.count() ? d->mapFromModel(modelIndex) : 0;
if (index < 0) {
int i = d->visibleItems.count() - 1;
while (i > 0 && d->visibleItems.at(i)->index == -1)
--i;
if (i == 0 && d->visibleItems.first()->index == -1) {
// there are no visible items except items marked for removal
index = d->visibleItems.count();
} else if (d->visibleItems.at(i)->index + 1 == modelIndex
&& d->visibleItems.at(i)->endPosition() < d->buffer+tempPos+d->size()-1) {
// Special case of appending an item to the model.
index = d->visibleItems.count();
} else {
if (modelIndex < d->visibleIndex) {
// Insert before visible items
d->visibleIndex += count;
for (int i = 0; i < d->visibleItems.count(); ++i) {
FxListItem *listItem = d->visibleItems.at(i);
if (listItem->index != -1 && listItem->index >= modelIndex)
listItem->index += count;
}
}
if (d->currentIndex >= modelIndex) {
// adjust current item index
d->currentIndex += count;
if (d->currentItem)
d->currentItem->index = d->currentIndex;
emit currentIndexChanged();
}
d->scheduleLayout();
d->itemCount += count;
emit countChanged();
return;
}
}
// index can be the next item past the end of the visible items list (i.e. appended)
int pos = 0;
if (d->visibleItems.count()) {
pos = index < d->visibleItems.count() ? d->visibleItems.at(index)->position()
: d->visibleItems.last()->endPosition()+d->spacing+1;
} else if (d->itemCount == 0 && d->header) {
pos = d->header->size();
}
int initialPos = pos;
int diff = 0;
QList<FxListItem*> added;
bool addedVisible = false;
FxListItem *firstVisible = d->firstVisibleItem();
if (firstVisible && pos < firstVisible->position()) {
// Insert items before the visible item.
int insertionIdx = index;
int i = 0;
int from = tempPos - d->buffer;
for (i = count-1; i >= 0 && pos > from; --i) {
if (!addedVisible) {
d->scheduleLayout();
addedVisible = true;
}
FxListItem *item = d->createItem(modelIndex + i);
d->visibleItems.insert(insertionIdx, item);
pos -= item->size() + d->spacing;
item->setPosition(pos);
index++;
}
if (i >= 0) {
// If we didn't insert all our new items - anything
// before the current index is not visible - remove it.
while (insertionIdx--) {
FxListItem *item = d->visibleItems.takeFirst();
if (item->index != -1)
d->visibleIndex++;
d->releaseItem(item);
}
} else {
// adjust pos of items before inserted items.
for (int i = insertionIdx-1; i >= 0; i--) {
FxListItem *listItem = d->visibleItems.at(i);
listItem->setPosition(listItem->position() - (initialPos - pos));
}
}
} else {
int i = 0;
int to = d->buffer+tempPos+d->size()-1;
for (i = 0; i < count && pos <= to; ++i) {
if (!addedVisible) {
d->scheduleLayout();
addedVisible = true;
}
FxListItem *item = d->createItem(modelIndex + i);
d->visibleItems.insert(index, item);
item->setPosition(pos);
added.append(item);
pos += item->size() + d->spacing;
++index;
}
if (i != count) {
// We didn't insert all our new items, which means anything
// beyond the current index is not visible - remove it.
while (d->visibleItems.count() > index)
d->releaseItem(d->visibleItems.takeLast());
}
diff = pos - initialPos;
}
if (d->itemCount && d->currentIndex >= modelIndex) {
// adjust current item index
d->currentIndex += count;
if (d->currentItem) {
d->currentItem->index = d->currentIndex;
d->currentItem->setPosition(d->currentItem->position() + diff);
}
emit currentIndexChanged();
} else if (!d->itemCount && (!d->currentIndex || (d->currentIndex < 0 && !d->currentIndexCleared))) {
d->updateCurrent(0);
}
// Update the indexes of the following visible items.
