/* Offscreen windows/Effects
*
* Offscreen windows can be used to render elements multiple times to achieve
* various effects.
*/
#include <gtk/gtk.h>
#define GTK_TYPE_MIRROR_BIN (gtk_mirror_bin_get_type ())
#define GTK_MIRROR_BIN(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GTK_TYPE_MIRROR_BIN, GtkMirrorBin))
#define GTK_MIRROR_BIN_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GTK_TYPE_MIRROR_BIN, GtkMirrorBinClass))
#define GTK_IS_MIRROR_BIN(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GTK_TYPE_MIRROR_BIN))
#define GTK_IS_MIRROR_BIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GTK_TYPE_MIRROR_BIN))
#define GTK_MIRROR_BIN_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_MIRROR_BIN, GtkMirrorBinClass))
typedef struct _GtkMirrorBin GtkMirrorBin;
typedef struct _GtkMirrorBinClass GtkMirrorBinClass;
struct _GtkMirrorBin
{
GtkContainer container;
GtkWidget *child;
GdkWindow *offscreen_window;
};
struct _GtkMirrorBinClass
{
GtkContainerClass parent_class;
};
GType gtk_mirror_bin_get_type (void) G_GNUC_CONST;
GtkWidget* gtk_mirror_bin_new (void);
/*** implementation ***/
static void gtk_mirror_bin_realize (GtkWidget *widget);
static void gtk_mirror_bin_unrealize (GtkWidget *widget);
static void gtk_mirror_bin_size_request (GtkWidget *widget,
GtkRequisition *requisition);
static void gtk_mirror_bin_size_allocate (GtkWidget *widget,
GtkAllocation *allocation);
static gboolean gtk_mirror_bin_damage (GtkWidget *widget,
GdkEventExpose *event);
static gboolean gtk_mirror_bin_expose (GtkWidget *widget,
GdkEventExpose *offscreen);
static void gtk_mirror_bin_add (GtkContainer *container,
GtkWidget *child);
static void gtk_mirror_bin_remove (GtkContainer *container,
GtkWidget *widget);
static void gtk_mirror_bin_forall (GtkContainer *container,
gboolean include_internals,
GtkCallback callback,
gpointer callback_data);
static GType gtk_mirror_bin_child_type (GtkContainer *container);
G_DEFINE_TYPE (GtkMirrorBin, gtk_mirror_bin, GTK_TYPE_CONTAINER);
static void
to_child (GtkMirrorBin *bin,
double widget_x,
double widget_y,
double *x_out,
double *y_out)
{
*x_out = widget_x;
*y_out = widget_y;
}
static void
to_parent (GtkMirrorBin *bin,
double offscreen_x,
double offscreen_y,
double *x_out,
double *y_out)
{
*x_out = offscreen_x;
*y_out = offscreen_y;
}
static void
gtk_mirror_bin_class_init (GtkMirrorBinClass *klass)
{
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
GtkContainerClass *container_class = GTK_CONTAINER_CLASS (klass);
widget_class->realize = gtk_mirror_bin_realize;
widget_class->unrealize = gtk_mirror_bin_unrealize;
widget_class->size_request = gtk_mirror_bin_size_request;
widget_class->size_allocate = gtk_mirror_bin_size_allocate;
widget_class->expose_event = gtk_mirror_bin_expose;
g_signal_override_class_closure (g_signal_lookup ("damage-event", GTK_TYPE_WIDGET),
GTK_TYPE_MIRROR_BIN,
g_cclosure_new (G_CALLBACK (gtk_mirror_bin_damage),
NULL, NULL));
container_class->add = gtk_mirror_bin_add;
container_class->remove = gtk_mirror_bin_remove;
container_class->forall = gtk_mirror_bin_forall;
container_class->child_type = gtk_mirror_bin_child_type;
}
static void
gtk_mirror_bin_init (GtkMirrorBin *bin)
{
gtk_widget_set_has_window (GTK_WIDGET (bin), TRUE);
}
GtkWidget *
gtk_mirror_bin_new (void)
{
return g_object_new (GTK_TYPE_MIRROR_BIN, NULL);
}
static GdkWindow *
pick_offscreen_child (GdkWindow *offscreen_window,
double widget_x,
double widget_y,
