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-rw-r--r--dom/base/Element.cpp18
-rw-r--r--dom/base/nsDocument.cpp21
-rw-r--r--dom/base/nsINode.cpp4
-rw-r--r--layout/base/RestyleManagerBase.cpp63
-rw-r--r--layout/base/nsCSSFrameConstructor.cpp15
-rw-r--r--layout/base/nsChangeHint.h55
-rw-r--r--layout/base/nsPresContext.cpp9
-rw-r--r--layout/base/nsPresContext.h22
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-1-ref.html18
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-1a.html23
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-1b.html23
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-1c.html19
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-2-ref.html15
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-2a.html26
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-2b.html26
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-2c.html24
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-2d.html24
-rw-r--r--layout/reftests/scrolling/propagated-overflow-style-2e.html15
-rw-r--r--layout/reftests/scrolling/reftest.list10
-rw-r--r--layout/style/nsStyleStruct.cpp28
-rw-r--r--layout/style/test/mochitest.ini1
-rw-r--r--layout/style/test/test_dynamic_change_causing_reflow.html107
-rw-r--r--layout/style/test/test_viewport_scrollbar_causing_reflow.html125
23 files changed, 651 insertions, 40 deletions
diff --git a/dom/base/Element.cpp b/dom/base/Element.cpp
index 8b9808aa30..0927555905 100644
--- a/dom/base/Element.cpp
+++ b/dom/base/Element.cpp
@@ -1844,6 +1844,24 @@ Element::UnbindFromTree(bool aDeep, bool aNullParent)
SetParentIsContent(false);
}
+#ifdef DEBUG
+ // If we can get access to the PresContext, then we sanity-check that
+ // we're not leaving behind a pointer to ourselves as the PresContext's
+ // cached provider of the viewport's scrollbar styles.
+ if (document) {
+ nsIPresShell* presShell = document->GetShell();
+ if (presShell) {
+ nsPresContext* presContext = presShell->GetPresContext();
+ if (presContext) {
+ MOZ_ASSERT(this !=
+ presContext->GetViewportScrollbarStylesOverrideNode(),
+ "Leaving behind a raw pointer to this node (as having "
+ "propagated scrollbar styles) - that's dangerous...");
+ }
+ }
+ }
+#endif
+
// Ensure that CSS transitions don't continue on an element at a
// different place in the tree (even if reinserted before next
// animation refresh).
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index d5954a62c4..fd3b529481 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -2054,10 +2054,17 @@ nsDocument::ResetToURI(nsIURI *aURI, nsILoadGroup *aLoadGroup,
mFirstChild = content->GetNextSibling();
}
mChildren.RemoveChildAt(i);
+ if (content == mCachedRootElement) {
+ // Immediately clear mCachedRootElement, now that it's been removed
+ // from mChildren, so that GetRootElement() will stop returning this
+ // now-stale value.
+ mCachedRootElement = nullptr;
+ }
nsNodeUtils::ContentRemoved(this, content, i, previousSibling);
content->UnbindFromTree();
}
- mCachedRootElement = nullptr;
+ MOZ_ASSERT(!mCachedRootElement,
+ "After removing all children, there should be no root elem");
}
mInUnlinkOrDeletion = oldVal;
@@ -3913,8 +3920,18 @@ nsDocument::RemoveChildAt(uint32_t aIndex, bool aNotify)
DestroyElementMaps();
}
- doRemoveChildAt(aIndex, aNotify, oldKid, mChildren);
+ // Preemptively clear mCachedRootElement, since we may be about to remove it
+ // from our child list, and we don't want to return this maybe-obsolete value
+ // from any GetRootElement() calls that happen inside of doRemoveChildAt().
+ // (NOTE: for this to be useful, doRemoveChildAt() must NOT trigger any
+ // GetRootElement() calls until after it's removed the child from mChildren.
