Configure CTM on touchscreen hotplug.

Subscribe OutputConfigurator to XI_HierarchyChanged events,
so it will configure CTM for touchscreens not only when monitor is plugged,
but also when touchscreen's USB is plugged.

BUG=235861
TEST=Hotplug external touchscreen into link, when external monitor is in
external display and mirror modes. Observe correct touches in paint.html

Review URL: https://chromiumcodereview.appspot.com/20093003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@213877 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 44 insertions, 11 deletions

diff --git a/chromeos/display/output_configurator.cc b/chromeos/display/output_configurator.cc
index 875513f..92f2953 100644
--- a/chromeos/display/output_configurator.cc
+++ b/chromeos/display/output_configurator.cc
@@ -6,6 +6,7 @@
 
 #include <X11/Xlib.h>
 #include <X11/extensions/Xrandr.h>
+#include <X11/extensions/XInput2.h>
 
 #include "base/bind.h"
 #include "base/chromeos/chromeos_version.h"
@@ -301,22 +302,30 @@ bool OutputConfigurator::Dispatch(const base::NativeEvent& event) {
       // Connecting/Disconnecting display may generate multiple
       // RRNotify. Defer configuring outputs to avoid
       // grabbing X and configuring displays multiple times.
-      if (configure_timer_.get()) {
-        configure_timer_->Reset();
-      } else {
-        configure_timer_.reset(new base::OneShotTimer<OutputConfigurator>());
-        configure_timer_->Start(
-            FROM_HERE,
-            base::TimeDelta::FromMilliseconds(kConfigureDelayMs),
-            this,
-            &OutputConfigurator::ConfigureOutputs);
-      }
+      ScheduleConfigureOutputs();
     }
   }
 
   return true;
 }
 
+base::EventStatus OutputConfigurator::WillProcessEvent(
+    const base::NativeEvent& event) {
+  // XI_HierarchyChanged events are special. There is no window associated with
+  // these events. So process them directly from here.
+  if (configure_display_ && event->type == GenericEvent &&
+      event->xgeneric.evtype == XI_HierarchyChanged) {
+    // Defer configuring outputs to not stall event processing.
+    // This also takes care of same event being received twice.
+    ScheduleConfigureOutputs();
+  }
+
+  return base::EVENT_CONTINUE;
+}
+
+void OutputConfigurator::DidProcessEvent(const base::NativeEvent& event) {
+}
+
 void OutputConfigurator::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
@@ -367,6 +376,19 @@ void OutputConfigurator::ConfigureOutputs() {
   delegate_->SendProjectingStateToPowerManager(IsProjecting(outputs));
 }
 
+void OutputConfigurator::ScheduleConfigureOutputs() {
+  if (configure_timer_.get()) {
+    configure_timer_->Reset();
+  } else {
+    configure_timer_.reset(new base::OneShotTimer<OutputConfigurator>());
+    configure_timer_->Start(
+        FROM_HERE,
+        base::TimeDelta::FromMilliseconds(kConfigureDelayMs),
+        this,
+        &OutputConfigurator::ConfigureOutputs);
+  }
+}
+
 void OutputConfigurator::NotifyOnDisplayChanged() {
   FOR_EACH_OBSERVER(Observer, observers_, OnDisplayModeChanged());
 }
diff --git a/chromeos/display/output_configurator.h b/chromeos/display/output_configurator.h
index 5285bde..6805efa 100644
--- a/chromeos/display/output_configurator.h
+++ b/chromeos/display/output_configurator.h
@@ -39,7 +39,8 @@ enum OutputState {
 // This class interacts directly with the underlying Xrandr API to manipulate
 // CTRCs and Outputs.
 class CHROMEOS_EXPORT OutputConfigurator
-    : public base::MessageLoop::Dispatcher {
+    : public base::MessageLoop::Dispatcher,
+      public base::MessagePumpObserver {
  public:
   // Information about an output's current state.
   struct OutputSnapshot {
@@ -279,6 +280,12 @@ class CHROMEOS_EXPORT OutputConfigurator
   // Spurious events will have no effect.
   virtual bool Dispatch(const base::NativeEvent& event) OVERRIDE;
 
+  // Overridden from base::MessagePumpObserver:
+  virtual base::EventStatus WillProcessEvent(
+      const base::NativeEvent& event) OVERRIDE;
+  virtual void DidProcessEvent(
+      const base::NativeEvent& event) OVERRIDE;
+
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
@@ -299,6 +306,10 @@ class CHROMEOS_EXPORT OutputConfigurator
   // Configure outputs.
   void ConfigureOutputs();
 
+  // Configure outputs with |kConfigureDelayMs| delay,
+  // so that time-consuming ConfigureOutputs() won't be called multiple times.
+  void ScheduleConfigureOutputs();
+
   // Fires OnDisplayModeChanged() event to the observers.
   void NotifyOnDisplayChanged();