root/trunk/WebCore/platform/gtk/gtk2drawing.c

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *  Brian Ryner <bryner@brianryner.com>  (Original Author)
 *  Pierre Chanial <p_ch@verizon.net>
 *  Michael Ventnor <m.ventnor@gmail.com>
 *  Alp Toker <alp@nuanti.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/*
 * This file contains painting functions for each of the gtk2 widgets.
 * Adapted from the gtkdrawing.c, and gtk+2.0 source.
 */

#include <gtk/gtk.h>
#include <gdk/gdkprivate.h>
#include <string.h>
#include "gtkdrawing.h"

#include <math.h>

#define XTHICKNESS(style) (style->xthickness)
#define YTHICKNESS(style) (style->ythickness)
#define WINDOW_IS_MAPPED(window) ((window) && GDK_IS_WINDOW(window) && gdk_window_is_visible(window))

static GtkWidget* gProtoWindow;
static GtkWidget* gButtonWidget;
static GtkWidget* gToggleButtonWidget;
static GtkWidget* gButtonArrowWidget;
static GtkWidget* gCheckboxWidget;
static GtkWidget* gRadiobuttonWidget;
static GtkWidget* gHorizScrollbarWidget;
static GtkWidget* gVertScrollbarWidget;
static GtkWidget* gSpinWidget;
static GtkWidget* gHScaleWidget;
static GtkWidget* gVScaleWidget;
static GtkWidget* gEntryWidget;
static GtkWidget* gComboBoxWidget;
static GtkWidget* gComboBoxButtonWidget;
static GtkWidget* gComboBoxArrowWidget;
static GtkWidget* gComboBoxSeparatorWidget;
static GtkWidget* gComboBoxEntryWidget;
static GtkWidget* gComboBoxEntryTextareaWidget;
static GtkWidget* gComboBoxEntryButtonWidget;
static GtkWidget* gComboBoxEntryArrowWidget;
static GtkWidget* gHandleBoxWidget;
static GtkWidget* gToolbarWidget;
static GtkWidget* gFrameWidget;
static GtkWidget* gStatusbarWidget;
static GtkWidget* gProgressWidget;
static GtkWidget* gTabWidget;
static GtkWidget* gTooltipWidget;
static GtkWidget* gMenuBarWidget;
static GtkWidget* gMenuBarItemWidget;
static GtkWidget* gMenuPopupWidget;
static GtkWidget* gMenuItemWidget;
static GtkWidget* gImageMenuItemWidget;
static GtkWidget* gCheckMenuItemWidget;
static GtkWidget* gTreeViewWidget;
static GtkWidget* gMiddleTreeViewColumn;
static GtkWidget* gTreeHeaderCellWidget;
static GtkWidget* gTreeHeaderSortArrowWidget;
static GtkWidget* gExpanderWidget;
static GtkWidget* gToolbarSeparatorWidget;
static GtkWidget* gMenuSeparatorWidget;
static GtkWidget* gHPanedWidget;
static GtkWidget* gVPanedWidget;
static GtkWidget* gScrolledWindowWidget;

static style_prop_t style_prop_func;
static gboolean have_arrow_scaling;
static gboolean have_2_10;
static gboolean is_initialized;

/* Because we have such an unconventional way of drawing widgets, signal to the GTK theme engine
   that they are drawing for Mozilla instead of a conventional GTK app so they can do any specific
   things they may want to do. */
static void
moz_gtk_set_widget_name(GtkWidget* widget)
{
    gtk_widget_set_name(widget, "MozillaGtkWidget");
}

gint
moz_gtk_enable_style_props(style_prop_t styleGetProp)
{
    style_prop_func = styleGetProp;
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_window_widget()
{
    if (!gProtoWindow) {
        gProtoWindow = gtk_window_new(GTK_WINDOW_POPUP);
        gtk_widget_realize(gProtoWindow);
        moz_gtk_set_widget_name(gProtoWindow);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
setup_widget_prototype(GtkWidget* widget)
{
    static GtkWidget* protoLayout;
    ensure_window_widget();
    if (!protoLayout) {
        protoLayout = gtk_fixed_new();
        gtk_container_add(GTK_CONTAINER(gProtoWindow), protoLayout);
    }