+ // Any call before that point would restore this soon-to-be-obsolete cached
+ // answer, and our clearing here would be fruitless.)
mCachedRootElement = nullptr;
+ doRemoveChildAt(aIndex, aNotify, oldKid, mChildren);
+ MOZ_ASSERT(mCachedRootElement != oldKid,
+ "Stale pointer in mCachedRootElement, after we tried to clear it "
+ "(maybe somebody called GetRootElement() too early?)");
}
void
diff --git a/dom/base/nsINode.cpp b/dom/base/nsINode.cpp
index 3a649a61d0..715ca93eab 100644
--- a/dom/base/nsINode.cpp
+++ b/dom/base/nsINode.cpp
@@ -1907,6 +1907,10 @@ void
nsINode::doRemoveChildAt(uint32_t aIndex, bool aNotify,
nsIContent* aKid, nsAttrAndChildArray& aChildArray)
{
+ // NOTE: This function must not trigger any calls to
+ // nsIDocument::GetRootElement() calls until *after* it has removed aKid from
+ // aChildArray. Any calls before then could potentially restore a stale
+ // value for our cached root element, per note in nsDocument::RemoveChildAt().
NS_PRECONDITION(aKid && aKid->GetParentNode() == this &&
aKid == GetChildAt(aIndex) &&
IndexOf(aKid) == (int32_t)aIndex, "Bogus aKid");
diff --git a/layout/base/RestyleManagerBase.cpp b/layout/base/RestyleManagerBase.cpp
index 9a5ce43ebf..d96d9dbbb0 100644
--- a/layout/base/RestyleManagerBase.cpp
+++ b/layout/base/RestyleManagerBase.cpp
@@ -154,7 +154,7 @@ RestyleManagerBase::ChangeHintToString(nsChangeHint aHint)
"NeutralChange", "InvalidateRenderingObservers",
"ReflowChangesSizeOrPosition", "UpdateComputedBSize",
"UpdateUsesOpacity", "UpdateBackgroundPosition",
- "AddOrRemoveTransform"
+ "AddOrRemoveTransform", "CSSOverflowChange",
};
static_assert(nsChangeHint_AllHints == (1 << ArrayLength(names)) - 1,
"Name list doesn't match change hints.");
@@ -1070,6 +1070,67 @@ RestyleManagerBase::ProcessRestyledFrames(nsStyleChangeList& aChangeList)
FramePropertyTable* propTable = presContext->PropertyTable();
nsCSSFrameConstructor* frameConstructor = presContext->FrameConstructor();
+ // Handle nsChangeHint_CSSOverflowChange, by either updating the
+ // scrollbars on the viewport, or upgrading the change hint to frame-reconstruct.
+ for (nsStyleChangeData& data : aChangeList) {
+ if (data.mHint & nsChangeHint_CSSOverflowChange) {
+ data.mHint &= ~nsChangeHint_CSSOverflowChange;
+ bool doReconstruct = true; // assume the worst
+
+ // Only bother with this if we're html/body, since:
+ // (a) It'd be *expensive* to reframe these particular nodes. They're
+ // at the root, so reframing would mean rebuilding the world.
+ // (b) It's often *unnecessary* to reframe for "overflow" changes on
+ // these particular nodes. In general, the only reason we reframe
+ // for "overflow" changes is so we can construct (or destroy) a
+ // scrollframe & scrollbars -- and the html/body nodes often don't
+ // need their own scrollframe/scrollbars because they coopt the ones
+ // on the viewport (which always exist). So depending on whether
+ // that's happening, we can skip the reframe for these nodes.
+ if (data.mContent->IsAnyOfHTMLElements(nsGkAtoms::body,
+ nsGkAtoms::html)) {
+ // If the restyled element provided/provides the scrollbar styles for
+ // the viewport before and/or after this restyle, AND it's not coopting
+ // that responsibility from some other element (which would need
+ // reconstruction to make its own scrollframe now), THEN: we don't need
+ // to reconstruct - we can just reflow, because no scrollframe is being
+ // added/removed.
+ nsIContent* prevOverrideNode =
+ presContext->GetViewportScrollbarStylesOverrideNode();
+ nsIContent* newOverrideNode =
+ presContext->UpdateViewportScrollbarStylesOverride();
+
+ if (data.mContent == prevOverrideNode ||
+ data.mContent == newOverrideNode) {
+ // If we get here, the restyled element provided the scrollbar styles
+ // for viewport before this restyle, OR it will provide them after.
