New InputMethod api for Views.

views/ime/input_method_gtk.cc

+// Copyright (c) 2011 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 "views/ime/input_method_gtk.h"
+
+#include <gdk/gdk.h>
+#include <gdk/gdkkeysyms.h>
+
+#include <algorithm>
+
+#include "base/basictypes.h"
+#include "base/logging.h"
+#include "base/string_util.h"
+#include "base/third_party/icu/icu_utf.h"
+#include "base/utf_string_conversions.h"
+#include "ui/base/gtk/event_synthesis_gtk.h"
+#include "ui/base/gtk/gtk_im_context_util.h"
+#include "ui/base/keycodes/keyboard_codes.h"
+#include "ui/base/keycodes/keyboard_code_conversion_gtk.h"
+#include "views/events/event.h"
+#include "views/widget/widget.h"
+
+namespace views {
+
+InputMethodGtk::InputMethodGtk(internal::InputMethodDelegate* delegate)
+    : delegate_(delegate),
+      widget_(NULL),
+      focused_view_(NULL),
+      context_(NULL),
+      context_simple_(NULL),
+      widget_realize_id_(0),
+      widget_unrealize_id_(0),
+      widget_focus_in_id_(0),
+      widget_focus_out_id_(0),
+      widget_focused_(false),
+      context_focused_(false),
+      handling_key_event_(false),
+      composing_text_(false),
+      composition_changed_(false),
+      suppress_next_result_(false) {
+}
+
+InputMethodGtk::~InputMethodGtk() {
+  if (widget_) {
+    widget_->GetFocusManager()->RemoveFocusChangeListener(this);
+    GtkWidget* native_view = widget_->GetNativeView();
+    if (native_view) {
+      g_signal_handler_disconnect(native_view, widget_realize_id_);
+      g_signal_handler_disconnect(native_view, widget_unrealize_id_);
+      g_signal_handler_disconnect(native_view, widget_focus_in_id_);
+      g_signal_handler_disconnect(native_view, widget_focus_out_id_);
+    }
+    widget_ = NULL;
+  }
+  if (context_) {
+    g_object_unref(context_);
+    context_ = NULL;
+  }
+  if (context_simple_) {
+    g_object_unref(context_simple_);
+    context_simple_ = NULL;
+  }
+}
+
+void InputMethodGtk::set_delegate(internal::InputMethodDelegate* delegate) {
+  delegate_ = delegate;

[oshima, 2011/03/21 20:30:56]

can delegate be NULL? DCHECK if not.

[James Su, 2011/03/21 21:21:16]

Done.

