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 <utility>
 
 #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 |updated_view| has called ImeCancelComposition on
     // TextInputManager.
     virtual void OnImeCancelComposition(
         TextInputManager* text_input_manager,
         RenderWidgetHostViewBase* updated_view) {}
+    // 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);
 
   // The current IME composition has been cancelled on the renderer side for
   // the widget corresponding to |view|.
   void ImeCancelComposition(RenderWidgetHostViewBase* view);
 
+  // Updates the selection bounds for the |view|. In Aura, selection bounds are
+  // used to provide the InputMethod with the position of the caret, e.g., in
+  // setting the position of the ui::ImeWindow.
+  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);
 
   // Returns true if |view| is already registered.
   bool IsRegistered(RenderWidgetHostViewBase* view) const;
 
   // Add and remove observers for notifications regarding updates in the
   // TextInputState. Clients must be sure to remove themselves before they go
   // away.
   // Only the tab's RWHV should observer TextInputManager. In tests, however,
   // in addition to the tab's RWHV, one or more test observers might observe
   // TextInputManager.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
   RenderWidgetHostViewBase* active_view_for_testing() { return active_view_; }
   size_t GetRegisteredViewsCountForTesting();
   ui::TextInputType GetTextInputTypeForViewForTesting(
       RenderWidgetHostViewBase* view);
 
  private:
+  // Text selection bounds.
+  struct SelectionRegion {
+    SelectionRegion();
+    SelectionRegion(const SelectionRegion& other);
+
+    // The begining of the selection region.
+    gfx::SelectionBound anchor;
+    // The end of the selection region (caret position).
+    gfx::SelectionBound focus;
+  };
+
+  // This class is used to create maps which hold specific IME state for a
+  // view.
+  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_;
+
+  // Text selection bounds information for registered views.
+  ViewMap<SelectionRegion> selection_region_map_;
 
   base::ObserverList<Observer> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(TextInputManager);
 };
 }
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_TEXT_INPUT_MANAGER_H__