+ if (!prevOverrideNode || !newOverrideNode ||
+ prevOverrideNode == newOverrideNode) {
+ // If we get here, the restyled element is NOT replacing (or being
+ // replaced by) some other element as the viewport's
+ // scrollbar-styles provider. (If it were, we'd potentially need to
+ // reframe to create a dedicated scrollframe for whichever element
+ // is being booted from providing viewport scrollbar styles.)
+ //
+ // Under these conditions, we're OK to assume that this "overflow"
+ // change only impacts the root viewport's scrollframe, which
+ // already exists, so we can simply reflow instead of reframing.
+ // When requesting this reflow, we send the exact same change hints
+ // that "width" and "height" would send (since conceptually,
+ // adding/removing scrollbars is like changing the available
+ // space).
+ data.mHint |= (nsChangeHint_ReflowHintsForISizeChange |
+ nsChangeHint_ReflowHintsForBSizeChange);
+ doReconstruct = false;
+ }
+ }
+ }
+ if (doReconstruct) {
+ data.mHint |= nsChangeHint_ReconstructFrame;
+ }
+ }
+ }
+
// Make sure to not rebuild quote or counter lists while we're
// processing restyles
frameConstructor->BeginUpdate();
diff --git a/layout/base/nsCSSFrameConstructor.cpp b/layout/base/nsCSSFrameConstructor.cpp
index f8c7f52a9e..767298b85c 100644
--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -8246,11 +8246,19 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent* aContainer,
*aDestroyedFramesFor = aChild;
}
+ nsPresContext* presContext = mPresShell->GetPresContext();
+ MOZ_ASSERT(presContext, "Our presShell should have a valid presContext");
+
if (aChild->IsHTMLElement(nsGkAtoms::body) ||
(!aContainer && aChild->IsElement())) {
- // This might be the element we propagated viewport scrollbar
- // styles from. Recompute those.
- mPresShell->GetPresContext()->UpdateViewportScrollbarStylesOverride();
+ // We might be removing the element that we propagated viewport scrollbar
+ // styles from. Recompute those. (This clause covers two of the three
+ // possible scrollbar-propagation sources: the <body> [as aChild or a
+ // descendant] and the root node. The other possible scrollbar-propagation
+ // source is a fullscreen element, and we have code elsewhere to update
+ // scrollbars after fullscreen elements are removed -- specifically, it's
+ // part of the fullscreen cleanup code called by Element::UnbindFromTree.)
+ presContext->UpdateViewportScrollbarStylesOverride();
}
// XXXldb Do we need to re-resolve style to handle the CSS2 + combinator and
@@ -8316,7 +8324,6 @@ nsCSSFrameConstructor::ContentRemoved(nsIContent* aContainer,
ClearDisplayContentsIn(aChild, aContainer);
}
- nsPresContext* presContext = mPresShell->GetPresContext();
#ifdef MOZ_XUL
if (NotifyListBoxBody(presContext, aContainer, aChild, aOldNextSibling,
childFrame, CONTENT_REMOVED)) {
diff --git a/layout/base/nsChangeHint.h b/layout/base/nsChangeHint.h
index 318b848407..eb2709de65 100644
--- a/layout/base/nsChangeHint.h
+++ b/layout/base/nsChangeHint.h
@@ -217,6 +217,16 @@ enum nsChangeHint {
*/
nsChangeHint_AddOrRemoveTransform = 1 << 27,
+ /**
+ * Indicates that the overflow-x and/or overflow-y property changed.
+ *
+ * In most cases, this is equivalent to nsChangeHint_ReconstructFrame. But
+ * in some special cases where the change is really targeting the viewport's
+ * scrollframe, this is instead equivalent to nsChangeHint_AllReflowHints
+ * (because the viewport always has an associated scrollframe).
