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 #include "content/browser/renderer_host/legacy_render_widget_host_win.h"
6
7 #include "base/command_line.h"
8 #include "base/memory/scoped_ptr.h"
9 #include "base/win/windows_version.h"
10 #include "content/browser/accessibility/browser_accessibility_manager_win.h"
11 #include "content/browser/accessibility/browser_accessibility_win.h"
12 #include "content/public/browser/browser_accessibility_state.h"
13 #include "content/public/common/content_switches.h"
14 #include "ui/base/touch/touch_enabled.h"
15 #include "ui/base/view_prop.h"
16 #include "ui/base/win/internal_constants.h"
17 #include "ui/base/win/window_event_target.h"
18 #include "ui/gfx/geometry/rect.h"
19 #include "ui/gfx/win/dpi.h"
20
21 namespace content {
22
23 // A custom MSAA object id used to determine if a screen reader or some
24 // other client is listening on MSAA events - if so, we enable full web
25 // accessibility support.
26 const int kIdScreenReaderHoneyPot = 1;
27
~LegacyRenderWidgetHostHWND()28 LegacyRenderWidgetHostHWND::~LegacyRenderWidgetHostHWND() {
29 ::DestroyWindow(hwnd());
30 }
31
32 // static
Create(HWND parent)33 scoped_ptr<LegacyRenderWidgetHostHWND> LegacyRenderWidgetHostHWND::Create(
34 HWND parent) {
35 // content_unittests passes in the desktop window as the parent. We allow
36 // the LegacyRenderWidgetHostHWND instance to be created in this case for
37 // these tests to pass.
38 if (CommandLine::ForCurrentProcess()->HasSwitch(
39 switches::kDisableLegacyIntermediateWindow) ||
40 (!GetWindowEventTarget(parent) && parent != ::GetDesktopWindow()))
41 return scoped_ptr<LegacyRenderWidgetHostHWND>();
42
43 scoped_ptr<LegacyRenderWidgetHostHWND> legacy_window_instance;
44 legacy_window_instance.reset(new LegacyRenderWidgetHostHWND(parent));
45 // If we failed to create the child, or if the switch to disable the legacy
46 // window is passed in, then return NULL.
47 if (!::IsWindow(legacy_window_instance->hwnd()))
48 return scoped_ptr<LegacyRenderWidgetHostHWND>();
49
50 legacy_window_instance->Init();
51 return legacy_window_instance.Pass();
52 }
53
UpdateParent(HWND parent)54 void LegacyRenderWidgetHostHWND::UpdateParent(HWND parent) {
55 ::SetParent(hwnd(), parent);
56 // If the new parent is the desktop Window, then we disable the child window
57 // to ensure that it does not receive any input events. It should not because
58 // of WS_EX_TRANSPARENT. This is only for safety.
59 if (parent == ::GetDesktopWindow()) {
60 ::EnableWindow(hwnd(), FALSE);
61 } else {
62 ::EnableWindow(hwnd(), TRUE);
63 }
64 }
65
GetParent()66 HWND LegacyRenderWidgetHostHWND::GetParent() {
67 return ::GetParent(hwnd());
68 }
69
OnManagerDeleted()70 void LegacyRenderWidgetHostHWND::OnManagerDeleted() {
71 manager_ = NULL;
72 }
73
Show()74 void LegacyRenderWidgetHostHWND::Show() {
75 ::ShowWindow(hwnd(), SW_SHOW);
76 }
77
Hide()78 void LegacyRenderWidgetHostHWND::Hide() {
79 ::ShowWindow(hwnd(), SW_HIDE);
80 }
81
SetBounds(const gfx::Rect & bounds)82 void LegacyRenderWidgetHostHWND::SetBounds(const gfx::Rect& bounds) {
83 gfx::Rect bounds_in_pixel = gfx::win::DIPToScreenRect(bounds);
84 ::SetWindowPos(hwnd(), NULL, bounds_in_pixel.x(), bounds_in_pixel.y(),
85 bounds_in_pixel.width(), bounds_in_pixel.height(), 0);