GtkMirrorBin *bin)
{
GtkAllocation child_area;
double x, y;
if (bin->child && gtk_widget_get_visible (bin->child))
{
to_child (bin, widget_x, widget_y, &x, &y);
gtk_widget_get_allocation (bin->child, &child_area);
if (x >= 0 && x < child_area.width &&
y >= 0 && y < child_area.height)
return bin->offscreen_window;
}
return NULL;
}
static void
offscreen_window_to_parent (GdkWindow *offscreen_window,
double offscreen_x,
double offscreen_y,
double *parent_x,
double *parent_y,
GtkMirrorBin *bin)
{
to_parent (bin, offscreen_x, offscreen_y, parent_x, parent_y);
}
static void
offscreen_window_from_parent (GdkWindow *window,
double parent_x,
double parent_y,
double *offscreen_x,
double *offscreen_y,
GtkMirrorBin *bin)
{
to_child (bin, parent_x, parent_y, offscreen_x, offscreen_y);
}
static void
gtk_mirror_bin_realize (GtkWidget *widget)
{
GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
GdkWindowAttr attributes;
GdkWindow *gdk_window;
gint attributes_mask;
gint border_width;
GtkRequisition child_requisition;
GtkAllocation widget_allocation, bin_child_allocation;
GtkStyle *style;
gtk_widget_set_realized (widget, TRUE);
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
gtk_widget_get_allocation (widget, &widget_allocation);
attributes.x = widget_allocation.x + border_width;
attributes.y = widget_allocation.y + border_width;
attributes.width = widget_allocation.width - 2 * border_width;
attributes.height = widget_allocation.height - 2 * border_width;
attributes.window_type = GDK_WINDOW_CHILD;
attributes.event_mask = gtk_widget_get_events (widget)
| GDK_EXPOSURE_MASK
| GDK_POINTER_MOTION_MASK
| GDK_BUTTON_PRESS_MASK
| GDK_BUTTON_RELEASE_MASK
| GDK_SCROLL_MASK
| GDK_ENTER_NOTIFY_MASK
| GDK_LEAVE_NOTIFY_MASK;
attributes.visual = gtk_widget_get_visual (widget);
attributes.colormap = gtk_widget_get_colormap (widget);
attributes.wclass = GDK_INPUT_OUTPUT;
attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
gdk_window = gdk_window_new (gtk_widget_get_parent_window (widget),
&attributes, attributes_mask);
gtk_widget_set_window (widget, gdk_window);
gdk_window_set_user_data (gdk_window, widget);
g_signal_connect (gdk_window, "pick-embedded-child",
G_CALLBACK (pick_offscreen_child), bin);
attributes.window_type = GDK_WINDOW_OFFSCREEN;
child_requisition.width = child_requisition.height = 0;
if (bin->child && gtk_widget_get_visible (bin->child))
{
gtk_widget_get_allocation (bin->child, &bin_child_allocation);
attributes.width = bin_child_allocation.width;
attributes.height = bin_child_allocation.height;
}
bin->offscreen_window = gdk_window_new (gtk_widget_get_root_window (widget),
&attributes, attributes_mask);
gdk_window_set_user_data (bin->offscreen_window, widget);
if (bin->child)
gtk_widget_set_parent_window (bin->child, bin->offscreen_window);
gdk_offscreen_window_set_embedder (bin->offscreen_window, gtk_widget_get_window (widget));
g_signal_connect (bin->offscreen_window, "to-embedder",
G_CALLBACK (offscreen_window_to_parent), bin);
g_signal_connect (bin->offscreen_window, "from-embedder",
G_CALLBACK (offscreen_window_from_parent), bin);
gtk_widget_style_attach (widget);
style = gtk_widget_get_style (widget);
gtk_style_set_background (style, gdk_window, GTK_STATE_NORMAL);
gtk_style_set_background (style, bin->offscreen_window, GTK_STATE_NORMAL);
gdk_window_show (bin->offscreen_window);
}
static void
gtk_mirror_bin_unrealize (GtkWidget *widget)
{
GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
gdk_window_set_user_data (bin->offscreen_window, NULL);
gdk_window_destroy (bin->offscreen_window);
bin->offscreen_window = NULL;
GTK_WIDGET_CLASS (gtk_mirror_bin_parent_class)->unrealize (widget);
}
static GType
gtk_mirror_bin_child_type (GtkContainer *container)
{
GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
if (bin->child)
return G_TYPE_NONE;
return GTK_TYPE_WIDGET;
}
static void
gtk_mirror_bin_add (GtkContainer *container,
GtkWidget *widget)
{
GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
if (!bin->child)
{
gtk_widget_set_parent_window (widget, bin->offscreen_window);
gtk_widget_set_parent (widget, GTK_WIDGET (bin));
bin->child = widget;
}
else
g_warning ("GtkMirrorBin cannot have more than one child\n");
}
static void
gtk_mirror_bin_remove (GtkContainer *container,
GtkWidget *widget)
{
GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
gboolean was_visible;
was_visible = gtk_widget_get_visible (widget);
if (bin->child == widget)
{
gtk_widget_unparent (widget);
bin->child = NULL;
if (was_visible && gtk_widget_get_visible (GTK_WIDGET (container)))
gtk_widget_queue_resize (GTK_WIDGET (container));
}
}
static void
gtk_mirror_bin_forall (GtkContainer *container,
gboolean include_internals,
GtkCallback callback,
gpointer callback_data)
{
GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
g_return_if_fail (callback != NULL);
if (bin->child)
(*callback) (bin->child, callback_data);
}
static void
gtk_mirror_bin_size_request (GtkWidget *widget,
GtkRequisition *requisition)
{
GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
GtkRequisition child_requisition;
gint border_width;
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
child_requisition.width = 0;
child_requisition.height = 0;
if (bin->child && gtk_widget_get_visible (bin->child))
gtk_widget_size_request (bin->child, &child_requisition);
requisition->width = border_width * 2 + child_requisition.width + 10;
requisition->height = border_width * 2 + child_requisition.height * 2 + 10;
}
static void
gtk_mirror_bin_size_allocate (GtkWidget *widget,
GtkAllocation *allocation)
{
GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
gint border_width;
gint w, h;
gtk_widget_set_allocation (widget, allocation);
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
w = allocation->width - border_width * 2;
h = allocation->height - border_width * 2;
if (gtk_widget_get_realized (widget))
gdk_window_move_resize (gtk_widget_get_window (widget),
allocation->x + border_width,
allocation->y + border_width,
w, h);
if (bin->child && gtk_widget_get_visible (bin->child))
{
GtkRequisition child_requisition;
GtkAllocation child_allocation;
gtk_widget_get_child_requisition (bin->child, &child_requisition);
child_allocation.x = 0;
child_allocation.y = 0;
child_allocation.height = child_requisition.height;
child_allocation.width = child_requisition.width;
if (gtk_widget_get_realized (widget))
gdk_window_move_resize (bin->offscreen_window,
allocation->x + border_width,
allocation->y + border_width,
child_allocation.width, child_allocation.height);
gtk_widget_size_allocate (bin->child, &child_allocation);
}
}
static gboolean
gtk_mirror_bin_damage (GtkWidget *widget,
GdkEventExpose *event)
{
gdk_window_invalidate_rect (gtk_widget_get_window (widget), NULL, FALSE);
return TRUE;
}
static gboolean
gtk_mirror_bin_expose (GtkWidget *widget,
GdkEventExpose *event)
{
GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
gint width, height;
if (gtk_widget_is_drawable (widget))
{
if (event->window == gtk_widget_get_window (widget))
{
GdkPixmap *pixmap;
cairo_t *cr;
cairo_matrix_t matrix;
cairo_pattern_t *mask;
if (bin->child && gtk_widget_get_visible (bin->child))
{
pixmap = gdk_offscreen_window_get_pixmap (bin->offscreen_window);
gdk_pixmap_get_size (pixmap, &width, &height);
cr = gdk_cairo_create (gtk_widget_get_window (widget));
cairo_save (cr);
cairo_rectangle (cr, 0, 0, width, height);
cairo_clip (cr);
/* paint the offscreen child */
gdk_cairo_set_source_pixmap (cr, pixmap, 0, 0);
cairo_paint (cr);
cairo_restore (cr);
cairo_matrix_init (&matrix, 1.0, 0.0, 0.3, 1.0, 0.0, 0.0);
cairo_matrix_scale (&matrix, 1.0, -1.0);
cairo_matrix_translate (&matrix, -10, - 3 * height - 10);
cairo_transform (cr, &matrix);
cairo_rectangle (cr, 0, height, width, height);
cairo_clip (cr);
gdk_cairo_set_source_pixmap (cr, pixmap, 0, height);
/* create linear gradient as mask-pattern to fade out the source */
mask = cairo_pattern_create_linear (0.0, height, 0.0, 2*height);
cairo_pattern_add_color_stop_rgba (mask, 0.0, 0.0, 0.0, 0.0, 0.0);
cairo_pattern_add_color_stop_rgba (mask, 0.25, 0.0, 0.0, 0.0, 0.01);
cairo_pattern_add_color_stop_rgba (mask, 0.5, 0.0, 0.0, 0.0, 0.25);
cairo_pattern_add_color_stop_rgba (mask, 0.75, 0.0, 0.0, 0.0, 0.5);
cairo_pattern_add_color_stop_rgba (mask, 1.0, 0.0, 0.0, 0.0, 1.0);
/* paint the reflection */
cairo_mask (cr, mask);
cairo_pattern_destroy (mask);
cairo_destroy (cr);
}
}
else if (event->window == bin->offscreen_window)
{
gtk_paint_flat_box (gtk_widget_get_style (widget), event->window,
GTK_STATE_NORMAL, GTK_SHADOW_NONE,
&event->area, widget, "blah",
0, 0, -1, -1);
if (bin->child)
gtk_container_propagate_expose (GTK_CONTAINER (widget),
bin->child,
event);
}
}
return FALSE;
}
/*** ***/
static GtkWidget *window = NULL;
GtkWidget *
do_offscreen_window2 (GtkWidget *do_widget)
{
if (!window)
{
GtkWidget *bin, *vbox;
GtkWidget *hbox, *entry, *applybutton, *backbutton;
GtkSizeGroup *group;
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_screen (GTK_WINDOW (window),
gtk_widget_get_screen (do_widget));
gtk_window_set_title (GTK_WINDOW (window), "Effects");
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_widget_destroyed), &window);
gtk_container_set_border_width (GTK_CONTAINER (window), 10);
vbox = gtk_vbox_new (0, FALSE);
bin = gtk_mirror_bin_new ();
group = gtk_size_group_new (GTK_SIZE_GROUP_VERTICAL);
hbox = gtk_hbox_new (FALSE, 6);
backbutton = gtk_button_new ();
gtk_container_add (GTK_CONTAINER (backbutton),
gtk_image_new_from_stock (GTK_STOCK_GO_BACK, 4));
gtk_size_group_add_widget (group, backbutton);
entry = gtk_entry_new ();
gtk_size_group_add_widget (group, entry);
applybutton = gtk_button_new ();
gtk_size_group_add_widget (group, applybutton);
gtk_container_add (GTK_CONTAINER (applybutton),
gtk_image_new_from_stock (GTK_STOCK_APPLY, 4));
gtk_container_add (GTK_CONTAINER (window), vbox);
gtk_box_pack_start (GTK_BOX (vbox), bin, TRUE, TRUE, 0);
gtk_container_add (GTK_CONTAINER (bin), hbox);
gtk_box_pack_start (GTK_BOX (hbox), backbutton, FALSE, FALSE, 0);
gtk_box_pack_start (GTK_BOX (hbox), entry, TRUE, TRUE, 0);
gtk_box_pack_start (GTK_BOX (hbox), applybutton, FALSE, FALSE, 0);
}
if (!gtk_widget_get_visible (window))
gtk_widget_show_all (window);
else
{
gtk_widget_destroy (window);
window = NULL;
}
return window;
}