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      1 // Copyright (c) 2014 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 CONTENT_BROWSER_RENDERER_HOST_LEGACY_RENDER_WIDGET_HOST_WIN_H_
      6 #define CONTENT_BROWSER_RENDERER_HOST_LEGACY_RENDER_WIDGET_HOST_WIN_H_
      7 
      8 #include <atlbase.h>
      9 #include <atlwin.h>
     10 #include <atlcrack.h>
     11 #include <oleacc.h>
     12 
     13 #include "base/basictypes.h"
     14 #include "base/memory/scoped_ptr.h"
     15 #include "base/win/scoped_comptr.h"
     16 #include "content/common/content_export.h"
     17 #include "ui/gfx/rect.h"
     18 
     19 namespace ui {
     20 class WindowEventTarget;
     21 }
     22 
     23 namespace content {
     24 class BrowserAccessibilityManagerWin;
     25 
     26 // Reasons for the existence of this class outlined below:-
     27 // 1. Some screen readers expect every tab / every unique web content container
     28 //    to be in its own HWND with class name Chrome_RenderWidgetHostHWND.
     29 //    With Aura there is one main HWND which comprises the whole browser window
     30 //    or the whole desktop. So, we need a fake HWND with the window class as
     31 //    Chrome_RenderWidgetHostHWND as the root of the accessibility tree for
     32 //    each tab.
     33 // 2. There are legacy drivers for trackpads/trackpoints which have special
     34 //    code for sending mouse wheel and scroll events to the
     35 //    Chrome_RenderWidgetHostHWND window.
     36 // 3. Windowless NPAPI plugins like Flash and Silverlight which expect the
     37 //    container window to have the same bounds as the web page. In Aura, the
     38 //    default container window is the whole window which includes the web page
     39 //    WebContents, etc. This causes the plugin mouse event calculations to
     40 //    fail.
     41 //    We should look to get rid of this code when all of the above are fixed.
     42 
     43 // This class implements a child HWND with the same size as the content area,
     44 // that delegates its accessibility implementation to the root of the
     45 // BrowserAccessibilityManager tree. This HWND is hooked up as the parent of
     46 // the root object in the BrowserAccessibilityManager tree, so when any
     47 // accessibility client calls ::WindowFromAccessibleObject, they get this
     48 // HWND instead of the DesktopWindowTreeHostWin.
     49 class CONTENT_EXPORT LegacyRenderWidgetHostHWND
     50     : public ATL::CWindowImpl<LegacyRenderWidgetHostHWND,
     51                               NON_EXPORTED_BASE(ATL::CWindow),
     52                               ATL::CWinTraits<WS_CHILD> > {
     53  public:
     54   DECLARE_WND_CLASS_EX(L"Chrome_RenderWidgetHostHWND", CS_DBLCLKS, 0);
     55 
     56   typedef ATL::CWindowImpl<LegacyRenderWidgetHostHWND,
     57                            NON_EXPORTED_BASE(ATL::CWindow),
     58                            ATL::CWinTraits<WS_CHILD> > Base;
     59 
     60   ~LegacyRenderWidgetHostHWND();
     61 
     62   // Creates and returns an instance of the LegacyRenderWidgetHostHWND class on
     63   // successful creation of a child window parented to the parent window passed
     64   // in.
