Bug 798821 - On Windows, restrict enabling of W3C touch interfaces to devices that support touch input. Also convert touch pref to 3-state value. r=bsmedberg

b2g/app/b2g.js

@@ -273,7 +273,7 @@ pref("image.mem.min_discard_timeout_ms", 10000);
 pref("image.mem.max_decoded_image_kb", 5120); /* 5MB */
 
 // enable touch events interfaces
-pref("dom.w3c_touch_events.enabled", true);
+pref("dom.w3c_touch_events.enabled", 1);
 pref("dom.w3c_touch_events.safetyX", 0); // escape borders in units of 1/240"
 pref("dom.w3c_touch_events.safetyY", 120); // escape borders in units of 1/240"
 

build/automation.py.in

@@ -407,7 +407,7 @@ user_pref("security.warn_viewing_mixed", false);
 user_pref("app.update.enabled", false);
 user_pref("app.update.staging.enabled", false);
 user_pref("browser.panorama.experienced_first_run", true); // Assume experienced
-user_pref("dom.w3c_touch_events.enabled", true);
+user_pref("dom.w3c_touch_events.enabled", 1);
 user_pref("toolkit.telemetry.prompted", 2);
 // Existing tests assume there is no font size inflation.
 user_pref("font.size.inflation.emPerLine", 0);

content/events/src/nsDOMTouchEvent.cpp

@@ -380,6 +380,13 @@ nsDOMTouchEvent::GetShiftKey(bool* aShiftKey)
   return NS_OK;
 }
 
+#ifdef XP_WIN
+namespace mozilla {
+namespace widget {
+extern int32_t IsTouchDeviceSupportPresent();
+} }
+#endif
+
 bool
 nsDOMTouchEvent::PrefEnabled()
 {
@@ -387,7 +394,21 @@ nsDOMTouchEvent::PrefEnabled()
   static bool sPrefValue = false;
   if (!sDidCheckPref) {
     sDidCheckPref = true;
-    sPrefValue = Preferences::GetBool("dom.w3c_touch_events.enabled", false);
+    int32_t flag = 0;
+    if (NS_SUCCEEDED(Preferences::GetInt("dom.w3c_touch_events.enabled",
+                                         &flag))) {
+      if (flag == 2) {
+#ifdef XP_WIN
+        // On Windows we auto-detect based on device support.
+        sPrefValue = mozilla::widget::IsTouchDeviceSupportPresent();
+#else
+        NS_WARNING("dom.w3c_touch_events.enabled=2 not implemented!");
+        sPrefValue = false;
+#endif
+      } else {
+        sPrefValue = !!flag;
+      }
+    }
     if (sPrefValue) {
       nsContentUtils::InitializeTouchEventTable();
     }

dom/browser-element/BrowserElementParent.js

@@ -35,6 +35,15 @@ function getBoolPref(prefName, def) {
   }
 }
 
+function getIntPref(prefName, def) {
+  try {
+    return Services.prefs.getIntPref(prefName);
+  }
+  catch(err) {
+    return def;
+  }
+}
+
 function exposeAll(obj) {
   // Filter for Objects and Arrays.
   if (typeof obj !== "object" || !obj)
@@ -236,7 +245,9 @@ function BrowserElementParent(frameLoader, hasRemoteFrame) {
   // Define methods on the frame element.
   defineMethod('setVisible', this._setVisible);
   defineMethod('sendMouseEvent', this._sendMouseEvent);
-  if (getBoolPref(TOUCH_EVENTS_ENABLED_PREF, false)) {
+
+  // 0 = disabled, 1 = enabled, 2 - auto detect
+  if (getIntPref(TOUCH_EVENTS_ENABLED_PREF, 0) != 0) {
     defineMethod('sendTouchEvent', this._sendTouchEvent);
   }
   defineMethod('goBack', this._goBack);

