/**************************************************************************** | |
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** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). | |
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** This file is part of the Qt Designer of the Qt Toolkit. | |
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** GNU Lesser General Public License Usage | |
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** 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 | |
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** file. Please review the following information to ensure the GNU General | |
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// | |
// W A R N I N G | |
// ------------- | |
// | |
// This file is not part of the Qt API. It exists for the convenience | |
// of Qt Designer. This header | |
// file may change from version to version without notice, or even be removed. | |
// | |
// We mean it. | |
// | |
#ifndef DESIGNERWIDGETITEM_H | |
#define DESIGNERWIDGETITEM_H | |
#include "shared_global_p.h" | |
#include <QtGui/QLayoutItem> | |
#include <QtCore/QObject> | |
QT_BEGIN_NAMESPACE | |
class QDesignerFormEditorInterface; | |
namespace qdesigner_internal { | |
// QDesignerWidgetItem: A Layout Item that is used for non-containerextension- | |
// containers (QFrame, etc) on Designer forms. It prevents its widget | |
// from being slammed to size 0 if the widget has no layout: | |
// Pre 4.5, this item ensured only that QWidgets and QFrames were not squeezed | |
// to size 0 since they have an invalid size hint when non-laid out. | |
// Since 4.5, the item is used for every non-containerextension-container. | |
// In case the container has itself a layout, it merely tracks the minimum | |
// size. If the container has no layout and is not subject to some stretch | |
// factor, it will return the last valid size. The effect is that after | |
// breaking a layout on a container within a layout, it just maintains its | |
// last size and is not slammed to 0,0. In addition, it can be resized. | |
// The class keeps track of the containing layout by tracking widget reparent | |
// and destroyed slots as Designer will for example re-create grid layouts to | |
// shrink them. | |
class QDESIGNER_SHARED_EXPORT QDesignerWidgetItem : public QObject, public QWidgetItemV2 { | |
Q_DISABLE_COPY(QDesignerWidgetItem) | |
Q_OBJECT | |
public: | |
explicit QDesignerWidgetItem(const QLayout *containingLayout, QWidget *w, Qt::Orientations o = Qt::Horizontal|Qt::Vertical); | |
const QLayout *containingLayout() const; | |
inline QWidget *constWidget() const { return const_cast<QDesignerWidgetItem*>(this)->widget(); } | |
virtual QSize minimumSize() const; | |
virtual QSize sizeHint() const; | |
// Resize: Takes effect if the contained widget does not have a layout | |
QSize nonLaidOutMinSize() const; | |
void setNonLaidOutMinSize(const QSize &s); | |
QSize nonLaidOutSizeHint() const; | |
void setNonLaidOutSizeHint(const QSize &s); | |
// Check whether a QDesignerWidgetItem should be installed | |
static bool check(const QLayout *layout, QWidget *w, Qt::Orientations *ptrToOrientations = 0); | |
// Register itself using QLayoutPrivate's widget item factory method hook | |
static void install(); | |
static void deinstall(); | |
// Check for a non-container extension container | |
static bool isContainer(const QDesignerFormEditorInterface *core, QWidget *w); | |
static bool subjectToStretch(const QLayout *layout, QWidget *w); | |
virtual bool eventFilter(QObject * watched, QEvent * event); | |
private slots: | |
void layoutChanged(); | |
private: | |
void expand(QSize *s) const; | |
bool subjectToStretch() const; | |
const Qt::Orientations m_orientations; | |
mutable QSize m_nonLaidOutMinSize; | |
mutable QSize m_nonLaidOutSizeHint; | |
mutable const QLayout *m_cachedContainingLayout; | |
}; | |
// Helper class that ensures QDesignerWidgetItem is installed while an | |
// instance is in scope. | |
class QDESIGNER_SHARED_EXPORT QDesignerWidgetItemInstaller { | |
Q_DISABLE_COPY(QDesignerWidgetItemInstaller) | |
public: | |
QDesignerWidgetItemInstaller(); | |
~QDesignerWidgetItemInstaller(); | |
private: | |
static int m_instanceCount; | |
}; | |
} // namespace qdesigner_internal | |
QT_END_NAMESPACE | |
#endif |