Add a range of alpha values

Fix redrawing when resized

1 files changed, 20 insertions, 7 deletions

diff --git a/alphademo.c b/alphademo.c
index 5e19429..49cc616 100644
--- a/alphademo.c
+++ b/alphademo.c
@@ -22,17 +22,17 @@ int main(int argc, char **argv)
 {
     /* boilerplate initialization code */
     gtk_init(&argc, &argv);
-    
+
     GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
     gtk_window_set_title(GTK_WINDOW(window), "Alpha Demo");
     g_signal_connect(G_OBJECT(window), "delete-event", gtk_main_quit, NULL);
 
-
     /* Tell GTK+ that we want to draw the windows background ourself.
      * If we don't do this then GTK+ will clear the window to the
      * opaque theme default color, which isn't what we want.
      */
     gtk_widget_set_app_paintable(window, TRUE);
+    gtk_widget_set_double_buffered(window, FALSE);
 
     /* We need to handle two events ourself: "expose-event" and "screen-changed".
      *
@@ -48,6 +48,7 @@ int main(int argc, char **argv)
      * same features, so we need to check each time.
      */
 
+    g_signal_connect(G_OBJECT(window), "check-resize", G_CALLBACK(expose), NULL);
     g_signal_connect(G_OBJECT(window), "expose-event", G_CALLBACK(expose), NULL);
     g_signal_connect(G_OBJECT(window), "screen-changed", G_CALLBACK(screen_changed), NULL);
 
@@ -95,6 +96,8 @@ static void screen_changed(GtkWidget *widget, GdkScreen *old_screen, gpointer us
 /* This is called when we need to draw the windows contents */
 static gboolean expose(GtkWidget *widget, GdkEventExpose *event, gpointer userdata)
 {
+    printf("Exposed\n");
+
     cairo_t *cr = gdk_cairo_create(widget->window);
 
     if (supports_alpha)
@@ -106,21 +109,31 @@ static gboolean expose(GtkWidget *widget, GdkEventExpose *event, gpointer userda
     cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
     cairo_paint (cr);
 
-    /* draw a circle */
     int width, height;
     gtk_window_get_size(GTK_WINDOW(widget), &width, &height);
 
-    cairo_set_source_rgba(cr, 1, 0.2, 0.2, 0.6);
-    cairo_arc(cr, width / 2, height / 2, (width < height ? width : height) / 2 - 8 , 0, 2 * 3.14);
+    int radius = (width < height ? width : height);
+
+    /* draw a circle */
+    cairo_set_source_rgba(cr, 1, 0.2, 0.2, 0.5);
+    cairo_arc(cr, width / 2, height / 2, radius / 2 - 8 , 0, 2 * 3.14);
     cairo_fill(cr);
-    cairo_stroke(cr);
-    
+
+    cairo_set_source_rgba(cr, 0.2, 1, 0.2, 0.75);
+    cairo_arc(cr, width / 2, height / 2, radius *3/8 - 8 , 0, 2 * 3.14);
+    cairo_fill(cr);
+
+    cairo_set_source_rgba(cr, 0.2, 0.2, 1.0, 1.0);
+    cairo_arc(cr, width / 2, height / 2, radius / 4 - 8 , 0, 2 * 3.14);
+    cairo_fill(cr);
+
     cairo_destroy(cr);
     return FALSE;
 }
 
 static void clicked(GtkWindow *win, GdkEventButton *event, gpointer user_data)
 {
+    printf("Toggling frame\n");
     /* toggle window manager frames */
     gtk_window_set_decorated(win, !gtk_window_get_decorated(win));
 }