[Initiatives.wiki] Upload attachment hello.c

[Alexander Mikhaylenko <alexm src gnome org>]

commit 28d4c8afdee6b37ebdc52ce9a444119459603b11
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Tue Sep 28 22:53:13 2021 +0000

    Upload attachment hello.c

 uploads/76dfcc9b07d234cb8922cf800e743f02/hello.c | 197 +++++++++++++++++++++++
 1 file changed, 197 insertions(+)
---
diff --git a/uploads/76dfcc9b07d234cb8922cf800e743f02/hello.c 
b/uploads/76dfcc9b07d234cb8922cf800e743f02/hello.c
new file mode 100644
index 0000000..c3b0026
--- /dev/null
+++ b/uploads/76dfcc9b07d234cb8922cf800e743f02/hello.c
@@ -0,0 +1,197 @@
+#include <gio/gio.h>
+#include <SDL.h>
+
+typedef struct {
+  SDL_Window *window;
+  SDL_Renderer *renderer;
+  GMainLoop *main_loop;
+  GDBusProxy *settings_portal;
+  gboolean dark;
+  gboolean queue_redraw;
+} SampleData;
+
+typedef enum {
+  DEFAULT,
+  PREFER_DARK,
+  PREFER_LIGHT
+} ColorScheme;
+
+static void
+set_color_scheme (SampleData *data,
+                  GVariant   *variant)
+{
+  ColorScheme color_scheme = g_variant_get_uint32 (variant);
+
+  if (color_scheme > PREFER_LIGHT)
+    color_scheme = DEFAULT;
+
+  data->dark = color_scheme == PREFER_DARK;
+  data->queue_redraw = TRUE;
+}
+
+static void
+settings_portal_changed_cb (GDBusProxy *proxy,
+                            const char *sender_name,
+                            const char *signal_name,
+                            GVariant   *parameters,
+                            SampleData *data)
+{
+  const char *namespace;
+  const char *name;
+  g_autoptr (GVariant) value = NULL;
+
+  if (g_strcmp0 (signal_name, "SettingChanged"))
+    return;
+
+  g_variant_get (parameters, "(&s&sv)", &namespace, &name, &value);
+
+  if (g_strcmp0 (namespace, "org.freedesktop.appearance") ||
+      g_strcmp0 (name, "color-scheme"))
+    return;
+  
+  set_color_scheme (data, value);
+}
+
+static gboolean
+read_color_scheme (GDBusProxy  *proxy,
+                   GVariant   **out)
+{
+  g_autoptr (GError) error = NULL;
+  g_autoptr (GVariant) ret = NULL;
+  g_autoptr (GVariant) child = NULL;
+  uint32_t test = 0;
+
+  ret = g_dbus_proxy_call_sync (proxy,
+                                "Read",
+                                g_variant_new ("(ss)",
+                                               "org.freedesktop.appearance",
+                                               "color-scheme"),
+                                G_DBUS_CALL_FLAGS_NONE,
+                                G_MAXINT,
+                                NULL,
+                                &error);
+
+  if (error) {
+    if (error->domain == G_DBUS_ERROR &&
+        error->code == G_DBUS_ERROR_SERVICE_UNKNOWN) {
+      g_debug ("Portal not found: %s", error->message);
+
+      return FALSE;
+    }
+
+    g_critical ("Couldn't read the color-scheme setting: %s", error->message);
+
+    return FALSE;
+  }
+
+  g_variant_get (ret, "(v)", &child);
+  g_variant_get (child, "v", out);
+
+  return TRUE;
+}
+
+static void
+init_portal (SampleData *data)
+{
+  g_autoptr (GError) error = NULL;
+  g_autoptr (GVariant) value = NULL;
+
+  data->settings_portal = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SESSION,
+                                                         G_DBUS_PROXY_FLAGS_NONE,
+                                                         NULL,
+                                                         "org.freedesktop.portal.Desktop",
+                                                         "/org/freedesktop/portal/desktop",
+                                                         "org.freedesktop.portal.Settings",
+                                                         NULL,
+                                                         &error);
+  if (error) {
+    g_debug ("Settings portal not found: %s", error->message);
+
+    return;
+  }
+
+  if (!read_color_scheme (data->settings_portal, &value))
+    return;
+
+  set_color_scheme (data, value);
+
+  g_signal_connect (data->settings_portal, "g-signal",
+                    G_CALLBACK (settings_portal_changed_cb), data);
+}
+
+static gboolean
+main_loop (SampleData *data)
+{
+  SDL_Event e;
+
+  SDL_Rect rect = { 220, 140, 200, 200 };
+
+  while (SDL_PollEvent(&e) > 0) {
+    if (e.type == SDL_QUIT) {
+        g_main_loop_quit (data->main_loop);
+        return G_SOURCE_REMOVE;
+    }
+  }
+
+  if (data->queue_redraw) {
+    SDL_RenderClear (data->renderer);
+
+    if (data->dark) {
+      SDL_SetRenderDrawColor (data->renderer, 100, 100, 100, 255);
+      SDL_RenderFillRect (data->renderer, &rect);
+      SDL_SetRenderDrawColor (data->renderer, 30, 30, 30, 255);
+    } else {
+      SDL_SetRenderDrawColor (data->renderer, 255, 0, 0, 255);
+      SDL_RenderFillRect (data->renderer, &rect);
+      SDL_SetRenderDrawColor (data->renderer, 240, 240, 240, 255);
+    }
+
+    SDL_RenderPresent (data->renderer);
+    SDL_UpdateWindowSurface (data->window);
+  }
+
+  return G_SOURCE_CONTINUE;
+}
+
+int
+main (int   argc,
+      char *argv[])
+{
+  SampleData data;
+
+  if (SDL_Init (SDL_INIT_VIDEO) < 0) {
+    g_critical ("Failed to initialize SDL: %s", SDL_GetError());
+    return 1;
+  }
+
+  data.window = SDL_CreateWindow ("Example",
+                                  SDL_WINDOWPOS_CENTERED,
+                                  SDL_WINDOWPOS_CENTERED,
+                                  640, 480,
+                                  SDL_WINDOW_BORDERLESS);
+
+  if (!data.window) {
+    g_critical ("Failed to create window: %s", SDL_GetError());
+    return 1;
+  }
+
+  data.renderer = SDL_CreateRenderer (data.window, -1,
+                                      SDL_RENDERER_ACCELERATED |
+                                      SDL_RENDERER_PRESENTVSYNC);
+
+  if (!data.renderer) {
+    g_critical ("Failed to create renderer: %s", SDL_GetError());
+    return 1;
+  }
+
+  data.main_loop = g_main_loop_new (NULL, FALSE);
+  data.queue_redraw = TRUE;
+
+  init_portal (&data);
+
+  g_idle_add (G_SOURCE_FUNC (main_loop), &data);
+
+  g_main_loop_run (data.main_loop);
+
+  return 0;
+}