gecko-dev/widget/gtk/gtkdrawing.h
Martin Stransky 659fc0cc75 Bug 1454897 - Ubuntu/Ambiance - Render scrollbar thumb with different sizes in active/normal state, r=jhorak
This patch implements a workaround which alows us to emulate
overlay scrollbars for some Gtk+ themes (Ubuntu/Ambiance),
when an inactive scrollbar thumb is smaller than the active one.

We calculate thumb margin as thumb class margin + difference margin
between active and inactive scrollbars.

Also remove boolean parameter from GetScrollbarMetrics() and implement
GetActiveScrollbarMetrics() to get metrics for active scrollbar.

MozReview-Commit-ID: 2zje5OZskYw

--HG--
extra : rebase_source : dd50dc52d9d0942c9dcfbf72d217f3c6ee82c21a
2018-04-24 12:27:38 +02:00

636 lines
20 KiB
C++

/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* gtkdrawing.h: GTK widget rendering utilities
*
* gtkdrawing provides an API for rendering GTK widgets in the
* current theme to a pixmap or window, without requiring an actual
* widget instantiation, similar to the Macintosh Appearance Manager
* or Windows XP's DrawThemeBackground() API.
*/
#ifndef _GTK_DRAWING_H_
#define _GTK_DRAWING_H_
#include <gdk/gdk.h>
#include <gtk/gtk.h>
#include <algorithm>
/*** type definitions ***/
typedef struct {
guint8 active;
guint8 focused;
guint8 inHover;
guint8 disabled;
guint8 isDefault;
guint8 canDefault;
/* The depressed state is for buttons which remain active for a longer period:
* activated toggle buttons or buttons showing a popup menu. */
guint8 depressed;
gint32 curpos; /* curpos and maxpos are used for scrollbars */
gint32 maxpos;
gint32 scale; /* actual widget scale */
} GtkWidgetState;
/**
* A size in the same GTK pixel units as GtkBorder and GdkRectangle.
*/
struct MozGtkSize {
gint width;
gint height;
MozGtkSize& operator+=(const GtkBorder& aBorder)
{
width += aBorder.left + aBorder.right;
height += aBorder.top + aBorder.bottom;
return *this;
}
MozGtkSize operator+(const GtkBorder& aBorder) const
{
MozGtkSize result = *this;
return result += aBorder;
}
bool operator<(const MozGtkSize &aOther) const
{
return (width < aOther.width && height <= aOther.height) ||
(width <= aOther.width && height < aOther.height);
}
void Include(MozGtkSize aOther)
{
width = std::max(width, aOther.width);
height = std::max(height, aOther.height);
}
void Rotate()
{
gint tmp = width;
width = height;
height = tmp;
}
};
typedef struct {
bool initialized;
struct {
MozGtkSize scrollbar;
MozGtkSize thumb;
MozGtkSize button;
} size;
struct {
GtkBorder scrollbar;
GtkBorder track;
} border;
struct {
GtkBorder thumb;
} margin;
} ScrollbarGTKMetrics;
typedef struct {
bool initialized;
MozGtkSize minSizeWithBorder;
GtkBorder borderAndPadding;
} ToggleGTKMetrics;
typedef struct {
