livetrax/libs/gtkmm2ext/utils.cc

/*
 * Copyright (C) 1999-2016 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2005-2008 Doug McLain <doug@nostar.net>
 * Copyright (C) 2010-2012 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2011-2015 David Robillard <d@drobilla.net>
 * Copyright (C) 2014-2016 John Emmas <john@creativepost.co.uk>
 * Copyright (C) 2014-2019 Robin Gareus <robin@gareus.org>
 * Copyright (C) 2016 Julien "_FrnchFrgg_" RIVAUD <frnchfrgg@free.fr>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <map>
#include <algorithm>
#include <iostream>

#include <gtk/gtkpaned.h>
#include <gtk/gtk.h>

#include <gtkmm/widget.h>
#include <gtkmm/button.h>
#include <gtkmm/window.h>
#include <gtkmm/paned.h>
#include <gtkmm/label.h>
#include <gtkmm/comboboxtext.h>
#include <gtkmm/tooltip.h>
#include <gtkmm/menuitem.h>

#include "gtkmm2ext/utils.h"
#include "gtkmm2ext/persistent_tooltip.h"

#include "pbd/i18n.h"

using namespace std;

void
Gtkmm2ext::init (const char* localedir)
{
#if ENABLE_NLS
	(void) bindtextdomain(PACKAGE, localedir);
	(void) bind_textdomain_codeset (PACKAGE, "UTF-8");
#endif
}

void
Gtkmm2ext::get_ink_pixel_size (Glib::RefPtr<Pango::Layout> layout,
			       int& width,
			       int& height)
{
	Pango::Rectangle ink_rect = layout->get_ink_extents ();

	width = PANGO_PIXELS(ink_rect.get_width());
	height = PANGO_PIXELS(ink_rect.get_height());
}

static void
_set_size_request_to_display_given_text (Glib::RefPtr<Gtk::Style> const& sty, Gtk::Widget* w, std::string const& text,
						   gint hpadding, gint vpadding)
{
	w->ensure_style ();
	if (sty && sty->get_font() == w->get_style()->get_font()) {
		return;
	}

	int width, height;
	w->create_pango_layout (text)->get_pixel_size (width, height);
	w->set_size_request(width + hpadding, height + vpadding);
}

void
Gtkmm2ext::set_size_request_to_display_given_text (Gtk::Widget &w, std::string const& text,
						   gint hpadding, gint vpadding)
{
	w.signal_style_changed().connect (sigc::bind (sigc::ptr_fun (_set_size_request_to_display_given_text), &w, text, hpadding, vpadding));
	_set_size_request_to_display_given_text (Glib::RefPtr<Gtk::Style>(), &w, text, hpadding, vpadding);
}

static inline guint8
demultiply_alpha (guint8 src,
                  guint8 alpha)
{
	/* cairo pixel buffer data contains RGB values with the alpha
	 * values premultiplied.
	 *
	 * GdkPixbuf pixel buffer data contains RGB values without the
	 * alpha value applied.
	 *
	 * this removes the alpha component from the cairo version and
	 * returns the GdkPixbuf version.
	 */
	return alpha ? ((guint (src) << 8) - src) / alpha : 0;
}

void
Gtkmm2ext::convert_bgra_to_rgba (guint8 const* src,
				 guint8*       dst,
				 int           width,
				 int           height)
{
	guint8 const* src_pixel = src;
	guint8*       dst_pixel = dst;

	/* cairo pixel data is endian-dependent ARGB with A in the most significant 8 bits,
	 * with premultipled alpha values (see preceding function)
	 *
	 * GdkPixbuf pixel data is non-endian-dependent RGBA with R in the lowest addressable
	 * 8 bits, and non-premultiplied alpha values.
	 *
	 * convert from the cairo values to the GdkPixbuf ones.
	 */

	for (int y = 0; y < height; y++) {
		for (int x = 0; x < width; x++) {
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
			/* Cairo [ B G R A ] is actually  [ B G R A ] in memory SOURCE
				 0 1 2 3
				 Pixbuf [ R G B A ] is actually [ R G B A ] in memory DEST
				 */
			dst_pixel[0] = demultiply_alpha (src_pixel[2],
					src_pixel[3]); // R [0] <= [ 2 ]
			dst_pixel[1] = demultiply_alpha (src_pixel[1],
					src_pixel[3]); // G [1] <= [ 1 ]
			dst_pixel[2] = demultiply_alpha (src_pixel[0],
					src_pixel[3]); // B [2] <= [ 0 ]
			dst_pixel[3] = src_pixel[3]; // alpha

