diff options
Diffstat (limited to 'chrome/views/focus_manager.cc')
| -rw-r--r-- | chrome/views/focus_manager.cc | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/chrome/views/focus_manager.cc b/chrome/views/focus_manager.cc index da23bda..b48fe594 100644 --- a/chrome/views/focus_manager.cc +++ b/chrome/views/focus_manager.cc @@ -4,6 +4,7 @@ #include <algorithm> +#include "base/histogram.h" #include "base/logging.h" #include "base/win_util.h" #include "chrome/browser/render_widget_host_view_win.h" @@ -30,6 +31,16 @@ static const wchar_t* const kFocusManagerKey = L"__VIEW_CONTAINER__"; // - 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 { static bool IsCompatibleWithMouseWheelRedirection(HWND window) { @@ -209,15 +220,29 @@ FocusManager* FocusManager::CreateFocusManager(HWND window, // static void FocusManager::InstallFocusSubclass(HWND window, View* view) { DCHECK(window); - win_util::Subclass(window, &FocusWindowCallback); + + 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(L"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)) + if (win_util::Unsubclass(window, &FocusWindowCallback)) { RemoveProp(window, kViewKey); + RemoveProp(window, kFocusSubclassInstalled); + } } // static |