Relanding focus manager refactoring

views/focus/focus_manager.cc

Index: views/focus/focus_manager.cc
===================================================================
--- views/focus/focus_manager.cc	(revision 19153)
+++ views/focus/focus_manager.cc	(working copy)
@@ -12,7 +12,6 @@
 #include <gtk/gtk.h>
 #endif
 
-#include "base/histogram.h"
 #include "base/logging.h"
 #include "views/accelerator.h"
 #include "views/focus/view_storage.h"
@@ -24,158 +23,17 @@
 #include "base/win_util.h"
 #endif
 
-// The following keys are used in SetProp/GetProp to associate additional
-// information needed for focus tracking with a window.
-
-// Maps to the FocusManager instance for a top level window. See
-// CreateFocusManager/DestoryFocusManager for usage.
-static const wchar_t* const kFocusManagerKey = L"__VIEW_CONTAINER__";
-
-// Maps to the View associated with a window.
-// We register views with window so we can:
-// - keep in sync the native focus with the view focus (when the native
-//   component gets the focus, we get the WM_SETFOCUS event and we can focus the
-//   associated view).
-// - prevent tab key events from being sent to views.
-static const wchar_t* const kViewKey = L"__CHROME_VIEW__";
-
-// A property set to 1 to indicate whether the focus manager has subclassed that
-// window.  We are doing this to ensure we are not subclassing several times.
-// Subclassing twice is not a problem if no one is subclassing the HWND between
-// the 2 subclassings (the 2nd subclassing is ignored since the WinProc is the
-// same as the current one).  However if some other app goes and subclasses the
-// HWND between the 2 subclassings, we will end up subclassing twice.
-// This flag lets us test that whether we have or not subclassed yet.
-static const wchar_t* const kFocusSubclassInstalled =
-    L"__FOCUS_SUBCLASS_INSTALLED__";
-
 namespace views {
 
-#if defined(OS_WIN)
-// Callback installed via InstallFocusSubclass.
-static LRESULT CALLBACK FocusWindowCallback(HWND window, UINT message,
-                                            WPARAM wParam, LPARAM lParam) {
-  if (!::IsWindow(window)) {
-    // QEMU has reported crashes when calling GetProp (this seems to happen for
-    // some weird messages, not sure what they are).
-    // Here we are just trying to avoid the crasher.
-    NOTREACHED();
-    return 0;
-  }
-
-  WNDPROC original_handler = win_util::GetSuperclassWNDPROC(window);
-  DCHECK(original_handler);
-  FocusManager* focus_manager = FocusManager::GetFocusManager(window);
-  // There are cases when we have no FocusManager for the window. This happens
-  // because we subclass certain windows (such as the TabContents window)
-  // but that window may not have an associated FocusManager.
-  if (focus_manager) {
-    switch (message) {
-      case WM_NCDESTROY:
-        if (!focus_manager->OnNCDestroy(window))
-          return 0;
-        break;
-      default:
-        break;
-    }
-  }
-  return CallWindowProc(original_handler, window, message, wParam, lParam);
-}
-
-#endif
-
 // FocusManager -----------------------------------------------------
 
-#if defined(OS_WIN)
-// static
-FocusManager* FocusManager::CreateFocusManager(HWND window,
-                                               RootView* root_view) {
-  DCHECK(window);
-  DCHECK(root_view);
-  InstallFocusSubclass(window, NULL);
-  FocusManager* focus_manager = new FocusManager(window, root_view);
-  SetProp(window, kFocusManagerKey, focus_manager);
-
-  return focus_manager;
-}
-
-// static
-void FocusManager::InstallFocusSubclass(HWND window, View* view) {
-  DCHECK(window);
-
-  bool already_subclassed =
-      reinterpret_cast<bool>(GetProp(window,
-                                     kFocusSubclassInstalled));
-  if (already_subclassed &&
-      !win_util::IsSubclassed(window, &FocusWindowCallback)) {
-    NOTREACHED() << "window sub-classed by someone other than the FocusManager";
-    // Track in UMA so we know if this case happens.
-    UMA_HISTOGRAM_COUNTS("FocusManager.MultipleSubclass", 1);
-  } else {
-    win_util::Subclass(window, &FocusWindowCallback);
-    SetProp(window, kFocusSubclassInstalled, reinterpret_cast<HANDLE>(true));
-  }
-  if (view)
-    SetProp(window, kViewKey, view);
-}
-
-void FocusManager::UninstallFocusSubclass(HWND window) {
-  DCHECK(window);
-  if (win_util::Unsubclass(window, &FocusWindowCallback)) {
-    RemoveProp(window, kViewKey);
-    RemoveProp(window, kFocusSubclassInstalled);
-  }
-}
-
-#endif
-
-// static
-FocusManager* FocusManager::GetFocusManager(gfx::NativeView window) {
-#if defined(OS_WIN)
-  DCHECK(window);
-
-  // In case parent windows belong to a different process, yet
-  // have the kFocusManagerKey property set, we have to be careful
-  // to also check the process id of the window we're checking.
-  DWORD window_pid = 0, current_pid = GetCurrentProcessId();
-  FocusManager* focus_manager;
-  for (focus_manager = NULL; focus_manager == NULL && IsWindow(window);
-       window = GetParent(window)) {
-    GetWindowThreadProcessId(window, &window_pid);
-    if (current_pid != window_pid)
-      break;
-    focus_manager = reinterpret_cast<FocusManager*>(
-        GetProp(window, kFocusManagerKey));
-  }
-  return focus_manager;
-#else
-  NOTIMPLEMENTED();
-  return NULL;
-#endif
-}
-
-#if defined(OS_WIN)
-// static
-View* FocusManager::GetViewForWindow(gfx::NativeView window, bool look_in_parents) {
-  DCHECK(window);
-  do {
-    View* v = reinterpret_cast<View*>(GetProp(window, kViewKey));
-    if (v)
-      return v;
-  } while (look_in_parents && (window = ::GetParent(window)));
-  return NULL;
-}
-
-FocusManager::FocusManager(HWND root, RootView* root_view)
-    : root_(root),
-      top_root_view_(root_view),
-      focused_view_(NULL),
-      ignore_set_focus_msg_(false) {
+FocusManager::FocusManager(Widget* widget)
+    : widget_(widget),
+      focused_view_(NULL) {
+  DCHECK(widget_);
   stored_focused_view_storage_id_ =
       ViewStorage::GetSharedInstance()->CreateStorageID();
-  DCHECK(root_);
 }
-#endif
 