dom/browser-element/mochitest/browserElement_SendEvent.js

@@ -36,7 +36,7 @@ function runTest() {
         break;
       case "#click":
         ok(true, "Receive a click event.");
-        if (SpecialPowers.getBoolPref("dom.w3c_touch_events.enabled")) {
+        if (SpecialPowers.getIntPref("dom.w3c_touch_events.enabled") != 0) {
           iframe.sendTouchEvent("touchstart", [1], [10], [10], [2], [2],
                                 [20], [0.5], 1, 0);
         } else {

mobile/android/app/mobile.js

@@ -547,7 +547,7 @@ pref("content.image.allow_locking", false);
 pref("image.mem.min_discard_timeout_ms", 10000);
 
 // enable touch events interfaces
-pref("dom.w3c_touch_events.enabled", true);
+pref("dom.w3c_touch_events.enabled", 1);
 
 #ifdef MOZ_SAFE_BROWSING
 pref("browser.safebrowsing.enabled", true);

mobile/xul/app/mobile.js

@@ -579,7 +579,7 @@ pref("content.image.allow_locking", false);
 pref("image.mem.min_discard_timeout_ms", 10000);
 
 // enable touch events interfaces
-pref("dom.w3c_touch_events.enabled", true);
+pref("dom.w3c_touch_events.enabled", 1);
 pref("dom.w3c_touch_events.safetyX", 5); // escape borders in units of 1/240"
 pref("dom.w3c_touch_events.safetyY", 20); // escape borders in units of 1/240"
 

mobile/xul/chrome/content/content.js

@@ -1366,7 +1366,7 @@ var TouchEventHandler = {
   },
 
   sendEvent: function(aName, aData, aElement) {
-    if (!Services.prefs.getBoolPref("dom.w3c_touch_events.enabled"))
+    if (!Services.prefs.getIntPref("dom.w3c_touch_events.enabled"))
       return true;
 
     let evt = content.document.createEvent("touchevent");

modules/libpref/src/init/all.js

@@ -3750,8 +3750,9 @@ pref("dom.mozSettings.enabled", false);
 pref("dom.mozPermissionSettings.enabled", false);
 
 // W3C touch events
+// 0 - disabled, 1 - enabled, 2 - autodetect (win)
 #ifdef XP_WIN
-pref("dom.w3c_touch_events.enabled", true);
+pref("dom.w3c_touch_events.enabled", 2);
 #endif
 
 // enable JS dump() function.

widget/windows/nsLookAndFeel.cpp

@@ -39,18 +39,22 @@ static int32_t GetSystemParam(long flag, int32_t def)
     return ::SystemParametersInfo(flag, 0, &value, 0) ? value : def;
 }
 
-static int32_t IsTouchPresent()
+namespace mozilla {
+namespace widget {
+// This is in use here and in nsDOMTouchEvent.cpp
+int32_t IsTouchDeviceSupportPresent()
 {
   int32_t touchCapabilities;
   touchCapabilities = ::GetSystemMetrics(SM_DIGITIZER);
   return ((touchCapabilities & NID_READY) && 
           (touchCapabilities & (NID_EXTERNAL_TOUCH | NID_INTEGRATED_TOUCH)));
 }
+} }
 
 nsLookAndFeel::nsLookAndFeel() : nsXPLookAndFeel()
 {
   mozilla::Telemetry::Accumulate(mozilla::Telemetry::TOUCH_ENABLED_DEVICE,
-                                 IsTouchPresent());
+                                 IsTouchDeviceSupportPresent());
 }
 
 nsLookAndFeel::~nsLookAndFeel()
@@ -376,7 +380,7 @@ nsLookAndFeel::GetIntImpl(IntID aID, int32_t &aResult)
         aResult = !IsAppThemed();
         break;
     case eIntID_TouchEnabled:
-        aResult = IsTouchPresent();
+        aResult = IsTouchDeviceSupportPresent();
         break;
     case eIntID_WindowsDefaultTheme:
         aResult = nsUXThemeData::IsDefaultWindowTheme();