#elif G_BYTE_ORDER == G_BIG_ENDIAN
			/* Cairo [ B G R A ] is actually  [ A R G B ] in memory SOURCE
				 0 1 2 3
				 Pixbuf [ R G B A ] is actually [ R G B A ] in memory DEST
				 */
			dst_pixel[0] = demultiply_alpha (src_pixel[1],
					src_pixel[0]); // R [0] <= [ 1 ]
			dst_pixel[1] = demultiply_alpha (src_pixel[2],
					src_pixel[0]); // G [1] <= [ 2 ]
			dst_pixel[2] = demultiply_alpha (src_pixel[3],
					src_pixel[0]); // B [2] <= [ 3 ]
			dst_pixel[3] = src_pixel[0]; // alpha

#else
#error ardour does not currently support PDP-endianess
#endif

			dst_pixel += 4;
			src_pixel += 4;
		}
	}
}

Glib::RefPtr<Gdk::Pixbuf>
Gtkmm2ext::pixbuf_from_string(const string& name, const Pango::FontDescription& font, int clip_width, int clip_height, Gdk::Color fg)
{
	static Glib::RefPtr<Gdk::Pixbuf>* empty_pixbuf = 0;

	if (name.empty()) {
		if (empty_pixbuf == 0) {
			empty_pixbuf = new Glib::RefPtr<Gdk::Pixbuf>;
			*empty_pixbuf = Gdk::Pixbuf::create(Gdk::COLORSPACE_RGB, true, 8, clip_width, clip_height);
		}
		return *empty_pixbuf;
	}

	if (clip_width <= 0 || clip_height <= 0) {
		/* negative values mean padding around natural size */
		int width, height;
		pixel_size (name, font, width, height);
		if (clip_width <= 0) {
			clip_width = width - clip_width;
		}
		if (clip_height <= 0) {
			clip_height = height - clip_height;
		}
	}

	Glib::RefPtr<Gdk::Pixbuf> buf = Gdk::Pixbuf::create(Gdk::COLORSPACE_RGB, true, 8, clip_width, clip_height);

	cairo_surface_t* surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, clip_width, clip_height);
	cairo_t* cr = cairo_create (surface);
	cairo_text_extents_t te;

	cairo_set_source_rgba (cr, fg.get_red_p(), fg.get_green_p(), fg.get_blue_p(), 1.0);
	cairo_select_font_face (cr, font.get_family().c_str(),
				CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
	cairo_set_font_size (cr,  font.get_size() / Pango::SCALE);
	cairo_text_extents (cr, name.c_str(), &te);

	cairo_move_to (cr, 0.5, int (0.5 - te.height / 2 - te.y_bearing + clip_height / 2));
	cairo_show_text (cr, name.c_str());

	convert_bgra_to_rgba(cairo_image_surface_get_data (surface), buf->get_pixels(), clip_width, clip_height);

	cairo_destroy(cr);
	cairo_surface_destroy(surface);

	return buf;
}

static void
_position_menu_anchored (int& x, int& y, bool& push_in,
                                   Gtk::Menu* const menu,
                                   Gtk::Widget* const anchor,
                                   const std::string& selected)
{
	using namespace Gtk;
	using namespace Gtk::Menu_Helpers;

	 /* TODO: lacks support for rotated dropdown buttons */

	if (!anchor->has_screen () || !anchor->get_has_window ()) {
		return;
	}

	Gdk::Rectangle monitor;
	{
		const int monitor_num = anchor->get_screen ()->get_monitor_at_window (
				anchor->get_window ());
		anchor->get_screen ()->get_monitor_geometry (
				(monitor_num < 0) ? 0 : monitor_num, monitor);
	}

	const Requisition menu_req = menu->size_request();
	const Gdk::Rectangle allocation = anchor->get_allocation();

	/* The x and y position are handled separately.
	 *
	 * For the x position if the direction is LTR (or RTL), then we try in order:
	 *  a) align the left (right) of the menu with the left (right) of the button
	 *     if there's enough room until the right (left) border of the screen;
	 *  b) align the right (left) of the menu with the right (left) of the button
	 *     if there's enough room until the left (right) border of the screen;
	 *  c) align the right (left) border of the menu with the right (left) border
	 *     of the screen if there's enough space;
	 *  d) align the left (right) border of the menu with the left (right) border
	 *     of the screen, with the rightmost (leftmost) part of the menu that
	 *     overflows the screen.
	 *     XXX We always align left regardless of the direction because if x is
	 *     left of the current monitor, the menu popup code after us notices it
	 *     and enforces that the menu stays in the monitor that's at the left...*/

	anchor->get_window ()->get_origin (x, y);