    gtk_container_add(GTK_CONTAINER(protoLayout), widget);
    gtk_widget_realize(widget);
    g_object_set_data(G_OBJECT(widget), "transparent-bg-hint", TRUE);
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_button_widget()
{
    if (!gButtonWidget) {
        gButtonWidget = gtk_button_new_with_label("M");
        setup_widget_prototype(gButtonWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_hpaned_widget()
{
    if (!gHPanedWidget) {
        gHPanedWidget = gtk_hpaned_new();
        setup_widget_prototype(gHPanedWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_vpaned_widget()
{
    if (!gVPanedWidget) {
        gVPanedWidget = gtk_vpaned_new();
        setup_widget_prototype(gVPanedWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_toggle_button_widget()
{
    if (!gToggleButtonWidget) {
        gToggleButtonWidget = gtk_toggle_button_new();
        setup_widget_prototype(gToggleButtonWidget);
        /* toggle button must be set active to get the right style on hover. */
        GTK_TOGGLE_BUTTON(gToggleButtonWidget)->active = TRUE;
  }
  return MOZ_GTK_SUCCESS;
}

static gint
ensure_button_arrow_widget()
{
    if (!gButtonArrowWidget) {
        ensure_toggle_button_widget();

        gButtonArrowWidget = gtk_arrow_new(GTK_ARROW_DOWN, GTK_SHADOW_OUT);
        gtk_container_add(GTK_CONTAINER(gToggleButtonWidget), gButtonArrowWidget);
        gtk_widget_realize(gButtonArrowWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_checkbox_widget()
{
    if (!gCheckboxWidget) {
        gCheckboxWidget = gtk_check_button_new_with_label("M");
        setup_widget_prototype(gCheckboxWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_radiobutton_widget()
{
    if (!gRadiobuttonWidget) {
        gRadiobuttonWidget = gtk_radio_button_new_with_label(NULL, "M");
        setup_widget_prototype(gRadiobuttonWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_scrollbar_widget()
{
    if (!gVertScrollbarWidget) {
        gVertScrollbarWidget = gtk_vscrollbar_new(NULL);
        setup_widget_prototype(gVertScrollbarWidget);
    }
    if (!gHorizScrollbarWidget) {
        gHorizScrollbarWidget = gtk_hscrollbar_new(NULL);
        setup_widget_prototype(gHorizScrollbarWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_spin_widget()
{
  if (!gSpinWidget) {
    gSpinWidget = gtk_spin_button_new(NULL, 1, 0);
    setup_widget_prototype(gSpinWidget);
  }
  return MOZ_GTK_SUCCESS;
}

static gint
ensure_scale_widget()
{
  if (!gHScaleWidget) {
    gHScaleWidget = gtk_hscale_new(NULL);
    setup_widget_prototype(gHScaleWidget);
  }
  if (!gVScaleWidget) {
    gVScaleWidget = gtk_vscale_new(NULL);
    setup_widget_prototype(gVScaleWidget);
  }
  return MOZ_GTK_SUCCESS;
}

static gint
ensure_entry_widget()
{
    if (!gEntryWidget) {
        gEntryWidget = gtk_entry_new();
        setup_widget_prototype(gEntryWidget);
    }
    return MOZ_GTK_SUCCESS;
}

/* We need to have pointers to the inner widgets (button, separator, arrow)
 * of the ComboBox to get the correct rendering from theme engines which
 * special cases their look. Since the inner layout can change, we ask GTK
 * to NULL our pointers when they are about to become invalid because the
 * corresponding widgets don't exist anymore. It's the role of
 * g_object_add_weak_pointer().
 * Note that if we don't find the inner widgets (which shouldn't happen), we
 * fallback to use generic "non-inner" widgets, and they don't need that kind
 * of weak pointer since they are explicit children of gProtoWindow and as
 * such GTK holds a strong reference to them. */
static void
moz_gtk_get_combo_box_inner_button(GtkWidget *widget, gpointer client_data)
{
    if (GTK_IS_TOGGLE_BUTTON(widget)) {
        gComboBoxButtonWidget = widget;
        g_object_add_weak_pointer(G_OBJECT(widget),
                                  (gpointer) &gComboBoxButtonWidget);
        gtk_widget_realize(widget);
        g_object_set_data(G_OBJECT(widget), "transparent-bg-hint", TRUE);
    }
}

