tests: Add a box-shadow test

The original support for CSS based shadows has been extended with
support for an optional spread radius and the 'inset' keyword,
so with the additional complexity a dedicated test case looks
appropriate.

https://bugzilla.gnome.org/show_bug.cgi?id=642334

tests/Makefile.am

@@ -6,6 +6,7 @@ TEST_JS =					\
 	interactive/border-radius.js		\
 	interactive/border-width.js		\
 	interactive/box-layout.js		\
+	interactive/box-shadows.js		\
 	interactive/calendar.js			\
 	interactive/css-fonts.js		\
 	interactive/entry.js			\

tests/interactive/box-shadows.js

@@ -0,0 +1,58 @@
+/* -*- 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 = 640;
+stage.height = 480;
+
+let vbox = new St.BoxLayout({ width: stage.width,
+                              height: stage.height,
+                              style: 'background: #ffee88;' });
+stage.add_actor(vbox);
+
+let scroll = new St.ScrollView();
+vbox.add(scroll, { expand: true });
+
+let box = new St.BoxLayout({ vertical: true,
+                             style: 'padding: 10px;'
+                                    + 'spacing: 20px;' });
+scroll.add_actor(box);
+
+
+function addTestCase(inset, offsetX, offsetY, blur, spread) {
+    let shadowStyle = 'box-shadow: ' + (inset ? 'inset ' : '') +
+                      offsetX + 'px ' + offsetY + 'px ' + blur + 'px ' +
+                      (spread > 0 ? (' ' + spread + 'px ') : '') +
+                      'rgba(0,0,0,0.5);';
+    let label = new St.Label({ style: 'border: 4px solid black;' +
+                                      'border-radius: 5px;' +
+                                      'background-color: white; ' +
+                                      'padding: 5px;' +
+                                      shadowStyle,
+                               text: shadowStyle });
+    box.add(label, { x_fill: false, y_fill: false } );
+}
+
+addTestCase (false, 3, 4, 0, 0);
+addTestCase (false, 3, 4, 0, 4);
+addTestCase (false, 3, 4, 4, 0);
+addTestCase (false, 3, 4, 4, 4);
+addTestCase (false, -3, -4, 4, 0);
+addTestCase (false, 0, 0, 0, 4);
+addTestCase (false, 0, 0, 4, 0);
+addTestCase (true, 3, 4, 0, 0);
+addTestCase (true, 3, 4, 0, 4);
+addTestCase (true, 3, 4, 4, 0);
+addTestCase (true, 3, 4, 4, 4);
+addTestCase (true, -3, -4, 4, 0);
+addTestCase (true, 0, 0, 0, 4);
+addTestCase (true, 0, 0, 4, 0);
+
+stage.show();
+Clutter.main();
+stage.destroy();