	if (anchor->get_direction() == TEXT_DIR_RTL) {
		if (monitor.get_x() <= x + allocation.get_width() - menu_req.width) {
			/* a) align menu right and button right */
			x += allocation.get_width() - menu_req.width;
		} else if (x + menu_req.width <= monitor.get_x() + monitor.get_width()) {
			/* b) align menu left and button left: nothing to do*/
		} else if (menu_req.width <= monitor.get_width()) {
			/* c) align menu left and screen left, guaranteed to fit */
			x = monitor.get_x();
		} else {
			/* d) XXX align left or the menu might change monitors */
			x = monitor.get_x();
		}
	} else { /* LTR */
		if (x + menu_req.width <= monitor.get_x() + monitor.get_width()) {
			/* a) align menu left and button left: nothing to do*/
		} else if (monitor.get_x() <= x + allocation.get_width() - menu_req.width) {
			/* b) align menu right and button right */
			x += allocation.get_width() - menu_req.width;
		} else if (menu_req.width <= monitor.get_width()) {
			/* c) align menu right and screen right, guaranteed to fit */
			x = monitor.get_x() + monitor.get_width() - menu_req.width;
		} else {
			/* d) align left */
			x = monitor.get_x();
		}
	}

	/* For the y position, try in order:
	 *  a) if there is a menu item with the same text as the button, align it
	 *     with the button, unless that makes the menu overflow the monitor.
	 *  b) align the top of the menu with the bottom of the button if there is
	 *     enough room below the button;
	 *  c) align the bottom of the menu with the top of the button if there is
	 *     enough room above the button;
	 *  d) try aligning the selected menu item again, this time with scrollbars;
	 *  e) if there is no selected menu item, align the menu above the button or
	 *     below the button, depending on where there is more space.
	 * For the d) and e) cases, the menu contents will be aligned as told, but
	 * the menu itself will be bigger than that to accommodate the menu items
	 * that are scrolled out of view, thanks to |push_in = true|.
	 */

	const MenuList& items = menu->items ();
	int offset = 0;

	MenuList::const_iterator i = items.begin();
	for ( ; i != items.end(); ++i) {
		const Label* label_widget = dynamic_cast<const Label*>(i->get_child());
		if (label_widget && selected == ((std::string) label_widget->get_label())) {
			offset += (i->size_request().height - allocation.get_height()) / 2;
			menu->select_item(*i);
			break;
		}
		offset += i->size_request().height;
	}
	if (i != items.end() &&
	    y - offset >= monitor.get_y() &&
	    y - offset + menu_req.height <= monitor.get_y() + monitor.get_height()) {
		y -= offset; /* a) */
	} else if (y + allocation.get_height() + menu_req.height <= monitor.get_y() + monitor.get_height()) {
		y += allocation.get_height(); /* b) */
	} else if ((y - menu_req.height) >= monitor.get_y()) {
		y -= menu_req.height; /* c) */
	} else if (i != items.end()) {
		y -= offset; /* d) */
		menu->gobj()->upper_arrow_visible = 1; /* work around a gtk bug for the first show */
	} else if (monitor.get_height() - allocation.get_height() >= 2*(y - monitor.get_y())) {
		y += allocation.get_height(); /* e), more space below */
		menu->gobj()->upper_arrow_visible = 1; /* work around a gtk bug for the first show */
	} else {
		y -= menu_req.height; /* e), more space above */
		menu->gobj()->upper_arrow_visible = 1; /* work around a gtk bug for the first show */
	}

	/* Workaround a bug in GTK where they don't tweak the scroll offset by the arrow height
	 * if the scroll offset is negative. See the condition at:
	 * https://gitlab.gnome.org/GNOME/gtk/blob/2.24.32/gtk/gtkmenu.c#L4395
	 * and the computation of scroll_offset at:
	 * https://gitlab.gnome.org/GNOME/gtk/blob/2.24.32/gtk/gtkmenu.c#L4360
	 * */
	int arrow_height;
	GtkArrowPlacement arrow_placement;
	gtk_widget_style_get (GTK_WIDGET (menu->gobj()),
	        "scroll-arrow-vlength", &arrow_height,
	        "arrow_placement", &arrow_placement,
	        NULL);
	int scroll_tweak = menu_req.height - monitor.get_height();
	int scroll_offset = scroll_tweak + monitor.get_y() + monitor.get_height() - y - menu_req.height;
	if (arrow_placement != GTK_ARROWS_END && scroll_tweak > 0 && scroll_offset < 0) {
		y -= arrow_height;
	}

	push_in = true;
}

void
Gtkmm2ext::anchored_menu_popup (Gtk::Menu* const menu,
                                Gtk::Widget* const anchor,
                                const std::string& selected,
                                guint button, guint32 time)
{
	menu->popup(
		sigc::bind (sigc::ptr_fun(&_position_menu_anchored),
		            menu, anchor, selected),
		button,
		time);
}