for (; index < d->visibleItems.count(); ++index) {
FxListItem *listItem = d->visibleItems.at(index);
if (d->currentItem && listItem->item != d->currentItem->item)
listItem->setPosition(listItem->position() + diff);
if (listItem->index != -1)
listItem->index += count;
}
// everything is in order now - emit add() signal
for (int j = 0; j < added.count(); ++j)
added.at(j)->attached->emitAdd();
d->updateSections();
d->itemCount += count;
emit countChanged();
}
void QDeclarativeListView::itemsRemoved(int modelIndex, int count)
{
Q_D(QDeclarativeListView);
if (!isComponentComplete())
return;
d->moveReason = QDeclarativeListViewPrivate::Other;
d->updateUnrequestedIndexes();
d->itemCount -= count;
FxListItem *firstVisible = d->firstVisibleItem();
int preRemovedSize = 0;
bool removedVisible = false;
// Remove the items from the visible list, skipping anything already marked for removal
QList<FxListItem*>::Iterator it = d->visibleItems.begin();
while (it != d->visibleItems.end()) {
FxListItem *item = *it;
if (item->index == -1 || item->index < modelIndex) {
// already removed, or before removed items
++it;
} else if (item->index >= modelIndex + count) {
// after removed items
item->index -= count;
++it;
} else {
// removed item
if (!removedVisible) {
d->scheduleLayout();
removedVisible = true;
}
item->attached->emitRemove();
if (item->attached->delayRemove()) {
item->index = -1;
connect(item->attached, SIGNAL(delayRemoveChanged()), this, SLOT(destroyRemoved()), Qt::QueuedConnection);
++it;
} else {
if (item == firstVisible)
firstVisible = 0;
if (firstVisible && item->position() < firstVisible->position())
preRemovedSize += item->size();
it = d->visibleItems.erase(it);
d->releaseItem(item);
}
}
}
if (firstVisible && d->visibleItems.first() != firstVisible)
d->visibleItems.first()->setPosition(d->visibleItems.first()->position() + preRemovedSize);
// fix current
if (d->currentIndex >= modelIndex + count) {
d->currentIndex -= count;
if (d->currentItem)
d->currentItem->index -= count;
emit currentIndexChanged();
} else if (d->currentIndex >= modelIndex && d->currentIndex < modelIndex + count) {
// current item has been removed.
d->currentItem->attached->setIsCurrentItem(false);
d->releaseItem(d->currentItem);
d->currentItem = 0;
d->currentIndex = -1;
if (d->itemCount)
d->updateCurrent(qMin(modelIndex, d->itemCount-1));
else
emit currentIndexChanged();
}
// update visibleIndex
bool haveVisibleIndex = false;
for (it = d->visibleItems.begin(); it != d->visibleItems.end(); ++it) {
if ((*it)->index != -1) {
d->visibleIndex = (*it)->index;
haveVisibleIndex = true;
break;
}
}
if (!haveVisibleIndex) {
d->timeline.clear();
if (removedVisible && d->itemCount == 0) {
d->visibleIndex = 0;
d->visiblePos = d->header ? d->header->size() : 0;
d->setPosition(0);
d->updateHeader();
d->updateFooter();
update();
} else {
if (modelIndex < d->visibleIndex)
d->visibleIndex = modelIndex+1;
d->visibleIndex = qMax(qMin(d->visibleIndex, d->itemCount-1), 0);
}
}
d->updateSections();
emit countChanged();
}
void QDeclarativeListView::destroyRemoved()
{
Q_D(QDeclarativeListView);
for (QList<FxListItem*>::Iterator it = d->visibleItems.begin();
it != d->visibleItems.end();) {
FxListItem *listItem = *it;
if (listItem->index == -1 && listItem->attached->delayRemove() == false) {
d->releaseItem(listItem);
it = d->visibleItems.erase(it);
} else {
++it;
}
}
// Correct the positioning of the items
d->updateSections();
d->layout();
}
void QDeclarativeListView::itemsMoved(int from, int to, int count)
{
Q_D(QDeclarativeListView);
if (!isComponentComplete())
return;
d->updateUnrequestedIndexes();
if (d->visibleItems.isEmpty()) {
refill();
return;
}
d->moveReason = QDeclarativeListViewPrivate::Other;
FxListItem *firstVisible = d->firstVisibleItem();
qreal firstItemPos = firstVisible->position();
QHash<int,FxListItem*> moved;
int moveBy = 0;
QList<FxListItem*>::Iterator it = d->visibleItems.begin();
while (it != d->visibleItems.end()) {
FxListItem *item = *it;
if (item->index >= from && item->index < from + count) {
// take the items that are moving
item->index += (to-from);
moved.insert(item->index, item);
if (item->position() < firstItemPos)
moveBy += item->size();
it = d->visibleItems.erase(it);
} else {
// move everything after the moved items.