MozGtkSize minSizeWithBorderMargin;
GtkBorder buttonMargin;
gint iconXPosition;
gint iconYPosition;
bool visible;
bool firstButton;
bool lastButton;
} ToolbarButtonGTKMetrics;
#define TOOLBAR_BUTTONS 3
typedef struct {
bool initialized;
ToolbarButtonGTKMetrics button[TOOLBAR_BUTTONS];
} ToolbarGTKMetrics;
typedef enum {
MOZ_GTK_STEPPER_DOWN = 1 << 0,
MOZ_GTK_STEPPER_BOTTOM = 1 << 1,
MOZ_GTK_STEPPER_VERTICAL = 1 << 2
} GtkScrollbarButtonFlags;
typedef enum {
MOZ_GTK_TRACK_OPAQUE = 1 << 0
} GtkScrollbarTrackFlags;
/** flags for tab state **/
typedef enum {
/* first eight bits are used to pass a margin */
MOZ_GTK_TAB_MARGIN_MASK = 0xFF,
/* the first tab in the group */
MOZ_GTK_TAB_FIRST = 1 << 9,
/* the selected tab */
MOZ_GTK_TAB_SELECTED = 1 << 10
} GtkTabFlags;
/*** result/error codes ***/
#define MOZ_GTK_SUCCESS 0
#define MOZ_GTK_UNKNOWN_WIDGET -1
#define MOZ_GTK_UNSAFE_THEME -2
/*** checkbox/radio flags ***/
#define MOZ_GTK_WIDGET_CHECKED 1
#define MOZ_GTK_WIDGET_INCONSISTENT (1 << 1)
/*** widget type constants ***/
typedef enum {
/* Paints a GtkButton. flags is a GtkReliefStyle. */
MOZ_GTK_BUTTON,
/* Paints a button with image and no text */
MOZ_GTK_TOOLBAR_BUTTON,
/* Paints a toggle button */
MOZ_GTK_TOGGLE_BUTTON,
/* Paints a button arrow */
MOZ_GTK_BUTTON_ARROW,
/* Paints the container part of a GtkCheckButton. */
MOZ_GTK_CHECKBUTTON_CONTAINER,
/* Paints a GtkCheckButton. flags is a boolean, 1=checked, 0=not checked. */
MOZ_GTK_CHECKBUTTON,
/* Paints the label of a GtkCheckButton (focus outline) */
MOZ_GTK_CHECKBUTTON_LABEL,
/* Paints the container part of a GtkRadioButton. */
MOZ_GTK_RADIOBUTTON_CONTAINER,
/* Paints a GtkRadioButton. flags is a boolean, 1=checked, 0=not checked. */
MOZ_GTK_RADIOBUTTON,
/* Paints the label of a GtkRadioButton (focus outline) */
MOZ_GTK_RADIOBUTTON_LABEL,
/**
* Paints the button of a GtkScrollbar. flags is a GtkArrowType giving
* the arrow direction.
*/
MOZ_GTK_SCROLLBAR_BUTTON,
/* Horizontal GtkScrollbar counterparts */
MOZ_GTK_SCROLLBAR_HORIZONTAL,
MOZ_GTK_SCROLLBAR_CONTENTS_HORIZONTAL,
/* Paints the trough (track) of a GtkScrollbar. */
MOZ_GTK_SCROLLBAR_TROUGH_HORIZONTAL,
/* Paints the slider (thumb) of a GtkScrollbar. */
MOZ_GTK_SCROLLBAR_THUMB_HORIZONTAL,
/* Vertical GtkScrollbar counterparts */
MOZ_GTK_SCROLLBAR_VERTICAL,
MOZ_GTK_SCROLLBAR_CONTENTS_VERTICAL,
MOZ_GTK_SCROLLBAR_TROUGH_VERTICAL,
MOZ_GTK_SCROLLBAR_THUMB_VERTICAL,
/* Paints a GtkScale. */
MOZ_GTK_SCALE_HORIZONTAL,
MOZ_GTK_SCALE_VERTICAL,
/* Paints a GtkScale trough. */
MOZ_GTK_SCALE_CONTENTS_HORIZONTAL,
MOZ_GTK_SCALE_CONTENTS_VERTICAL,
MOZ_GTK_SCALE_TROUGH_HORIZONTAL,
MOZ_GTK_SCALE_TROUGH_VERTICAL,
/* Paints a GtkScale thumb. */
MOZ_GTK_SCALE_THUMB_HORIZONTAL,
MOZ_GTK_SCALE_THUMB_VERTICAL,
/* Paints a GtkSpinButton */