+ */
+ nsChangeHint_CSSOverflowChange = 1 << 28,
+
// IMPORTANT NOTE: When adding new hints, consider whether you need
// to add them to NS_HintsNotHandledForDescendantsIn() below. Please
// also add them to RestyleManager::ChangeHintToString and modify
@@ -225,7 +235,7 @@ enum nsChangeHint {
/**
* Dummy hint value for all hints. It exists for compile time check.
*/
- nsChangeHint_AllHints = (1 << 28) - 1,
+ nsChangeHint_AllHints = (1 << 29) - 1,
};
// Redefine these operators to return nothing. This will catch any use
@@ -306,6 +316,7 @@ inline nsChangeHint operator^=(nsChangeHint& aLeft, nsChangeHint aRight)
nsChangeHint_UpdatePostTransformOverflow | \
nsChangeHint_UpdateParentOverflow | \
nsChangeHint_ChildrenOnlyTransform | \
+ nsChangeHint_CSSOverflowChange | \
nsChangeHint_RecomputePosition | \
nsChangeHint_UpdateContainingBlock | \
nsChangeHint_AddOrRemoveTransform | \
@@ -374,6 +385,48 @@ inline nsChangeHint NS_HintsNotHandledForDescendantsIn(nsChangeHint aChangeHint)
nsChangeHint_ClearAncestorIntrinsics | \
nsChangeHint_ClearDescendantIntrinsics | \
nsChangeHint_NeedDirtyReflow)
+
+// Below are the change hints that we send for ISize & BSize changes.
+// Each is similar to nsChangeHint_AllReflowHints with a few changes.
+
+// * For an ISize change, we send nsChangeHint_AllReflowHints, with two bits
+// excluded: nsChangeHint_ClearDescendantIntrinsics (because an ancestor's
+// inline-size change can't affect descendant intrinsic sizes), and
+// nsChangeHint_NeedDirtyReflow (because ISize changes don't need to *force*
+// all descendants to reflow).
+#define nsChangeHint_ReflowHintsForISizeChange \
+ nsChangeHint(nsChangeHint_AllReflowHints & \
+ ~(nsChangeHint_ClearDescendantIntrinsics | \
+ nsChangeHint_NeedDirtyReflow))
+
+// * For a BSize change, we send almost the same hints as for ISize changes,
+// with one extra: nsChangeHint_UpdateComputedBSize. We need this hint because
+// BSize changes CAN affect descendant intrinsic sizes, due to replaced
+// elements with percentage BSizes in descendants which also have percentage
+// BSizes. nsChangeHint_UpdateComputedBSize clears intrinsic sizes for frames
+// that have such replaced elements. (We could instead send
+// nsChangeHint_ClearDescendantIntrinsics, but that's broader than we need.)
+//
+// NOTE: You might think that BSize changes could exclude
+// nsChangeHint_ClearAncestorIntrinsics (which is inline-axis specific), but we
+// do need to send it, to clear cached results from CSS Flex measuring reflows.
+#define nsChangeHint_ReflowHintsForBSizeChange \
+ nsChangeHint((nsChangeHint_AllReflowHints | \
+ nsChangeHint_UpdateComputedBSize) & \
+ ~(nsChangeHint_ClearDescendantIntrinsics | \
+ nsChangeHint_NeedDirtyReflow))
+
+// * For changes to the float area of an already-floated element, we need all
+// reflow hints, but not the ones that apply to descendants.
+// Our descendants aren't impacted when our float area only changes
+// placement but not size/shape. (e.g. if we change which side we float to).
+// But our ancestors/siblings are potentially impacted, so we need to send
+// the non-descendant reflow hints.
