Backout 41722f2e0c33 (bug 422132), 69da5f098237 (bug 782903), 5c601428c70b (bug 422132) for bug 782903

content/events/src/nsEventStateManager.cpp

@@ -2516,13 +2516,6 @@ nsEventStateManager::DispatchLegacyMouseScrollEvents(nsIFrame* aTargetFrame,
     nsPresContext::AppUnitsToIntCSSPixels(scrollAmount.width),
     nsPresContext::AppUnitsToIntCSSPixels(scrollAmount.height));
 
-  // XXX We don't deal with fractional amount in legacy event, though the
-  //     default action handler (DoScrollText()) deals with it.
-  //     If we implemented such strict computation, we would need additional
-  //     accumulated delta values. It would made the code more complicated.
-  //     And also it would compute different delta values from the older
-  //     version.  It doesn't make sense to implement such code for legacy
-  //     events and rare cases.
   PRInt32 scrollDeltaX, scrollDeltaY, pixelDeltaX, pixelDeltaY;
   switch (aEvent->deltaMode) {
     case nsIDOMWheelEvent::DOM_DELTA_PAGE:
@@ -2741,23 +2734,26 @@ nsEventStateManager::ComputeScrollTarget(nsIFrame* aTargetFrame,
       continue;
     }
 
-    // For default action, we should climb up the tree if cannot scroll it
+    // Check if the scrollable view can be scrolled any further.
-    // by the event actually.
+    if (frameToScroll->GetLineScrollAmount().height) {
-    bool canScroll = CanScrollOn(frameToScroll,
+      // For default action, we should climb up the tree if cannot scroll it
-                                 aEvent->deltaX, aEvent->deltaY);
+      // by the event actually.
-    // Comboboxes need special care.
+      bool canScroll = CanScrollOn(frameToScroll,
-    nsIComboboxControlFrame* comboBox = do_QueryFrame(scrollFrame);
+                                   aEvent->deltaX, aEvent->deltaY);
-    if (comboBox) {
+      // Comboboxes need special care.
-      if (comboBox->IsDroppedDown()) {
+      nsIComboboxControlFrame* comboBox = do_QueryFrame(scrollFrame);
-        // Don't propagate to parent when drop down menu is active.
+      if (comboBox) {
-        return canScroll ? frameToScroll : nullptr;
+        if (comboBox->IsDroppedDown()) {
+          // Don't propagate to parent when drop down menu is active.
+          return canScroll ? frameToScroll : nullptr;
+        }
+        // Always propagate when not dropped down (even if focused).
+        continue;
       }
-      // Always propagate when not dropped down (even if focused).
-      continue;
-    }
 
-    if (canScroll) {
+      if (canScroll) {
-      return frameToScroll;
+        return frameToScroll;
+      }
     }
   }
 
@@ -2829,6 +2825,18 @@ nsEventStateManager::DoScrollText(nsIScrollableFrame* aScrollableFrame,
     return;
   }
 
+  // If the wheel event is line scroll and the delta value is computed from
+  // system settings, allow to override the system speed.
+  bool allowScrollSpeedOverride =
+    (!aEvent->customizedByUserPrefs &&
+     aEvent->deltaMode == nsIDOMWheelEvent::DOM_DELTA_LINE);
+  DeltaValues acceleratedDelta =
+    nsMouseWheelTransaction::AccelerateWheelDelta(aEvent,
+                                                  allowScrollSpeedOverride);
+
+  bool isDeltaModePixel =
+    (aEvent->deltaMode == nsIDOMWheelEvent::DOM_DELTA_PIXEL);
+
   // Default action's actual scroll amount should be computed from device
   // pixels.
   nsPresContext* pc = scrollFrame->PresContext();
@@ -2836,9 +2844,17 @@ nsEventStateManager::DoScrollText(nsIScrollableFrame* aScrollableFrame,
   nsIntSize scrollAmountInDevPixels(
     pc->AppUnitsToDevPixels(scrollAmount.width),
     pc->AppUnitsToDevPixels(scrollAmount.height));
-  nsIntPoint actualDevPixelScrollAmount =
+
-    DeltaAccumulator::GetInstance()->
+  nsIntPoint actualDevPixelScrollAmount(0, 0);
-      ComputeScrollAmountForDefaultAction(aEvent, scrollAmountInDevPixels);
+  if (isDeltaModePixel) {
+    actualDevPixelScrollAmount.x = RoundDown(acceleratedDelta.deltaX);
+    actualDevPixelScrollAmount.y = RoundDown(acceleratedDelta.deltaY);
+  } else {
+    actualDevPixelScrollAmount.x =
+      RoundDown(scrollAmountInDevPixels.width * acceleratedDelta.deltaX);
+    actualDevPixelScrollAmount.y =
+      RoundDown(scrollAmountInDevPixels.height * acceleratedDelta.deltaY);
+  }
 
   nsIAtom* origin = nullptr;
   switch (aEvent->deltaMode) {
@@ -2872,9 +2888,6 @@ nsEventStateManager::DoScrollText(nsIScrollableFrame* aScrollableFrame,
                                             -devPixelPageSize.height;
   }
 