MOZ_GTK_INNER_SPIN_BUTTON,
MOZ_GTK_SPINBUTTON,
MOZ_GTK_SPINBUTTON_UP,
MOZ_GTK_SPINBUTTON_DOWN,
MOZ_GTK_SPINBUTTON_ENTRY,
/* Paints the gripper of a GtkHandleBox. */
MOZ_GTK_GRIPPER,
/* Paints a GtkEntry. */
MOZ_GTK_ENTRY,
/* Paints a GtkExpander. */
MOZ_GTK_EXPANDER,
/* Paints a GtkTextView or gets the style context corresponding to the
root node of a GtkTextView. */
MOZ_GTK_TEXT_VIEW,
/* The "text" window or node of a GtkTextView */
MOZ_GTK_TEXT_VIEW_TEXT,
/* Paints a GtkOptionMenu. */
MOZ_GTK_DROPDOWN,
/* Paints a dropdown arrow (a GtkButton containing a down GtkArrow). */
MOZ_GTK_DROPDOWN_ARROW,
/* Paints an entry in an editable option menu */
MOZ_GTK_DROPDOWN_ENTRY,
/* Paints the background of a GtkHandleBox. */
MOZ_GTK_TOOLBAR,
/* Paints a toolbar separator */
MOZ_GTK_TOOLBAR_SEPARATOR,
/* Paints a GtkToolTip */
MOZ_GTK_TOOLTIP,
/* Paints a GtkBox from GtkToolTip */
MOZ_GTK_TOOLTIP_BOX,
/* Paints a GtkLabel of GtkToolTip */
MOZ_GTK_TOOLTIP_BOX_LABEL,
/* Paints a GtkFrame (e.g. a status bar panel). */
MOZ_GTK_FRAME,
/* Paints the border of a GtkFrame */
MOZ_GTK_FRAME_BORDER,
/* Paints a resize grip for a GtkTextView */
MOZ_GTK_RESIZER,
/* Paints a GtkProgressBar. */
MOZ_GTK_PROGRESSBAR,
/* Paints a trough (track) of a GtkProgressBar */
MOZ_GTK_PROGRESS_TROUGH,
/* Paints a progress chunk of a GtkProgressBar. */
MOZ_GTK_PROGRESS_CHUNK,
/* Paints a progress chunk of an indeterminated GtkProgressBar. */
MOZ_GTK_PROGRESS_CHUNK_INDETERMINATE,
/* Paints a progress chunk of a vertical indeterminated GtkProgressBar. */
MOZ_GTK_PROGRESS_CHUNK_VERTICAL_INDETERMINATE,
/* Used as root style of whole GtkNotebook widget */
MOZ_GTK_NOTEBOOK,
/* Used as root style of active GtkNotebook area which contains tabs and arrows. */
MOZ_GTK_NOTEBOOK_HEADER,
/* Paints a tab of a GtkNotebook. flags is a GtkTabFlags, defined above. */
MOZ_GTK_TAB_TOP,
/* Paints a tab of a GtkNotebook. flags is a GtkTabFlags, defined above. */
MOZ_GTK_TAB_BOTTOM,
/* Paints the background and border of a GtkNotebook. */
MOZ_GTK_TABPANELS,
/* Paints a GtkArrow for a GtkNotebook. flags is a GtkArrowType. */
MOZ_GTK_TAB_SCROLLARROW,
/* Paints the expander and border of a GtkTreeView */
MOZ_GTK_TREEVIEW,
/* Paints the border of a GtkTreeView */
MOZ_GTK_TREEVIEW_VIEW,
/* Paints treeheader cells */
MOZ_GTK_TREE_HEADER_CELL,
/* Paints sort arrows in treeheader cells */
MOZ_GTK_TREE_HEADER_SORTARROW,
/* Paints an expander for a GtkTreeView */
MOZ_GTK_TREEVIEW_EXPANDER,
/* Paints the background of the menu bar. */
MOZ_GTK_MENUBAR,
/* Paints the background of menus, context menus. */
MOZ_GTK_MENUPOPUP,
/* Paints the arrow of menuitems that contain submenus */
MOZ_GTK_MENUARROW,
/* Paints an arrow in a toolbar button. flags is a GtkArrowType. */
