Tracking SelectionBounds for all RenderWidgets on the Browser Side (Aura Only)

content/browser/renderer_host/text_input_manager.h

 // Copyright 2016 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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_TEXT_INPUT_MANAGER_H__
 #define CONTENT_BROWSER_RENDERER_HOST_TEXT_INPUT_MANAGER_H__
 
 #include <unordered_map>
 
 #include "base/observer_list.h"
 #include "content/common/content_export.h"
 #include "content/common/text_input_state.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/selection_bound.h"
+
+struct ViewHostMsg_SelectionBounds_Params;
 
 namespace content {
 
 class RenderWidgetHostImpl;
 class RenderWidgetHostView;
 class RenderWidgetHostViewBase;
 class WebContents;
 
 // A class which receives updates of TextInputState from multiple sources and
 // decides what the new TextInputState is. It also notifies the observers when
 // text input state is updated.
 class CONTENT_EXPORT TextInputManager {
  public:
   // The tab's top-level RWHV should be an observer of TextInputManager to get
   // notifications about changes in TextInputState or other IME related state
   // for child frames.
   class CONTENT_EXPORT Observer {
    public:
     // Called when a view has called UpdateTextInputState on TextInputManager.
     // If the call has led to a change in TextInputState, |did_update_state| is
     // true. In some plaforms, we need this update even when the state has not
     // changed (e.g., Aura for updating IME).
     virtual void OnUpdateTextInputStateCalled(
         TextInputManager* text_input_manager,
         RenderWidgetHostViewBase* updated_view,
         bool did_update_state) {}
+    // Called when the selection bounds for the |updated_view| has changed.
+    virtual void OnSelectionBoundsChanged(
+        TextInputManager* text_input_manager,
+        RenderWidgetHostViewBase* updated_view) {}
   };
 
   TextInputManager();
   ~TextInputManager();
 
   // ---------------------------------------------------------------------------
   // The following methods can be used to obtain information about IME-related
   // state for the active RenderWidget.
 
   // Returns the currently active widget, i.e., the RWH which is associated with
   // |active_view_|.
   RenderWidgetHostImpl* GetActiveWidget() const;
 
   // Returns the TextInputState corresponding to |active_view_|.
   // Users of this method should not hold on to the pointer as it might become
   // dangling if the TextInputManager or |active_view_| might go away.
   const TextInputState* GetTextInputState();
 
+  // Returns the rect between selection bounds for the |active_view_|.
+  gfx::Rect GetSelectionBoundsRect();
+
   // ---------------------------------------------------------------------------
   // The following methods are called by RWHVs on the tab to update their IME-
   // related state.
 
   // Updates the TextInputState for |view|.
   void UpdateTextInputState(RenderWidgetHostViewBase* view,
                             const TextInputState& state);
 
+  void SelectionBoundsChanged(RenderWidgetHostViewBase* view,
+                              const ViewHostMsg_SelectionBounds_Params& params);
+
   // Registers the given |view| for tracking its TextInputState. This is called
   // by any view which has updates in its TextInputState (whether tab's RWHV or
   // that of a child frame). The |view| must unregister itself before being
   // destroyed (i.e., call TextInputManager::Unregister).
   void Register(RenderWidgetHostViewBase* view);
 
   // Clears the TextInputState from the |view|. If |view == active_view_|, this
   // call will lead to a TextInputState update since the TextInputState.type
   // should be reset to none.
   void Unregister(RenderWidgetHostViewBase* view);
@@ skipping 10 matching lines @@
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
   RenderWidgetHostViewBase* active_view_for_testing() { return active_view_; }
 
  private:
   friend bool GetTextInputTypeForView(WebContents* web_contents,
                                       RenderWidgetHostView* view,
                                       ui::TextInputType* type);
 
+  template <class Value>
+  class ViewMap : public std::unordered_map<RenderWidgetHostViewBase*, Value> {
+  };
+
   void NotifyObserversAboutInputStateUpdate(RenderWidgetHostViewBase* view,
                                             bool did_update_state);
 
   // The view with active text input state, i.e., a focused <input> element.
   // It will be nullptr if no such view exists. Note that the active view
   // cannot have a |TextInputState.type| of ui::TEXT_INPUT_TYPE_NONE.
   RenderWidgetHostViewBase* active_view_;
 
-  std::unordered_map<RenderWidgetHostViewBase*, TextInputState>
-      text_input_state_map_;
+  ViewMap<TextInputState> text_input_state_map_;
+  ViewMap<gfx::SelectionBound> selection_anchor_map_;
+  ViewMap<gfx::SelectionBound> selection_focus_map_;

[kenrb, 2016/06/28 19:15:23]

I'm not sure about this, but is it better to do it this way or to have a single
map, from RenderWidgetHostView to a struct containing all of the state for that
view? Selection anchor and selection focus bounds seem to be always accessed and
set together, at least, but TextInputState is get and set at different times
from those.

[EhsanK, 2016/06/29 17:09:58]

I made the two selection related one a map into a pair of selection bounds. But
I might have to do a refactoring after finishing the code for MAC.

 
   base::ObserverList<Observer> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(TextInputManager);
 };
 }
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_TEXT_INPUT_MANAGER_H__