Add testsubsurface

A very simple test that just checks that re(attaching) textures
to subsurfaces and changing stacking order works.

tests/meson.build

@@ -149,3 +149,11 @@ foreach t: gtk_tests
     dependencies: [libgtk_dep, libm],
   )
 endforeach
+
+executable('testsubsurface',
+  sources: '@0@.c'.format('testsubsurface'),
+  c_args: common_cflags + ['-DGTK_COMPILATION'],
+  dependencies: libgtk_static_dep,
+  install: false,
+)
+

tests/testsubsurface.c

@@ -0,0 +1,161 @@
+#include <gtk/gtk.h>
+#include "gtk/gtkwidgetprivate.h"
+#include "gdk/gdksurfaceprivate.h"
+
+static GdkTexture *
+make_shm_color_texture (int width,
+                        int height,
+                        GdkRGBA *color)
+{
+  cairo_surface_t *surface;
+  cairo_t *cr;
+  guchar *data;
+  gsize stride;
+  GBytes *bytes;
+  GdkTexture *texture;
+
+  stride = 4 * width;
+  data = g_new (guchar, stride * height);
+
+  surface = cairo_image_surface_create_for_data (data,
+                                                 CAIRO_FORMAT_ARGB32,
+                                                 width, height,
+                                                 stride);
+  cr = cairo_create (surface);
+  gdk_cairo_set_source_rgba (cr, color);
+  cairo_paint (cr);
+
+  cairo_destroy (cr);
+  cairo_surface_destroy (surface);
+
+  bytes = g_bytes_new_take (data, stride * height);
+  texture = gdk_memory_texture_new (width, height, GDK_MEMORY_DEFAULT, bytes, stride);
+  g_bytes_unref (bytes);
+
+  return texture;
+}
+
+static GdkTexture *
+make_color_texture (int width,
+                    int height,
+                    GdkRGBA *color)
+{
+  return make_shm_color_texture (width, height, color);
+}
+
+static GdkSubsurface *
+add_subsurface (GtkWidget *window,
+                GdkRGBA *color,
+                const graphene_rect_t *rect)
+{
+  GdkSurface *surface;
+  GdkSubsurface *subsurface;
+  GdkTexture *texture;
+
+  surface = gtk_widget_get_surface (GTK_WIDGET (window));
+
+  subsurface = gdk_surface_create_subsurface (surface);
+
+  texture = make_color_texture (20, 20, color);
+
+  gdk_subsurface_attach (subsurface, texture, rect);
+
+  g_object_unref (texture);
+
+  return subsurface;
+}
+
+static GdkSubsurface *red, *blue;
+
+static void red_above_blue (GtkButton *button) { gdk_subsurface_place_above (red, blue); }
+static void red_below_blue (GtkButton *button) { gdk_subsurface_place_below (red, blue); }
+static void blue_above_red (GtkButton *button) { gdk_subsurface_place_above (blue, red); }
+static void blue_below_red (GtkButton *button) { gdk_subsurface_place_below (blue, red); }
+static void red_above_main (GtkButton *button) { gdk_subsurface_place_above (red, NULL); }
+static void red_below_main (GtkButton *button) { gdk_subsurface_place_below (red, NULL); }
+static void blue_above_main (GtkButton *button) { gdk_subsurface_place_above (blue, NULL); }
+static void blue_below_main (GtkButton *button) { gdk_subsurface_place_below (blue, NULL); }
+
+static GtkWidget *
+make_button (const char *name, gpointer cb)
+{
+  GtkWidget *button;
+
+  button = gtk_button_new_with_label (name);
+  g_signal_connect (button, "clicked", G_CALLBACK (cb), NULL);
+
+  return button;
+}
+
+static void
+change_colors (GtkButton *button)
+{
+  GdkRGBA color;
+  GdkTexture *texture;
+
+  color.red = g_random_double_range (0.5, 1);
+  color.green = g_random_double_range (0, 0.5);
+  color.blue = g_random_double_range (0, 0.5);
+  color.alpha = 1;
+
+  texture = make_color_texture (20, 20, &color);
+  gdk_subsurface_attach (red, texture, &GRAPHENE_RECT_INIT (200, 100, 50, 50));
+  g_object_unref (texture);
+
+  color.red = g_random_double_range (0, 0.5);
+  color.green = g_random_double_range (0, 0.5);
+  color.blue = g_random_double_range (0.5, 1);
+  color.alpha = 1;
+
+  texture = make_color_texture (20, 20, &color);
+  gdk_subsurface_attach (blue, texture, &GRAPHENE_RECT_INIT (180, 120, 100, 20));
+  g_object_unref (texture);
+}
+
+static GtkWidget *
+make_buttons (void)
+{
+  GtkWidget *box;
+
+  box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
+  gtk_box_append (GTK_BOX (box), make_button ("Red above blue", red_above_blue));
+  gtk_box_append (GTK_BOX (box), make_button ("Red below blue", red_below_blue));
+  gtk_box_append (GTK_BOX (box), make_button ("Red above main", red_above_main));
+  gtk_box_append (GTK_BOX (box), make_button ("Red below main", red_below_main));
+  gtk_box_append (GTK_BOX (box), make_button ("Blue above red", blue_above_red));
+  gtk_box_append (GTK_BOX (box), make_button ("Blue below red", blue_below_red));
+  gtk_box_append (GTK_BOX (box), make_button ("Blue above main", blue_above_main));
+  gtk_box_append (GTK_BOX (box), make_button ("Blue below main", blue_below_main));
+  gtk_box_append (GTK_BOX (box), make_button ("Change colors", change_colors));
+
+  return box;
+}
+
+int
+main (int argc, char *argv[])
+{
+  GtkWidget *window, *box;
+
+  gtk_init ();
+
+  window = gtk_window_new ();
+  gtk_window_set_default_size (GTK_WINDOW (window), 210, -1);
+  gtk_window_set_resizable (GTK_WINDOW (window), TRUE);
+
+  gtk_widget_realize (window);
+
+  red = add_subsurface (window, &(GdkRGBA) { 1, 0, 0, 1 }, &GRAPHENE_RECT_INIT (200, 100, 50, 50));
+  blue = add_subsurface (window, &(GdkRGBA) { 0, 0, 1, 1 }, &GRAPHENE_RECT_INIT (180, 120, 100, 20));
+
+  box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+  gtk_window_set_child (GTK_WINDOW (window), box);
+
+  gtk_box_append (GTK_BOX (box), make_buttons ());
+
+  gtk_window_present (GTK_WINDOW (window));
+
+  while (g_list_model_get_n_items (gtk_window_get_toplevels ()) > 0)
+    g_main_context_iteration (NULL, TRUE);
+
+  return 0;
+}