86 }
87
OnFinalMessage(HWND hwnd)88 void LegacyRenderWidgetHostHWND::OnFinalMessage(HWND hwnd) {
89 if (manager_)
90 manager_->OnAccessibleHwndDeleted();
91 }
92
LegacyRenderWidgetHostHWND(HWND parent)93 LegacyRenderWidgetHostHWND::LegacyRenderWidgetHostHWND(HWND parent)
94 : manager_(NULL),
95 mouse_tracking_enabled_(false) {
96 RECT rect = {0};
97 Base::Create(parent, rect, L"Chrome Legacy Window",
98 WS_CHILDWINDOW | WS_CLIPCHILDREN | WS_CLIPSIBLINGS,
99 WS_EX_TRANSPARENT);
100 }
101
Init()102 bool LegacyRenderWidgetHostHWND::Init() {
103 if (base::win::GetVersion() >= base::win::VERSION_WIN7 &&
104 ui::AreTouchEventsEnabled())
105 RegisterTouchWindow(hwnd(), TWF_WANTPALM);
106
107 HRESULT hr = ::CreateStdAccessibleObject(
108 hwnd(), OBJID_WINDOW, IID_IAccessible,
109 reinterpret_cast<void **>(window_accessible_.Receive()));
110 DCHECK(SUCCEEDED(hr));
111
112 if (!BrowserAccessibilityState::GetInstance()->IsAccessibleBrowser()) {
113 // Attempt to detect screen readers or other clients who want full
114 // accessibility support, by seeing if they respond to this event.
115 NotifyWinEvent(EVENT_SYSTEM_ALERT, hwnd(), kIdScreenReaderHoneyPot,
116 CHILDID_SELF);
117 }
118
119 return !!SUCCEEDED(hr);
120 }
121
122 // static
GetWindowEventTarget(HWND parent)123 ui::WindowEventTarget* LegacyRenderWidgetHostHWND::GetWindowEventTarget(
124 HWND parent) {
125 return reinterpret_cast<ui::WindowEventTarget*>(ui::ViewProp::GetValue(
126 parent, ui::WindowEventTarget::kWin32InputEventTarget));
127 }
128
OnEraseBkGnd(UINT message,WPARAM w_param,LPARAM l_param)129 LRESULT LegacyRenderWidgetHostHWND::OnEraseBkGnd(UINT message,
130 WPARAM w_param,
131 LPARAM l_param) {
132 return 1;
133 }
134
OnGetObject(UINT message,WPARAM w_param,LPARAM l_param)135 LRESULT LegacyRenderWidgetHostHWND::OnGetObject(UINT message,
136 WPARAM w_param,
137 LPARAM l_param) {
138 // Only the lower 32 bits of l_param are valid when checking the object id
139 // because it sometimes gets sign-extended incorrectly (but not always).
140 DWORD obj_id = static_cast<DWORD>(static_cast<DWORD_PTR>(l_param));
141
142 if (kIdScreenReaderHoneyPot == obj_id) {
143 // When an MSAA client has responded to our fake event on this id,
144 // enable screen reader support.
145 BrowserAccessibilityState::GetInstance()->OnScreenReaderDetected();
146 return static_cast<LRESULT>(0L);
147 }
148
149 if (OBJID_CLIENT != obj_id || !manager_)
150 return static_cast<LRESULT>(0L);
151
152 base::win::ScopedComPtr<IAccessible> root(
153 manager_->GetRoot()->ToBrowserAccessibilityWin());
154 return LresultFromObject(IID_IAccessible, w_param,
155 static_cast<IAccessible*>(root.Detach()));
156 }
157
158 // We send keyboard/mouse/touch messages to the parent window via SendMessage.
159 // While this works, this has the side effect of converting input messages into
160 // sent messages which changes their priority and could technically result
161 // in these messages starving other messages in the queue. Additionally
162 // keyboard/mouse hooks would not see these messages. The alternative approach
163 // is to set and release capture as needed on the parent to ensure that it
164 // receives all mouse events. However that was shelved due to possible issues
165 // with capture changes.
