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

content/browser/renderer_host/render_widget_host_view_win.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_win.h"
 
 #include <InputScope.h>
 #include <wtsapi32.h>
 #pragma comment(lib, "wtsapi32.lib")
 
@@ skipping 310 matching lines @@
   screen_info.depth = dev_mode.dmBitsPerPel;
   screen_info.depthPerComponent = dev_mode.dmBitsPerPel / 3;  // Assumes RGB
   screen_info.deviceScaleFactor = ui::win::GetDeviceScaleFactor();
   screen_info.isMonochrome = dev_mode.dmColor == DMCOLOR_MONOCHROME;
   screen_info.rect = gfx::Rect(monitor_info.rcMonitor);
   screen_info.availableRect = gfx::Rect(monitor_info.rcWork);
 
   *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";
 
 // Wrapper for maintaining touchstate associated with a WebTouchEvent.
 class WebTouchState {
  public:
   explicit WebTouchState(const RenderWidgetHostViewWin* window);
 
   // Updates the current touchpoint state with the supplied touches.
@@ skipping 60 matching lines @@
       is_loading_(false),
       text_input_type_(ui::TEXT_INPUT_TYPE_NONE),
       can_compose_inline_(true),
       is_fullscreen_(false),
       ignore_mouse_movement_(true),
       composition_range_(ui::Range::InvalidRange()),
       touch_state_(new WebTouchState(this)),
       pointer_down_context_(false),
       last_touch_location_(-1, -1),
       touch_events_enabled_(false),
       gesture_recognizer_(ui::GestureRecognizer::Create(this)) {

[flackr, 2013/07/24 18:41:52]

Rather than duplicate the touch events settting, you could get the pref set by
WebContentsImpl here by calling
WebContentsImpl::GetWebkitPrefs(RenderViewHost::From(widget)).touch_enabled.

   render_widget_host_->SetView(this);
   registrar_.Add(this,
                  NOTIFICATION_RENDERER_PROCESS_TERMINATED,
                  NotificationService::AllBrowserContextsAndSources());
 }
 
 RenderWidgetHostViewWin::~RenderWidgetHostViewWin() {
   UnlockMouse();
   ResetTooltip();
 }
@@ skipping 497 matching lines @@
       end = events.end(); iter != end; ++iter)  {
     scoped_ptr<ui::GestureRecognizer::Gestures> gestures;
     gestures.reset(gesture_recognizer_->ProcessTouchEventForGesture(
         *(*iter), result, this));
     ProcessGestures(gestures.get());
   }
 }
 
 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);
+  static bool touch_mode = IsTouchModeEnabled();
 
-  if (!touch_mode)
-    return;
-
-  // 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_);
   }
 }
 
 bool RenderWidgetHostViewWin::DispatchLongPressGestureEvent(
     ui::GestureEvent* event) {
   return ForwardGestureEventToRenderer(event);
 }
 
 bool RenderWidgetHostViewWin::DispatchCancelTouchEvent(
     ui::TouchEvent* event) {
@@ skipping 2230 matching lines @@
   return new RenderWidgetHostViewWin(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(
       WebKit::WebScreenInfo* results) {
   GetScreenInfoForWindow(0, results);
 }
 
 }  // namespace content