content/browser/renderer_host/legacy_render_widget_host_win.h

   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/win/scoped_comptr.h"
  15 #include "content/common/content_export.h"
  16 #include "ui/gfx/geometry/rect.h"
  17
  18 namespace ui {
  19 class WindowEventTarget;
  20 }
  21
  22 namespace content {
  23 class RenderWidgetHostViewAura;
  24
  25 // Reasons for the existence of this class outlined below:-
  26 // 1. Some screen readers expect every tab / every unique web content container
  27 //    to be in its own HWND with class name Chrome_RenderWidgetHostHWND.
  28 //    With Aura there is one main HWND which comprises the whole browser window
  29 //    or the whole desktop. So, we need a fake HWND with the window class as
  30 //    Chrome_RenderWidgetHostHWND as the root of the accessibility tree for
  31 //    each tab.
  32 // 2. There are legacy drivers for trackpads/trackpoints which have special
  33 //    code for sending mouse wheel and scroll events to the
  34 //    Chrome_RenderWidgetHostHWND window.
  35 // 3. Windowless NPAPI plugins like Flash and Silverlight which expect the
  36 //    container window to have the same bounds as the web page. In Aura, the
  37 //    default container window is the whole window which includes the web page
  38 //    WebContents, etc. This causes the plugin mouse event calculations to
  39 //    fail.
  40 //    We should look to get rid of this code when all of the above are fixed.
  41
  42 // This class implements a child HWND with the same size as the content area,
  43 // that delegates its accessibility implementation to the root of the
  44 // BrowserAccessibilityManager tree. This HWND is hooked up as the parent of
  45 // the root object in the BrowserAccessibilityManager tree, so when any
  46 // accessibility client calls ::WindowFromAccessibleObject, they get this
  47 // HWND instead of the DesktopWindowTreeHostWin.
  48 class CONTENT_EXPORT LegacyRenderWidgetHostHWND
  49     : public ATL::CWindowImpl<LegacyRenderWidgetHostHWND,
  50                               NON_EXPORTED_BASE(ATL::CWindow),
  51                               ATL::CWinTraits<WS_CHILD> > {
  52  public:
  53   DECLARE_WND_CLASS_EX(L"Chrome_RenderWidgetHostHWND", CS_DBLCLKS, 0);
  54
  55   typedef ATL::CWindowImpl<LegacyRenderWidgetHostHWND,
  56                            NON_EXPORTED_BASE(ATL::CWindow),
  57                            ATL::CWinTraits<WS_CHILD> > Base;
  58
  59   // Creates and returns an instance of the LegacyRenderWidgetHostHWND class on
  60   // successful creation of a child window parented to the parent window passed
  61   // in.
  62   static LegacyRenderWidgetHostHWND* Create(HWND parent);
  63
  64   // Destroys the HWND managed by this class.
  65   void Destroy();
  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_.get(); }
  95
  96   // Functions to show and hide the window.
  97   void Show();
  98   void Hide();
  99
 100   // Resizes the window to the bounds passed in.
 101   void SetBounds(const gfx::Rect& bounds);
 102
 103   // The pointer to the containing RenderWidgetHostViewAura instance is passed
 104   // here.
 105   void set_host(RenderWidgetHostViewAura* host) {
 106     host_ = host;
 107   }
 108
 109  protected:
 110   void OnFinalMessage(HWND hwnd) override;
 111
 112  private:
 113   explicit LegacyRenderWidgetHostHWND(HWND parent);
 114   ~LegacyRenderWidgetHostHWND() override;
 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   base::win::ScopedComPtr<IAccessible> window_accessible_;
 140
 141   // Set to true if we turned on mouse tracking.
 142   bool mouse_tracking_enabled_;
 143
 144   RenderWidgetHostViewAura* host_;
 145
 146   DISALLOW_COPY_AND_ASSIGN(LegacyRenderWidgetHostHWND);
 147 };
 148
 149 }  // namespace content
 150
 151 #endif  // CONTENT_BROWSER_RENDERER_HOST_LEGACY_RENDER_WIDGET_HOST_WIN_H_
 152