+}
+
+void InputMethodGtk::Init(Widget* widget) {
+  DCHECK(widget);
+  DCHECK(GTK_IS_WIDGET(widget->GetNativeView()));
+  DCHECK(widget->GetFocusManager());
+
+  if (widget_) {
+    NOTREACHED() << "The input method is already initialized.";
+    return;
+  }
+
+  widget_ = widget;
+  widget->GetFocusManager()->AddFocusChangeListener(this);
+
+  widget_realize_id_ =
+      g_signal_connect(widget->GetNativeView(), "realize",
+                       G_CALLBACK(OnWidgetRealizeThunk), this);
+  widget_unrealize_id_ =
+      g_signal_connect(widget->GetNativeView(), "unrealize",
+                       G_CALLBACK(OnWidgetUnrealizeThunk), this);
+  widget_focus_in_id_ =
+      g_signal_connect(widget->GetNativeView(), "focus-in-event",
+                       G_CALLBACK(OnWidgetFocusInThunk), this);
+  widget_focus_out_id_ =
+      g_signal_connect(widget->GetNativeView(), "focus-out-event",
+                       G_CALLBACK(OnWidgetFocusOutThunk), this);
+
+  context_ = gtk_im_multicontext_new();
+  context_simple_ = gtk_im_context_simple_new();
+
+  // context_ and context_simple_ share the same callback handlers.
+  // All data come from them are treated equally.
+  // context_ is for full input method support.
+  // context_simple_ is for supporting dead/compose keys when input method is
+  // disabled, eg. in password input box.
+  g_signal_connect(context_, "commit",
+                   G_CALLBACK(OnCommitThunk), this);
+  g_signal_connect(context_, "preedit_start",
+                   G_CALLBACK(OnPreeditStartThunk), this);
+  g_signal_connect(context_, "preedit_end",
+                   G_CALLBACK(OnPreeditEndThunk), this);
+  g_signal_connect(context_, "preedit_changed",
+                   G_CALLBACK(OnPreeditChangedThunk), this);
+
+  g_signal_connect(context_simple_, "commit",
+                   G_CALLBACK(OnCommitThunk), this);
+  g_signal_connect(context_simple_, "preedit_start",
+                   G_CALLBACK(OnPreeditStartThunk), this);
+  g_signal_connect(context_simple_, "preedit_end",
+                   G_CALLBACK(OnPreeditEndThunk), this);
+  g_signal_connect(context_simple_, "preedit_changed",
+                   G_CALLBACK(OnPreeditChangedThunk), this);
+
+  // Set client window if the widget is already realized.
+  OnWidgetRealize(widget->GetNativeView());
+}
+
+void InputMethodGtk::DispatchKeyEvent(const KeyEvent& key) {
+  suppress_next_result_ = false;
+
+  if (!context_focused_) {
+    DispatchKeyEventPostIME(key);
+    return;
+  }
+
+  handling_key_event_ = true;
+  composition_changed_ = false;
+  result_text_.clear();
+
+  GdkEvent* event = key.native_event();
+  DCHECK(!event || event->type == GDK_KEY_PRESS ||
+         event->type == GDK_KEY_RELEASE);
+
+  // If it's a fake key event, then we need to synthesis a GdkEventKey.
+  bool need_free_event = false;
+  if (!event) {
+    event = SynthesizeGdkEventKey(key);
+    need_free_event = true;
+  }
+
+  gboolean filtered = false;
+  if (GetTextInputType() == ui::TEXT_INPUT_TYPE_TEXT)
+    filtered = gtk_im_context_filter_keypress(context_, &event->key);
+  else
+    filtered = gtk_im_context_filter_keypress(context_simple_, &event->key);
+
+  handling_key_event_ = false;
+
+  View* old_focused_view = focused_view_;
+  if (key.type() == ui::ET_KEY_PRESSED && filtered)
+    ProcessFilteredKeyPressEvent(key);
+
+  if (old_focused_view != focused_view_)
+    return;
+
+  if (HasInputMethodResult())
+    ProcessInputMethodResult(key, filtered);
+
+  if (old_focused_view != focused_view_)
+    return;
+
+  if (key.type() == ui::ET_KEY_PRESSED && !filtered)
+    ProcessUnfilteredKeyPressEvent(key);
+  else if (key.type() == ui::ET_KEY_RELEASED)
+    DispatchKeyEventPostIME(key);
+
+  if (need_free_event)
+    gdk_event_free(event);
+}
+
+void InputMethodGtk::OnTextInputTypeChanged(View* view) {
+  if (IsViewFocused(view))
+    UpdateContextFocusState();
+}
+
+void InputMethodGtk::OnCaretBoundsChanged(View* view) {
+  if (!IsViewFocused(view))
+    return;
+
+  TextInputClient* client = view->GetTextInputClient();
+  if (!client)
+    return;
+
+  gfx::Rect rect = client->GetCaretBounds();
+  gfx::Point origin = rect.origin();
+  gfx::Point end = gfx::Point(rect.right(), rect.bottom());
+
+  View::ConvertPointToWidget(view, &origin);
+  View::ConvertPointToWidget(view, &end);
+
+  GdkRectangle gdk_rect =
+      { origin.x(), origin.y(), end.x() - origin.x(), end.y() - origin.y() };
+
+  // We need to translate the coordinates to the toplevel widget if the view is
+  // inside a child widget.
+  if (view->GetWidget() != widget_) {
+    gboolean result = gtk_widget_translate_coordinates(
+        view->GetWidget()->GetNativeView(), widget_->GetNativeView(),
+        gdk_rect.x, gdk_rect.y, &gdk_rect.x, &gdk_rect.y);
+    DCHECK(result);
+  }
+
+  gtk_im_context_set_cursor_location(context_, &gdk_rect);
+}
+
+void InputMethodGtk::CancelComposition(View* view) {
+  if (IsViewFocused(view))
+    ResetContext();
+}
+
+std::string InputMethodGtk::GetInputLocale() {
+  // Not supported.
+  return std::string("");
+}
+
+base::i18n::TextDirection InputMethodGtk::GetInputTextDirection() {
+  // Not supported.
+  return base::i18n::UNKNOWN_DIRECTION;
+}
+
+bool InputMethodGtk::IsActive() {
+  // We always need to send keyboard events to either |context_| or
+  // |context_simple_|, so just return true here.
+  return true;
+}
+
+void InputMethodGtk::FocusWillChange(View* focused_before, View* focused) {
+  DCHECK_EQ(focused_view_, focused_before);
+  ConfirmComposition();
+  focused_view_ = focused;
+  UpdateContextFocusState();
+}
+
+void InputMethodGtk::ConfirmComposition() {
+  TextInputClient* client = GetTextInputClient();
+  if (client && client->HasComposition())
+    client->ConfirmComposition();
+
+  ResetContext();
+}
+
+void InputMethodGtk::ResetContext() {
+  if (!context_focused_)
+    return;
+
+  DCHECK(widget_focused_);
+  DCHECK(focused_view_);
+  DCHECK(!handling_key_event_);
+
+  // To prevent any text from being committed when resetting the |context_|;

[oshima, 2011/03/21 20:30:56]

Does this mean  
filtered = gtk_im_context_filter_keypress,
gtk_im_context_reset, gtk_im_context_focus_out/in functions may send 
commit signal?