static void
moz_gtk_get_combo_box_button_inner_widgets(GtkWidget *widget,
                                           gpointer client_data)
{
    if (GTK_IS_SEPARATOR(widget)) {
        gComboBoxSeparatorWidget = widget;
        g_object_add_weak_pointer(G_OBJECT(widget),
                                  (gpointer) &gComboBoxSeparatorWidget);
    } else if (GTK_IS_ARROW(widget)) {
        gComboBoxArrowWidget = widget;
        g_object_add_weak_pointer(G_OBJECT(widget),
                                  (gpointer) &gComboBoxArrowWidget);
    } else
        return;
    gtk_widget_realize(widget);
    g_object_set_data(G_OBJECT(widget), "transparent-bg-hint", TRUE);
}

static gint
ensure_combo_box_widgets()
{
    GtkWidget* buttonChild;

    if (gComboBoxButtonWidget && gComboBoxArrowWidget)
        return MOZ_GTK_SUCCESS;

    /* Create a ComboBox if needed */
    if (!gComboBoxWidget) {
        gComboBoxWidget = gtk_combo_box_new();
        setup_widget_prototype(gComboBoxWidget);
    }

    /* Get its inner Button */
    gtk_container_forall(GTK_CONTAINER(gComboBoxWidget),
                         moz_gtk_get_combo_box_inner_button,
                         NULL);

    if (gComboBoxButtonWidget) {
        /* Get the widgets inside the Button */
        buttonChild = GTK_BIN(gComboBoxButtonWidget)->child;
        if (GTK_IS_HBOX(buttonChild)) {
            /* appears-as-list = FALSE, cell-view = TRUE; the button
             * contains an hbox. This hbox is there because the ComboBox
             * needs to place a cell renderer, a separator, and an arrow in
             * the button when appears-as-list is FALSE. */
            gtk_container_forall(GTK_CONTAINER(buttonChild),
                                 moz_gtk_get_combo_box_button_inner_widgets,
                                 NULL);
        } else if(GTK_IS_ARROW(buttonChild)) {
            /* appears-as-list = TRUE, or cell-view = FALSE;
             * the button only contains an arrow */
            gComboBoxArrowWidget = buttonChild;
            g_object_add_weak_pointer(G_OBJECT(buttonChild), (gpointer)
                                      &gComboBoxArrowWidget);
            gtk_widget_realize(gComboBoxArrowWidget);
            g_object_set_data(G_OBJECT(gComboBoxArrowWidget),
                              "transparent-bg-hint", TRUE);
        }
    } else {
        /* Shouldn't be reached with current internal gtk implementation; we
         * use a generic toggle button as last resort fallback to avoid
         * crashing. */
        ensure_toggle_button_widget();
        gComboBoxButtonWidget = gToggleButtonWidget;
    }

    if (!gComboBoxArrowWidget) {
        /* Shouldn't be reached with current internal gtk implementation;
         * we gButtonArrowWidget as last resort fallback to avoid
         * crashing. */
        ensure_button_arrow_widget();
        gComboBoxArrowWidget = gButtonArrowWidget;
    }

    /* We don't test the validity of gComboBoxSeparatorWidget since there
     * is none when "appears-as-list" = TRUE or "cell-view" = FALSE; if it
     * is invalid we just won't paint it. */

    return MOZ_GTK_SUCCESS;
}

/* We need to have pointers to the inner widgets (entry, button, arrow) of
 * the ComboBoxEntry to get the correct rendering from theme engines which
 * special cases their look. Since the inner layout can change, we ask GTK
 * to NULL our pointers when they are about to become invalid because the
 * corresponding widgets don't exist anymore. It's the role of
 * g_object_add_weak_pointer().
 * Note that if we don't find the inner widgets (which shouldn't happen), we
 * fallback to use generic "non-inner" widgets, and they don't need that kind
 * of weak pointer since they are explicit children of gProtoWindow and as
 * such GTK holds a strong reference to them. */
static void
moz_gtk_get_combo_box_entry_inner_widgets(GtkWidget *widget,
                                          gpointer client_data)
{
    if (GTK_IS_TOGGLE_BUTTON(widget)) {
        gComboBoxEntryButtonWidget = widget;
        g_object_add_weak_pointer(G_OBJECT(widget),
                                  (gpointer) &gComboBoxEntryButtonWidget);
    } else if (GTK_IS_ENTRY(widget)) {
        gComboBoxEntryTextareaWidget = widget;
        g_object_add_weak_pointer(G_OBJECT(widget),
                                  (gpointer) &gComboBoxEntryTextareaWidget);
    } else
        return;
    gtk_widget_realize(widget);
    g_object_set_data(G_OBJECT(widget), "transparent-bg-hint", TRUE);
}

