Bug 832101 - Don't fluff out click targets for events from non-touch input [r=roc]

layout/base/PositionedEventTargeting.cpp

@@ -63,6 +63,7 @@ struct EventRadiusPrefs
   uint32_t mSideRadii[4]; // TRBL order, in millimetres
   bool mEnabled;
   bool mRegistered;
+  bool mTouchOnly;
 };
 
 static EventRadiusPrefs sMouseEventRadiusPrefs;
@@ -99,6 +100,13 @@ GetPrefsFor(nsEventStructType aEventStructType)
       nsPrintfCString radiusPref("ui.%s.radius.%s", prefBranch, prefNames[i]);
       Preferences::AddUintVarCache(&prefs->mSideRadii[i], radiusPref.get(), 0);
     }
+
+    if (aEventStructType == NS_MOUSE_EVENT) {
+      Preferences::AddBoolVarCache(&prefs->mTouchOnly,
+          "ui.mouse.radius.inputSource.touchOnly", true);
+    } else {
+      prefs->mTouchOnly = false;
+    }
   }
 
   return prefs;
@@ -236,7 +244,7 @@ GetClosest(nsIFrame* aRoot, const nsPoint& aPointRelativeToRootFrame,
 }
 
 nsIFrame*
-FindFrameTargetedByInputEvent(nsEventStructType aEventStructType,
+FindFrameTargetedByInputEvent(const nsGUIEvent *aEvent,
                               nsIFrame* aRootFrame,
                               const nsPoint& aPointRelativeToRootFrame,
                               uint32_t aFlags)
@@ -245,11 +253,21 @@ FindFrameTargetedByInputEvent(nsEventStructType aEventStructType,
   nsIFrame* target =
     nsLayoutUtils::GetFrameForPoint(aRootFrame, aPointRelativeToRootFrame,
                                     false, ignoreRootScrollFrame);
-  const EventRadiusPrefs* prefs = GetPrefsFor(aEventStructType);
+
+  const EventRadiusPrefs* prefs = GetPrefsFor(aEvent->eventStructType);
   if (!prefs || !prefs->mEnabled || (target && IsElementClickable(target))) {
     return target;
   }
 
+  // Do not modify targeting for actual mouse hardware; only for mouse
+  // events generated by touch-screen hardware.
+  if (aEvent->eventStructType == NS_MOUSE_EVENT &&
+      prefs->mTouchOnly &&
+      static_cast<const nsMouseEvent*>(aEvent)->inputSource !=
+          nsIDOMMouseEvent::MOZ_SOURCE_TOUCH) {
+      return target;
+  }
+
   nsRect targetRect = GetTargetRect(aRootFrame, aPointRelativeToRootFrame, prefs);
   nsAutoTArray<nsIFrame*,8> candidates;
   nsresult rv = nsLayoutUtils::GetFramesForArea(aRootFrame, targetRect, candidates,

layout/base/PositionedEventTargeting.h

@@ -21,7 +21,7 @@ enum {
  * that are suitable targets, to account for inaccurate pointing devices.
  */
 nsIFrame*
-FindFrameTargetedByInputEvent(nsEventStructType aEventStructType,
+FindFrameTargetedByInputEvent(const nsGUIEvent *aEvent,
                               nsIFrame* aRootFrame,
                               const nsPoint& aPointRelativeToRootFrame,
                               uint32_t aFlags = 0);

layout/base/nsPresShell.cpp

@@ -5960,11 +5960,10 @@ PresShell::HandleEvent(nsIFrame        *aFrame,
             eventPoint = nsLayoutUtils::GetEventCoordinatesRelativeTo(aEvent,
                                                               touch->mRefPoint,
                                                               frame);
-            nsIFrame* target =
-                          FindFrameTargetedByInputEvent(aEvent->eventStructType,
-                                                        frame,
-                                                        eventPoint,
-                                                        flags);
+            nsIFrame* target = FindFrameTargetedByInputEvent(aEvent,
+                                                             frame,
+                                                             eventPoint,
+                                                             flags);
             if (target && !anyTarget) {
               target->GetContentForEvent(aEvent, getter_AddRefs(anyTarget));
               while (anyTarget && !anyTarget->IsElement()) {
@@ -6032,7 +6031,7 @@ PresShell::HandleEvent(nsIFrame        *aFrame,
         flags |= INPUT_IGNORE_ROOT_SCROLL_FRAME;
       }
       nsIFrame* target =
-        FindFrameTargetedByInputEvent(aEvent->eventStructType, frame, eventPoint, flags);
+        FindFrameTargetedByInputEvent(aEvent, frame, eventPoint, flags);
       if (target) {
         frame = target;
       }

