ui/base/ime/input_method_base.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_BASE_IME_INPUT_METHOD_BASE_H_
   6 #define UI_BASE_IME_INPUT_METHOD_BASE_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/observer_list.h"
  12 #include "ui/base/ime/input_method.h"
  13 #include "ui/base/ui_base_export.h"
  14
  15 namespace gfx {
  16 class Rect;
  17 }  // namespace gfx
  18
  19 namespace ui {
  20
  21 class InputMethodObserver;
  22 class KeyEvent;
  23 class TextInputClient;
  24
  25 // A helper class providing functionalities shared among ui::InputMethod
  26 // implementations.
  27 class UI_BASE_EXPORT InputMethodBase
  28    : NON_EXPORTED_BASE(public InputMethod),
  29      public base::SupportsWeakPtr<InputMethodBase> {
  30  public:
  31   InputMethodBase();
  32   virtual ~InputMethodBase();
  33
  34   // Overriden from InputMethod.
  35   virtual void SetDelegate(internal::InputMethodDelegate* delegate) OVERRIDE;
  36   virtual void Init(bool focused) OVERRIDE;
  37   // If a derived class overrides OnFocus()/OnBlur(), it should call parent's
  38   // implementation first, to make sure |system_toplevel_window_focused_| flag
  39   // can be updated correctly.
  40   virtual void OnFocus() OVERRIDE;
  41   virtual void OnBlur() OVERRIDE;
  42   virtual void SetFocusedTextInputClient(TextInputClient* client) OVERRIDE;
  43   virtual void DetachTextInputClient(TextInputClient* client) OVERRIDE;
  44   virtual TextInputClient* GetTextInputClient() const OVERRIDE;
  45
  46   // If a derived class overrides this method, it should call parent's
  47   // implementation.
  48   virtual void OnTextInputTypeChanged(const TextInputClient* client) OVERRIDE;
  49
  50   virtual TextInputType GetTextInputType() const OVERRIDE;
  51   virtual TextInputMode GetTextInputMode() const OVERRIDE;
  52   virtual bool CanComposeInline() const OVERRIDE;
  53   virtual void ShowImeIfNeeded() OVERRIDE;
  54
  55   virtual void AddObserver(InputMethodObserver* observer) OVERRIDE;
  56   virtual void RemoveObserver(InputMethodObserver* observer) OVERRIDE;
  57
  58  protected:
  59   virtual void OnWillChangeFocusedClient(TextInputClient* focused_before,
  60                                          TextInputClient* focused) {}
  61   virtual void OnDidChangeFocusedClient(TextInputClient* focused_before,
  62                                         TextInputClient* focused) {}
  63
  64   // Returns true if |client| is currently focused.
  65   bool IsTextInputClientFocused(const TextInputClient* client);
  66
  67   // Checks if the focused text input client's text input type is
  68   // TEXT_INPUT_TYPE_NONE. Also returns true if there is no focused text
  69   // input client.
  70   bool IsTextInputTypeNone() const;
  71
  72   // Convenience method to call the focused text input client's
  73   // OnInputMethodChanged() method. It'll only take effect if the current text
  74   // input type is not TEXT_INPUT_TYPE_NONE.
  75   void OnInputMethodChanged() const;
  76
  77   // Convenience method to call delegate_->DispatchKeyEventPostIME().
  78   // Returns true if the event was processed
  79   bool DispatchKeyEventPostIME(const ui::KeyEvent& event) const;
  80
  81   // Convenience method to notify all observers of TextInputClient changes.
  82   void NotifyTextInputStateChanged(const TextInputClient* client);
  83
  84   // Interface for for signalling candidate window events.
  85   // See also *Callback functions below. To avoid reentrancy issue that
  86   // TextInputClient manipulates IME state during even handling, these methods
  87   // defer sending actual signals to renderer.
  88   void OnCandidateWindowShown();
  89   void OnCandidateWindowUpdated();
  90   void OnCandidateWindowHidden();
  91
  92   bool system_toplevel_window_focused() const {
  93     return system_toplevel_window_focused_;
  94   }
  95
  96  private:
  97   void SetFocusedTextInputClientInternal(TextInputClient* client);
  98
  99   // Deferred callbacks for signalling TextInputClient about candidate window
 100   // appearance changes.
 101   void CandidateWindowShownCallback();
 102   void CandidateWindowUpdatedCallback();
 103   void CandidateWindowHiddenCallback();
 104
 105   internal::InputMethodDelegate* delegate_;
 106   TextInputClient* text_input_client_;
 107
 108   ObserverList<InputMethodObserver> observer_list_;
 109
 110   bool system_toplevel_window_focused_;
 111
 112   DISALLOW_COPY_AND_ASSIGN(InputMethodBase);
 113 };
 114
 115 }  // namespace ui
 116
 117 #endif  // UI_BASE_IME_INPUT_METHOD_BASE_H_