 FocusManager::~FocusManager() {
   // If there are still registered FocusChange listeners, chances are they were
@@ -185,29 +43,12 @@
 
 #if defined(OS_WIN)
 // Message handlers.
-bool FocusManager::OnNCDestroy(HWND window) {
-  // Window is being destroyed, undo the subclassing.
-  FocusManager::UninstallFocusSubclass(window);
-
-  if (window == root_) {
-    // We are the top window.
-
-    DCHECK(GetProp(window, kFocusManagerKey));
-
-    // Make sure this is called on the window that was set with the
-    // FocusManager.
-    RemoveProp(window, kFocusManagerKey);
-
-    delete this;
-  }
-  return true;
-}
-
 bool FocusManager::OnKeyDown(HWND window, UINT message, WPARAM wparam,
                              LPARAM lparam) {
   DCHECK((message == WM_KEYDOWN) || (message == WM_SYSKEYDOWN));
+  HWND hwnd = widget_->GetNativeView();
 
-  if (!IsWindowVisible(root_)) {
+  if (!IsWindowVisible(hwnd)) {
     // We got a message for a hidden window. Because WidgetWin::Close hides the
     // window, then destroys it, it it possible to get a message after we've
     // hidden the window. If we allow the message to be dispatched chances are
@@ -245,9 +86,10 @@
   // Note that we don't do focus traversal if the root window is not part of the
   // active window hierarchy as this would mean we have no focused view and
   // would focus the first focusable view.
+  HWND top_window = widget_->GetNativeView();
   HWND active_window = ::GetActiveWindow();
-  if ((active_window == root_ || ::IsChild(active_window, root_)) &&
-      IsTabTraversalKeyEvent(key_event)) {
+  if ((active_window == top_window || ::IsChild(active_window, top_window)) &&
+       IsTabTraversalKeyEvent(key_event)) {
     AdvanceFocus(win_util::IsShiftPressed());
     return false;
   }
@@ -324,9 +166,10 @@
   if (!widget)
     return false;
 
+  gfx::NativeView top_window = widget_->GetNativeView();
   gfx::NativeView window = widget->GetNativeView();
   while (window) {
-    if (window == root_)
+    if (window == top_window)
       return true;
 #if defined(OS_WIN)
     window = ::GetParent(window);
@@ -377,7 +220,7 @@
       starting_view = original_starting_view;
     }
   } else {
-    focus_traversable = top_root_view_;
+    focus_traversable = widget_->GetRootView();
   }
 
   // Traverse the FocusTraversable tree down to find the focusable view.
@@ -457,30 +300,9 @@
 
 void FocusManager::ClearFocus() {
   SetFocusedView(NULL);
-  ClearHWNDFocus();
+  ClearNativeFocus();
 }
 
-void FocusManager::ClearHWNDFocus() {
-  // Keep the top root window focused so we get keyboard events.
-  ignore_set_focus_msg_ = true;
-#if defined(OS_WIN)
-  ::SetFocus(root_);
-#else
-  NOTIMPLEMENTED();
-#endif
-  ignore_set_focus_msg_ = false;
-}
-
-#if defined(OS_WIN)
-void FocusManager::FocusHWND(HWND hwnd) {
-  ignore_set_focus_msg_ = true;
-  // Only reset focus if hwnd is not already focused.
-  if (hwnd && ::GetFocus() != hwnd)
-    ::SetFocus(hwnd);
-  ignore_set_focus_msg_ = false;
-}
-#endif
-
 void FocusManager::StoreFocusedView() {
   ViewStorage* view_storage = ViewStorage::GetSharedInstance();
   if (!view_storage) {
@@ -535,19 +357,6 @@
   view_storage->RemoveView(stored_focused_view_storage_id_);
 }
 
-FocusManager* FocusManager::GetParentFocusManager() const {
-#if defined(OS_WIN)
-  HWND parent = ::GetParent(root_);
-#else
-  GtkWidget* parent = gtk_widget_get_parent(root_);
-#endif
-  // If we are a top window, we don't have a parent FocusManager.
-  if (!parent)
-    return NULL;
-
-  return GetFocusManager(parent);
-}
-
 // Find the next (previous if reverse is true) focusable view for the specified
 // FocusTraversable, starting at the specified view, traversing down the
 // FocusTraversable hierarchy.
@@ -629,13 +438,6 @@
     }
   }
 
-  // When dealing with child windows that have their own FocusManager (such
-  // as ConstrainedWindow), we still want the parent FocusManager to process
-  // the accelerator if the child window did not process it.
-  FocusManager* parent_focus_manager = GetParentFocusManager();
-  if (parent_focus_manager)
-    return parent_focus_manager->ProcessAccelerator(accelerator);
-
   return false;
 }