[James Su, 2011/03/21 21:21:16]

yes.

+  handling_key_event_ = true;
+  suppress_next_result_ = true;
+
+  gtk_im_context_reset(context_);
+  gtk_im_context_reset(context_simple_);
+
+  // Some input methods may not honour the reset call. Focusing out/in the
+  // |context_| to make sure it gets reset correctly.
+  gtk_im_context_focus_out(context_);
+  gtk_im_context_focus_in(context_);

[oshima, 2011/03/21 20:30:56]

don't we have to do this for contet_simple_? And if this  has to be done anyway,
do  we need gtk_im_context_reset?

[James Su, 2011/03/21 21:21:16]

context_simple_ doesn't have this problem, reset is enough.

+
+  composition_.Clear();
+  result_text_.clear();
+  handling_key_event_ = false;
+  composing_text_ = false;
+  composition_changed_ = false;
+}
+
+void InputMethodGtk::UpdateContextFocusState() {
+  bool old_context_focused = context_focused_;
+  context_focused_ = (GetTextInputClient() != NULL);
+
+  if (old_context_focused && !context_focused_) {
+    gtk_im_context_focus_out(context_);
+    gtk_im_context_focus_out(context_simple_);
+  } else if (!old_context_focused && context_focused_) {
+    gtk_im_context_focus_in(context_);
+    gtk_im_context_focus_in(context_simple_);
+  }
+}
+
+void InputMethodGtk::ProcessFilteredKeyPressEvent(const KeyEvent& key) {
+  if (NeedInsertChar()) {
+    DispatchKeyEventPostIME(key);
+  } else {
+    KeyEvent key(ui::ET_KEY_PRESSED, ui::VKEY_PROCESSKEY, key.flags());
+    DispatchKeyEventPostIME(key);
+  }
+}
+
+void InputMethodGtk::ProcessUnfilteredKeyPressEvent(const KeyEvent& key) {
+  DispatchKeyEventPostIME(key);
+
+  // If a key event was not filtered by |context_| or |context_simple_|, then
+  // it means the key event didn't generate any result text. For some cases,
+  // the key event may still generate a valid character, eg. a control-key
+  // event (ctrl-a, return, tab, etc.). We need to send the character to the
+  // focused text input client by calling TextInputClient::InsertChar().
+  char16 ch = key.GetCharacter();
+  TextInputClient* client = GetTextInputClient();
+  if (ch && client)
+    client->InsertChar(ch, key.flags());
+}
+
+void InputMethodGtk::ProcessInputMethodResult(const KeyEvent& key,
+                                              bool filtered) {
+  TextInputClient* client = GetTextInputClient();
+  DCHECK(client);
+
+  if (result_text_.length()) {
+    if (filtered && NeedInsertChar()) {
+      for (string16::const_iterator i = result_text_.begin();
+           i != result_text_.end(); ++i) {
+        client->InsertChar(*i, key.flags());
+      }
+    } else {
+      client->InsertText(result_text_);
+      composing_text_ = false;
+    }
+  }
+
+  if (composition_changed_ && GetTextInputType() != ui::TEXT_INPUT_TYPE_NONE) {
+    if (composition_.text.length()) {
+      composing_text_ = true;
+      client->SetComposition(composition_);
+    } else if (result_text_.empty()) {
+      client->ClearComposition();
+    }
+  }
+}
+
+TextInputClient* InputMethodGtk::GetTextInputClient() const {
+  return (widget_focused_ && focused_view_) ?
+      focused_view_->GetTextInputClient() : NULL;
+}
+
+ui::TextInputType InputMethodGtk::GetTextInputType() const {
+  TextInputClient* client = GetTextInputClient();
+  return client ? client->GetTextInputType() : ui::TEXT_INPUT_TYPE_NONE;
+}
+
+bool InputMethodGtk::IsViewFocused(View* view) const {
+  return widget_focused_ && view && focused_view_ == view;
+}
+
+bool InputMethodGtk::NeedInsertChar() const {
+  return GetTextInputType() == ui::TEXT_INPUT_TYPE_NONE ||
+      (!composing_text_ && result_text_.length() == 1);
+}
+
+bool InputMethodGtk::HasInputMethodResult() const {
+  return result_text_.length() || composition_changed_;
+}
+
+void InputMethodGtk::SendFakeProcessKeyEvent(bool pressed) const {
+  KeyEvent key(pressed ? ui::ET_KEY_PRESSED : ui::ET_KEY_RELEASED,
+               ui::VKEY_PROCESSKEY, 0);
+  DispatchKeyEventPostIME(key);
+}
+
