1 // Copyright (c) 2012 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 "ui/views/widget/desktop_aura/x11_whole_screen_move_loop.h"
6
7 #include <stddef.h>
8
9 #include <memory>
10 #include <utility>
11
12 #include "base/bind.h"
13 #include "base/logging.h"
14 #include "base/message_loop/message_loop_current.h"
15 #include "base/run_loop.h"
16 #include "base/single_thread_task_runner.h"
17 #include "base/stl_util.h"
18 #include "base/threading/thread_task_runner_handle.h"
19 #include "ui/aura/client/capture_client.h"
20 #include "ui/aura/env.h"
21 #include "ui/aura/window.h"
22 #include "ui/aura/window_event_dispatcher.h"
23 #include "ui/aura/window_tree_host.h"
24 #include "ui/base/mojom/cursor_type.mojom-shared.h"
25 #include "ui/base/x/x11_pointer_grab.h"
26 #include "ui/base/x/x11_util.h"
27 #include "ui/events/event.h"
28 #include "ui/events/event_utils.h"
29 #include "ui/events/keycodes/keyboard_code_conversion_x.h"
30 #include "ui/events/platform/platform_event_source.h"
31 #include "ui/events/platform/scoped_event_dispatcher.h"
32 #include "ui/events/platform/x11/x11_event_source.h"
33 #include "ui/events/x/events_x_utils.h"
34 #include "ui/events/x/x11_window_event_manager.h"
35 #include "ui/gfx/x/x11.h"
36
37 namespace views {
38
39 // XGrabKey requires the modifier mask to explicitly be specified.
40 const unsigned int kModifiersMasks[] = {0, // No additional modifier.
41 Mod2Mask, // Num lock
42 LockMask, // Caps lock
43 Mod5Mask, // Scroll lock
44 Mod2Mask | LockMask,
45 Mod2Mask | Mod5Mask,
46 LockMask | Mod5Mask,
47 Mod2Mask | LockMask | Mod5Mask};
48
X11WholeScreenMoveLoop(X11MoveLoopDelegate * delegate)49 X11WholeScreenMoveLoop::X11WholeScreenMoveLoop(X11MoveLoopDelegate* delegate)
50 : delegate_(delegate),
51 in_move_loop_(false),
52 initial_cursor_(ui::mojom::CursorType::kNull),
53 should_reset_mouse_flags_(false),
54 grab_input_window_(x11::None),
55 grabbed_pointer_(false),
56 canceled_(false) {}
57
58 X11WholeScreenMoveLoop::~X11WholeScreenMoveLoop() = default;
59
DispatchMouseMovement()60 void X11WholeScreenMoveLoop::DispatchMouseMovement() {
61 if (!last_motion_in_screen_)
62 return;
63 delegate_->OnMouseMovement(last_motion_in_screen_->root_location(),
64 last_motion_in_screen_->flags(),
65 last_motion_in_screen_->time_stamp());
66 last_motion_in_screen_.reset();
67 }
68
PostDispatchIfNeeded(const ui::MouseEvent & event)69 void X11WholeScreenMoveLoop::PostDispatchIfNeeded(const ui::MouseEvent& event) {
70 bool dispatch_mouse_event = !last_motion_in_screen_;
71 last_motion_in_screen_ = std::make_unique<ui::MouseEvent>(event);
72 if (dispatch_mouse_event) {
73 // Post a task to dispatch mouse movement event when control returns to the
74 // message loop. This allows smoother dragging since the events are
75 // dispatched without waiting for the drag widget updates.
76 base::ThreadTaskRunnerHandle::Get()->PostTask(
77 FROM_HERE,
78 base::BindOnce(&X11WholeScreenMoveLoop::DispatchMouseMovement,
79 weak_factory_.GetWeakPtr()));
80 }
81 }
82
83 ////////////////////////////////////////////////////////////////////////////////
84 // DesktopWindowTreeHostLinux, ui::PlatformEventDispatcher implementation:
85
CanDispatchEvent(const ui::PlatformEvent & event)86 bool X11WholeScreenMoveLoop::CanDispatchEvent(const ui::PlatformEvent& event) {
87 return in_move_loop_;
88 }
89
DispatchEvent(const ui::PlatformEvent & event)90 uint32_t X11WholeScreenMoveLoop::DispatchEvent(const ui::PlatformEvent& event) {
91 DCHECK(base::MessageLoopCurrentForUI::IsSet());
92
93 // This method processes all events while the move loop is active.
