Support minimizing the panel into 3-pixel line on Windows. Also support bringing up/down the titl...

chrome/browser/ui/panels/panel_mouse_watcher_win.cc

+// 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 "chrome/browser/ui/panels/panel_mouse_watcher_win.h"
+
+#include "base/logging.h"
+#include "base/scoped_ptr.h"
+#include "chrome/browser/ui/panels/panel.h"
+#include "chrome/browser/ui/panels/panel_manager.h"
+
+#include <windows.h>
+
+namespace {
+
+HMODULE GetModuleHandleFromAddress(void *address) {
+  MEMORY_BASIC_INFORMATION mbi;
+  SIZE_T result = ::VirtualQuery(address, &mbi, sizeof(mbi));
+  return static_cast<HMODULE>(mbi.AllocationBase);
+}
+
+
+// Gets the handle to the currently executing module.
+HMODULE GetCurrentModuleHandle() {
+  return ::GetModuleHandleFromAddress(GetCurrentModuleHandle);
+}
+
+class PanelMouseWatcherWin {
+ public:
+  PanelMouseWatcherWin();
+  ~PanelMouseWatcherWin();
+
+ private:
+  static LRESULT CALLBACK MouseHookProc(int code, WPARAM wparam, LPARAM lparam);
+
+  void OnMouseAction(int mouse_x, int mouse_y);
+
+  HHOOK mouse_hook_;
+  bool bring_up_titlebar_;
+
+  DISALLOW_COPY_AND_ASSIGN(PanelMouseWatcherWin);
+};
+
+scoped_ptr<PanelMouseWatcherWin> mouse_watcher;
+
+PanelMouseWatcherWin::PanelMouseWatcherWin()
+    : mouse_hook_(NULL),
+      bring_up_titlebar_(false) {
+  mouse_hook_ = ::SetWindowsHookEx(
+      WH_MOUSE_LL, MouseHookProc, GetCurrentModuleHandle(), 0);
+  DCHECK(mouse_hook_);
+}
+
+PanelMouseWatcherWin::~PanelMouseWatcherWin() {
+  ::UnhookWindowsHookEx(mouse_hook_);
+}
+
+LRESULT CALLBACK PanelMouseWatcherWin::MouseHookProc(int code,
+                                                     WPARAM wparam,
+                                                     LPARAM lparam) {
+  if (code == HC_ACTION) {
+    MOUSEHOOKSTRUCT* hook_struct = reinterpret_cast<MOUSEHOOKSTRUCT*>(lparam);
+    if (hook_struct)
+      mouse_watcher->OnMouseAction(hook_struct->pt.x, hook_struct->pt.y);
+  }
+  return ::CallNextHookEx(NULL, code, wparam, lparam);
+}
+
+void PanelMouseWatcherWin::OnMouseAction(int mouse_x, int mouse_y) {
+  PanelManager* panel_manager = PanelManager::GetInstance();
+
+  bool bring_up_titlebar =
+      panel_manager->ShouldBringUpTitleBarForAllMinimizedPanels(
+          mouse_x, mouse_y);
+  if (bring_up_titlebar == bring_up_titlebar_)
+    return;
+  bring_up_titlebar_ = bring_up_titlebar;
+
+  panel_manager->BringUpOrDownTitleBarForAllMinimizedPanels(bring_up_titlebar);
+}
+
+}
+
+void EnsureMouseWatcherStarted() {
+  if (!mouse_watcher.get())
+    mouse_watcher.reset(new PanelMouseWatcherWin());
+}
+
+void StopMouseWatcher() {
+  mouse_watcher.reset(NULL);
+}
+
+bool IsMouseWatcherStarted() {
+  return mouse_watcher.get() != NULL;
+}