+GdkEvent* InputMethodGtk::SynthesizeGdkEventKey(const KeyEvent& key) const {
+  guint keyval =
+      ui::GdkKeyCodeForWindowsKeyCode(key.key_code(), key.IsShiftDown());
+  guint state = 0;
+  if (key.IsShiftDown())
+    state |= GDK_SHIFT_MASK;
+  if (key.IsControlDown())
+    state |= GDK_CONTROL_MASK;
+  if (key.IsAltDown())
+    state |= GDK_MOD1_MASK;
+  if (key.IsCapsLockDown())
+    state |= GDK_LOCK_MASK;
+
+  DCHECK(widget_->GetNativeView()->window);
+  return ui::SynthesizeKeyEvent(widget_->GetNativeView()->window,
+                                key.type() == ui::ET_KEY_PRESSED,
+                                keyval, state);
+}
+
+void InputMethodGtk::DispatchKeyEventPostIME(const KeyEvent& key) const {
+  if (delegate_)
+    delegate_->DispatchKeyEventPostIME(key);
+}
+
+void InputMethodGtk::OnCommit(GtkIMContext* context, gchar* text) {
+  if (suppress_next_result_) {
+    suppress_next_result_ = false;
+    return;
+  }
+
+  if (!context_focused_)
+    return;
+
+  string16 utf16_text(UTF8ToUTF16(text));
+
+  // Append the text to the buffer, because commit signal might be fired
+  // multiple times when processing a key event.
+  result_text_.append(utf16_text);
+  if (!handling_key_event_) {
+    TextInputClient* client = GetTextInputClient();
+    if (client && client->GetTextInputType() != ui::TEXT_INPUT_TYPE_NONE) {
+      SendFakeProcessKeyEvent(true);
+      client->InsertText(utf16_text);
+      SendFakeProcessKeyEvent(false);
+    }
+  }
+}
+
+void InputMethodGtk::OnPreeditStart(GtkIMContext* context) {
+  if (suppress_next_result_ || !context_focused_)
+    return;
+
+  composing_text_ = true;
+}
+
+void InputMethodGtk::OnPreeditChanged(GtkIMContext* context) {
+  if (suppress_next_result_ || !context_focused_)
+    return;
+
+  gchar* text = NULL;
+  PangoAttrList* attrs = NULL;
+  gint cursor_position = 0;
+  gtk_im_context_get_preedit_string(context, &text, &attrs, &cursor_position);
+
+  ui::ExtractCompositionInfoFromGtkPreedit(text, attrs, cursor_position,
+                                           &composition_);
+  composition_changed_ = true;
+
+  g_free(text);
+  pango_attr_list_unref(attrs);
+
+  if (composition_.text.length())
+    composing_text_ = true;
+
+  if (!handling_key_event_) {
+    TextInputClient* client = GetTextInputClient();
+    if (client && client->GetTextInputType() != ui::TEXT_INPUT_TYPE_NONE) {
+      SendFakeProcessKeyEvent(true);
+      client->SetComposition(composition_);
+      SendFakeProcessKeyEvent(false);
+    }
+  }
+}
+
+void InputMethodGtk::OnPreeditEnd(GtkIMContext* context) {
+  if (!context_focused_ || composition_.text.empty())
+    return;
+
+  composition_changed_ = true;
+  composition_.Clear();
+
+  if (!handling_key_event_) {
+    TextInputClient* client = GetTextInputClient();
+    if (client && client->HasComposition())
+      client->ClearComposition();
+  }
+}
+
+void InputMethodGtk::OnWidgetRealize(GtkWidget* widget) {
+  // We should only set im context's client window once, because when setting
+  // client window, im context may destroy and recreate its internal states and
+  // objects.
+  if (widget->window) {
+    gtk_im_context_set_client_window(context_, widget->window);
+    gtk_im_context_set_client_window(context_simple_, widget->window);
+  }
+}
+
+void InputMethodGtk::OnWidgetUnrealize(GtkWidget* widget) {
+  gtk_im_context_set_client_window(context_, NULL);
+  gtk_im_context_set_client_window(context_simple_, NULL);
+}
+
+gboolean InputMethodGtk::OnWidgetFocusIn(GtkWidget* widget,
+                                         GdkEventFocus* event) {
+  if (!widget_focused_) {
+    widget_focused_ = true;
+    UpdateContextFocusState();
+  }
+  return false;
+}
+
+gboolean InputMethodGtk::OnWidgetFocusOut(GtkWidget* widget,
+                                          GdkEventFocus* event) {
+  if (widget_focused_) {
+    ConfirmComposition();
+    widget_focused_ = false;
+    UpdateContextFocusState();
+  }
+  return false;
+}
+
+}  // namespace views