if (item->index > from && item->index != -1)
item->index -= count;
++it;
}
}
int remaining = count;
int endIndex = d->visibleIndex;
it = d->visibleItems.begin();
while (it != d->visibleItems.end()) {
FxListItem *item = *it;
if (remaining && item->index >= to && item->index < to + count) {
// place items in the target position, reusing any existing items
FxListItem *movedItem = moved.take(item->index);
if (!movedItem)
movedItem = d->createItem(item->index);
if (item->index <= firstVisible->index)
moveBy -= movedItem->size();
it = d->visibleItems.insert(it, movedItem);
++it;
--remaining;
} else {
if (item->index != -1) {
if (item->index >= to) {
// update everything after the moved items.
item->index += count;
}
endIndex = item->index;
}
++it;
}
}
// If we have moved items to the end of the visible items
// then add any existing moved items that we have
while (FxListItem *item = moved.take(endIndex+1)) {
d->visibleItems.append(item);
++endIndex;
}
// update visibleIndex
for (it = d->visibleItems.begin(); it != d->visibleItems.end(); ++it) {
if ((*it)->index != -1) {
d->visibleIndex = (*it)->index;
break;
}
}
// Fix current index
if (d->currentIndex >= 0 && d->currentItem) {
int oldCurrent = d->currentIndex;
d->currentIndex = d->model->indexOf(d->currentItem->item, this);
if (oldCurrent != d->currentIndex) {
d->currentItem->index = d->currentIndex;
emit currentIndexChanged();
}
}
// Whatever moved items remain are no longer visible items.
while (moved.count()) {
int idx = moved.begin().key();
FxListItem *item = moved.take(idx);
if (d->currentItem && item->item == d->currentItem->item)
item->setPosition(d->positionAt(idx));
d->releaseItem(item);
}
// Ensure we don't cause an ugly list scroll.
d->visibleItems.first()->setPosition(d->visibleItems.first()->position() + moveBy);
d->updateSections();
d->layout();
}
void QDeclarativeListView::itemsChanged(int, int)
{
Q_D(QDeclarativeListView);
d->updateSections();
d->layout();
}
void QDeclarativeListView::modelReset()
{
Q_D(QDeclarativeListView);
d->moveReason = QDeclarativeListViewPrivate::SetIndex;
d->regenerate();
if (d->highlight && d->currentItem) {
if (d->autoHighlight)
d->highlight->setPosition(d->currentItem->position());
d->updateTrackedItem();
}
d->moveReason = QDeclarativeListViewPrivate::Other;
emit countChanged();
}
void QDeclarativeListView::createdItem(int index, QDeclarativeItem *item)
{
Q_D(QDeclarativeListView);
if (d->requestedIndex != index) {
item->setParentItem(contentItem());
d->unrequestedItems.insert(item, index);
if (d->orient == QDeclarativeListView::Vertical) {
item->setY(d->positionAt(index));
} else {
if (d->isRightToLeft())
item->setX(-d->positionAt(index)-item->width());
else
item->setX(d->positionAt(index));
}
}
}
void QDeclarativeListView::destroyingItem(QDeclarativeItem *item)
{
Q_D(QDeclarativeListView);
d->unrequestedItems.remove(item);
}
void QDeclarativeListView::animStopped()
{
Q_D(QDeclarativeListView);
d->bufferMode = QDeclarativeListViewPrivate::NoBuffer;
if (d->haveHighlightRange && d->highlightRange == QDeclarativeListView::StrictlyEnforceRange)
d->updateHighlight();
}
QDeclarativeListViewAttached *QDeclarativeListView::qmlAttachedProperties(QObject *obj)
{
return new QDeclarativeListViewAttached(obj);
}
QT_END_NAMESPACE