Maintain key state in the plugin delegate if UIPI is enabled.

webkit/plugins/npapi/webplugin_delegate_impl_win.cc

Index: webkit/plugins/npapi/webplugin_delegate_impl_win.cc
===================================================================
--- webkit/plugins/npapi/webplugin_delegate_impl_win.cc	(revision 95591)
+++ webkit/plugins/npapi/webplugin_delegate_impl_win.cc	(working copy)
@@ -86,6 +86,27 @@
 base::LazyInstance<base::win::IATPatchFunction> g_iat_patch_reg_enum_key_ex_w(
     base::LINKER_INITIALIZED);
 
+// Helper object for patching the GetKeyState API.
+base::LazyInstance<base::win::IATPatchFunction> g_iat_patch_get_key_state(
+    base::LINKER_INITIALIZED);
+
+// Saved key state globals and helper access functions
+SHORT (WINAPI *g_iat_orig_get_key_state)(int vkey);
+size_t g_saved_key_state[256 / sizeof(size_t)];

[jam, 2011/08/09 16:26:18]

I'm not sure I follow why size_t is used here?

[jschuh, 2011/08/09 16:48:04]

No major reason. I figured it made sense to use a machine-word type width. Is
there a better type to use?

[jschuh, 2011/08/09 18:06:45]

Just talked to you but I figured I'd record for reference. I'd intended to write
this as a static bit-array, but I see that I forgot one important detail. I'll
have new patch up shortly.

+
+void SetSavedKeyState(WPARAM vkey) {
+  g_saved_key_state[vkey / sizeof(size_t)] |= 1 << (vkey % sizeof(size_t));
+}
+
+void UnsetSavedKeyState(WPARAM vkey) {
+  g_saved_key_state[vkey / sizeof(size_t)] &= ~(1 << (vkey % sizeof(size_t)));
+}
+
+void ClearSavedKeyState() {
+  ::ZeroMemory(g_saved_key_state, sizeof(g_saved_key_state));
+}
+
+
 // http://crbug.com/16114
 // Enforces providing a valid device context in NPWindow, so that NPP_SetWindow
 // is never called with NPNWindoTypeDrawable and NPWindow set to NULL.
@@ -257,6 +278,15 @@
   return CallNextHookEx(NULL, code, wParam, lParam);
 }
 
+// In addition to the key state we maintain, we also mask in the original
+// return value. This is done because it system keys (e.g. tab, enter, shift)
+// and toggles (e.g. capslock) don't ever seem to be blocked.
+SHORT WINAPI WebPluginDelegateImpl::GetKeyStatePatch(int vkey) {
+  if (g_saved_key_state[vkey / sizeof(size_t)] & 1 << (vkey % sizeof(size_t)))
+    return 0x8000 | g_iat_orig_get_key_state(vkey);
+  return g_iat_orig_get_key_state(vkey);
+}
+
 WebPluginDelegateImpl::WebPluginDelegateImpl(
     gfx::PluginWindowHandle containing_view,
     PluginInstance *instance)
@@ -300,7 +330,8 @@
     quirks_ |= PLUGIN_QUIRK_ALWAYS_NOTIFY_SUCCESS;
     quirks_ |= PLUGIN_QUIRK_HANDLE_MOUSE_CAPTURE;
     if (filename == kBuiltinFlashPlugin)
-      quirks_ |= PLUGIN_QUIRK_REPARENT_IN_BROWSER;
+      quirks_ |= PLUGIN_QUIRK_REPARENT_IN_BROWSER |
+                 PLUGIN_QUIRK_PATCH_GETKEYSTATE;
   } else if (filename == kAcrobatReaderPlugin) {
     // Check for the version number above or equal 9.
     int major_version = GetPluginMajorVersion(plugin_info);
@@ -441,6 +472,18 @@
         WebPluginDelegateImpl::RegEnumKeyExWPatch);
   }
 
+  // Under UIPI the key state does not get forwarded properly to the child
+  // plugin window. So, instead we track the key state manually and intercept
+  // GetKeyState.
+  if ((quirks_ & PLUGIN_QUIRK_PATCH_GETKEYSTATE) &&
+      base::win::GetVersion() >= base::win::VERSION_VISTA &&

[jam, 2011/08/09 16:26:18]

nit: probably you want to do this OS check when you enable the quirk

[jschuh, 2011/08/09 16:48:04]

Done.

+      !g_iat_patch_get_key_state.Pointer()->is_patched()) {
+    g_iat_orig_get_key_state = ::GetKeyState;
+    g_iat_patch_get_key_state.Pointer()->Patch(
+        L"gcswf32.dll", "user32.dll", "GetKeyState",
+        WebPluginDelegateImpl::GetKeyStatePatch);
+  }
+
   return true;
 }
 
@@ -941,6 +984,31 @@
     return FALSE;
   }
 
+  // Track the keystate to work around a UIPI issue.
+  if (delegate->GetQuirks() & PLUGIN_QUIRK_PATCH_GETKEYSTATE) {
+    switch (message) {
+      case WM_KEYDOWN:
+        SetSavedKeyState(wparam);
+        break;
+
+      case WM_KEYUP:
+        UnsetSavedKeyState(wparam);
+        break;
+
+      // Clear out the saved keystate whenever the Flash thread loses focus.
+      case WM_KILLFOCUS:
+      case WM_SETFOCUS:
+        if (::GetCurrentThreadId() != ::GetWindowThreadProcessId(
+            reinterpret_cast<HWND>(wparam), NULL)) {
+          ClearSavedKeyState();
+        }
+        break;
+
+      default:
+        break;
+    }
+  }
+
   LRESULT result;
   uint32 old_message = delegate->last_message_;
   delegate->last_message_ = message;