OnKeyboardRange(UINT message,WPARAM w_param,LPARAM l_param,BOOL & handled)166 LRESULT LegacyRenderWidgetHostHWND::OnKeyboardRange(UINT message,
167 WPARAM w_param,
168 LPARAM l_param,
169 BOOL& handled) {
170 if (GetWindowEventTarget(GetParent())) {
171 return GetWindowEventTarget(GetParent())->HandleKeyboardMessage(
172 message, w_param, l_param);
173 }
174 return 0;
175 }
176
OnMouseRange(UINT message,WPARAM w_param,LPARAM l_param,BOOL & handled)177 LRESULT LegacyRenderWidgetHostHWND::OnMouseRange(UINT message,
178 WPARAM w_param,
179 LPARAM l_param,
180 BOOL& handled) {
181 if (message == WM_MOUSEMOVE) {
182 if (!mouse_tracking_enabled_) {
183 mouse_tracking_enabled_ = true;
184 TRACKMOUSEEVENT tme;
185 tme.cbSize = sizeof(tme);
186 tme.dwFlags = TME_LEAVE;
187 tme.hwndTrack = hwnd();
188 tme.dwHoverTime = 0;
189 TrackMouseEvent(&tme);
190 }
191 }
192 // The offsets for WM_NCXXX and WM_MOUSEWHEEL and WM_MOUSEHWHEEL messages are
193 // in screen coordinates. We should not be converting them to parent
194 // coordinates.
195 if ((message >= WM_MOUSEFIRST && message <= WM_MOUSELAST) &&
196 (message != WM_MOUSEWHEEL && message != WM_MOUSEHWHEEL)) {
197 POINT mouse_coords;
198 mouse_coords.x = GET_X_LPARAM(l_param);
199 mouse_coords.y = GET_Y_LPARAM(l_param);
200 ::MapWindowPoints(hwnd(), GetParent(), &mouse_coords, 1);
201 l_param = MAKELPARAM(mouse_coords.x, mouse_coords.y);
202 }
203 if (GetWindowEventTarget(GetParent())) {
204 return GetWindowEventTarget(GetParent())->HandleMouseMessage(
205 message, w_param, l_param);
206 }
207 return 0;
208 }
209
OnMouseLeave(UINT message,WPARAM w_param,LPARAM l_param)210 LRESULT LegacyRenderWidgetHostHWND::OnMouseLeave(UINT message,
211 WPARAM w_param,
212 LPARAM l_param) {
213 mouse_tracking_enabled_ = false;
214 if ((::GetCapture() != GetParent()) && GetWindowEventTarget(GetParent())) {
215 // We should send a WM_MOUSELEAVE to the parent window only if the mouse
216 // has moved outside the bounds of the parent.
217 POINT cursor_pos;
218 ::GetCursorPos(&cursor_pos);
219 if (::WindowFromPoint(cursor_pos) != GetParent()) {
220 return GetWindowEventTarget(GetParent())->HandleMouseMessage(
221 message, w_param, l_param);
222 }
223 }
224 return 0;
225 }
226
OnMouseActivate(UINT message,WPARAM w_param,LPARAM l_param)227 LRESULT LegacyRenderWidgetHostHWND::OnMouseActivate(UINT message,
228 WPARAM w_param,
229 LPARAM l_param) {
230 // Don't pass this to DefWindowProc. That results in the WM_MOUSEACTIVATE
231 // message going all the way to the parent which then messes up state
232 // related to focused views, etc. This is because it treats this as if
233 // it lost activation.
234 // Our dummy window should not interfere with focus and activation in
235 // the parent. Return MA_ACTIVATE here ensures that focus state in the parent
236 // is preserved. The only exception is if the parent was created with the
237 // WS_EX_NOACTIVATE style.
238 if (::GetWindowLong(GetParent(), GWL_EXSTYLE) & WS_EX_NOACTIVATE)
239 return MA_NOACTIVATE;
240 // On Windows, if we select the menu item by touch and if the window at the
241 // location is another window on the same thread, that window gets a
242 // WM_MOUSEACTIVATE message and ends up activating itself, which is not
243 // correct. We workaround this by setting a property on the window at the
244 // current cursor location. We check for this property in our
245 // WM_MOUSEACTIVATE handler and don't activate the window if the property is
246 // set.