94 if (!in_move_loop_)
95 return ui::POST_DISPATCH_PERFORM_DEFAULT;
96
97 switch (event->type()) {
98 case ui::ET_MOUSE_MOVED:
99 case ui::ET_MOUSE_DRAGGED: {
100 PostDispatchIfNeeded(*event->AsMouseEvent());
101 return ui::POST_DISPATCH_NONE;
102 }
103 case ui::ET_MOUSE_RELEASED: {
104 if (event->AsMouseEvent()->IsLeftMouseButton()) {
105 // Assume that drags are being done with the left mouse button. Only
106 // break the drag if the left mouse button was released.
107 DispatchMouseMovement();
108 delegate_->OnMouseReleased();
109
110 if (!grabbed_pointer_) {
111 // If the source widget had capture prior to the move loop starting,
112 // it may be relying on views::Widget getting the mouse release and
113 // releasing capture in Widget::OnMouseEvent().
114 return ui::POST_DISPATCH_PERFORM_DEFAULT;
115 }
116 }
117 return ui::POST_DISPATCH_NONE;
118 }
119 case ui::ET_KEY_PRESSED:
120 if (event->AsKeyEvent()->key_code() == ui::VKEY_ESCAPE) {
121 canceled_ = true;
122 EndMoveLoop();
123 return ui::POST_DISPATCH_NONE;
124 }
125 break;
126 default:
127 break;
128 }
129 return ui::POST_DISPATCH_PERFORM_DEFAULT;
130 }
131
RunMoveLoop(aura::Window * source,gfx::NativeCursor cursor)132 bool X11WholeScreenMoveLoop::RunMoveLoop(aura::Window* source,
133 gfx::NativeCursor cursor) {
134 DCHECK(!in_move_loop_); // Can only handle one nested loop at a time.
135
136 // Query the mouse cursor prior to the move loop starting so that it can be
137 // restored when the move loop finishes.
138 initial_cursor_ = source->GetHost()->last_cursor();
139
140 CreateDragInputWindow(gfx::GetXDisplay());
141
142 // Only grab mouse capture of |grab_input_window_| if |source| does not have
143 // capture.
144 // - The caller may intend to transfer capture to a different aura::Window
145 // when the move loop ends and not release capture.
146 // - Releasing capture and X window destruction are both asynchronous. We drop
147 // events targeted at |grab_input_window_| in the time between the move
148 // loop ends and |grab_input_window_| loses capture.
149 grabbed_pointer_ = false;
150 if (!source->HasCapture()) {
151 aura::client::CaptureClient* capture_client =
152 aura::client::GetCaptureClient(source->GetRootWindow());
153 CHECK(capture_client->GetGlobalCaptureWindow() == nullptr);
154 grabbed_pointer_ = GrabPointer(cursor);
155 if (!grabbed_pointer_) {
156 XDestroyWindow(gfx::GetXDisplay(), grab_input_window_);
157 return false;
158 }
159 }
160
161 GrabEscKey();
162
163 std::unique_ptr<ui::ScopedEventDispatcher> old_dispatcher =
164 std::move(nested_dispatcher_);
165 nested_dispatcher_ =
166 ui::PlatformEventSource::GetInstance()->OverrideDispatcher(this);
167
168 // We are handling a mouse drag outside of the aura::Window system. We must
169 // manually make aura think that the mouse button is pressed so that we don't
170 // draw extraneous tooltips.