+#define nsChangeHint_ReflowHintsForFloatAreaChange \
+ nsChangeHint(nsChangeHint_AllReflowHints & \
+ ~(nsChangeHint_ClearDescendantIntrinsics | \
+ nsChangeHint_NeedDirtyReflow))
+
#define NS_STYLE_HINT_REFLOW \
nsChangeHint(NS_STYLE_HINT_VISUAL | nsChangeHint_AllReflowHints)
diff --git a/layout/base/nsPresContext.cpp b/layout/base/nsPresContext.cpp
index d9f7b368c7..4a54a84323 100644
--- a/layout/base/nsPresContext.cpp
+++ b/layout/base/nsPresContext.cpp
@@ -208,6 +208,7 @@ nsPresContext::nsPresContext(nsIDocument* aDocument, nsPresContextType aType)
mTextZoom(1.0), mFullZoom(1.0), mOverrideDPPX(0.0),
mLastFontInflationScreenSize(gfxSize(-1.0, -1.0)),
mPageSize(-1, -1), mPPScale(1.0f),
+ mViewportScrollbarOverrideNode(nullptr),
mViewportStyleScrollbar(NS_STYLE_OVERFLOW_AUTO, NS_STYLE_OVERFLOW_AUTO),
mImageAnimationModePref(imgIContainer::kNormalAnimMode),
mAllInvalidated(false),
@@ -1423,10 +1424,10 @@ nsPresContext::UpdateViewportScrollbarStylesOverride()
// Start off with our default styles, and then update them as needed.
mViewportStyleScrollbar = ScrollbarStyles(NS_STYLE_OVERFLOW_AUTO,
NS_STYLE_OVERFLOW_AUTO);
- nsIContent* propagatedFrom = nullptr;
+ mViewportScrollbarOverrideNode = nullptr;
// Don't propagate the scrollbar state in printing or print preview.
if (!IsPaginated()) {
- propagatedFrom =
+ mViewportScrollbarOverrideNode =
GetPropagatedScrollbarStylesForViewport(this, &mViewportStyleScrollbar);
}
@@ -1438,13 +1439,13 @@ nsPresContext::UpdateViewportScrollbarStylesOverride()
// the styles are from, so that the state of those elements is not
// affected across fullscreen change.
if (fullscreenElement != document->GetRootElement() &&
- fullscreenElement != propagatedFrom) {
+ fullscreenElement != mViewportScrollbarOverrideNode) {
mViewportStyleScrollbar = ScrollbarStyles(NS_STYLE_OVERFLOW_HIDDEN,
NS_STYLE_OVERFLOW_HIDDEN);
}
}
- return propagatedFrom;
+ return mViewportScrollbarOverrideNode;
}
bool
diff --git a/layout/base/nsPresContext.h b/layout/base/nsPresContext.h
index 4fdc60a2ea..d8f876291c 100644
--- a/layout/base/nsPresContext.h
+++ b/layout/base/nsPresContext.h
@@ -719,7 +719,18 @@ public:
* it was propagated from.
*/
nsIContent* UpdateViewportScrollbarStylesOverride();
- const ScrollbarStyles& GetViewportScrollbarStylesOverride()
+
+ /**
+ * Returns the cached result from the last call to
+ * UpdateViewportScrollbarStylesOverride() -- i.e. return the node
+ * whose scrollbar styles we have propagated to the viewport (or nullptr if
+ * there is no such node).
+ */
+ nsIContent* GetViewportScrollbarStylesOverrideNode() const {
+ return mViewportScrollbarOverrideNode;
+ }
+
+ const ScrollbarStyles& GetViewportScrollbarStylesOverride() const
{
return mViewportStyleScrollbar;
}
@@ -1310,7 +1321,16 @@ protected:
nscolor mBodyTextColor;
+ // This is a non-owning pointer. May be null. If non-null, it's guaranteed
+ // to be pointing to a node that's still alive, because we'll reset it in
+ // UpdateViewportScrollbarStylesOverride() as part of the cleanup code
+ // when this node is removed from the document. (For <body> and the root node,
+ // this call happens in nsCSSFrameConstructor::ContentRemoved(). For
+ // fullscreen elements, it happens in the fullscreen-specific cleanup
+ // invoked by Element::UnbindFromTree().)
+ nsIContent* MOZ_NON_OWNING_REF mViewportScrollbarOverrideNode;
ScrollbarStyles mViewportStyleScrollbar;
+
uint8_t mFocusRingWidth;
bool mExistThrottledUpdates;
diff --git a/layout/reftests/scrolling/propagated-overflow-style-1-ref.html b/layout/reftests/scrolling/propagated-overflow-style-1-ref.html
new file mode 100644
index 0000000000..7c2b1b3150
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-1-ref.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html>
+<head>
+ <title>
+ Reference case with body and html *independently* scrollable.
