[Linux] Workaround issue 45478: IME dysfunctional after BACKSPACE

chrome/browser/renderer_host/gtk_im_context_wrapper.cc

 // Copyright (c) 2010 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/renderer_host/gtk_im_context_wrapper.h"
 
 #include <gdk/gdk.h>
 #include <gdk/gdkkeysyms.h>
 #include <gtk/gtk.h>
 #include <algorithm>
@@ skipping 10 matching lines @@
 #endif
 #include "chrome/browser/renderer_host/render_widget_host.h"
 #include "chrome/browser/renderer_host/render_widget_host_view_gtk.h"
 #include "chrome/common/native_web_keyboard_event.h"
 #include "chrome/common/render_messages.h"
 #include "gfx/gtk_util.h"
 #include "gfx/rect.h"
 #include "grit/generated_resources.h"
 #include "third_party/skia/include/core/SkColor.h"
 
+namespace {
+// Copied from third_party/WebKit/WebCore/page/EventHandler.cpp
+//
+// Match key code of composition keydown event on windows.
+// IE sends VK_PROCESSKEY which has value 229;
+//
+// Please refer to following documents for detals:
+// - Virtual-Key Codes
+//   http://msdn.microsoft.com/en-us/library/ms645540(VS.85).aspx
+// - How the IME System Works
+//   http://msdn.microsoft.com/en-us/library/cc194848.aspx
+// - ImmGetVirtualKey Function
+//   http://msdn.microsoft.com/en-us/library/dd318570(VS.85).aspx
+const int kCompositionEventKeyCode = 229;
+}  // namespace
+
 GtkIMContextWrapper::GtkIMContextWrapper(RenderWidgetHostViewGtk* host_view)
     : host_view_(host_view),
       context_(gtk_im_multicontext_new()),
       context_simple_(gtk_im_context_simple_new()),
       is_focused_(false),
       is_composing_text_(false),
       is_enabled_(false),
       is_in_key_event_handler_(false),
       preedit_selection_start_(0),
       preedit_selection_end_(0),
@@ skipping 269 matching lines @@
   // If there is no composition text and has only one character to be
   // committed, then the character will be send to webkit as a Char event
   // instead of a confirmed composition text.
   // It should be fine to handle BMP character only, as non-BMP characters
   // can always be committed as confirmed composition text.
   return !is_composing_text_ && commit_text_.length() == 1;
 }
 
 void GtkIMContextWrapper::ProcessFilteredKeyPressEvent(
     NativeWebKeyboardEvent* wke) {
-  // Copied from third_party/WebKit/WebCore/page/EventHandler.cpp
-  //
-  // Match key code of composition keydown event on windows.
-  // IE sends VK_PROCESSKEY which has value 229;
-  //
-  // Please refer to following documents for detals:
-  // - Virtual-Key Codes
-  //   http://msdn.microsoft.com/en-us/library/ms645540(VS.85).aspx
-  // - How the IME System Works
-  //   http://msdn.microsoft.com/en-us/library/cc194848.aspx
-  // - ImmGetVirtualKey Function
-  //   http://msdn.microsoft.com/en-us/library/dd318570(VS.85).aspx
-  const int kCompositionEventKeyCode = 229;
-
   // If IME has filtered this event, then replace virtual key code with
   // VK_PROCESSKEY. See comment in ProcessKeyEvent() for details.
   // It's only required for keydown events.
   // To emulate windows behavior, when input method is enabled, if the commit
   // text can be emulated by a Char event, then don't do this replacement.
   if (!NeedCommitByForwardingCharEvent()) {
     wke->windowsKeyCode = kCompositionEventKeyCode;
     // keyidentifier must be updated accordingly, otherwise this key event may
     // still be processed by webkit.
     wke->setKeyIdentifierFromWindowsKeyCode();
@@ skipping 99 matching lines @@
 
   // Append the text to the buffer, because commit signal might be fired
   // multiple times when processing a key event.
   commit_text_.append(text);
   // Nothing needs to do, if it's currently in ProcessKeyEvent()
   // handler, which will send commit text to webkit later. Otherwise,
   // we need send it here.
   // It's possible that commit signal is fired without a key event, for
   // example when user input via a voice or handwriting recognition software.
   // In this case, the text must be committed directly.
-  if (!is_in_key_event_handler_ && host_view_->GetRenderWidgetHost())
+  if (!is_in_key_event_handler_ && host_view_->GetRenderWidgetHost()) {
+    // Workaround http://crbug.com/45478 by sending fake key down/up events.
+    NativeWebKeyboardEvent fake_event;
+    fake_event.windowsKeyCode = kCompositionEventKeyCode;
+    fake_event.skip_in_browser = true;
+    fake_event.type = WebKit::WebInputEvent::RawKeyDown;
+    host_view_->ForwardKeyboardEvent(fake_event);
+
     host_view_->GetRenderWidgetHost()->ImeConfirmComposition(text);
+
+    fake_event.type = WebKit::WebInputEvent::KeyUp;
+    host_view_->ForwardKeyboardEvent(fake_event);
+  }
 }
 
 void GtkIMContextWrapper::HandlePreeditStart() {
   // Ignore preedit related signals triggered by CancelComposition() method.
   if (suppress_next_commit_)
     return;
   is_composing_text_ = true;
 }
 
 void GtkIMContextWrapper::HandlePreeditChanged(const gchar* text,
@@ skipping 18 matching lines @@
   // In case we are using a buggy input method which doesn't fire
   // "preedit_start" signal.
   if (preedit_text_.length())
     is_composing_text_ = true;
 
   // Nothing needs to do, if it's currently in ProcessKeyEvent()
   // handler, which will send preedit text to webkit later.
   // Otherwise, we need send it here if it's been changed.
   if (!is_in_key_event_handler_ && is_composing_text_ &&
       host_view_->GetRenderWidgetHost()) {
+    // Workaround http://crbug.com/45478 by sending fake key down/up events.
+    NativeWebKeyboardEvent fake_event;
+    fake_event.windowsKeyCode = kCompositionEventKeyCode;
+    fake_event.skip_in_browser = true;
+    fake_event.type = WebKit::WebInputEvent::RawKeyDown;
+    host_view_->ForwardKeyboardEvent(fake_event);

[Evan Martin, 2010/12/13 22:46:00]

Since this occurs twice, maybe this could be refactored?  E.g.
SendFakeKeyUpDownEvent() that takes a bool for the up vs down logic.

+
     host_view_->GetRenderWidgetHost()->ImeSetComposition(
         preedit_text_, preedit_underlines_, preedit_selection_start_,
         preedit_selection_end_);
+
+    fake_event.type = WebKit::WebInputEvent::KeyUp;
+    host_view_->ForwardKeyboardEvent(fake_event);
   }
 }
 
 void GtkIMContextWrapper::HandlePreeditEnd() {
   if (preedit_text_.length()) {
     // The composition session has been finished.
     preedit_text_.clear();
     preedit_underlines_.clear();
     is_preedit_changed_ = true;
 
@@ skipping 145 matching lines @@
     } while (pango_attr_iterator_next(iter));
     pango_attr_iterator_destroy(iter);
   }
 
   // Use a black thin underline by default.
   if (underlines->empty()) {
     underlines->push_back(
         WebKit::WebCompositionUnderline(0, length, SK_ColorBLACK, false));
   }
 }