-  bool isDeltaModePixel =
-    (aEvent->deltaMode == nsIDOMWheelEvent::DOM_DELTA_PIXEL);
-
   nsIScrollableFrame::ScrollMode mode;
   switch (aEvent->scrollType) {
     case widget::WheelEvent::SCROLL_DEFAULT:
@@ -5074,6 +5087,13 @@ nsEventStateManager::DeltaAccumulator::InitLineOrPageDelta(
   MOZ_ASSERT(aESM);
   MOZ_ASSERT(aEvent);
 
+  if (!(aEvent->deltaMode == nsIDOMWheelEvent::DOM_DELTA_PIXEL &&
+        aEvent->isPixelOnlyDevice) &&
+      !WheelPrefs::GetInstance()->NeedToComputeLineOrPageDelta(aEvent)) {
+    Reset();
+    return;
+  }
+
   // Reset if the previous wheel event is too old.
   if (!mLastTime.IsNull()) {
     TimeDuration duration = TimeStamp::Now() - mLastTime;
@@ -5082,7 +5102,7 @@ nsEventStateManager::DeltaAccumulator::InitLineOrPageDelta(
     }
   }
   // If we have accumulated delta,  we may need to reset it.
-  if (IsInTransaction()) {
+  if (mHandlingDeltaMode != PR_UINT32_MAX) {
     // If wheel event type is changed, reset the values.
     if (mHandlingDeltaMode != aEvent->deltaMode ||
         mHandlingPixelOnlyDevice != aEvent->isPixelOnlyDevice) {
@@ -5091,10 +5111,10 @@ nsEventStateManager::DeltaAccumulator::InitLineOrPageDelta(
       // If the delta direction is changed, we should reset only the
       // accumulated values.
       if (mX && aEvent->deltaX && ((aEvent->deltaX > 0.0) != (mX > 0.0))) {
-        mX = mPendingScrollAmountX = 0.0;
+        mX = 0.0;
       }
       if (mY && aEvent->deltaY && ((aEvent->deltaY > 0.0) != (mY > 0.0))) {
-        mY = mPendingScrollAmountY = 0.0;
+        mY = 0.0;
       }
     }
   }
@@ -5102,28 +5122,6 @@ nsEventStateManager::DeltaAccumulator::InitLineOrPageDelta(
   mHandlingDeltaMode = aEvent->deltaMode;
   mHandlingPixelOnlyDevice = aEvent->isPixelOnlyDevice;
 
-  // If it's handling neither pixel scroll mode for pixel only device nor
-  // delta values multiplied by prefs, we must not modify lineOrPageDelta
-  // values.
-  if (!(mHandlingDeltaMode == nsIDOMWheelEvent::DOM_DELTA_PIXEL &&
-        mHandlingPixelOnlyDevice) &&
-      !nsEventStateManager::WheelPrefs::GetInstance()->
-        NeedToComputeLineOrPageDelta(aEvent)) {
-    // Set the delta values to mX and mY.  They would be used when above block
-    // resets mX/mY/mPendingScrollAmountX/mPendingScrollAmountY if the direction
-    // is changed.
-    // NOTE: We shouldn't accumulate the delta values, it might could cause
-    //       overflow even though it's not a realistic situation.
-    if (aEvent->deltaX) {
-      mX = aEvent->deltaX;
-    }
-    if (aEvent->deltaY) {
-      mY = aEvent->deltaY;
-    }
-    mLastTime = TimeStamp::Now();
-    return;
-  }
-
   mX += aEvent->deltaX;
   mY += aEvent->deltaY;
 
@@ -5164,45 +5162,10 @@ void
 nsEventStateManager::DeltaAccumulator::Reset()
 {
   mX = mY = 0.0;
-  mPendingScrollAmountX = mPendingScrollAmountY = 0.0;
   mHandlingDeltaMode = PR_UINT32_MAX;
   mHandlingPixelOnlyDevice = false;
 }
 