static void
moz_gtk_get_combo_box_entry_arrow(GtkWidget *widget, gpointer client_data)
{
    if (GTK_IS_ARROW(widget)) {
        gComboBoxEntryArrowWidget = widget;
        g_object_add_weak_pointer(G_OBJECT(widget),
                                  (gpointer) &gComboBoxEntryArrowWidget);
        gtk_widget_realize(widget);
        g_object_set_data(G_OBJECT(widget), "transparent-bg-hint", TRUE);
    }
}

static gint
ensure_combo_box_entry_widgets()
{
    GtkWidget* buttonChild;

    if (gComboBoxEntryTextareaWidget &&
            gComboBoxEntryButtonWidget &&
            gComboBoxEntryArrowWidget)
        return MOZ_GTK_SUCCESS;

    /* Create a ComboBoxEntry if needed */
    if (!gComboBoxEntryWidget) {
        gComboBoxEntryWidget = gtk_combo_box_entry_new();
        setup_widget_prototype(gComboBoxEntryWidget);
    }

    /* Get its inner Entry and Button */
    gtk_container_forall(GTK_CONTAINER(gComboBoxEntryWidget),
                         moz_gtk_get_combo_box_entry_inner_widgets,
                         NULL);

    if (!gComboBoxEntryTextareaWidget) {
        ensure_entry_widget();
        gComboBoxEntryTextareaWidget = gEntryWidget;
    }

    if (gComboBoxEntryButtonWidget) {
        /* Get the Arrow inside the Button */
        buttonChild = GTK_BIN(gComboBoxEntryButtonWidget)->child;
        if (GTK_IS_HBOX(buttonChild)) {
            /* appears-as-list = FALSE, cell-view = TRUE; the button
             * contains an hbox. This hbox is there because ComboBoxEntry
             * inherits from ComboBox which needs to place a cell renderer,
             * a separator, and an arrow in the button when appears-as-list
             * is FALSE. Here the hbox should only contain an arrow, since
             * a ComboBoxEntry doesn't need all those widgets in the
             * button. */
            gtk_container_forall(GTK_CONTAINER(buttonChild),
                                 moz_gtk_get_combo_box_entry_arrow,
                                 NULL);
        } else if(GTK_IS_ARROW(buttonChild)) {
            /* appears-as-list = TRUE, or cell-view = FALSE;
             * the button only contains an arrow */
            gComboBoxEntryArrowWidget = buttonChild;
            g_object_add_weak_pointer(G_OBJECT(buttonChild), (gpointer)
                                      &gComboBoxEntryArrowWidget);
            gtk_widget_realize(gComboBoxEntryArrowWidget);
            g_object_set_data(G_OBJECT(gComboBoxEntryArrowWidget),
                              "transparent-bg-hint", TRUE);
        }
    } else {
        /* Shouldn't be reached with current internal gtk implementation;
         * we use a generic toggle button as last resort fallback to avoid
         * crashing. */
        ensure_toggle_button_widget();
        gComboBoxEntryButtonWidget = gToggleButtonWidget;
    }

    if (!gComboBoxEntryArrowWidget) {
        /* Shouldn't be reached with current internal gtk implementation;
         * we gButtonArrowWidget as last resort fallback to avoid
         * crashing. */
        ensure_button_arrow_widget();
        gComboBoxEntryArrowWidget = gButtonArrowWidget;
    }