void
Gtkmm2ext::set_popdown_strings (Gtk::ComboBoxText& cr, const vector<string>& strings)
{
	vector<string>::const_iterator i;

	cr.clear ();

	for (i = strings.begin(); i != strings.end(); ++i) {
		cr.append (*i);
	}
}

void
Gtkmm2ext::get_popdown_strings (Gtk::ComboBoxText& cr, std::vector<std::string>& strings)
{
	strings.clear ();
	Glib::RefPtr<const Gtk::TreeModel> m = cr.get_model();
	if (!m) {
		return;
	}
	for(Gtk::TreeModel::iterator i = m->children().begin(); i != m->children().end(); ++i) {
		Glib::ustring txt;
		(*i)->get_value(0, txt);
		strings.push_back (txt);
	}
}

size_t
Gtkmm2ext::get_popdown_string_count (Gtk::ComboBoxText& cr)
{
	Glib::RefPtr<const Gtk::TreeModel> m = cr.get_model();
	if (!m) {
		return 0;
	}
	return m->children().size();
}

bool
Gtkmm2ext::contains_value (Gtk::ComboBoxText& cr, const std::string text)
{
	std::vector<std::string> s;
	get_popdown_strings (cr, s);
	return (std::find (s.begin(), s.end(), text) != s.end());
}

bool
Gtkmm2ext::set_active_text_if_present (Gtk::ComboBoxText& cr, const std::string text)
{
	if (contains_value(cr, text)) {
		cr.set_active_text (text);
		return true;
	}
	return false;
}

GdkWindow*
Gtkmm2ext::get_paned_handle (Gtk::Paned& paned)
{
	return GTK_PANED(paned.gobj())->handle;
}

void
Gtkmm2ext::set_decoration (Gtk::Window* win, Gdk::WMDecoration decor)
{
	win->get_window()->set_decorations (decor);
}

void Gtkmm2ext::set_treeview_header_as_default_label(Gtk::TreeViewColumn* c)
{
	gtk_tree_view_column_set_widget( c->gobj(), GTK_WIDGET(0) );
}

void
Gtkmm2ext::detach_menu (Gtk::Menu& menu)
{
	/* its possible for a Gtk::Menu to have no gobj() because it has
	   not yet been instantiated. Catch this and provide a safe
	   detach method.
	*/
	if (menu.gobj()) {
		if (menu.get_attach_widget()) {
			menu.detach ();
		}
	}
}

bool
Gtkmm2ext::possibly_translate_keyval_to_make_legal_accelerator (uint32_t& keyval)
{
	int fakekey = GDK_VoidSymbol;

	switch (keyval) {
	case GDK_Tab:
	case GDK_ISO_Left_Tab:
		fakekey = GDK_nabla;
		break;

	case GDK_Up:
		fakekey = GDK_uparrow;
		break;

	case GDK_Down:
		fakekey = GDK_downarrow;
		break;

	case GDK_Right:
		fakekey = GDK_rightarrow;
		break;

	case GDK_Left:
		fakekey = GDK_leftarrow;
		break;

	case GDK_Return:
		fakekey = GDK_3270_Enter;
		break;

	case GDK_KP_Enter:
		fakekey = GDK_F35;
		break;

	default:
		break;
	}

	if (fakekey != GDK_VoidSymbol) {
		keyval = fakekey;
		return true;
	}

	return false;
}

uint32_t
Gtkmm2ext::possibly_translate_legal_accelerator_to_real_key (uint32_t keyval)
{
	switch (keyval) {
	case GDK_nabla:
		return GDK_Tab;
		break;

	case GDK_uparrow:
		return GDK_Up;
		break;

	case GDK_downarrow:
		return GDK_Down;
		break;

	case GDK_rightarrow:
		return GDK_Right;
		break;

	case GDK_leftarrow:
		return GDK_Left;
		break;

	case GDK_3270_Enter:
		return GDK_Return;

	case GDK_F35:
		return GDK_KP_Enter;
		break;
	}

	return keyval;
}

int
Gtkmm2ext::physical_screen_height (Glib::RefPtr<Gdk::Window> win)
{
	GdkScreen* scr = gdk_screen_get_default();

	if (win) {
		GdkRectangle r;
		gint monitor = gdk_screen_get_monitor_at_window (scr, win->gobj());
		gdk_screen_get_monitor_geometry (scr, monitor, &r);
		return r.height;
	} else {
		return gdk_screen_get_height (scr);
	}
}

int
Gtkmm2ext::physical_screen_width (Glib::RefPtr<Gdk::Window> win)
{
	GdkScreen* scr = gdk_screen_get_default();

