/*
 * Copyright (C) 2007 Apple Inc.
 * Copyright (C) 2007 Alp Toker <alp@atoker.com>
 * Copyright (C) 2008 Collabora Ltd.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#include "config.h"
#include "RenderThemeGtk.h"

#include "TransformationMatrix.h"
#include "GraphicsContext.h"
#include "NotImplemented.h"
#include "RenderBox.h"
#include "RenderObject.h"
#include "gtkdrawing.h"

#include <gdk/gdk.h>

namespace WebCore {

RenderTheme* theme()
{
    static RenderThemeGtk gtkTheme;
    return &gtkTheme;
}

static bool mozGtkInitialized = false;

RenderThemeGtk::RenderThemeGtk()
    : m_gtkWindow(0)
    , m_gtkContainer(0)
    , m_gtkEntry(0)
    , m_gtkTreeView(0)
{
    if (!mozGtkInitialized) {
        mozGtkInitialized = true;
        moz_gtk_init();
    }
}

static bool supportsFocus(ControlPart appearance)
{
    switch (appearance) {
        case PushButtonPart:
        case ButtonPart:
        case TextFieldPart:
        case TextAreaPart:
        case SearchFieldPart:
        case MenulistPart:
        case RadioPart:
        case CheckboxPart:
            return true;
        default:
            return false;
    }
}

bool RenderThemeGtk::supportsFocusRing(const RenderStyle* style) const
{
    return supportsFocus(style->appearance());
}

bool RenderThemeGtk::controlSupportsTints(const RenderObject* o) const
{
    return isEnabled(o);
}

int RenderThemeGtk::baselinePosition(const RenderObject* o) const
{
    if (!o->isBox())
        return 0;

    // FIXME: This strategy is possibly incorrect for the GTK+ port.
    if (o->style()->appearance() == CheckboxPart ||
        o->style()->appearance() == RadioPart) {
        const RenderBox* box = toRenderBox(o);
        return box->marginTop() + box->height() - 2;
    }

    return RenderTheme::baselinePosition(o);
}

static GtkTextDirection gtkTextDirection(TextDirection direction)
{
    switch (direction) {
    case RTL:
        return GTK_TEXT_DIR_RTL;
    case LTR:
        return GTK_TEXT_DIR_LTR;
    default:
        return GTK_TEXT_DIR_NONE;
    }
}

static void adjustMozStyle(RenderStyle* style, GtkThemeWidgetType type)
{
    gint left, top, right, bottom;
    GtkTextDirection direction = gtkTextDirection(style->direction());
    gboolean inhtml = true;

    if (moz_gtk_get_widget_border(type, &left, &top, &right, &bottom, direction, inhtml) != MOZ_GTK_SUCCESS)
        return;

    // FIXME: This approach is likely to be incorrect. See other ports and layout tests to see the problem.
    const int xpadding = 1;
    const int ypadding = 1;

    style->setPaddingLeft(Length(xpadding + left, Fixed));
    style->setPaddingTop(Length(ypadding + top, Fixed));
    style->setPaddingRight(Length(xpadding + right, Fixed));
    style->setPaddingBottom(Length(ypadding + bottom, Fixed));
}

static void setMozState(RenderTheme* theme, GtkWidgetState* state, RenderObject* o)
{
    state->active = theme->isPressed(o);
    state->focused = theme->isFocused(o);
    state->inHover = theme->isHovered(o);
    // FIXME: Disabled does not always give the correct appearance for ReadOnly
    state->disabled = !theme->isEnabled(o) || theme->isReadOnlyControl(o);
    state->isDefault = false;
    state->canDefault = false;
    state->depressed = false;
}

static bool paintMozWidget(RenderTheme* theme, GtkThemeWidgetType type, RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    // No GdkWindow to render to, so return true to fall back
    if (!i.context->gdkDrawable())
        return true;

    // Painting is disabled so just claim to have succeeded
    if (i.context->paintingDisabled())
        return false;

    GtkWidgetState mozState;
    setMozState(theme, &mozState, o);

    int flags;

    // We might want to make setting flags the caller's job at some point rather than doing it here.
    switch (type) {
        case MOZ_GTK_BUTTON:
            flags = GTK_RELIEF_NORMAL;
            break;
        case MOZ_GTK_CHECKBUTTON:
        case MOZ_GTK_RADIOBUTTON:
            flags = theme->isChecked(o);
            break;
        default:
            flags = 0;
            break;
    }

    TransformationMatrix ctm = i.context->getCTM();

    IntPoint pos = ctm.mapPoint(rect.location());
    GdkRectangle gdkRect = IntRect(pos.x(), pos.y(), rect.width(), rect.height());
    GtkTextDirection direction = gtkTextDirection(o->style()->direction());

#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1,4,0)
    // Find the clip rectangle
    cairo_t *cr = i.context->platformContext();
    double clipX1, clipX2, clipY1, clipY2;
    cairo_clip_extents(cr, &clipX1, &clipY1, &clipX2, &clipY2);

