Don't allow "touch optimized ui" mode to change after chrome startup.

Since we don't yet properly support dynamic changing of touch optimized UI mode (see crbug.com/124399), we need to ensure the UI sees a consistent value for the life of the process to avoid painting issues like those in issue 131606.

Also output a log message if we see touch device status change after startup in order to help understand issues with some devices being slow to initialize.

Adds a temporary hack to force touch-optimized-ui mode on when command line arguments suggest we're expecting a touch screen.

BUG=131606
TEST=


Review URL: https://chromiumcodereview.appspot.com/10532161

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@142493 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 33 insertions, 5 deletions

diff --git a/ui/base/layout.cc b/ui/base/layout.cc
index 36614fa..368a395 100644
--- a/ui/base/layout.cc
+++ b/ui/base/layout.cc
@@ -25,8 +25,9 @@ namespace {
 bool UseTouchOptimizedUI() {
   // If --touch-optimized-ui is specified and not set to "auto", then override
   // the hardware-determined setting (eg. for testing purposes).
-  if (CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kTouchOptimizedUI)) {
+  static bool has_touch_optimized_ui = CommandLine::ForCurrentProcess()->
+      HasSwitch(switches::kTouchOptimizedUI);
+  if (has_touch_optimized_ui) {
     const std::string switch_value = CommandLine::ForCurrentProcess()->
         GetSwitchValueASCII(switches::kTouchOptimizedUI);
 
@@ -47,9 +48,20 @@ bool UseTouchOptimizedUI() {
   return base::win::GetMetroModule() != NULL;
 #elif defined(USE_AURA) && defined(USE_X11)
   // Determine whether touch-screen hardware is currently available.
-  // For now we assume this won't change over the life of the process, but
-  // we'll probably want to support that.  crbug.com/124399
-  return ui::TouchFactory::GetInstance()->IsTouchDevicePresent();
+  // For now we must ensure this won't change over the life of the process,
+  // since we don't yet support updating the UI.  crbug.com/124399
+  static bool has_touch_device =
+      ui::TouchFactory::GetInstance()->IsTouchDevicePresent();
+
+  // Work-around for late device detection in some cases.  If we've asked for
+  // touch calibration then we're certainly expecting a touch screen, it must
+  // just not be ready yet.  Force-enable touch-ui mode in this case.
+  static bool enable_touch_calibration = CommandLine::ForCurrentProcess()->
+      HasSwitch(switches::kEnableTouchCalibration);
+  if (!has_touch_device && enable_touch_calibration)
+    has_touch_device = true;
+
+  return has_touch_device;
 #else
   return false;
 #endif
diff --git a/ui/base/touch/touch_factory.cc b/ui/base/touch/touch_factory.cc
index a274b2d..c66bb58 100644
--- a/ui/base/touch/touch_factory.cc
+++ b/ui/base/touch/touch_factory.cc
@@ -34,6 +34,7 @@ TouchFactory::TouchFactory()
       cursor_timer_(),
       pointer_device_lookup_(),
       touch_device_available_(false),
+      touch_present_called_(false),
       touch_device_list_(),
 #if defined(USE_XI2_MT)
       min_available_slot_(0),
@@ -132,6 +133,7 @@ void TouchFactory::UpdateDeviceList(Display* display) {
   // If XInput2 is not supported, this will return null (with count of -1) so
   // we assume there cannot be any touch devices.
   int count = 0;
+  bool last_touch_device_available = touch_device_available_;
   touch_device_available_ = false;
   touch_device_lookup_.reset();
   touch_device_list_.clear();
@@ -187,6 +189,16 @@ void TouchFactory::UpdateDeviceList(Display* display) {
   }
   if (devices)
     XIFreeDeviceInfo(devices);
+
+  if ((last_touch_device_available != touch_device_available_) &&
+      touch_events_allowed_ && touch_present_called_) {
+    // Touch_device_available_ has changed after it's been queried.
+    // TODO(rbyers): Should dispatch an event to indicate that the availability
+    // of touch devices has changed.  crbug.com/124399.
+    LOG(WARNING) << "Touch screen "
+        << (touch_device_available_ ? "added" : "removed")
+        << " after startup, which is not yet fully supported.";
+  }
 }
 
 bool TouchFactory::ShouldProcessXI2Event(XEvent* xev) {
@@ -400,6 +412,7 @@ void TouchFactory::SetCursorVisible(bool show, bool start_timer) {
 }
 
 bool TouchFactory::IsTouchDevicePresent() {
+  touch_present_called_ = true;
   return (touch_device_available_ && touch_events_allowed_);
 }
 
diff --git a/ui/base/touch/touch_factory.h b/ui/base/touch/touch_factory.h
index e2c8750..b12538e 100644
--- a/ui/base/touch/touch_factory.h
+++ b/ui/base/touch/touch_factory.h
@@ -139,6 +139,9 @@ class UI_EXPORT TouchFactory {
   // Indicates whether a touch device is currently available or not.
   bool touch_device_available_;
 
+  // Whether IsTouchDevicePresent() has been called yet.
+  bool touch_present_called_;
+
   // The list of touch devices. For testing/debugging purposes, a single-pointer
   // device (mouse or touch screen without sufficient X/driver support for MT)
   // can sometimes be treated as a touch device. The key in the map represents