[evolution] EColorCombo - Improve the widget

[Tomas Popela <tpopela src gnome org>]

commit 4fb6719f9212ddaf359056fcad0f76241cc45642
Author: Tomas Popela <tpopela redhat com>
Date:   Thu Oct 2 10:39:56 2014 +0200

    EColorCombo - Improve the widget
    
    Take into account the full transparent color (alpha channel is 0). When it
    is set render the current color differently (gray and white squares).

 e-util/e-color-combo.c |   59 ++++++++++++++++++++++++++++++++++++++++++-----
 1 files changed, 52 insertions(+), 7 deletions(-)
---
diff --git a/e-util/e-color-combo.c b/e-util/e-color-combo.c
index a43ebfe..ea26388 100644
--- a/e-util/e-color-combo.c
+++ b/e-util/e-color-combo.c
@@ -383,6 +383,44 @@ color_combo_swatch_color_changed (EColorCombo *combo,
 }
 
 static void
+draw_transparent_graphic (cairo_t *cr,
+                          gint width,
+                          gint height)
+{
+       gint ii, step, x_offset, y_offset;
+
+       step = height / 2;
+       x_offset = width % step;
+       y_offset = height % step;
+
+       for (ii = 0; ii < width; ii += step) {
+               if (ii % 2)
+                       cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
+               else
+                       cairo_set_source_rgb (cr, 0.8, 0.8, 0.8);
+
+               if (ii + step >= width)
+                       cairo_rectangle (cr, ii, 0, step + x_offset, step);
+               else
+                       cairo_rectangle (cr, ii, 0, step, step);
+
+               cairo_fill (cr);
+
+               if (ii % 2)
+                       cairo_set_source_rgb (cr, 0.8, 0.8, 0.8);
+               else
+                       cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
+
+               if (ii + step >= width)
+                       cairo_rectangle (cr, ii, step, step + x_offset, step + y_offset);
+               else
+                       cairo_rectangle (cr, ii, step, step, step + y_offset);
+
+               cairo_fill (cr);
+       }
+}
+
+static void
 color_combo_draw_frame_cb (GtkWidget *widget,
                            cairo_t *cr,
                            gpointer user_data)
@@ -398,9 +436,13 @@ color_combo_draw_frame_cb (GtkWidget *widget,
        width = allocation.width;
        height = allocation.height;
 
-       cairo_rectangle (cr, 0, 0, width - 10, height);
-       cairo_set_source_rgb (cr, rgba.red, rgba.green, rgba.blue);
-       cairo_fill (cr);
+       if (rgba.alpha == 0) {
+               draw_transparent_graphic (cr, width, height);
+       } else {
+               cairo_set_source_rgb (cr, rgba.red, rgba.green, rgba.blue);
+               cairo_rectangle (cr, 0, 0, width, height);
+               cairo_fill (cr);
+       }
 }
 
 static void
@@ -411,6 +453,7 @@ color_combo_set_default_color_cb (EColorCombo *combo,
 
        e_color_combo_get_default_color (combo, &color);
        e_color_combo_set_current_color (combo, &color);
+       e_color_combo_set_default_transparent (combo, (color.alpha == 0));
 
        g_signal_emit (combo, signals[ACTIVATED], 0, &color);
 }
@@ -683,7 +726,7 @@ e_color_combo_init (EColorCombo *combo)
 
        combo->priv = E_COLOR_COMBO_GET_PRIVATE (combo);
 
-       widget = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+       widget = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
        gtk_container_add (GTK_CONTAINER (combo), widget);
 
        container = widget;
@@ -878,10 +921,8 @@ e_color_combo_set_default_color (EColorCombo *combo,
                color = &black;
 
        if (combo->priv->default_color) {
-
-               if (gdk_rgba_equal (color, combo->priv->default_color)) {
+               if (gdk_rgba_equal (color, combo->priv->default_color))
                        return;
-               }
 
                gdk_rgba_free (combo->priv->default_color);
        }
@@ -890,6 +931,8 @@ e_color_combo_set_default_color (EColorCombo *combo,
        gtk_color_chooser_set_rgba (
                GTK_COLOR_CHOOSER (combo->priv->chooser_widget), color);
 
+       e_color_combo_set_default_transparent (combo, (color->alpha == 0));
+
        g_object_notify (G_OBJECT (combo), "default-color");
 }
 
@@ -927,6 +970,8 @@ e_color_combo_set_default_transparent (EColorCombo *combo,
        g_return_if_fail (E_IS_COLOR_COMBO (combo));
 
        combo->priv->default_transparent = transparent;
+       if (transparent)
+               combo->priv->default_color->alpha = 0;
 
        g_object_notify (G_OBJECT (combo), "default-transparent");
 }