Support auto-hide taskbar for panels on Windows.

chrome/browser/ui/panels/auto_hiding_desktop_bar_win.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_AUTO_HIDING_DESKTOP_BAR_WIN_H_
+#define CHROME_BROWSER_UI_PANELS_AUTO_HIDING_DESKTOP_BAR_WIN_H_
+#pragma once
+
+#include "chrome/browser/ui/panels/auto_hiding_desktop_bar.h"
+
+#include <windows.h>
+#include "base/compiler_specific.h"
+#include "base/timer.h"
+#include "ui/gfx/rect.h"
+
+class AutoHidingDesktopBarWin : public AutoHidingDesktopBar {
+ public:
+  explicit AutoHidingDesktopBarWin(Observer* observer);
+  virtual ~AutoHidingDesktopBarWin();
+
+  // Overridden from AutoHidingDesktopBar:
+  virtual void UpdateWorkArea(const gfx::Rect& work_area) OVERRIDE;
+  virtual bool IsEnabled(Alignment alignment) OVERRIDE;
+  virtual int GetThickness(Alignment alignment) const OVERRIDE;
+  virtual Visibility GetVisibility(Alignment alignment) const OVERRIDE;
+
+#ifdef UNIT_TEST
+  void set_work_area(const gfx::Rect& work_area) {
+    work_area_ = work_area;
+  }
+#endif
+
+ private:
+  friend class AutoHidingDesktopBarWinTest;
+
+  struct Taskbar {
+    HWND window;
+    AutoHidingDesktopBar::Visibility visibility;
+    int thickness;
+  };
+
+  // Callback to perform periodic check for taskbar changes.
+  void OnPollingTimer();
+
+  // Returns true if there is at least one auto-hiding taskbar found.
+  bool CheckTaskbars(bool notify_observer);
+
+  gfx::Rect GetBounds(Alignment alignment) const;
+  int GetThicknessFromBounds(
+      Alignment alignment, const gfx::Rect& taskbar_bounds) const;
+  Visibility GetVisibilityFromBounds(
+      Alignment alignment, const gfx::Rect& taskbar_bounds) const;
+
+  // Maximum number of taskbars we're interested in: bottom, left, and right.
+  static const int kMaxTaskbars = 3;
+
+  Observer* observer_;
+  gfx::Rect work_area_;
+  HMONITOR monitor_;
+  Taskbar taskbars_[kMaxTaskbars];
+  base::RepeatingTimer<AutoHidingDesktopBarWin> polling_timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(AutoHidingDesktopBarWin);
+};
+
+#endif  // CHROME_BROWSER_UI_PANELS_AUTO_HIDING_DESKTOP_BAR_WIN_H_