    return MOZ_GTK_SUCCESS;
}


static gint
ensure_handlebox_widget()
{
    if (!gHandleBoxWidget) {
        gHandleBoxWidget = gtk_handle_box_new();
        setup_widget_prototype(gHandleBoxWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_toolbar_widget()
{
    if (!gToolbarWidget) {
        ensure_handlebox_widget();
        gToolbarWidget = gtk_toolbar_new();
        gtk_container_add(GTK_CONTAINER(gHandleBoxWidget), gToolbarWidget);
        gtk_widget_realize(gToolbarWidget);
        g_object_set_data(G_OBJECT(gToolbarWidget), "transparent-bg-hint", TRUE);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_toolbar_separator_widget()
{
    if (!gToolbarSeparatorWidget) {
        ensure_toolbar_widget();
        gToolbarSeparatorWidget = GTK_WIDGET(gtk_separator_tool_item_new());
        setup_widget_prototype(gToolbarSeparatorWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_tooltip_widget()
{
    if (!gTooltipWidget) {
        gTooltipWidget = gtk_window_new(GTK_WINDOW_POPUP);
        gtk_widget_realize(gTooltipWidget);
        moz_gtk_set_widget_name(gTooltipWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_tab_widget()
{
    if (!gTabWidget) {
        gTabWidget = gtk_notebook_new();
        setup_widget_prototype(gTabWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_progress_widget()
{
    if (!gProgressWidget) {
        gProgressWidget = gtk_progress_bar_new();
        setup_widget_prototype(gProgressWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_statusbar_widget()
{
    if (!gStatusbarWidget) {
      gStatusbarWidget = gtk_statusbar_new();
      setup_widget_prototype(gStatusbarWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_frame_widget()
{
    if (!gFrameWidget) {
        ensure_statusbar_widget();
        gFrameWidget = gtk_frame_new(NULL);
        gtk_container_add(GTK_CONTAINER(gStatusbarWidget), gFrameWidget);
        gtk_widget_realize(gFrameWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_menu_bar_widget()
{
    if (!gMenuBarWidget) {
        gMenuBarWidget = gtk_menu_bar_new();
        setup_widget_prototype(gMenuBarWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_menu_bar_item_widget()
{
    if (!gMenuBarItemWidget) {
        ensure_menu_bar_widget();
        gMenuBarItemWidget = gtk_menu_item_new();
        gtk_menu_shell_append(GTK_MENU_SHELL(gMenuBarWidget),
                              gMenuBarItemWidget);
        gtk_widget_realize(gMenuBarItemWidget);
        g_object_set_data(G_OBJECT(gMenuBarItemWidget),
                          "transparent-bg-hint", TRUE);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_menu_popup_widget()
{
    if (!gMenuPopupWidget) {
        ensure_menu_bar_item_widget();
        gMenuPopupWidget = gtk_menu_new();
        gtk_menu_item_set_submenu(GTK_MENU_ITEM(gMenuBarItemWidget),
                                  gMenuPopupWidget);
        gtk_widget_realize(gMenuPopupWidget);
        g_object_set_data(G_OBJECT(gMenuPopupWidget),
                          "transparent-bg-hint", TRUE);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_menu_item_widget()
{
    if (!gMenuItemWidget) {
        ensure_menu_popup_widget();
        gMenuItemWidget = gtk_menu_item_new_with_label("M");
        gtk_menu_shell_append(GTK_MENU_SHELL(gMenuPopupWidget),
                              gMenuItemWidget);
        gtk_widget_realize(gMenuItemWidget);
        g_object_set_data(G_OBJECT(gMenuItemWidget),
                          "transparent-bg-hint", TRUE);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_image_menu_item_widget()
{
    if (!gImageMenuItemWidget) {
        ensure_menu_popup_widget();
        gImageMenuItemWidget = gtk_image_menu_item_new();
        gtk_menu_shell_append(GTK_MENU_SHELL(gMenuPopupWidget),
                              gImageMenuItemWidget);
        gtk_widget_realize(gImageMenuItemWidget);
        g_object_set_data(G_OBJECT(gImageMenuItemWidget),
                          "transparent-bg-hint", TRUE);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_menu_separator_widget()
{
    if (!gMenuSeparatorWidget) {
        ensure_menu_popup_widget();
        gMenuSeparatorWidget = gtk_separator_menu_item_new();
        gtk_menu_shell_append(GTK_MENU_SHELL(gMenuPopupWidget),
                              gMenuSeparatorWidget);
        gtk_widget_realize(gMenuSeparatorWidget);
        g_object_set_data(G_OBJECT(gMenuSeparatorWidget),
                          "transparent-bg-hint", TRUE);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_check_menu_item_widget()
{
    if (!gCheckMenuItemWidget) {
        ensure_menu_popup_widget();
        gCheckMenuItemWidget = gtk_check_menu_item_new_with_label("M");
        gtk_menu_shell_append(GTK_MENU_SHELL(gMenuPopupWidget),
                              gCheckMenuItemWidget);
        gtk_widget_realize(gCheckMenuItemWidget);
        g_object_set_data(G_OBJECT(gCheckMenuItemWidget),
                          "transparent-bg-hint", TRUE);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_tree_view_widget()
{
    if (!gTreeViewWidget) {
        gTreeViewWidget = gtk_tree_view_new();
        setup_widget_prototype(gTreeViewWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_tree_header_cell_widget()
{
    if(!gTreeHeaderCellWidget) {
        /*
         * Some GTK engines paint the first and last cell
         * of a TreeView header with a highlight.
         * Since we do not know where our widget will be relative
         * to the other buttons in the TreeView header, we must
         * paint it as a button that is between two others,
         * thus ensuring it is neither the first or last button
         * in the header.
         * GTK doesn't give us a way to do this explicitly,
         * so we must paint with a button that is between two
         * others.
         */