-nsIntPoint
-nsEventStateManager::DeltaAccumulator::ComputeScrollAmountForDefaultAction(
-                       widget::WheelEvent* aEvent,
-                       const nsIntSize& aScrollAmountInDevPixels)
-{
-  MOZ_ASSERT(aEvent);
-
-  // If the wheel event is line scroll and the delta value is computed from
-  // system settings, allow to override the system speed.
-  bool allowScrollSpeedOverride =
-    (!aEvent->customizedByUserPrefs &&
-     aEvent->deltaMode == nsIDOMWheelEvent::DOM_DELTA_LINE);
-  DeltaValues acceleratedDelta =
-    nsMouseWheelTransaction::AccelerateWheelDelta(aEvent,
-                                                  allowScrollSpeedOverride);
-
-  nsIntPoint result(0, 0);
-  if (aEvent->deltaMode == nsIDOMWheelEvent::DOM_DELTA_PIXEL) {
-    mPendingScrollAmountX += acceleratedDelta.deltaX;
-    mPendingScrollAmountY += acceleratedDelta.deltaY;
-  } else {
-    mPendingScrollAmountX +=
-      aScrollAmountInDevPixels.width * acceleratedDelta.deltaX;
-    mPendingScrollAmountY +=
-      aScrollAmountInDevPixels.height * acceleratedDelta.deltaY;
-  }
-  result.x = RoundDown(mPendingScrollAmountX);
-  result.y = RoundDown(mPendingScrollAmountY);
-  mPendingScrollAmountX -= result.x;
-  mPendingScrollAmountY -= result.y;
-
-  return result;
-}
-
 /******************************************************************/
 /* nsEventStateManager::WheelPrefs                                */
 /******************************************************************/

content/events/src/nsEventStateManager.h

@@ -529,8 +529,6 @@ protected:
       sInstance = nullptr;
     }
 
-    bool IsInTransaction() { return mHandlingDeltaMode != PR_UINT32_MAX; }
-
     /**
      * InitLineOrPageDelta() stores pixel delta values of WheelEvents which are
      * caused if it's needed.  And if the accumulated delta becomes a
@@ -541,34 +539,19 @@ protected:
                              mozilla::widget::WheelEvent* aEvent);
 
     /**
-     * Reset() resets all members.
+     * Reset() resets both delta values.
      */
     void Reset();
 
-    /**
-     * ComputeScrollAmountForDefaultAction() computes the default action's
-     * scroll amount in device pixels with mPendingScrollAmount*.
-     */
-    nsIntPoint ComputeScrollAmountForDefaultAction(
-                 mozilla::widget::WheelEvent* aEvent,
-                 const nsIntSize& aScrollAmountInDevPixels);
-
   private:
     DeltaAccumulator() :
-      mX(0.0), mY(0.0), mPendingScrollAmountX(0.0), mPendingScrollAmountY(0.0),
+      mX(0.0), mY(0.0), mHandlingDeltaMode(PR_UINT32_MAX),
-      mHandlingDeltaMode(PR_UINT32_MAX), mHandlingPixelOnlyDevice(false)
+      mHandlingPixelOnlyDevice(false)
     {
     }
 
     double mX;
     double mY;
-
-    // When default action of a wheel event is scroll but some delta values
-    // are ignored because the computed amount values are not integer, the
-    // fractional values are saved by these members.
-    double mPendingScrollAmountX;
-    double mPendingScrollAmountY;
-
     TimeStamp mLastTime;
 
     PRUint32 mHandlingDeltaMode;

content/events/test/Makefile.in

@@ -34,7 +34,6 @@ MOCHITEST_FILES = \
 		test_bug405632.html \
 		test_bug409604.html \
 		test_bug412567.html \
-		test_bug422132.html \
 		test_bug426082.html \
 		test_bug427537.html \
 		test_bug432698.html \