	if (win) {
		GdkRectangle r;
		gint monitor = gdk_screen_get_monitor_at_window (scr, win->gobj());
		gdk_screen_get_monitor_geometry (scr, monitor, &r);
		return r.width;
	} else {
		return gdk_screen_get_width (scr);
	}
}

void
Gtkmm2ext::container_clear (Gtk::Container& c, bool and_delete)
{
	list<Gtk::Widget*> children = c.get_children();
	for (list<Gtk::Widget*>::iterator child = children.begin(); child != children.end(); ++child) {
		(*child)->hide ();
		c.remove (**child);
		if (and_delete) {
			delete *child;
		}
	}
}

void
Gtkmm2ext::rounded_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
{
	rounded_rectangle (context->cobj(), x, y, w, h, r);
}
void
Gtkmm2ext::rounded_top_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
{
	rounded_top_rectangle (context->cobj(), x, y, w, h, r);
}
void
Gtkmm2ext::rounded_top_left_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
{
	rounded_top_left_rectangle (context->cobj(), x, y, w, h, r);
}
void
Gtkmm2ext::rounded_top_right_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
{
	rounded_top_right_rectangle (context->cobj(), x, y, w, h, r);
}
void
Gtkmm2ext::rounded_top_half_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
{
	rounded_top_half_rectangle (context->cobj(), x, y, w, h, r);
}
void
Gtkmm2ext::rounded_bottom_half_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
{
	rounded_bottom_half_rectangle (context->cobj(), x, y, w, h, r);
}

void
Gtkmm2ext::rounded_left_half_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
{
	rounded_left_half_rectangle (context->cobj(), x, y, w, h, r);
}

void
Gtkmm2ext::rounded_right_half_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r)
{
	rounded_right_half_rectangle (context->cobj(), x, y, w, h, r);
}

void
Gtkmm2ext::rounded_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
{
	static const double degrees = M_PI / 180.0;
	if (r < 1) {
		cairo_rectangle (cr, x, y, w, h);
		return;
	}

	cairo_new_sub_path (cr);
	cairo_arc (cr, x + w - r, y + r, r, -90 * degrees, 0 * degrees);  //tr
	cairo_arc (cr, x + w - r, y + h - r, r, 0 * degrees, 90 * degrees);  //br
	cairo_arc (cr, x + r, y + h - r, r, 90 * degrees, 180 * degrees);  //bl
	cairo_arc (cr, x + r, y + r, r, 180 * degrees, 270 * degrees);  //tl
	cairo_close_path (cr);
}

void
Gtkmm2ext::rounded_left_half_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
{
	static const double degrees = M_PI / 180.0;

	cairo_new_sub_path (cr);
	cairo_line_to (cr, x+w, y); // tr
	cairo_line_to (cr, x+w, y + h); // br
	cairo_arc (cr, x + r, y + h - r, r, 90 * degrees, 180 * degrees);  //bl
	cairo_arc (cr, x + r, y + r, r, 180 * degrees, 270 * degrees);  //tl
	cairo_close_path (cr);
}

void
Gtkmm2ext::rounded_right_half_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
{
	static const double degrees = M_PI / 180.0;

	cairo_new_sub_path (cr);
	cairo_arc (cr, x + w - r, y + r, r, -90 * degrees, 0 * degrees);  //tr
	cairo_arc (cr, x + w - r, y + h - r, r, 0 * degrees, 90 * degrees);  //br
	cairo_line_to (cr, x, y + h); // bl
	cairo_line_to (cr, x, y); // tl
	cairo_close_path (cr);
}

void
Gtkmm2ext::rounded_top_half_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
{
	static const double degrees = M_PI / 180.0;

	cairo_new_sub_path (cr);
	cairo_move_to (cr, x+w, y+h);
	cairo_line_to (cr, x, y+h);
	cairo_arc (cr, x + r, y + r, r, 180 * degrees, 270 * degrees);  //tl
	cairo_arc (cr, x + w - r, y + r, r, -90 * degrees, 0 * degrees);  //tr
	cairo_close_path (cr);
}

void
Gtkmm2ext::rounded_bottom_half_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
{
	static const double degrees = M_PI / 180.0;

	cairo_new_sub_path (cr);
	cairo_move_to (cr, x, y);
	cairo_line_to (cr, x+w, y);
	cairo_arc (cr, x + w - r, y + h - r, r, 0 * degrees, 90 * degrees);  //br
	cairo_arc (cr, x + r, y + h - r, r, 90 * degrees, 180 * degrees);  //bl
	cairo_close_path (cr);
}


void
Gtkmm2ext::rounded_top_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
{
	static const double degrees = M_PI / 180.0;

