touch: Hide the X cursor when not in use.

views/touchui/touch_factory.cc

 // Copyright (c) 2011 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.
 
 #include "views/touchui/touch_factory.h"
 
 #include <gdk/gdkx.h>
 #include <X11/extensions/XInput2.h>
 
+#include "base/compiler_specific.h"
 #include "base/logging.h"
+#include "ui/base/x/x11_util.h"
+
+// The X cursor is hidden if it is idle for kCursorIdleSeconds seconds.
+static int kCursorIdleSeconds = 5;
 
 namespace views {
 
 // static
 TouchFactory* TouchFactory::GetInstance() {
   return Singleton<TouchFactory>::get();
 }
 
 TouchFactory::TouchFactory()
-    : touch_device_lookup_(),
+    : hiding_cursor_(false),
+      ALLOW_THIS_IN_INITIALIZER_LIST(cursor_timer_(
+          base::TimeDelta::FromSeconds(kCursorIdleSeconds), this,
+          &TouchFactory::HideCursorForInactivity)),
+      touch_device_lookup_(),
       touch_device_list_() {
+  Pixmap blank;
+  XColor black;
+  static char nodata[] = { 0,0,0,0,0,0,0,0 };
+  black.red = black.green = black.blue = 0;
+  Display* display = ui::GetXDisplay();
+
+  blank = XCreateBitmapFromData(display, ui::GetX11RootWindow(), nodata, 8, 8);
+  invisible_ = XCreatePixmapCursor(display, blank, blank, &black, &black, 0, 0);
+
+  SetCursorVisibility(false);
+}
+
+TouchFactory::~TouchFactory() {
+  SetCursorVisibility(true);
+  XFreeCursor(ui::GetXDisplay(), invisible_);
 }
 
 void TouchFactory::SetTouchDeviceList(
     const std::vector<unsigned int>& devices) {
   touch_device_lookup_.reset();
   touch_device_list_.clear();
   for (std::vector<unsigned int>::const_iterator iter = devices.begin();
        iter != devices.end(); ++iter) {
     DCHECK(*iter < touch_device_lookup_.size());
     touch_device_lookup_[*iter] = true;
@@ skipping 37 matching lines @@
   bool success = true;
   for (std::vector<int>::const_iterator iter =
        touch_device_list_.begin();
        iter != touch_device_list_.end(); ++iter) {
     Status status = XIUngrabDevice(display, *iter, CurrentTime);
     success = success && status == GrabSuccess;
   }
   return success;
 }
 
+void TouchFactory::SetCursorVisibility(bool show) {
+  // The cursor is going to be shown. Reset the timer for hiding it.
+  if (show)
+    cursor_timer_.Reset();

[sky, 2011/01/26 16:17:00]

Would this trigger if the user presses the mouse and holds it down for 5
seconds?

[sadrul, 2011/01/26 17:57:11]

It would! I hadn't considered this scenario. I suspect we don't want the cursor
to hide when this happens? How about when the cursor is made visible
(SetCursorVisible(true)) from accelerator_handler_touch, it also determines
whether or not to start the timer to hide it?

+
+  if (show == !hiding_cursor_)
+    return;
+
+  hiding_cursor_ = !show;
+
+  GdkDisplay* display = gdk_display_get_default();
+  if (!display)
+    return;
+
+  Display* xdisplay = GDK_DISPLAY_XDISPLAY(display);
+  Window window = DefaultRootWindow(xdisplay);
+
+  if (hiding_cursor_) {
+    XDefineCursor(xdisplay, window, invisible_);
+  } else {
+    XUndefineCursor(xdisplay, window);
+  }
+}
+
 }  // namespace views