        GtkTreeViewColumn* firstTreeViewColumn;
        GtkTreeViewColumn* lastTreeViewColumn;

        ensure_tree_view_widget();

        /* Create and append our three columns */
        firstTreeViewColumn = gtk_tree_view_column_new();
        gtk_tree_view_column_set_title(firstTreeViewColumn, "M");
        gtk_tree_view_append_column(GTK_TREE_VIEW(gTreeViewWidget), firstTreeViewColumn);

        gMiddleTreeViewColumn = gtk_tree_view_column_new();
        gtk_tree_view_column_set_title(GTK_TREE_VIEW_COLUMN(gMiddleTreeViewColumn), "M");
        gtk_tree_view_append_column(GTK_TREE_VIEW(gTreeViewWidget),
                                    GTK_TREE_VIEW_COLUMN(gMiddleTreeViewColumn));

        lastTreeViewColumn = gtk_tree_view_column_new();
        gtk_tree_view_column_set_title(lastTreeViewColumn, "M");
        gtk_tree_view_append_column(GTK_TREE_VIEW(gTreeViewWidget), lastTreeViewColumn);

        /* Use the middle column's header for our button */
        gTreeHeaderCellWidget = GTK_TREE_VIEW_COLUMN(gMiddleTreeViewColumn)->button;
        gTreeHeaderSortArrowWidget = GTK_TREE_VIEW_COLUMN(gMiddleTreeViewColumn)->arrow;
        g_object_set_data(G_OBJECT(gTreeHeaderCellWidget),
                          "transparent-bg-hint", TRUE);
        g_object_set_data(G_OBJECT(gTreeHeaderSortArrowWidget),
                          "transparent-bg-hint", TRUE);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_expander_widget()
{
    if (!gExpanderWidget) {
        gExpanderWidget = gtk_expander_new("M");
        setup_widget_prototype(gExpanderWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static gint
ensure_scrolled_window_widget()
{
    if (!gScrolledWindowWidget) {
        gScrolledWindowWidget = gtk_scrolled_window_new(NULL, NULL);
        setup_widget_prototype(gScrolledWindowWidget);
    }
    return MOZ_GTK_SUCCESS;
}

static GtkStateType
ConvertGtkState(GtkWidgetState* state)
{
    if (state->disabled)
        return GTK_STATE_INSENSITIVE;
    else if (state->depressed)
        return (state->inHover ? GTK_STATE_PRELIGHT : GTK_STATE_ACTIVE);
    else if (state->inHover)
        return (state->active ? GTK_STATE_ACTIVE : GTK_STATE_PRELIGHT);
    else
        return GTK_STATE_NORMAL;
}

static gint
TSOffsetStyleGCArray(GdkGC** gcs, gint xorigin, gint yorigin)
{
    int i;
    /* there are 5 gc's in each array, for each of the widget states */
    for (i = 0; i < 5; ++i)
        gdk_gc_set_ts_origin(gcs[i], xorigin, yorigin);
    return MOZ_GTK_SUCCESS;
}

static gint
TSOffsetStyleGCs(GtkStyle* style, gint xorigin, gint yorigin)
{
    TSOffsetStyleGCArray(style->fg_gc, xorigin, yorigin);
    TSOffsetStyleGCArray(style->bg_gc, xorigin, yorigin);
    TSOffsetStyleGCArray(style->light_gc, xorigin, yorigin);
    TSOffsetStyleGCArray(style->dark_gc, xorigin, yorigin);
    TSOffsetStyleGCArray(