    GdkRectangle gdkClipRect;
    gdkClipRect.width = clipX2 - clipX1;
    gdkClipRect.height = clipY2 - clipY1;
    IntPoint clipPos = ctm.mapPoint(IntPoint(clipX1, clipY1));
    gdkClipRect.x = clipPos.x();
    gdkClipRect.y = clipPos.y();

    gdk_rectangle_intersect(&gdkRect, &gdkClipRect, &gdkClipRect);
#else
    GdkRectangle gdkClipRect = gdkRect;
#endif

    return moz_gtk_widget_paint(type, i.context->gdkDrawable(), &gdkRect, &gdkClipRect, &mozState, flags, direction) != MOZ_GTK_SUCCESS;
}

static void setButtonPadding(RenderStyle* style)
{
    // FIXME: This looks incorrect.
    const int padding = 8;
    style->setPaddingLeft(Length(padding, Fixed));
    style->setPaddingRight(Length(padding, Fixed));
    style->setPaddingTop(Length(padding / 2, Fixed));
    style->setPaddingBottom(Length(padding / 2, Fixed));
}

static void setToggleSize(RenderStyle* style, ControlPart appearance)
{
    // The width and height are both specified, so we shouldn't change them.
    if (!style->width().isIntrinsicOrAuto() && !style->height().isAuto())
        return;

    // FIXME: This is probably not correct use of indicator_size and indicator_spacing.
    gint indicator_size, indicator_spacing;

    switch (appearance) {
        case CheckboxPart:
            if (moz_gtk_checkbox_get_metrics(&indicator_size, &indicator_spacing) != MOZ_GTK_SUCCESS)
                return;
            break;
        case RadioPart:
            if (moz_gtk_radio_get_metrics(&indicator_size, &indicator_spacing) != MOZ_GTK_SUCCESS)
                return;
            break;
        default:
            return;
    }

    // Other ports hard-code this to 13, but GTK+ users tend to demand the native look.
    // It could be made a configuration option values other than 13 actually break site compatibility.
    int length = indicator_size + indicator_spacing;
    if (style->width().isIntrinsicOrAuto())
        style->setWidth(Length(length, Fixed));

    if (style->height().isAuto())
        style->setHeight(Length(length, Fixed));
}

void RenderThemeGtk::setCheckboxSize(RenderStyle* style) const
{
    setToggleSize(style, RadioPart);
}

bool RenderThemeGtk::paintCheckbox(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    return paintMozWidget(this, MOZ_GTK_CHECKBUTTON, o, i, rect);
}

void RenderThemeGtk::setRadioSize(RenderStyle* style) const
{
    setToggleSize(style, RadioPart);
}

bool RenderThemeGtk::paintRadio(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    return paintMozWidget(this, MOZ_GTK_RADIOBUTTON, o, i, rect);
}

void RenderThemeGtk::adjustButtonStyle(CSSStyleSelector* selector, RenderStyle* style, WebCore::Element* e) const
{
    // FIXME: Is this condition necessary?
    if (style->appearance() == PushButtonPart) {
        style->resetBorder();
        style->setHeight(Length(Auto));
        style->setWhiteSpace(PRE);
        setButtonPadding(style);
    } else {
        // FIXME: This should not be hard-coded.
        style->setMinHeight(Length(14, Fixed));
        style->resetBorderTop();
        style->resetBorderBottom();
    }
}

bool RenderThemeGtk::paintButton(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    return paintMozWidget(this, MOZ_GTK_BUTTON, o, i, rect);
}

void RenderThemeGtk::adjustMenuListStyle(CSSStyleSelector* selector, RenderStyle* style, WebCore::Element* e) const
{
    style->resetBorder();
    style->resetPadding();
    style->setHeight(Length(Auto));
    style->setWhiteSpace(PRE);
    adjustMozStyle(style, MOZ_GTK_DROPDOWN);
}

bool RenderThemeGtk::paintMenuList(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    return paintMozWidget(this, MOZ_GTK_DROPDOWN, o, i, rect);
}

void RenderThemeGtk::adjustTextFieldStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const
{
    style->resetBorder();
    style->resetPadding();
    style->setHeight(Length(Auto));
    style->setWhiteSpace(PRE);
    adjustMozStyle(style, MOZ_GTK_ENTRY);
}

bool RenderThemeGtk::paintTextField(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    return paintMozWidget(this, MOZ_GTK_ENTRY, o, i, rect);
}

void RenderThemeGtk::adjustTextAreaStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const
{
    adjustTextFieldStyle(selector, style, e);
}

bool RenderThemeGtk::paintTextArea(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r)
{
    return paintTextField(o, i, r);
}

void RenderThemeGtk::adjustSearchFieldResultsButtonStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const
{
    adjustSearchFieldCancelButtonStyle(selector, style, e);
}

bool RenderThemeGtk::paintSearchFieldResultsButton(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    return paintMozWidget(this, MOZ_GTK_DROPDOWN_ARROW, o, i, rect);
}

void RenderThemeGtk::adjustSearchFieldResultsDecorationStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const
{
    style->resetBorder();
    style->resetPadding();