MOZ_GTK_TOOLBARBUTTON_ARROW,
/* Paints items of menubar. */
MOZ_GTK_MENUBARITEM,
/* Paints items of popup menus. */
MOZ_GTK_MENUITEM,
/* Paints a menuitem with check indicator, or the gets the style context for
a menuitem that contains a checkbox. */
MOZ_GTK_CHECKMENUITEM,
/* Gets the style context for a checkbox in a check menuitem. */
MOZ_GTK_CHECKMENUITEM_INDICATOR,
MOZ_GTK_RADIOMENUITEM,
MOZ_GTK_RADIOMENUITEM_INDICATOR,
MOZ_GTK_MENUSEPARATOR,
/* GtkVPaned base class */
MOZ_GTK_SPLITTER_HORIZONTAL,
/* GtkHPaned base class */
MOZ_GTK_SPLITTER_VERTICAL,
/* Paints a GtkVPaned separator */
MOZ_GTK_SPLITTER_SEPARATOR_HORIZONTAL,
/* Paints a GtkHPaned separator */
MOZ_GTK_SPLITTER_SEPARATOR_VERTICAL,
/* Paints the background of a window, dialog or page. */
MOZ_GTK_WINDOW,
/* Used only as a container for MOZ_GTK_HEADER_BAR_MAXIMIZED. */
MOZ_GTK_WINDOW_MAXIMIZED,
/* Window container for all widgets */
MOZ_GTK_WINDOW_CONTAINER,
/* Paints a GtkInfoBar, for notifications. */
MOZ_GTK_INFO_BAR,
/* Used for widget tree construction. */
MOZ_GTK_COMBOBOX,
/* Paints a GtkComboBox button widget. */
MOZ_GTK_COMBOBOX_BUTTON,
/* Paints a GtkComboBox arrow widget. */
MOZ_GTK_COMBOBOX_ARROW,
/* Paints a GtkComboBox separator widget. */
MOZ_GTK_COMBOBOX_SEPARATOR,
/* Used for widget tree construction. */
MOZ_GTK_COMBOBOX_ENTRY,
/* Paints a GtkComboBox entry widget. */
MOZ_GTK_COMBOBOX_ENTRY_TEXTAREA,
/* Paints a GtkComboBox entry button widget. */
MOZ_GTK_COMBOBOX_ENTRY_BUTTON,
/* Paints a GtkComboBox entry arrow widget. */
MOZ_GTK_COMBOBOX_ENTRY_ARROW,
/* Used for scrolled window shell. */
MOZ_GTK_SCROLLED_WINDOW,
/* Paints a GtkHeaderBar */
MOZ_GTK_HEADER_BAR,
/* Paints a GtkHeaderBar in maximized state */
MOZ_GTK_HEADER_BAR_MAXIMIZED,
/* Paints GtkHeaderBar title buttons.
* Keep the order here as MOZ_GTK_HEADER_BAR_BUTTON_* are processed
* as an array from MOZ_GTK_HEADER_BAR_BUTTON_CLOSE to the last one.
*/
MOZ_GTK_HEADER_BAR_BUTTON_CLOSE,
MOZ_GTK_HEADER_BAR_BUTTON_MINIMIZE,
MOZ_GTK_HEADER_BAR_BUTTON_MAXIMIZE,
/* MOZ_GTK_HEADER_BAR_BUTTON_MAXIMIZE_RESTORE is a state of
* MOZ_GTK_HEADER_BAR_BUTTON_MAXIMIZE button and it's used as
* an icon placeholder only.
*/
MOZ_GTK_HEADER_BAR_BUTTON_MAXIMIZE_RESTORE,
/* Client-side window decoration node. Available on GTK 3.20+. */
MOZ_GTK_WINDOW_DECORATION,
MOZ_GTK_WINDOW_DECORATION_SOLID,
MOZ_GTK_WIDGET_NODE_COUNT
} WidgetNodeType;
/*** General library functions ***/
/**
* Initializes the drawing library. You must call this function
* prior to using any other functionality.
* returns: MOZ_GTK_SUCCESS if there were no errors
* MOZ_GTK_UNSAFE_THEME if the current theme engine is known
* to crash with gtkdrawing.
*/
gint moz_gtk_init();
/**
* Updates the drawing library when the theme changes.