	cairo_new_sub_path (cr);
	cairo_move_to (cr, x+w, y+h);
	cairo_line_to (cr, x, y+h);
	cairo_arc (cr, x + r, y + r, r, 180 * degrees, 270 * degrees);  //tl
	cairo_arc (cr, x + w - r, y + r, r, -90 * degrees, 0 * degrees);  //tr
	cairo_close_path (cr);
}

void
Gtkmm2ext::rounded_top_left_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
{
/*    A****B
      H    *
      *    *
      *    *
      F****E
*/
	cairo_move_to (cr, x+r,y); // Move to A
	cairo_line_to (cr, x+w,y); // Straight line to B
	cairo_line_to (cr, x+w,y+h); // Move to E
	cairo_line_to (cr, x,y+h); // Line to F
	cairo_line_to (cr, x,y+r); // Line to H
	cairo_curve_to (cr, x,y,x,y,x+r,y); // Curve to A
}

void
Gtkmm2ext::rounded_top_right_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
{
/*    A****BQ
      *    C
      *    *
      *    *
      F****E
*/
	cairo_move_to (cr, x,y); // Move to A
	cairo_line_to (cr, x+w-r,y); // Straight line to B
	cairo_curve_to (cr, x+w,y,x+w,y,x+w,y+r); // Curve to C, Control points are both at Q
	cairo_line_to (cr, x+w,y+h); // Move to E
	cairo_line_to (cr, x,y+h); // Line to F
	cairo_line_to (cr, x,y); // Line to A
}

void
Gtkmm2ext::add_reflection (cairo_t* cr, double w, double h)
{
	cairo_pattern_t* convex_pattern = cairo_pattern_create_linear (0.0, 0, 0.3, h * 0.7);
	cairo_pattern_add_color_stop_rgba (convex_pattern, 0.0,  1, 1, 1, 0.10);
	cairo_pattern_add_color_stop_rgba (convex_pattern, 0.79, 1, 1, 1, 0.03);
	cairo_pattern_add_color_stop_rgba (convex_pattern, 1.0,  1, 1, 1, 0.0);
	cairo_set_source (cr, convex_pattern);
	Gtkmm2ext::rounded_rectangle (cr, 2, 2, w - 4, h - 4, 4);
	cairo_fill (cr);
	cairo_pattern_destroy(convex_pattern);
}

Glib::RefPtr<Gdk::Window>
Gtkmm2ext::window_to_draw_on (Gtk::Widget& w, Gtk::Widget** parent)
{
	if (w.get_has_window()) {
		return w.get_window();
	}

	(*parent) = w.get_parent();

	while (*parent) {
		if ((*parent)->get_has_window()) {
			return (*parent)->get_window ();
		}
		(*parent) = (*parent)->get_parent ();
	}

	return Glib::RefPtr<Gdk::Window> ();
}

int
Gtkmm2ext::pixel_width (const string& str, const Pango::FontDescription& font)
{
	Glib::RefPtr<Pango::Context> context = Glib::wrap (gdk_pango_context_get());
	Glib::RefPtr<Pango::Layout> layout = Pango::Layout::create (context);

	layout->set_font_description (font);
	layout->set_text (str);

	int width, height;
	Gtkmm2ext::get_ink_pixel_size (layout, width, height);

#ifdef __APPLE__
	// Pango returns incorrect text width on some OS X
	// So we have to make a correction
	// To determine the correct indent take the largest symbol for which the width is correct
	// and make the calculation
	//
	// see also libs/canvas/text.cc
	int cor_width;
	layout->set_text ("H");
	layout->get_pixel_size (cor_width, height);
	width += cor_width * 1.5;
#endif

	return width;
}

void
Gtkmm2ext::pixel_size (const string& str, const Pango::FontDescription& font, int& width, int& height)
{
	Gtk::Label foo;
	Glib::RefPtr<Pango::Layout> layout = foo.create_pango_layout ("");

	layout->set_font_description (font);
	layout->set_text (str);

	Gtkmm2ext::get_ink_pixel_size (layout, width, height);
}

#if 0
string
Gtkmm2ext::fit_to_pixels (const string& str, int pixel_width, Pango::FontDescription& font, int& actual_width, bool with_ellipses)
{
	/* DECEMBER 2011: THIS PROTOTYPE OF fit_to_pixels() IS NOT USED
	   ANYWHERE AND HAS NOT BEEN TESTED.
	*/
	Gtk::Label foo;
	Glib::RefPtr<Pango::Layout> layout = foo.create_pango_layout (str);
	Glib::RefPtr<const Pango::LayoutLine> line;

	layout->set_font_description (font);
	layout->set_width (pixel_width * PANGO_SCALE);

	if (with_ellipses) {
		layout->set_ellipsize (Pango::ELLIPSIZE_END);
	} else {
		layout->set_wrap (Pango::WRAP_CHAR);
	}

	line = layout->get_line (0);

