chromeos: Add support for dimming the screen.

This makes Chrome listen for messages from the power manager
asking it to dim or undim the screen.  We'll use this on
desktop devices with external displays to dim the screen
just before blanking it when the user is idle.

BUG=125176
TEST=added, also did manual testing with powerd changes


Review URL: http://codereview.chromium.org/10263011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@134638 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 78 insertions, 0 deletions

diff --git a/ash/wm/screen_dimmer_unittest.cc b/ash/wm/screen_dimmer_unittest.cc
new file mode 100644
index 0000000..b66cd2f
--- /dev/null
+++ b/ash/wm/screen_dimmer_unittest.cc
@@ -0,0 +1,78 @@
+// Copyright (c) 2012 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 "ash/wm/screen_dimmer.h"
+
+#include "ash/shell.h"
+#include "ash/test/ash_test_base.h"
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "ui/aura/root_window.h"
+#include "ui/gfx/compositor/layer.h"
+
+namespace ash {
+namespace test {
+
+class ScreenDimmerTest : public AshTestBase {
+ public:
+  ScreenDimmerTest() : dimmer_(NULL) {}
+  virtual ~ScreenDimmerTest() {}
+
+  void SetUp() OVERRIDE {
+    AshTestBase::SetUp();
+    dimmer_ = Shell::GetInstance()->screen_dimmer();
+    test_api_.reset(new internal::ScreenDimmer::TestApi(dimmer_));
+  }
+
+ protected:
+  internal::ScreenDimmer* dimmer_;  // not owned
+
+  scoped_ptr<internal::ScreenDimmer::TestApi> test_api_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ScreenDimmerTest);
+};
+
+TEST_F(ScreenDimmerTest, DimAndUndim) {
+  // Don't create a layer until we need to.
+  EXPECT_TRUE(test_api_->layer() == NULL);
+  dimmer_->SetDimming(false);
+  EXPECT_TRUE(test_api_->layer() == NULL);
+
+  // When we enable dimming, the layer should be created and stacked at the top
+  // of the root's children.
+  dimmer_->SetDimming(true);
+  ASSERT_TRUE(test_api_->layer() != NULL);
+  ui::Layer* root_layer = Shell::GetInstance()->GetRootWindow()->layer();
+  ASSERT_TRUE(!root_layer->children().empty());
+  EXPECT_EQ(test_api_->layer(), root_layer->children().back());
+  EXPECT_TRUE(test_api_->layer()->visible());
+  EXPECT_GT(test_api_->layer()->GetTargetOpacity(), 0.0f);
+
+  // When we disable dimming, the layer should be animated back to full
+  // transparency.
+  dimmer_->SetDimming(false);
+  ASSERT_TRUE(test_api_->layer() != NULL);
+  EXPECT_TRUE(test_api_->layer()->visible());
+  EXPECT_FLOAT_EQ(0.0f, test_api_->layer()->GetTargetOpacity());
+}
+
+TEST_F(ScreenDimmerTest, ResizeLayer) {
+  // The dimming layer should be initially sized to cover the root window.
+  dimmer_->SetDimming(true);
+  ui::Layer* dimming_layer = test_api_->layer();
+  ASSERT_TRUE(dimming_layer != NULL);
+  ui::Layer* root_layer = Shell::GetInstance()->GetRootWindow()->layer();
+  EXPECT_EQ(gfx::Rect(root_layer->bounds().size()).ToString(),
+            dimming_layer->bounds().ToString());
+
+  // When we resize the root window, the dimming layer should be resized to
+  // match.
+  gfx::Size kNewSize(400, 300);
+  Shell::GetInstance()->GetRootWindow()->SetHostSize(kNewSize);
+  EXPECT_EQ(kNewSize.ToString(), dimming_layer->bounds().size().ToString());
+}
+
+}  // namespace test
+}  // namespace ash