*/
void moz_gtk_refresh();
/**
* Perform cleanup of the drawing library. You should call this function
* when your program exits, or you no longer need the library.
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint moz_gtk_shutdown();
/*** Widget drawing ***/
/**
* Paint a widget in the current theme.
* widget: a constant giving the widget to paint
* drawable: the drawable to paint to;
* it's colormap must be moz_gtk_widget_get_colormap().
* rect: the bounding rectangle for the widget
* state: the state of the widget. ignored for some widgets.
* flags: widget-dependant flags; see the WidgetNodeType definition.
* direction: the text direction, to draw the widget correctly LTR and RTL.
*/
gint
moz_gtk_widget_paint(WidgetNodeType widget, cairo_t *cr,
GdkRectangle* rect,
GtkWidgetState* state, gint flags,
GtkTextDirection direction);
/*** Widget metrics ***/
/**
* Get the border size of a widget
* left/right: [OUT] the widget's left/right border
* top/bottom: [OUT] the widget's top/bottom border
* direction: the text direction for the widget. Callers depend on this
* being used only for MOZ_GTK_DROPDOWN widgets, and cache
* results for other widget types across direction values.
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint moz_gtk_get_widget_border(WidgetNodeType widget, gint* left, gint* top,
gint* right, gint* bottom, GtkTextDirection direction);
/**
* Get the border size of a notebook tab
* left/right: [OUT] the tab's left/right border
* top/bottom: [OUT] the tab's top/bottom border
* direction: the text direction for the widget
* flags: tab-dependant flags; see the GtkTabFlags definition.
* widget: tab widget
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint
moz_gtk_get_tab_border(gint* left, gint* top, gint* right, gint* bottom,
GtkTextDirection direction, GtkTabFlags flags,
WidgetNodeType widget);
/**
* Get the desired size of a GtkCheckButton
* indicator_size: [OUT] the indicator size
* indicator_spacing: [OUT] the spacing between the indicator and its
* container
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint
moz_gtk_checkbox_get_metrics(gint* indicator_size, gint* indicator_spacing);
/**
* Get metrics of the toggle (radio or checkbox)
* isRadio: [IN] true when requesting metrics for the radio button
* returns: pointer to ToggleGTKMetrics struct
*/
const ToggleGTKMetrics*
GetToggleMetrics(bool isRadio);
/**
* Get the desired size of a GtkRadioButton
* indicator_size: [OUT] the indicator size
* indicator_spacing: [OUT] the spacing between the indicator and its
* container
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint
moz_gtk_radio_get_metrics(gint* indicator_size, gint* indicator_spacing);
/** Get the extra size for the focus ring for outline:auto.
* widget: [IN] the widget to get the focus metrics for
* focus_h_width: [OUT] the horizontal width
* focus_v_width: [OUT] the vertical width
*
* returns: MOZ_GTK_SUCCESS
*/
gint
moz_gtk_get_focus_outline_size(gint* focus_h_width, gint* focus_v_width);
/** Get the horizontal padding for the menuitem widget or checkmenuitem widget.
* horizontal_padding: [OUT] The left and right padding of the menuitem or checkmenuitem
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint
moz_gtk_menuitem_get_horizontal_padding(gint* horizontal_padding);
gint
moz_gtk_checkmenuitem_get_horizontal_padding(gint* horizontal_padding);
/**
* Some GTK themes draw their indication for the default button outside
* the button (e.g. the glow in New Wave). This gets the extra space necessary.
*
* border_top: [OUT] extra space to add above
* border_left: [OUT] extra space to add to the left
* border_bottom: [OUT] extra space to add underneath
* border_right: [OUT] extra space to add to the right
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint
moz_gtk_button_get_default_overflow(gint* border_top, gint* border_left,
gint* border_bottom, gint* border_right);
/**
* Gets the minimum size of a GtkScale.
