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/ime/ui_base_ime_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_IME_EXPORT InputMethodBase
  28     : NON_EXPORTED_BASE(public InputMethod),
  29       public base::SupportsWeakPtr<InputMethodBase> {
  30  public:
  31   InputMethodBase();
  32   ~InputMethodBase() override;
  33
  34   // Overriden from InputMethod.
  35   void SetDelegate(internal::InputMethodDelegate* delegate) override;
  36   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   void OnFocus() override;
  41   void OnBlur() override;
  42   void SetFocusedTextInputClient(TextInputClient* client) override;
  43   void DetachTextInputClient(TextInputClient* client) override;
  44   TextInputClient* GetTextInputClient() const override;
  45
  46   // If a derived class overrides this method, it should call parent's
  47   // implementation.
  48   void OnTextInputTypeChanged(const TextInputClient* client) override;
  49
  50   TextInputType GetTextInputType() const override;
  51   TextInputMode GetTextInputMode() const override;
  52   int GetTextInputFlags() const override;
  53   bool CanComposeInline() const override;
  54   void ShowImeIfNeeded() override;
  55
  56   void AddObserver(InputMethodObserver* observer) override;
  57   void RemoveObserver(InputMethodObserver* observer) override;
  58
  59  protected:
  60   virtual void OnWillChangeFocusedClient(TextInputClient* focused_before,
  61                                          TextInputClient* focused) {}
  62   virtual void OnDidChangeFocusedClient(TextInputClient* focused_before,
  63                                         TextInputClient* focused) {}
  64
  65   // Returns true if |client| is currently focused.
  66   bool IsTextInputClientFocused(const TextInputClient* client);
  67
  68   // Checks if the focused text input client's text input type is
  69   // TEXT_INPUT_TYPE_NONE. Also returns true if there is no focused text
  70   // input client.
  71   bool IsTextInputTypeNone() const;
  72
  73   // Convenience method to call the focused text input client's
  74   // OnInputMethodChanged() method. It'll only take effect if the current text
  75   // input type is not TEXT_INPUT_TYPE_NONE.
  76   void OnInputMethodChanged() const;
  77
  78   // Convenience method to call delegate_->DispatchKeyEventPostIME().
  79   // Returns true if the event was processed
  80   bool DispatchKeyEventPostIME(const ui::KeyEvent& event) const;
  81
  82   // Convenience method to notify all observers of TextInputClient changes.
  83   void NotifyTextInputStateChanged(const TextInputClient* client);
  84
  85   // Convenience method to notify all observers of CaretBounds changes on
  86   // |client| which is the text input client with focus.
  87   void NotifyTextInputCaretBoundsChanged(const TextInputClient* client);
  88
  89   // Interface for for signalling candidate window events.
  90   // See also *Callback functions below. To avoid reentrancy issue that
  91   // TextInputClient manipulates IME state during even handling, these methods
  92   // defer sending actual signals to renderer.
  93   void OnCandidateWindowShown();
  94   void OnCandidateWindowUpdated();
  95   void OnCandidateWindowHidden();
  96
  97   bool system_toplevel_window_focused() const {
  98     return system_toplevel_window_focused_;
  99   }
 100
 101  private:
 102   void SetFocusedTextInputClientInternal(TextInputClient* client);
 103
 104   // Deferred callbacks for signalling TextInputClient about candidate window
 105   // appearance changes.
 106   void CandidateWindowShownCallback();
 107   void CandidateWindowUpdatedCallback();
 108   void CandidateWindowHiddenCallback();
 109
 110   internal::InputMethodDelegate* delegate_;
 111   TextInputClient* text_input_client_;
 112
 113   ObserverList<InputMethodObserver> observer_list_;
 114
 115   bool system_toplevel_window_focused_;
 116
 117   DISALLOW_COPY_AND_ASSIGN(InputMethodBase);
 118 };
 119
 120 }  // namespace ui
 121
 122 #endif  // UI_BASE_IME_INPUT_METHOD_BASE_H_