Add support for colored borders

Use BigRectangle to draw the border and background if there's
a border width or border radius and no border image. (Only
uniform borders are supported for now with some deviations
from the CSS model noted in the comments.)

The background color and image parameters are removed from
StWidget's draw_background() method since they were not used
for StButton (the only current user) and the encapsulation
break that they presented caused some minor problems.

Add a test case for borders, and also use borders to style
the buttons in the 'inline-style' test case.

https://bugzilla.gnome.org/show_bug.cgi?id=595993

src/st/st-button.c

@@ -425,13 +425,11 @@ st_button_unmap (ClutterActor *self)
 }
 
 static void
-st_button_draw_background (StWidget           *widget,
+st_button_draw_background (StWidget         *widget)
-                           ClutterActor       *background,
-                           const ClutterColor *color)
 {
   StButtonPrivate *priv;
 
-  ST_WIDGET_CLASS (st_button_parent_class)->draw_background (widget, background, color);
+  ST_WIDGET_CLASS (st_button_parent_class)->draw_background (widget);
 
   priv = ST_BUTTON (widget)->priv;
 

src/st/st-widget.c

@@ -63,6 +63,7 @@ struct _StWidgetPrivate
   gboolean      is_stylable : 1;
   gboolean      has_tooltip : 1;
   gboolean      is_style_dirty : 1;
+  gboolean      draw_bg_color : 1;
 
   StTooltip    *tooltip;
 };
@@ -353,18 +354,18 @@ st_widget_allocate (ClutterActor          *actor,
 }
 
 static void
-st_widget_real_draw_background (StWidget           *self,
+st_widget_real_draw_background (StWidget *self)
-                                ClutterActor       *background,
-                                const ClutterColor *color)
 {
+  StWidgetPrivate *priv = self->priv;
+
   /* Default implementation just draws the background
    * colour and the image on top
    */
-  if (color && color->alpha != 0)
+  if (priv->draw_bg_color)
     {
       ClutterActor *actor = CLUTTER_ACTOR (self);
       ClutterActorBox allocation = { 0, };
-      ClutterColor bg_color = *color;
+      ClutterColor bg_color = priv->bg_color;
       gfloat w, h;
 
       bg_color.alpha = clutter_actor_get_paint_opacity (actor)
@@ -383,8 +384,8 @@ st_widget_real_draw_background (StWidget           *self,
       cogl_rectangle (0, 0, w, h);
     }
 
-  if (background)
+  if (priv->border_image)
-    clutter_actor_paint (background);
+    clutter_actor_paint (priv->border_image);
 }
 
 static void
@@ -393,9 +394,7 @@ st_widget_paint (ClutterActor *self)
   StWidgetPrivate *priv = ST_WIDGET (self)->priv;
   StWidgetClass *klass = ST_WIDGET_GET_CLASS (self);
 
-  klass->draw_background (ST_WIDGET (self),
+  klass->draw_background (ST_WIDGET (self));
-                          priv->border_image,
-                          &priv->bg_color);
 
   if (priv->background_image != NULL)
     clutter_actor_paint (priv->background_image);
@@ -488,6 +487,11 @@ st_widget_real_style_changed (StWidget *self)
   gboolean relayout_needed = FALSE;
   gboolean has_changed = FALSE;
   ClutterColor color;
+  guint border_width = 0;
+  guint border_radius = 0;
+  ClutterColor border_color = { 0, };
+  StSide side;
+  StCorner corner;
 
   /* application has request this widget is not stylable */
   if (!priv->is_stylable)
@@ -499,6 +503,7 @@ st_widget_real_style_changed (StWidget *self)
   if (!clutter_color_equal (&color, &priv->bg_color))
     {
       priv->bg_color = color;
+      priv->draw_bg_color = color.alpha != 0;
       has_changed = TRUE;
     }
 
@@ -516,6 +521,62 @@ st_widget_real_style_changed (StWidget *self)
 
   texture_cache = st_texture_cache_get_default ();
 
+  /* StThemeNode supports different widths and colors for different sides
+   * of the border, and different radii for the different corners. We take
+   * the different border widths into account when positioning, but our current
+   * drawing code (using BigRectangle) can only handle a single width, color,
+   * and radius, so we arbitrarily pick the first non-zero width and radius,
+   * and use that.
+   */
+  for (side = ST_SIDE_TOP; side <= ST_SIDE_LEFT; side++)
+    {
+      double width = st_theme_node_get_border_width (theme_node, side);
+      if (width > 0.5)
+	{
+	  border_width = round (width);
+	  st_theme_node_get_border_color (theme_node, side, &border_color);
+	  break;
+	}
+    }
+
+  for (corner = ST_CORNER_TOPLEFT; corner <= ST_CORNER_BOTTOMLEFT; corner++)
+    {
+      double radius = st_theme_node_get_border_radius (theme_node, corner);
+      if (radius > 0.5)
+	{
+	  border_radius = round (radius);
+	  break;
+	}
+    }
+
+  /* Rough notes about the relationship of borders and backgrounds in CSS3;
+   * see http://www.w3.org/TR/css3-background/ for more accurate details.
+   *
+   * - Things are drawn in 4 layers, from the bottom:
+   *     Background color
+   *     Background image
+   *     Border color or border image
+   *     Content
+   * - The background color and image extend to and are clipped by the
+   *   edge of the border area, so will be rounded if the border is rounded.
+   *   (CSS3 background-clip property modifies this)
+   * - The border image replaces what would normally be drawn by the border
+   * - The border image is not clipped by a rounded border-radius
+   * - The border radius rounds the background even if the border is
+   *   zero width or a border image is being used.
+   *
+   * Deviations from the above as implemented here:
+   *  - The combination of border image and a non-zero border radius is
+   *    not supported; the background color will be drawn with square
+   *    corners.
+   *  - The background image is drawn above the border color or image,
+   *    not below it.
+   *  - We don't clip the background image to the (rounded) border area.
+   *
+   * The first two allow us always draw with no more than single border_image
+   * and a single background image above it.
+   */
+
   theme_image = st_theme_node_get_background_theme_image (theme_node);
   if (theme_image)
     {
@@ -544,6 +605,22 @@ st_widget_real_style_changed (StWidget *self)
                                                  border_left);
       clutter_actor_set_parent (priv->border_image, CLUTTER_ACTOR (self));
 
