mirror of
https://gitlab.gnome.org/GNOME/gtk.git
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95 lines
2.2 KiB
C
95 lines
2.2 KiB
C
#include <gtk/gtk.h>
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static gboolean
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da_expose (GtkWidget *widget,
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GdkEventExpose *event,
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gpointer user_data)
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{
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GtkOffscreenWindow *offscreen = (GtkOffscreenWindow *)user_data;
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GdkPixmap *pixmap;
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cairo_t *cr;
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if (gtk_widget_is_drawable (widget))
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{
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pixmap = gtk_offscreen_window_get_pixmap (offscreen);
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cr = gdk_cairo_create (widget->window);
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gdk_cairo_set_source_pixmap (cr, pixmap, 50, 50);
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cairo_paint (cr);
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cairo_destroy (cr);
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}
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return FALSE;
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}
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static gboolean
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offscreen_damage (GtkWidget *widget,
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GdkEventExpose *event,
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GtkWidget *da)
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{
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gtk_widget_queue_draw (da);
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return TRUE;
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}
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static gboolean
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da_button_press (GtkWidget *area, GdkEventButton *event, GtkWidget *button)
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{
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gtk_widget_set_size_request (button, 150, 60);
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return TRUE;
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}
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int
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main (int argc, char **argv)
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{
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GtkWidget *window;
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GtkWidget *button;
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GtkWidget *offscreen;
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GtkWidget *da;
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gtk_init (&argc, &argv);
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offscreen = gtk_offscreen_window_new ();
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button = gtk_button_new_with_label ("Test");
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gtk_widget_set_size_request (button, 50, 50);
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gtk_container_add (GTK_CONTAINER (offscreen), button);
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gtk_widget_show (button);
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gtk_widget_show (offscreen);
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/* Queue exposures and ensure they are handled so
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* that the result is uptodate for the first
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* expose of the window. If you want to get further
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* changes, also track damage on the offscreen
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* as done above.
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*/
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gtk_widget_queue_draw (offscreen);
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window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
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g_signal_connect (window, "delete-event",
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G_CALLBACK (gtk_main_quit), window);
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da = gtk_drawing_area_new ();
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gtk_container_add (GTK_CONTAINER (window), da);
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g_signal_connect (da,
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"expose-event",
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G_CALLBACK (da_expose),
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offscreen);
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g_signal_connect (offscreen,
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"damage-event",
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G_CALLBACK (offscreen_damage),
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da);
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gtk_widget_add_events (da, GDK_BUTTON_PRESS_MASK);
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g_signal_connect (da, "button_press_event", G_CALLBACK (da_button_press),
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button);
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gtk_widget_show_all (window);
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gtk_main();
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return 0;
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}
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