Refactored touch-events flag test, correcting "enabled" logic.

content/browser/renderer_host/render_widget_host_view_win.cc

Index: content/browser/renderer_host/render_widget_host_view_win.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_win.cc b/content/browser/renderer_host/render_widget_host_view_win.cc
index 50a658aa5151db97e5e43a8c99040bf77252d4b5..b31598fb48991e245ff0b7df7fe3d811e0bac8f9 100644
--- a/content/browser/renderer_host/render_widget_host_view_win.cc
+++ b/content/browser/renderer_host/render_widget_host_view_win.cc
@@ -328,6 +328,26 @@ void GetScreenInfoForWindow(gfx::NativeViewId id,
   *results = screen_info;
 }
 
+// Tests the tri-state touch-events flag. Note that --touch-events is the
+// same as --touch-events-enabled, but not giving the flag defaults to auto.
+bool IsTouchModeEnabled() {
+  if (base::win::GetVersion() >= base::win::VERSION_WIN7)
+    return false;
+
+  CommandLine* cmdline = CommandLine::ForCurrentProcess();
+  if (cmdline->HasSwitch(switches::kTouchEvents)) {
+    if (cmdline->GetSwitchValueASCII(switches::kTouchEvents) ==
+        switches::kTouchEventsDisabled)
+      return false;
+    else if (cmdline->GetSwitchValueASCII(switches::kTouchEvents) ==

[Ben Goodger (Google), 2013/07/24 19:26:13]

no else after return

+        switches::kTouchEventsAuto)
+      return ui::IsTouchDevicePresent();
+    else
+      return true;
+  }
+  return ui::IsTouchDevicePresent();
+}
+
 }  // namespace
 
 const wchar_t kRenderWidgetHostHWNDClass[] = L"Chrome_RenderWidgetHostHWND";
@@ -926,35 +946,11 @@ void RenderWidgetHostViewWin::ProcessAckedTouchEvent(
 
 void RenderWidgetHostViewWin::UpdateDesiredTouchMode() {
   // Make sure that touch events even make sense.
-  CommandLine* cmdline = CommandLine::ForCurrentProcess();
-  static bool touch_mode = base::win::GetVersion() >= base::win::VERSION_WIN7 &&
-      ui::IsTouchDevicePresent() && (
-          !cmdline->HasSwitch(switches::kTouchEvents) ||
-          cmdline->GetSwitchValueASCII(switches::kTouchEvents) !=
-              switches::kTouchEventsDisabled);
-
-  if (!touch_mode)
-    return;
+  static bool touch_mode = IsTouchModeEnabled();
 
-  // Now we know that the window's current state doesn't match the desired
-  // state. If we want touch mode, then we attempt to register for touch
-  // events, and otherwise to unregister.
-  touch_events_enabled_ = RegisterTouchWindow(m_hWnd, TWF_WANTPALM) == TRUE;
-
-  if (!touch_events_enabled_) {
-    UnregisterTouchWindow(m_hWnd);
-    // Single finger panning is consistent with other windows applications.
-    const DWORD gesture_allow = GC_PAN_WITH_SINGLE_FINGER_VERTICALLY |
-                                GC_PAN_WITH_SINGLE_FINGER_HORIZONTALLY;
-    const DWORD gesture_block = GC_PAN_WITH_GUTTER;
-    GESTURECONFIG gc[] = {
-        { GID_ZOOM, GC_ZOOM, 0 },
-        { GID_PAN, gesture_allow , gesture_block},
-        { GID_TWOFINGERTAP, GC_TWOFINGERTAP , 0},
-        { GID_PRESSANDTAP, GC_PRESSANDTAP , 0}
-    };
-    if (!SetGestureConfig(m_hWnd, 0, arraysize(gc), gc, sizeof(GESTURECONFIG)))
-      NOTREACHED();
+  if (touch_mode) {
+    touch_events_enabled_ = RegisterTouchWindow(m_hWnd, TWF_WANTPALM) == TRUE;
+    CHECK(touch_events_enabled_);
   }
 }