    // FIXME: This should not be hard-coded.
    IntSize size = IntSize(14, 14);
    style->setWidth(Length(size.width(), Fixed));
    style->setHeight(Length(size.height(), Fixed));
}

bool RenderThemeGtk::paintSearchFieldResultsDecoration(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    return paintMozWidget(this, MOZ_GTK_CHECKMENUITEM, o, i, rect);
}

void RenderThemeGtk::adjustSearchFieldCancelButtonStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const
{
    style->resetBorder();
    style->resetPadding();

    // FIXME: This should not be hard-coded.
    IntSize size = IntSize(14, 14);
    style->setWidth(Length(size.width(), Fixed));
    style->setHeight(Length(size.height(), Fixed));
}

bool RenderThemeGtk::paintSearchFieldCancelButton(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    return paintMozWidget(this, MOZ_GTK_CHECKMENUITEM, o, i, rect);
}

void RenderThemeGtk::adjustSearchFieldStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const
{
    adjustTextFieldStyle(selector, style, e);
}

bool RenderThemeGtk::paintSearchField(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& rect)
{
    return paintTextField(o, i, rect);
}

Color RenderThemeGtk::platformActiveSelectionBackgroundColor() const
{
    GtkWidget* widget = gtkEntry();
    return widget->style->base[GTK_STATE_SELECTED];
}

Color RenderThemeGtk::platformInactiveSelectionBackgroundColor() const
{
    GtkWidget* widget = gtkEntry();
    return widget->style->base[GTK_STATE_ACTIVE];
}

Color RenderThemeGtk::platformActiveSelectionForegroundColor() const
{
    GtkWidget* widget = gtkEntry();
    return widget->style->text[GTK_STATE_SELECTED];
}

Color RenderThemeGtk::platformInactiveSelectionForegroundColor() const
{
    GtkWidget* widget = gtkEntry();
    return widget->style->text[GTK_STATE_ACTIVE];
}

Color RenderThemeGtk::activeListBoxSelectionBackgroundColor() const
{
    GtkWidget* widget = gtkTreeView();
    return widget->style->base[GTK_STATE_SELECTED];
}

Color RenderThemeGtk::inactiveListBoxSelectionBackgroundColor() const
{
    GtkWidget* widget = gtkTreeView();
    return widget->style->base[GTK_STATE_ACTIVE];
}

Color RenderThemeGtk::activeListBoxSelectionForegroundColor() const
{
    GtkWidget* widget = gtkTreeView();
    return widget->style->text[GTK_STATE_SELECTED];
}

Color RenderThemeGtk::inactiveListBoxSelectionForegroundColor() const
{
    GtkWidget* widget = gtkTreeView();
    return widget->style->text[GTK_STATE_ACTIVE];
}

double RenderThemeGtk::caretBlinkInterval() const
{
    GtkSettings* settings = gtk_settings_get_default();

    gboolean shouldBlink;
    gint time;

    g_object_get(settings, "gtk-cursor-blink", &shouldBlink, "gtk-cursor-blink-time", &time, NULL);

    if (!shouldBlink)
        return 0;

    return time / 2000.;
}

void RenderThemeGtk::systemFont(int, FontDescription&) const
{
    // If you remove this notImplemented(), replace it with an comment that explains why.
    notImplemented();
}

static void gtkStyleSetCallback(GtkWidget* widget, GtkStyle* previous, RenderTheme* renderTheme)
{
    // FIXME: Make sure this function doesn't get called many times for a single GTK+ style change signal.
    renderTheme->platformColorsDidChange();
}

GtkContainer* RenderThemeGtk::gtkContainer() const
{
    if (m_gtkContainer)
        return m_gtkContainer;

    m_gtkWindow = gtk_window_new(GTK_WINDOW_POPUP);
    m_gtkContainer = GTK_CONTAINER(gtk_fixed_new());
    gtk_container_add(GTK_CONTAINER(m_gtkWindow), GTK_WIDGET(m_gtkContainer));
    gtk_widget_realize(m_gtkWindow);

    return m_gtkContainer;
}

GtkWidget* RenderThemeGtk::gtkEntry() const
{
    if (m_gtkEntry)
        return m_gtkEntry;

    m_gtkEntry = gtk_entry_new();
    g_signal_connect(m_gtkEntry, "style-set", G_CALLBACK(gtkStyleSetCallback), theme());
    gtk_container_add(gtkContainer(), m_gtkEntry);
    gtk_widget_realize(m_gtkEntry);

    return m_gtkEntry;
}

GtkWidget* RenderThemeGtk::gtkTreeView() const
{
    if (m_gtkTreeView)
        return m_gtkTreeView;

    m_gtkTreeView = gtk_tree_view_new();
    g_signal_connect(m_gtkTreeView, "style-set", G_CALLBACK(gtkStyleSetCallback), theme());
    gtk_container_add(gtkContainer(), m_gtkTreeView);
    gtk_widget_realize(m_gtkTreeView);

    return m_gtkTreeView;
}

}