aura: Preprocess an XEvent to make changes for 'alt-click to right-click' before dispatching begins.

This fixes a crash that happens from converting an alt-click to right-click.

BUG=126529
TEST=manually

Review URL: https://chromiumcodereview.appspot.com/10377071

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@136311 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 29 insertions, 23 deletions

diff --git a/ui/aura/dispatcher_linux.cc b/ui/aura/dispatcher_linux.cc
index b580be8..e6e70d0 100644
--- a/ui/aura/dispatcher_linux.cc
+++ b/ui/aura/dispatcher_linux.cc
@@ -8,6 +8,33 @@
 
 #include "ui/base/events.h"
 
+namespace {
+
+// Pro-processes an XEvent before it is handled. The pre-processings include:
+// - Map Alt+Button1 to Button3
+void PreprocessXEvent(XEvent* xevent) {
+  if (!xevent || xevent->type != GenericEvent)
+    return;
+
+  XIDeviceEvent* xievent = static_cast<XIDeviceEvent*>(xevent->xcookie.data);
+  if ((xievent->evtype == XI_ButtonPress ||
+      xievent->evtype == XI_ButtonRelease) &&
+        (xievent->mods.effective & Mod1Mask) &&
+        xievent->detail == 1) {
+    xievent->mods.effective &= ~Mod1Mask;
+    xievent->detail = 3;
+    if (xievent->evtype == XI_ButtonRelease) {
+      // On the release clear the left button from the existing state and the
+      // mods, and set the right button.
+      XISetMask(xievent->buttons.mask, 3);
+      XIClearMask(xievent->buttons.mask, 1);
+      xievent->mods.effective &= ~Button1Mask;
+    }
+  }
+}
+
+}  // namespace
+
 namespace aura {
 
 DispatcherLinux::DispatcherLinux() {
@@ -29,6 +56,8 @@ void DispatcherLinux::WindowDispatcherDestroying(::Window window) {
 }
 
 bool DispatcherLinux::Dispatch(const base::NativeEvent& xev) {
+  PreprocessXEvent(xev);
+
   // XI_HierarchyChanged events are special. There is no window associated with
   // these events. So process them directly from here.
   if (xev->type == GenericEvent &&
diff --git a/ui/base/x/events_x.cc b/ui/base/x/events_x.cc
index 1beb58f..6c57af0 100644
--- a/ui/base/x/events_x.cc
+++ b/ui/base/x/events_x.cc
@@ -409,23 +409,6 @@ int GetEventFlagsForButton(int button) {
   }
 }
 
-void DetectAltClick(XIDeviceEvent* xievent) {
-  if ((xievent->evtype == XI_ButtonPress ||
-      xievent->evtype == XI_ButtonRelease) &&
-        (xievent->mods.effective & Mod1Mask) &&
-        xievent->detail == 1) {
-    xievent->mods.effective &= ~Mod1Mask;
-    xievent->detail = 3;
-    if (xievent->evtype == XI_ButtonRelease) {
-      // On the release clear the left button from the existing state and the
-      // mods, and set the right button.
-      XISetMask(xievent->buttons.mask, 3);
-      XIClearMask(xievent->buttons.mask, 1);
-      xievent->mods.effective &= ~Button1Mask;
-    }
-  }
-}
-
 int GetButtonMaskForX2Event(XIDeviceEvent* xievent) {
   int buttonflags = 0;
   for (int i = 0; i < 8 * xievent->buttons.mask_len; i++) {
@@ -616,9 +599,6 @@ EventType EventTypeFromNative(const base::NativeEvent& native_event) {
       XIDeviceEvent* xievent =
           static_cast<XIDeviceEvent*>(native_event->xcookie.data);
 
-      // Map Alt+Button1 to Button3
-      DetectAltClick(xievent);
-
       if (factory->IsTouchDevice(xievent->sourceid))
         return GetTouchEventType(native_event);
 
@@ -677,9 +657,6 @@ int EventFlagsFromNative(const base::NativeEvent& native_event) {
       XIDeviceEvent* xievent =
           static_cast<XIDeviceEvent*>(native_event->xcookie.data);
 
-      // Map Alt+Button1 to Button3.
-      DetectAltClick(xievent);
-
       const bool touch =
           TouchFactory::GetInstance()->IsTouchDevice(xievent->sourceid);
       switch (xievent->evtype) {