Implement page icon based tab colors

Colorful Tabs now uses the icon of a page as the basis for the
tab color, if it has one, otherwise falls back to the previous
address based hash.
The forground color is also adjusted for dark colored tabs.

extensions/colorful-tabs.c

@@ -1,5 +1,6 @@
 /*
  Copyright (C) 2009 Christian Dywan <christian@twotoasts.de>
+ Copyright (C) 2010 Samuel Creshal <creshal@arcor.de>
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
@@ -11,56 +12,118 @@
 
 #include <midori/midori.h>
 
+static void
+colorful_tabs_modify_fg (GtkWidget* child,
+                         GdkColor* color)
+{
+    if (GTK_IS_LABEL (child))
+    {
+        gtk_widget_modify_fg (child, GTK_STATE_ACTIVE, color);
+        gtk_widget_modify_fg (child, GTK_STATE_NORMAL, color);
+    }
+}
+
 static void
 colorful_tabs_view_notify_uri_cb (MidoriView*      view,
                                   GParamSpec*      pspec,
                                   MidoriExtension* extension)
 {
+    GtkWidget* box;
     GtkWidget* label;
     SoupURI* uri;
-    gchar* hash;
     gchar* colorstr;
     GdkColor color;
+    GdkColor fgcolor;
+    GdkPixbuf* icon;
 
     label = midori_view_get_proxy_tab_label (view);
 
-    /* Find a color that is unique to an address. We merely compute
+    if ((uri = soup_uri_new (midori_view_get_display_uri (view)))
-       a hash value, pick the first 6 + 1 characters and turn the
+      && uri->host && (katze_object_get_enum (view, "load-status") == MIDORI_LOAD_FINISHED))
-       first into a hash sign, ie. #8b424b. In case a color is too
-       dark, we lighten it up a litte. Finally we make the event box
-       visible and modify its background. */
-
-    if ((uri = soup_uri_new (midori_view_get_display_uri (view))) && uri->host)
     {
-        hash = g_compute_checksum_for_string (G_CHECKSUM_MD5, uri->host, -1);
+        icon = midori_view_get_icon (view);
-        soup_uri_free (uri);
+
+        if (midori_view_get_icon_uri (view) != NULL)
+        {
+            GdkPixbuf* newpix;
+            guchar* pixels;
+
+            newpix = gdk_pixbuf_scale_simple (icon, 1, 1, GDK_INTERP_BILINEAR);
+            g_return_if_fail (gdk_pixbuf_get_bits_per_sample (newpix) == 8);
+            pixels = gdk_pixbuf_get_pixels (newpix);
+            color.red = pixels[0] * 225;
+            color.green = pixels[1] * 225;
+            color.blue = pixels[2] * 225;
+        }
+        else
+        {
+            gchar* hash = g_compute_checksum_for_string (G_CHECKSUM_MD5, uri->host, 1);
             colorstr = g_strndup (hash, 6 + 1);
             g_free (hash);
             colorstr[0] = '#';
             gdk_color_parse (colorstr, &color);
-        if (color.red < 35000)
+        }
-            color.red += 25000 + (color.blue + 1) / 2;
+        soup_uri_free (uri);
-        if (color.green < 35000)
+
-            color.green += 25000 + (color.red + 1) / 2;
+        if ((color.red   < 35000)
-        if (color.blue < 35000)
+         && (color.green < 35000)
-            color.blue += 25000 + (color.green + 1) / 2;
+         && (color.blue  < 35000))
+        {
+            color.red   += 20000;
+            color.green += 20000;
+            color.blue  += 20000;
+        }
+
+        /* Ensure high contrast by enforcing black/ white text colour. */
+        if ((color.red   < 41000)
+         && (color.green < 41000)
+         && (color.blue  < 41000))
+            gdk_color_parse ("#fff", &fgcolor);
+        else
+            gdk_color_parse ("#000", &fgcolor);
+
+        box = gtk_bin_get_child (GTK_BIN (label));
+
         gtk_event_box_set_visible_window (GTK_EVENT_BOX (label), TRUE);
+
+        gtk_container_foreach (GTK_CONTAINER (box),
+                               (GtkCallback) colorful_tabs_modify_fg,
+                               &fgcolor);
+
         gtk_widget_modify_bg (label, GTK_STATE_NORMAL, &color);
+
+        if (color.red < 10000)
+            color.red = 5000;
+        else
+            color.red -= 5000;
+        if (color.blue < 10000)
+            color.blue = 5000;
+        else
+            color.blue -= 5000;
+        if (color.green < 10000)
+            color.green = 5000;
+        else
+            color.green -= 5000;
+
         gtk_widget_modify_bg (label, GTK_STATE_ACTIVE, &color);
     }
     else
     {
         gtk_widget_modify_bg (label, GTK_STATE_NORMAL, NULL);
         gtk_widget_modify_bg (label, GTK_STATE_ACTIVE, NULL);
+        gtk_container_foreach (GTK_CONTAINER (gtk_bin_get_child (GTK_BIN (label))),
+                               (GtkCallback) colorful_tabs_modify_fg,
+                               NULL);
     }
 }
+
 static void
 colorful_tabs_browser_add_tab_cb (MidoriBrowser*   browser,
                                   GtkWidget*       view,
                                   MidoriExtension* extension)
 {
     colorful_tabs_view_notify_uri_cb (MIDORI_VIEW (view), NULL, extension);
-    g_signal_connect (view, "notify::uri",
+    g_signal_connect (view, "notify::icon",
         G_CALLBACK (colorful_tabs_view_notify_uri_cb), extension);
 }
 
@@ -90,6 +153,9 @@ colorful_tabs_deactivate_cb (MidoriExtension* extension,
         gtk_event_box_set_visible_window (GTK_EVENT_BOX (label), FALSE);
         gtk_widget_modify_bg (label, GTK_STATE_NORMAL, NULL);
         gtk_widget_modify_bg (label, GTK_STATE_ACTIVE, NULL);
+        gtk_container_foreach (GTK_CONTAINER (gtk_bin_get_child (GTK_BIN (label))),
+                               (GtkCallback) colorful_tabs_modify_fg,
+                               NULL);
         g_signal_handlers_disconnect_by_func (
             view, colorful_tabs_view_notify_uri_cb, extension);
     }
@@ -137,8 +203,8 @@ extension_init (void)
     MidoriExtension* extension = g_object_new (MIDORI_TYPE_EXTENSION,
         "name", _("Colorful Tabs"),
         "description", _("Tint each tab distinctly"),
-        "version", "0.1",
+        "version", "0.5",
-        "authors", "Christian Dywan <christian@twotoasts.de>",
+        "authors", "Christian Dywan <christian@twotoasts.de>, Samuel Creshal <creshal@arcor.de>",
         NULL);
 
     g_signal_connect (extension, "activate",