Support auto-hide taskbar for panels on Windows.

chrome/browser/ui/panels/bottom_bar.h

+// 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.
+
+#ifndef CHROME_BROWSER_UI_PANELS_BOTTOM_BAR_H_
+#define CHROME_BROWSER_UI_PANELS_BOTTOM_BAR_H_
+#pragma once
+
+// The file contains the helper functions to deal with the top-most system/app
+// bar located at the bottom of the screen, like Windows taskbar or MacOSX dock.
+// This bottom bar might be set to auto-hide.
+
+// Returns true if the bottom bar is set to auto-hide. In this mode, the bottom
+// bar will remain hidden most of the time and could be brought up when the user
+// move the mouse to the bottom of the screen.
+bool IsBottomBarInAutoHideMode();

[Dmitry Titov, 2011/08/17 22:56:38]

We should have a class here, with static members. It's better then to add
functions to the global namespace. This also will let to avoid adding BottomBar
to all the names, like: BottomBar::IsFoo() instead of IsBottomBarFoo().

[jianli, 2011/08/22 20:44:42]

Done.

+
+// Returns the fixed height of the bottom bar. Note that the height remains
+// unchanged no matter whether the bottom bar is brought up or down.
+int GetBottomBarHeight();
+
+// Returns true if the bottom bar is fully brought up from the hidden mode.
+// Otherwise, false is returned when the bottom bar is partially up during
+// animation or hidden.
+bool IsBottomBarFullyVisible();

[Dmitry Titov, 2011/08/17 22:56:38]

It seems there can be a single method returning enum value, since not all
combinations are valid - for example, if IsBottomBarInAutoHideMode == false,
then IsBottomBarHidden can only return false.

Something like { ALWAYS_VISIBLE, AUTOHIDE_HIDDEN, AUTOHIDE_SHOWN }

[jianli, 2011/08/22 20:44:42]

Done.

+
+// Returns true if the bottom bar is completely hidden.
+bool IsBottomBarHidden();
+
+#endif  // CHROME_BROWSER_UI_PANELS_BOTTOM_BAR_H_