content/events/test/test_bug422132.html

@@ -1,94 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<!--
-https://bugzilla.mozilla.org/show_bug.cgi?id=422132
--->
-<head>
-  <title>Test for Bug 422132</title>
-  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
-  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <script type="text/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
-</head>
-<body>
-<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=422132">Mozilla Bug 422132</a>
-<p id="display"></p>
-<div id="target" style="font-size: 0; width: 200px; height: 200px; overflow: auto;">
-  <div style="width: 1000px; height: 1000px;"></div>
-</div>
-<div id="content" style="display: none">
-  
-</div>
-<pre id="test">
-<script class="testbody" type="text/javascript">
-
-/** Test for Bug 422132 **/
-
-SimpleTest.waitForExplicitFinish();
-SimpleTest.waitForFocus(runTests, window);
-
-function hitEventLoop(aFunc, aTimes)
-{
-  if (--aTimes) {
-    setTimeout(hitEventLoop, 0, aFunc, aTimes);
-  } else {
-    setTimeout(aFunc, 20);
-  }
-}
-
-function runTests()
-{
-  SpecialPowers.setIntPref("mousewheel.min_line_scroll_amount", 1);
-  SpecialPowers.setIntPref("mousewheel.transaction.timeout", 100000);
-
-  var target = document.getElementById("target");
-
-  var scrollLeft = target.scrollLeft;
-  var scrollTop = target.scrollTop;
-  synthesizeWheel(target, 10, 10,
-    { deltaMode: WheelEvent.DOM_DELTA_PIXEL,
-      deltaX: 0.5, deltaY: 0.5, lineOrPageDeltaX: 0, lineOrPageDeltaY: 0 });
-  hitEventLoop(function () {
-    is(target.scrollLeft, scrollLeft, "scrolled to right by 0.5px delta value");
-    is(target.scrollTop, scrollTop, "scrolled to bottom by 0.5px delta value");
-    scrollLeft = target.scrollLeft;
-    scrollTop = target.scrollTop;
-    synthesizeWheel(target, 10, 10,
-      { deltaMode: WheelEvent.DOM_DELTA_PIXEL,
-        deltaX: 0.5, deltaY: 0.5, lineOrPageDeltaX: 0, lineOrPageDeltaY: 0 });
-    hitEventLoop(function () {
-      ok(target.scrollLeft > scrollLeft,
-         "not scrolled to right by 0.5px delta value with pending 0.5px delta");
-      ok(target.scrollTop > scrollTop,
-         "not scrolled to bottom by 0.5px delta value with pending 0.5px delta");
-      scrollLeft = target.scrollLeft;
-      scrollTop = target.scrollTop;
-      synthesizeWheel(target, 10, 10,
-        { deltaMode: WheelEvent.DOM_DELTA_LINE,
-          deltaX: 0.5, deltaY: 0.5, lineOrPageDeltaX: 0, lineOrPageDeltaY: 0 });
-      hitEventLoop(function () {
-        is(target.scrollLeft, scrollLeft, "scrolled to right by 0.5 line delta value");
-        is(target.scrollTop, scrollTop, "scrolled to bottom by 0.5 line delta value");
-        scrollLeft = target.scrollLeft;
-        scrollTop = target.scrollTop;
-        synthesizeWheel(target, 10, 10,
-          { deltaMode: WheelEvent.DOM_DELTA_LINE,
-            deltaX: 0.5, deltaY: 0.5, lineOrPageDeltaX: 1, lineOrPageDeltaY: 1 });
-        hitEventLoop(function () {
-          ok(target.scrollLeft > scrollLeft,
-             "not scrolled to right by 0.5 line delta value with pending 0.5 line delta");
-          ok(target.scrollTop > scrollTop,
-             "not scrolled to bottom by 0.5 line delta value with pending 0.5 line delta");
-          SpecialPowers.clearUserPref("mousewheel.min_line_scroll_amount");
-          SpecialPowers.clearUserPref("mousewheel.transaction.timeout");
-          SimpleTest.finish();
-        }, 20);
-      }, 20);
-    }, 20);
-  }, 20);
-}
-
-</script>
-</pre>
-</body>
-</html>

layout/generic/nsGfxScrollFrame.cpp

@@ -2548,16 +2548,9 @@ nsGfxScrollFrameInner::GetLineScrollAmount() const
   nsLayoutUtils::GetFontMetricsForFrame(mOuter, getter_AddRefs(fm),
     nsLayoutUtils::FontSizeInflationFor(mOuter));
   NS_ASSERTION(fm, "FontMetrics is null, assuming fontHeight == 1 appunit");
-  static nscoord sMinLineScrollAmountInPixels = -1;
+  nscoord fontHeight = 1;
-  if (sMinLineScrollAmountInPixels < 0) {
-    Preferences::AddIntVarCache(&sMinLineScrollAmountInPixels,
-                                "mousewheel.min_line_scroll_amount", 1);
-  }
-  PRUint32 appUnitsPerDevPixel = mOuter->PresContext()->AppUnitsPerDevPixel();
-  nscoord fontHeight =
-    NS_MAX(1, sMinLineScrollAmountInPixels) * appUnitsPerDevPixel;
   if (fm) {
-    fontHeight = NS_MAX(fm->MaxHeight(), fontHeight);
+    fontHeight = fm->MaxHeight();
   }
 
   return nsSize(fontHeight, fontHeight);

modules/libpref/src/init/all.js

@@ -1417,10 +1417,6 @@ pref("mousewheel.with_win.delta_multiplier_x", 100);
 pref("mousewheel.with_win.delta_multiplier_y", 100);
 pref("mousewheel.with_win.delta_multiplier_z", 100);
 
-// If line-height is lower than this value (in device pixels), 1 line scroll
-// scrolls this height.
-pref("mousewheel.min_line_scroll_amount", 5);
-
 // These define the smooth scroll behavior (min ms, max ms) for different triggers
 // Some triggers:
 // mouseWheel: Discrete mouse wheel events, Synaptics touchpads on windows (generate wheel events)