247 if (::GetProp(hwnd(), ui::kIgnoreTouchMouseActivateForWindow)) {
248 ::RemoveProp(hwnd(), ui::kIgnoreTouchMouseActivateForWindow);
249 return MA_NOACTIVATE;
250 }
251 return MA_ACTIVATE;
252 }
253
OnTouch(UINT message,WPARAM w_param,LPARAM l_param)254 LRESULT LegacyRenderWidgetHostHWND::OnTouch(UINT message,
255 WPARAM w_param,
256 LPARAM l_param) {
257 if (GetWindowEventTarget(GetParent())) {
258 return GetWindowEventTarget(GetParent())->HandleTouchMessage(
259 message, w_param, l_param);
260 }
261 return 0;
262 }
263
OnScroll(UINT message,WPARAM w_param,LPARAM l_param)264 LRESULT LegacyRenderWidgetHostHWND::OnScroll(UINT message,
265 WPARAM w_param,
266 LPARAM l_param) {
267 if (GetWindowEventTarget(GetParent())) {
268 return GetWindowEventTarget(GetParent())->HandleScrollMessage(
269 message, w_param, l_param);
270 }
271 return 0;
272 }
273
OnNCHitTest(UINT message,WPARAM w_param,LPARAM l_param)274 LRESULT LegacyRenderWidgetHostHWND::OnNCHitTest(UINT message,
275 WPARAM w_param,
276 LPARAM l_param) {
277 if (GetWindowEventTarget(GetParent())) {
278 LRESULT hit_test = GetWindowEventTarget(
279 GetParent())->HandleNcHitTestMessage(message, w_param, l_param);
280 // If the parent returns HTNOWHERE which can happen for popup windows, etc
281 // we return HTCLIENT.
282 if (hit_test == HTNOWHERE)
283 hit_test = HTCLIENT;
284 return hit_test;
285 }
286 return HTNOWHERE;
287 }
288
OnNCPaint(UINT message,WPARAM w_param,LPARAM l_param)289 LRESULT LegacyRenderWidgetHostHWND::OnNCPaint(UINT message,
290 WPARAM w_param,
291 LPARAM l_param) {
292 return 0;
293 }
294
OnPaint(UINT message,WPARAM w_param,LPARAM l_param)295 LRESULT LegacyRenderWidgetHostHWND::OnPaint(UINT message,
296 WPARAM w_param,
297 LPARAM l_param) {
298 PAINTSTRUCT ps = {0};
299 ::BeginPaint(hwnd(), &ps);
300 ::EndPaint(hwnd(), &ps);
301 return 0;
302 }
303
OnSetCursor(UINT message,WPARAM w_param,LPARAM l_param)304 LRESULT LegacyRenderWidgetHostHWND::OnSetCursor(UINT message,
305 WPARAM w_param,
306 LPARAM l_param) {
307 return 0;
308 }
309
OnNCCalcSize(UINT message,WPARAM w_param,LPARAM l_param)310 LRESULT LegacyRenderWidgetHostHWND::OnNCCalcSize(UINT message,
311 WPARAM w_param,
312 LPARAM l_param) {
313 // Prevent scrollbars, etc from drawing.
314 return 0;
315 }
316
OnSize(UINT message,WPARAM w_param,LPARAM l_param)317 LRESULT LegacyRenderWidgetHostHWND::OnSize(UINT message,
318 WPARAM w_param,
319 LPARAM l_param) {
320 // Certain trackpad drivers on Windows have bugs where in they don't generate
321 // WM_MOUSEWHEEL messages for the trackpoint and trackpad scrolling gestures
322 // unless there is an entry for Chrome with the class name of the Window.
323 // Additionally others check if the window WS_VSCROLL/WS_HSCROLL styles and
324 // generate the legacy WM_VSCROLL/WM_HSCROLL messages.
325 // We add these styles to ensure that trackpad/trackpoint scrolling
326 // work.
327 long current_style = ::GetWindowLong(hwnd(), GWL_STYLE);
328 ::SetWindowLong(hwnd(), GWL_STYLE,
329 current_style | WS_VSCROLL | WS_HSCROLL);
330 return 0;
331 }
332
333 } // namespace content
334