* orient: [IN] the scale orientation
* scale_width: [OUT] the width of the scale
* scale_height: [OUT] the height of the scale
*/
void
moz_gtk_get_scale_metrics(GtkOrientation orient, gint* scale_width,
gint* scale_height);
/**
* Get the desired size of a GtkScale thumb
* orient: [IN] the scale orientation
* thumb_length: [OUT] the length of the thumb
* thumb_height: [OUT] the height of the thumb
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint
moz_gtk_get_scalethumb_metrics(GtkOrientation orient, gint* thumb_length, gint* thumb_height);
/**
* Get the metrics in GTK pixels for a scrollbar.
* aOrientation: [IN] the scrollbar orientation
*/
const ScrollbarGTKMetrics*
GetScrollbarMetrics(GtkOrientation aOrientation);
/**
* Get the metrics in GTK pixels for a scrollbar which is active
* (selected by mouse pointer).
* aOrientation: [IN] the scrollbar orientation
*/
const ScrollbarGTKMetrics*
GetActiveScrollbarMetrics(GtkOrientation aOrientation);
/**
* Get the desired size of a dropdown arrow button
* width: [OUT] the desired width
* height: [OUT] the desired height
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint moz_gtk_get_combo_box_entry_button_size(gint* width, gint* height);
/**
* Get the desired size of a scroll arrow widget
* width: [OUT] the desired width
* height: [OUT] the desired height
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint moz_gtk_get_tab_scroll_arrow_size(gint* width, gint* height);
/**
* Get the desired size of an arrow in a button
*
* widgetType: [IN] the widget for which to get the arrow size
* width: [OUT] the desired width
* height: [OUT] the desired height
*/
void
moz_gtk_get_arrow_size(WidgetNodeType widgetType,
gint* width, gint* height);
/**
* Get the minimum height of a entry widget
* size: [OUT] the minimum height
*
*/
void moz_gtk_get_entry_min_height(gint* height);
/**
* Get the desired size of a toolbar separator
* size: [OUT] the desired width
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint moz_gtk_get_toolbar_separator_width(gint* size);
/**
* Get the size of a regular GTK expander that shows/hides content
* size: [OUT] the size of the GTK expander, size = width = height.
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint moz_gtk_get_expander_size(gint* size);
/**
* Get the size of a treeview's expander (we call them twisties)
* size: [OUT] the size of the GTK expander, size = width = height.
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint moz_gtk_get_treeview_expander_size(gint* size);
/**
* Get the desired height of a menu separator
* size: [OUT] the desired height
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint moz_gtk_get_menu_separator_height(gint* size);
/**
* Get the desired size of a splitter
* orientation: [IN] GTK_ORIENTATION_HORIZONTAL or GTK_ORIENTATION_VERTICAL
* size: [OUT] width or height of the splitter handle
*
* returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
*/
gint moz_gtk_splitter_get_metrics(gint orientation, gint* size);
/**
* Get the YTHICKNESS of a tab (notebook extension).
*/
gint
moz_gtk_get_tab_thickness(WidgetNodeType aNodeType);
/**
* Get ToolbarButtonGTKMetrics for recent theme.
*/
const ToolbarButtonGTKMetrics*
GetToolbarButtonMetrics(WidgetNodeType aWidgetType);
/**
* Get toolbar button layout.
* aButtonLayout: [IN][OUT] An array which will be filled by WidgetNodeType
* references to visible titlebar buttons.
Must contains at least TOOLBAR_BUTTONS entries.
* aMaxButtonNums: [IN] Allocated aButtonLayout entries. Must be at least
TOOLBAR_BUTTONS wide.
*
* returns: Number of returned entries at aButtonLayout.
*/
int
GetGtkHeaderBarButtonLayout(WidgetNodeType* aButtonLayout, int aMaxButtonNums);
/**
* Get size of CSD window extents of given GtkWindow.
*
* aGtkWindow [IN] Decorated window.
* aDecorationSize [OUT] Returns calculated (or estimated) decoration
* size of given aGtkWindow.
*
* returns: True if we have extract decoration size (for GTK 3.20+)
* False if we have only an estimation (for GTK+ before 3.20+)
*/
bool
GetCSDDecorationSize(GtkWindow *aGtkWindow, GtkBorder* aDecorationSize);
#endif