     65   static scoped_ptr<LegacyRenderWidgetHostHWND> Create(HWND parent);
     66 
     67   BEGIN_MSG_MAP_EX(LegacyRenderWidgetHostHWND)
     68     MESSAGE_HANDLER_EX(WM_GETOBJECT, OnGetObject)
     69     MESSAGE_RANGE_HANDLER(WM_KEYFIRST, WM_KEYLAST, OnKeyboardRange)
     70     MESSAGE_HANDLER_EX(WM_PAINT, OnPaint)
     71     MESSAGE_HANDLER_EX(WM_NCPAINT, OnNCPaint)
     72     MESSAGE_HANDLER_EX(WM_ERASEBKGND, OnEraseBkGnd)
     73     MESSAGE_RANGE_HANDLER(WM_MOUSEFIRST, WM_MOUSELAST, OnMouseRange)
     74     MESSAGE_HANDLER_EX(WM_MOUSELEAVE, OnMouseLeave)
     75     MESSAGE_HANDLER_EX(WM_MOUSEACTIVATE, OnMouseActivate)
     76     MESSAGE_HANDLER_EX(WM_SETCURSOR, OnSetCursor)
     77     MESSAGE_HANDLER_EX(WM_TOUCH, OnTouch)
     78     MESSAGE_HANDLER_EX(WM_HSCROLL, OnScroll)
     79     MESSAGE_HANDLER_EX(WM_VSCROLL, OnScroll)
     80     MESSAGE_HANDLER_EX(WM_NCHITTEST, OnNCHitTest)
     81     MESSAGE_RANGE_HANDLER(WM_NCMOUSEMOVE, WM_NCXBUTTONDBLCLK,
     82                           OnMouseRange)
     83     MESSAGE_HANDLER_EX(WM_NCCALCSIZE, OnNCCalcSize)
     84     MESSAGE_HANDLER_EX(WM_SIZE, OnSize)
     85   END_MSG_MAP()
     86 
     87   HWND hwnd() { return m_hWnd; }
     88 
     89   // Called when the child window is to be reparented to a new window.
     90   // The |parent| parameter contains the new parent window.
     91   void UpdateParent(HWND parent);
     92   HWND GetParent();
     93 
     94   IAccessible* window_accessible() { return window_accessible_; }
     95 
     96   void set_browser_accessibility_manager(
     97       content::BrowserAccessibilityManagerWin* manager) {
     98     manager_ = manager;
     99   }
    100 
    101   void OnManagerDeleted();
    102 
    103   // Functions to show and hide the window.
    104   void Show();
    105   void Hide();
    106 
    107   // Resizes the window to the bounds passed in.
    108   void SetBounds(const gfx::Rect& bounds);
    109 
    110  protected:
    111   virtual void OnFinalMessage(HWND hwnd) OVERRIDE;
    112 
    113  private:
    114   LegacyRenderWidgetHostHWND(HWND parent);
    115 
    116   bool Init();
    117 
    118   // Returns the target to which the windows input events are forwarded.
    119   static ui::WindowEventTarget* GetWindowEventTarget(HWND parent);
    120 
    121   LRESULT OnEraseBkGnd(UINT message, WPARAM w_param, LPARAM l_param);
    122   LRESULT OnGetObject(UINT message, WPARAM w_param, LPARAM l_param);
    123   LRESULT OnKeyboardRange(UINT message, WPARAM w_param, LPARAM l_param,
    124                           BOOL& handled);
    125   LRESULT OnMouseLeave(UINT message, WPARAM w_param, LPARAM l_param);
    126   LRESULT OnMouseRange(UINT message, WPARAM w_param, LPARAM l_param,
    127                        BOOL& handled);
    128   LRESULT OnMouseActivate(UINT message, WPARAM w_param, LPARAM l_param);
    129   LRESULT OnTouch(UINT message, WPARAM w_param, LPARAM l_param);
    130   LRESULT OnScroll(UINT message, WPARAM w_param, LPARAM l_param);
    131   LRESULT OnNCHitTest(UINT message, WPARAM w_param, LPARAM l_param);
    132 
    133   LRESULT OnNCPaint(UINT message, WPARAM w_param, LPARAM l_param);
    134   LRESULT OnPaint(UINT message, WPARAM w_param, LPARAM l_param);
    135   LRESULT OnSetCursor(UINT message, WPARAM w_param, LPARAM l_param);
    136   LRESULT OnNCCalcSize(UINT message, WPARAM w_param, LPARAM l_param);
    137   LRESULT OnSize(UINT message, WPARAM w_param, LPARAM l_param);
    138 
    139   content::BrowserAccessibilityManagerWin* manager_;
    140   base::win::ScopedComPtr<IAccessible> window_accessible_;
    141 
    142   // Set to true if we turned on mouse tracking.
    143   bool mouse_tracking_enabled_;
    144 
    145   DISALLOW_COPY_AND_ASSIGN(LegacyRenderWidgetHostHWND);
    146 };
    147 
    148 }  // namespace content
    149 
    150 #endif  // CONTENT_BROWSER_RENDERER_HOST_LEGACY_RENDER_WIDGET_HOST_WIN_H_
    151 
    152