171 aura::Env* env = aura::Env::GetInstance();
172 if (!env->IsMouseButtonDown()) {
173 env->set_mouse_button_flags(ui::EF_LEFT_MOUSE_BUTTON);
174 should_reset_mouse_flags_ = true;
175 }
176
177 base::WeakPtr<X11WholeScreenMoveLoop> alive(weak_factory_.GetWeakPtr());
178
179 in_move_loop_ = true;
180 canceled_ = false;
181 base::RunLoop run_loop(base::RunLoop::Type::kNestableTasksAllowed);
182 quit_closure_ = run_loop.QuitClosure();
183 run_loop.Run();
184
185 if (!alive)
186 return false;
187
188 nested_dispatcher_ = std::move(old_dispatcher);
189 return !canceled_;
190 }
191
UpdateCursor(gfx::NativeCursor cursor)192 void X11WholeScreenMoveLoop::UpdateCursor(gfx::NativeCursor cursor) {
193 if (in_move_loop_)
194 ui::ChangeActivePointerGrabCursor(cursor.platform());
195 }
196
EndMoveLoop()197 void X11WholeScreenMoveLoop::EndMoveLoop() {
198 if (!in_move_loop_)
199 return;
200
201 // Prevent DispatchMouseMovement from dispatching any posted motion event.
202 last_motion_in_screen_.reset();
203
204 // We undo our emulated mouse click from RunMoveLoop();
205 if (should_reset_mouse_flags_) {
206 aura::Env::GetInstance()->set_mouse_button_flags(0);
207 should_reset_mouse_flags_ = false;
208 }
209
210 // TODO(erg): Is this ungrab the cause of having to click to give input focus
211 // on drawn out windows? Not ungrabbing here screws the X server until I kill
212 // the chrome process.
213
214 // Ungrab before we let go of the window.
215 if (grabbed_pointer_)
216 ui::UngrabPointer();
217 else
218 UpdateCursor(initial_cursor_);
219
220 XDisplay* display = gfx::GetXDisplay();
221 unsigned int esc_keycode = XKeysymToKeycode(display, XK_Escape);
222 for (auto mask : kModifiersMasks)
223 XUngrabKey(display, esc_keycode, mask, grab_input_window_);
224
225 // Restore the previous dispatcher.
226 nested_dispatcher_.reset();
227 delegate_->OnMoveLoopEnded();
228 grab_input_window_events_.reset();
229 XDestroyWindow(display, grab_input_window_);
230 grab_input_window_ = x11::None;
231
232 in_move_loop_ = false;
233 std::move(quit_closure_).Run();
234 }
235
GrabPointer(gfx::NativeCursor cursor)236 bool X11WholeScreenMoveLoop::GrabPointer(gfx::NativeCursor cursor) {
237 XDisplay* display = gfx::GetXDisplay();
238
239 // Pass "owner_events" as false so that X sends all mouse events to
240 // |grab_input_window_|.
241 int ret = ui::GrabPointer(grab_input_window_, false, cursor.platform());
242 if (ret != GrabSuccess) {
243 DLOG(ERROR) << "Grabbing pointer for dragging failed: "
244 << ui::GetX11ErrorString(display, ret);
245 }
246 XFlush(display);
247 return ret == GrabSuccess;
248 }
249
GrabEscKey()250 void X11WholeScreenMoveLoop::GrabEscKey() {
251 XDisplay* display = gfx::GetXDisplay();
252 unsigned int esc_keycode = XKeysymToKeycode(display, XK_Escape);
253 for (auto mask : kModifiersMasks) {
254 XGrabKey(display, esc_keycode, mask, grab_input_window_, x11::False,
255 GrabModeAsync, GrabModeAsync);
256 }
257 }
258
CreateDragInputWindow(XDisplay * display)259 void X11WholeScreenMoveLoop::CreateDragInputWindow(XDisplay* display) {
260 XSetWindowAttributes swa;
261 memset(&swa, 0, sizeof(swa));
262 swa.override_redirect = x11::True;
263 grab_input_window_ = XCreateWindow(display, DefaultRootWindow(display), -100,
264 -100, 10, 10, 0, CopyFromParent, InputOnly,
265 CopyFromParent, CWOverrideRedirect, &swa);
266 uint32_t event_mask = ButtonPressMask | ButtonReleaseMask |
267 PointerMotionMask | KeyPressMask | KeyReleaseMask |
268 StructureNotifyMask;
269 grab_input_window_events_ = std::make_unique<ui::XScopedEventSelector>(
270 grab_input_window_, event_mask);
271
272 XMapRaised(display, grab_input_window_);
273 }
274
275 } // namespace views
276