	/* XXX: might need special care to get the ellipsis character, not sure
	 * how that works
	 */
	string s = string (layout->get_text ().substr(line->get_start_index(), line->get_length()));

	cerr << "fit to pixels of " << str << " returns " << s << endl;

	return s;
}
#endif

/** Try to fit a string into a given horizontal space by ellipsizing it.
 *  @param cr Cairo context in which the text will be plotted.
 *  @param name Text.
 *  @param avail Available horizontal space.
 *  @return (Text, possibly ellipsized) and (horizontal size of text)
 */
std::pair<std::string, double>
Gtkmm2ext::fit_to_pixels (cairo_t* cr, std::string name, double avail)
{
	/* XXX hopefully there exists a more efficient way of doing this */

	bool abbreviated = false;
	uint32_t width = 0;

	while (1) {
		cairo_text_extents_t ext;
		cairo_text_extents (cr, name.c_str(), &ext);

		if (ext.width < avail || name.length() <= 4) {
			width = ext.width;
			break;
		}

		if (abbreviated) {
			name = name.substr (0, name.length() - 4) + "...";
		} else {
			name = name.substr (0, name.length() - 3) + "...";
			abbreviated = true;
		}
	}

	return std::make_pair (name, width);
}

Gtk::Label *
Gtkmm2ext::left_aligned_label (string const & t)
{
	Gtk::Label* l = new Gtk::Label (t);
	l->set_alignment (0, 0.5);
	return l;
}

Gtk::Label *
Gtkmm2ext::right_aligned_label (string const & t)
{
	Gtk::Label* l = new Gtk::Label (t);
	l->set_alignment (1, 0.5);
	return l;
}

static bool
make_null_tooltip (int, int, bool, const Glib::RefPtr<Gtk::Tooltip>& t)
{
	t->set_tip_area (Gdk::Rectangle (0, 0, 0, 0));
	return true;
}

/** Hackily arrange for the provided widget to have no tooltip,
 *  and also to stop any other widget from providing one while
 * the mouse is over w.
 */
void
Gtkmm2ext::set_no_tooltip_whatsoever (Gtk::Widget& w)
{
	w.property_has_tooltip() = true;
	w.signal_query_tooltip().connect (sigc::ptr_fun (make_null_tooltip));
}

void
Gtkmm2ext::enable_tooltips ()
{
	gtk_rc_parse_string ("gtk-enable-tooltips = 1");
	PersistentTooltip::set_tooltips_enabled (true);
}

void
Gtkmm2ext::disable_tooltips ()
{
	gtk_rc_parse_string ("gtk-enable-tooltips = 0");
	PersistentTooltip::set_tooltips_enabled (false);
}

bool
Gtkmm2ext::event_inside_widget_window (Gtk::Widget& widget, GdkEvent* ev)
{
	gdouble evx, evy;

	if (!gdk_event_get_root_coords (ev, &evx, &evy)) {
		return false;
	}

	gint x, y;
	gint wx, wy;
	gint width, height, depth;

	Glib::RefPtr<Gdk::Window> widget_window = widget.get_window();

	widget_window->get_geometry (x, y, width, height, depth);
	widget_window->get_origin (wx, wy);

	if ((evx >= wx && evx < wx + width) &&
			(evy >= wy && evy < wy + height)) {
		return true;
	}

	return false;
}

const char*
Gtkmm2ext::event_type_string (int event_type)
{
	switch (event_type) {
	case GDK_NOTHING:
		return "nothing";
	case GDK_DELETE:
		return "delete";
	case GDK_DESTROY:
		return "destroy";
	case GDK_EXPOSE:
		return "expose";
	case GDK_MOTION_NOTIFY:
		return "motion_notify";
	case GDK_BUTTON_PRESS:
		return "button_press";
	case GDK_2BUTTON_PRESS:
		return "2button_press";
	case GDK_3BUTTON_PRESS:
		return "3button_press";
	case GDK_BUTTON_RELEASE:
		return "button_release";
	case GDK_KEY_PRESS:
		return "key_press";
	case GDK_KEY_RELEASE:
		return "key_release";
	case GDK_ENTER_NOTIFY:
		return "enter_notify";
	case GDK_LEAVE_NOTIFY:
		return "leave_notify";
	case GDK_FOCUS_CHANGE:
		return "focus_change";
	case GDK_CONFIGURE:
		return "configure";
	case GDK_MAP:
		return "map";
	case GDK_UNMAP:
		return "unmap";
	case GDK_PROPERTY_NOTIFY:
		return "property_notify";
	case GDK_SELECTION_CLEAR:
		return "selection_clear";
	case GDK_SELECTION_REQUEST:
		return "selection_request";
	case GDK_SELECTION_NOTIFY:
		return "selection_notify";
	case GDK_PROXIMITY_IN:
		return "proximity_in";
	case GDK_PROXIMITY_OUT:
		return "proximity_out";
	case GDK_DRAG_ENTER:
		return "drag_enter";
	case GDK_DRAG_LEAVE:
		return "drag_leave";
	case GDK_DRAG_MOTION:
		return "drag_motion";
	case GDK_DRAG_STATUS:
		return "drag_status";
	case GDK_DROP_START:
		return "drop_start";
	case GDK_DROP_FINISHED:
		return "drop_finished";
	case GDK_CLIENT_EVENT:
		return "client_event";
	case GDK_VISIBILITY_NOTIFY:
		return "visibility_notify";
	case GDK_NO_EXPOSE:
		return "no_expose";
	case GDK_SCROLL:
		return "scroll";
	case GDK_WINDOW_STATE:
		return "window_state";
	case GDK_SETTING:
		return "setting";
	case GDK_OWNER_CHANGE:
		return "owner_change";
	case GDK_GRAB_BROKEN:
		return "grab_broken";
	case GDK_DAMAGE:
		return "damage";
	}