+      has_changed = TRUE;
+      relayout_needed = TRUE;
+    }
+  else if ((border_width > 0 && border_color.alpha != 0) ||
+	   (border_radius > 0 && priv->bg_color.alpha != 0))
+    {
+      priv->draw_bg_color = FALSE;
+      priv->border_image = g_object_new (BIG_TYPE_RECTANGLE,
+					 "color", &priv->bg_color,
+					 "border-width", border_width,
+					 "border-color", &border_color,
+					 "corner-radius", border_radius,
+					 NULL);
+
+      clutter_actor_set_parent (priv->border_image, CLUTTER_ACTOR (self));
+
       has_changed = TRUE;
       relayout_needed = TRUE;
     }
@@ -1301,7 +1378,5 @@ st_widget_draw_background (StWidget *self)
   priv = self->priv;
 
   klass = ST_WIDGET_GET_CLASS (self);
-  klass->draw_background (ST_WIDGET (self),
+  klass->draw_background (ST_WIDGET (self));
-                          priv->border_image,
-                          &priv->bg_color);
 }

src/st/st-widget.h

@@ -72,10 +72,8 @@ struct _StWidgetClass
   ClutterActorClass parent_class;
 
   /* vfuncs */
-  void (* draw_background) (StWidget           *self,
+  void (* draw_background) (StWidget *self);
-                            ClutterActor       *background,
+  void (* style_changed)   (StWidget *self);
-                            const ClutterColor *color);
-  void (* style_changed)   (StWidget           *self);
 };
 
 GType st_widget_get_type (void) G_GNUC_CONST;

tests/interactive/borders.js

@@ -0,0 +1,57 @@
+/* -*- mode: js2; js2-basic-offset: 4; indent-tabs-mode: nil -*- */
+
+const Clutter = imports.gi.Clutter;
+const St = imports.gi.St;
+
+const UI = imports.testcommon.ui;
+
+UI.init();
+let stage = Clutter.Stage.get_default();
+stage.width = 600;
+stage.height = 600;
+
+let vbox = new St.BoxLayout({ vertical: true,
+                              width: stage.width,
+                              height: stage.height,
+                              spacing: 20,
+                              style: 'padding: 10px; background: #ffee88' });
+stage.add_actor(vbox);
+
+vbox.add(new St.Label({ text: "Hello World",
+                        style: 'border: 1px solid black; '
+                               + 'padding: 5px;' }));
+
+vbox.add(new St.Label({ text: "Hello Round World",
+                        style: 'border: 3px solid green; '
+                               + 'border-radius: 8px; '
+                               + 'padding: 5px;' }));
+
+vbox.add(new St.Label({ text: "Hello Background",
+                        style: 'border: 3px solid green; '
+                               + 'border-radius: 8px; '
+                               + 'background: white; '
+                               + 'padding: 5px;' }));
+
+vbox.add(new St.Label({ text: "Border, Padding, Content: 20px" }));
+
+let b1 = new St.BoxLayout({ vertical: true,
+                            style: 'border: 20px solid black; '
+                                   + 'background: white; '
+                                   + 'padding: 20px;' });
+vbox.add(b1);
+
+b1.add(new St.BoxLayout({ width: 20, height: 20,
+                          style: 'background: black' }));
+
+vbox.add(new St.Label({ text: "Translucent blue border",
+                        style: 'border: 20px solid rgba(0, 0, 255, 0.2); '
+                               + 'background: white; '
+                               + 'padding: 10px;' }));
+
+vbox.add(new St.Label({ text: "Border Image",
+                        style_class: "border-image",
+                        style: "padding: 10px;" }));
+
+stage.show();
+Clutter.main();
+stage.destroy();

tests/interactive/inline-style.js

@@ -25,16 +25,16 @@ function update_size() {
 }
 update_size();
 
-let button = new St.Button ({ label: 'Smaller',
+let button;
-                              style: 'padding: 4px; background: #eeddcc' });
+
+button = new St.Button ({ label: 'Smaller' });
 hbox.add (button);
 button.connect('clicked', function() {
                    size /= 1.2;
                    update_size ();
                });
 
-let button = new St.Button ({ label: 'Bigger',
+button = new St.Button ({ label: 'Bigger' });
-                              style: 'padding: 4px; background: #eeddcc' });
 hbox.add (button);
 button.connect('clicked', function() {
                    size *= 1.2;

tests/testcommon/test.css

@@ -31,3 +31,23 @@ stage {
 .monospace {
     font-family: monospace;
 }
+
+.border-image {
+    border: 15px;
+    -st-background-image: url('border-image.png') 16px;
+}
+
+StButton {
+    background: #eeddbb;
+    border: 1px solid black;
+    border-radius: 8px;
+    padding: 5px;
+}
+
+StButton:hover {
+    background: #ffeecc;
+}
+
+StButton:active {
+    background: #ccbb99;
+}