layout/base/tests/test_event_target_radius.html

@@ -44,6 +44,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=780847
 <script type="application/javascript">
 var prefBase = "ui.mouse.radius.";
 SpecialPowers.setBoolPref(prefBase + "enabled", true);
+SpecialPowers.setBoolPref(prefBase + "inputSource.touchOnly", false);
 SpecialPowers.setIntPref(prefBase + "leftmm", 12);
 SpecialPowers.setIntPref(prefBase + "topmm", 8);
 SpecialPowers.setIntPref(prefBase + "rightmm", 4);
@@ -57,6 +58,7 @@ ok(4*mm >= 10, "WARNING: mm " + mm + " too small in this configuration. Test res
 
 function endTest() {
   SpecialPowers.clearUserPref(prefBase + "enabled");
+  SpecialPowers.clearUserPref(prefBase + "inputSource.touchOnly");
   SpecialPowers.clearUserPref(prefBase + "leftmmm");
   SpecialPowers.clearUserPref(prefBase + "topmm");
   SpecialPowers.clearUserPref(prefBase + "rightmm");
@@ -68,9 +70,9 @@ function endTest() {
 var eventTarget;
 window.onmousedown = function(event) { eventTarget = event.target; };
 
-function testMouseClick(idPosition, dx, dy, idTarget, msg) {
+function testMouseClick(idPosition, dx, dy, idTarget, msg, options) {
   eventTarget = null;
-  synthesizeMouse(document.getElementById(idPosition), dx, dy, {});
+  synthesizeMouse(document.getElementById(idPosition), dx, dy, options || {});
   try {
     is(eventTarget.id, idTarget,
        "checking '" + idPosition + "' offset " + dx + "," + dy + " [" + msg + "]");
@@ -96,6 +98,18 @@ function runTest() {
   testMouseClick("t", -3*mm, 10, "t", "basic functionality");
   testMouseClick("t", 10, -5*mm, "body", "basic functionality");
   testMouseClick("t", 10, -3*mm, "t", "basic functionality");
+
+  // When inputSource.touchOnly is true, mouse input is not retargeted.
+  SpecialPowers.setBoolPref(prefBase + "inputSource.touchOnly", true);
+  testMouseClick("t", 100 + 11*mm, 10, "body", "disabled for mouse input");
+  testMouseClick("t", 100 + 11*mm, 10, "t", "enabled for touch input", {
+    inputSource: SpecialPowers.Ci.nsIDOMMouseEvent.MOZ_SOURCE_TOUCH
+  });
+  testMouseClick("t", 100 + 13*mm, 10, "body", "basic functionality for touch", {
+    inputSource: SpecialPowers.Ci.nsIDOMMouseEvent.MOZ_SOURCE_TOUCH
+  });
+  SpecialPowers.setBoolPref(prefBase + "inputSource.touchOnly", false);
+
   setShowing("t", false);
 
   // Now test the criteria we use to determine which elements are hittable

modules/libpref/src/init/all.js

@@ -1964,6 +1964,10 @@ pref("ui.mouse.radius.rightmm", 8);
 pref("ui.mouse.radius.bottommm", 4);
 pref("ui.mouse.radius.visitedWeight", 120);
 
+// When true, the ui.mouse.radius.* prefs will only affect simulated mouse events generated by touch input.
+// When false, the prefs will be used for all mouse events.
+pref("ui.mouse.radius.inputSource.touchOnly", true);
+
 #ifdef XP_WIN
 
 pref("font.name.serif.ar", "Times New Roman");