	return "unknown";
}

std::string
Gtkmm2ext::markup_escape_text (std::string const& s)
{
	return Glib::Markup::escape_text (s);
}

void
Gtkmm2ext::add_volume_shortcuts (Gtk::FileChooser& c)
{
#ifdef __APPLE__
	try {
		/* This is a first order approach, listing all mounted volumes (incl network).
		 * One could use `diskutil` or `mount` to query local disks only, or
		 * something even fancier if deemed appropriate.
		 */
		Glib::Dir dir("/Volumes");
		for (Glib::DirIterator di = dir.begin(); di != dir.end(); di++) {
			string fullpath = Glib::build_filename ("/Volumes", *di);
			if (!Glib::file_test (fullpath, Glib::FILE_TEST_IS_DIR)) continue;

			try { /* add_shortcut_folder throws an exception if the folder being added already has a shortcut */
				c.add_shortcut_folder (fullpath);
			}
			catch (Glib::Error& e) {
				std::cerr << "add_shortcut_folder() threw Glib::Error: " << e.what() << std::endl;
			}
		}
	}
	catch (Glib::FileError const& e) {
		std::cerr << "listing /Volumnes failed: " << e.what() << std::endl;
	}
#endif
}

float
Gtkmm2ext::paned_position_as_fraction (Gtk::Paned& paned, bool h)
{
	const guint pos = gtk_paned_get_position (const_cast<GtkPaned*>(static_cast<const Gtk::Paned*>(&paned)->gobj()));
	return (double) pos / (h ? paned.get_allocation().get_height() : paned.get_allocation().get_width());
}

void
Gtkmm2ext::paned_set_position_as_fraction (Gtk::Paned& paned, float fraction, bool h)
{
	gint v = (h ? paned.get_allocation().get_height() : paned.get_allocation().get_width());

	if (v < 1) {
		return;
	}

	paned.set_position ((guint) floor (fraction * v));
}

string
Gtkmm2ext::show_gdk_event_state (int state)
{
	string s;
	if (state & GDK_SHIFT_MASK) {
		s += "+SHIFT";
	}
	if (state & GDK_LOCK_MASK) {
		s += "+LOCK";
	}
	if (state & GDK_CONTROL_MASK) {
		s += "+CONTROL";
	}
	if (state & GDK_MOD1_MASK) {
		s += "+MOD1";
	}
	if (state & GDK_MOD2_MASK) {
		s += "+MOD2";
	}
	if (state & GDK_MOD3_MASK) {
		s += "+MOD3";
	}
	if (state & GDK_MOD4_MASK) {
		s += "+MOD4";
	}
	if (state & GDK_MOD5_MASK) {
		s += "+MOD5";
	}
	if (state & GDK_BUTTON1_MASK) {
		s += "+BUTTON1";
	}
	if (state & GDK_BUTTON2_MASK) {
		s += "+BUTTON2";
	}
	if (state & GDK_BUTTON3_MASK) {
		s += "+BUTTON3";
	}
	if (state & GDK_BUTTON4_MASK) {
		s += "+BUTTON4";
	}
	if (state & GDK_BUTTON5_MASK) {
		s += "+BUTTON5";
	}
	if (state & GDK_SUPER_MASK) {
		s += "+SUPER";
	}
	if (state & GDK_HYPER_MASK) {
		s += "+HYPER";
	}
	if (state & GDK_META_MASK) {
		s += "+META";
	}
	if (state & GDK_RELEASE_MASK) {
		s += "+RELEASE";
	}

	return s;
}