Adding focus to NaviteViewHost.

views/controls/native/native_view_host_win.cc

Index: views/controls/native/native_view_host_win.cc
===================================================================
--- views/controls/native/native_view_host_win.cc	(revision 27081)
+++ views/controls/native/native_view_host_win.cc	(working copy)
@@ -6,10 +6,13 @@
 
 #include "app/gfx/canvas.h"
 #include "base/logging.h"
+#include "base/win_util.h"
 #include "views/controls/native/native_view_host.h"
 #include "views/focus/focus_manager.h"
 #include "views/widget/widget.h"
 
+const wchar_t* kNativeViewHostWinKey = L"__NATIVE_VIEW_HOST_WIN__";
+
 namespace views {
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -17,7 +20,8 @@
 
 NativeViewHostWin::NativeViewHostWin(NativeViewHost* host)
     : host_(host),
-      installed_clip_(false) {
+      installed_clip_(false),
+      original_wndproc_(NULL) {
 }
 
 NativeViewHostWin::~NativeViewHostWin() {
@@ -37,10 +41,32 @@
   // Need to set the HWND's parent before changing its size to avoid flashing.
   SetParent(host_->native_view(), host_->GetWidget()->GetNativeView());
   host_->Layout();
+
+  // Subclass the appropriate HWND to get focus notifications.
+  HWND focus_hwnd = host_->focus_native_view();
+  DCHECK(focus_hwnd == host_->native_view() ||
+         ::IsChild(host_->native_view(), focus_hwnd));
+  original_wndproc_ =
+      win_util::SetWindowProc(focus_hwnd,
+                              &NativeViewHostWin::NativeViewHostWndProc);
+
+  // We use a property to retrieve the NativeViewHostWin from the window
+  // procedure.
+  ::SetProp(focus_hwnd, kNativeViewHostWinKey, this);
 }
 
 void NativeViewHostWin::NativeViewDetaching() {
   installed_clip_ = false;
+
+  // Restore the original Windows procedure.
+  DCHECK(original_wndproc_);
+  WNDPROC wndproc = win_util::SetWindowProc(host_->focus_native_view(),
+                                            original_wndproc_);
+  DCHECK(wndproc == &NativeViewHostWin::NativeViewHostWndProc);
+
+  // Also remove the property, it's not needed anymore.
+  HANDLE h = ::RemoveProp(host_->focus_native_view(), kNativeViewHostWinKey);
+  DCHECK(h == this);
 }
 
 void NativeViewHostWin::AddedToWidget() {
@@ -116,8 +142,22 @@
                SWP_NOREDRAW | SWP_NOOWNERZORDER);
 }
 
-void NativeViewHostWin::SetFocus() {
-  ::SetFocus(host_->native_view());
+// static
+LRESULT CALLBACK NativeViewHostWin::NativeViewHostWndProc(HWND window,
+                                                          UINT message,
+                                                          WPARAM w_param,
+                                                          LPARAM l_param) {
+  NativeViewHostWin* native_view_host =
+      static_cast<NativeViewHostWin*>(::GetProp(window, kNativeViewHostWinKey));
+  DCHECK(native_view_host);
+
+  if (message == WM_SETFOCUS)
+    native_view_host->host_->GotNativeFocus();
+  if (message == WM_DESTROY)
+    native_view_host->host_->Detach();
+
+  return CallWindowProc(native_view_host->original_wndproc_,
+                        window, message, w_param, l_param);
 }
 
 ////////////////////////////////////////////////////////////////////////////////