aura: Draw drop shadows under browsers and menus.

This is largely a port of the existing X window manager's
code for drawing shadows around windows.  It adds an
ImageGrid class for drawing a scaled 3x3 grid of gfx::Images
and a Shadow class (managed by aura_shell::ShadowController)
that uses ImageGrid to draw a shadow.  Shadows can be
disabled via --aura-no-shadows.

BUG=101977
TEST=added unit tests; also manually checked that shadows get drawn

Review URL: http://codereview.chromium.org/8555025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@111009 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 54 insertions, 0 deletions

diff --git a/ui/aura_shell/shadow.cc b/ui/aura_shell/shadow.cc
new file mode 100644
index 0000000..2963dd5
--- /dev/null
+++ b/ui/aura_shell/shadow.cc
@@ -0,0 +1,54 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/aura_shell/shadow.h"
+
+#include "grit/ui_resources.h"
+#include "ui/aura_shell/image_grid.h"
+#include "ui/base/resource/resource_bundle.h"
+
+namespace aura_shell {
+namespace internal {
+
+Shadow::Shadow() {
+}
+
+Shadow::~Shadow() {
+}
+
+ui::Layer* Shadow::layer() const { return image_grid_->layer(); }
+
+void Shadow::Init() {
+  image_grid_.reset(new ImageGrid);
+
+  ResourceBundle& res = ResourceBundle::GetSharedInstance();
+  image_grid_->Init(&res.GetImageNamed(IDR_AURA_SHADOW_RECT_TOP_LEFT),
+                    &res.GetImageNamed(IDR_AURA_SHADOW_RECT_TOP),
+                    &res.GetImageNamed(IDR_AURA_SHADOW_RECT_TOP_RIGHT),
+                    &res.GetImageNamed(IDR_AURA_SHADOW_RECT_LEFT),
+                    NULL,
+                    &res.GetImageNamed(IDR_AURA_SHADOW_RECT_RIGHT),
+                    &res.GetImageNamed(IDR_AURA_SHADOW_RECT_BOTTOM_LEFT),
+                    &res.GetImageNamed(IDR_AURA_SHADOW_RECT_BOTTOM),
+                    &res.GetImageNamed(IDR_AURA_SHADOW_RECT_BOTTOM_RIGHT));
+}
+
+void Shadow::SetContentBounds(const gfx::Rect& content_bounds) {
+  content_bounds_ = content_bounds;
+  image_grid_->SetSize(
+      gfx::Size(content_bounds.width() +
+                    image_grid_->left_image_width() +
+                    image_grid_->right_image_width(),
+                content_bounds.height() +
+                    image_grid_->top_image_height() +
+                    image_grid_->bottom_image_height()));
+  image_grid_->layer()->SetBounds(
+      gfx::Rect(content_bounds.x() - image_grid_->left_image_width(),
+                content_bounds.y() - image_grid_->top_image_height(),
+                image_grid_->layer()->bounds().width(),
+                image_grid_->layer()->bounds().height()));
+}
+
+}  // namespace internal
+}  // namespace aura_shell