+ </title>
+ <style>
+ html {
+ overflow: scroll;
+ }
+ body {
+ overflow: scroll;
+ }
+ </style>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/propagated-overflow-style-1a.html b/layout/reftests/scrolling/propagated-overflow-style-1a.html
new file mode 100644
index 0000000000..b5115d36fe
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-1a.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<head>
+ <title>
+ Testcase with body and html *independently* scrollable,
+ with body's "overflow" set dynamically.
+ </title>
+ <style>
+ html {
+ overflow: scroll;
+ }
+ </style>
+ <script>
+ function doTest() {
+ document.body.style.overflow = "scroll";
+ document.documentElement.removeAttribute("class");
+ }
+ window.addEventListener("MozReftestInvalidate", doTest);
+ </script>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/propagated-overflow-style-1b.html b/layout/reftests/scrolling/propagated-overflow-style-1b.html
new file mode 100644
index 0000000000..4608b87d62
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-1b.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<head>
+ <title>
+ Testcase with body and html *independently* scrollable,
+ with html's "overflow" set dynamically.
+ </title>
+ <style>
+ body {
+ overflow: scroll;
+ }
+ </style>
+ <script>
+ function doTest() {
+ document.documentElement.style.overflow = "scroll";
+ document.documentElement.removeAttribute("class");
+ }
+ window.addEventListener("MozReftestInvalidate", doTest);
+ </script>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/propagated-overflow-style-1c.html b/layout/reftests/scrolling/propagated-overflow-style-1c.html
new file mode 100644
index 0000000000..11809915a0
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-1c.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<head>
+ <title>
+ Testcase with body and html *independently* scrollable,
+ with both html & body's "overflow" set dynamically.
+ </title>
+ <script>
+ function doTest() {
+ document.documentElement.style.overflow = "scroll";
+ document.body.style.overflow = "scroll";
+ document.documentElement.removeAttribute("class");
+ }
+ window.addEventListener("MozReftestInvalidate", doTest);
+ </script>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/propagated-overflow-style-2-ref.html b/layout/reftests/scrolling/propagated-overflow-style-2-ref.html
new file mode 100644
index 0000000000..20c3b8ae5b
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-2-ref.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html>
+<head>
+ <title>
+ Reference case with the root viewport scrollable, via styles on html node.
+ </title>
+ <style>
+ html {
+ overflow: scroll;
+ }
+ </style>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/propagated-overflow-style-2a.html b/layout/reftests/scrolling/propagated-overflow-style-2a.html
new file mode 100644
index 0000000000..250bedd6c6
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-2a.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<head>
+ <title>
+ Testcase with only one of [html,body] being scrollable,
+ after body's "overflow" is reset dynamically.
+ </title>
+ <style>
+ html {
+ overflow: scroll;
+ }
+ body {
+ overflow: scroll;
+ }
+ </style>
+ <script>
+ function doTest() {
+ document.body.style.overflow = "visible";
+ document.documentElement.removeAttribute("class");
+ }
+ window.addEventListener("MozReftestInvalidate", doTest);
+ </script>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/propagated-overflow-style-2b.html b/layout/reftests/scrolling/propagated-overflow-style-2b.html
new file mode 100644
index 0000000000..c94ddedb26
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-2b.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<head>
+ <title>
+ Testcase with only one of [html,body] being scrollable,
+ after html's "overflow" is reset dynamically.
+ </title>
+ <style>
+ html {
+ overflow: scroll;
+ }
+ body {
+ overflow: scroll;
+ }
+ </style>
+ <script>
+ function doTest() {
+ document.documentElement.style.overflow = "visible";
+ document.documentElement.removeAttribute("class");
+ }
+ window.addEventListener("MozReftestInvalidate", doTest);
+ </script>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/propagated-overflow-style-2c.html b/layout/reftests/scrolling/propagated-overflow-style-2c.html
new file mode 100644
index 0000000000..0ceb1f21ab
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-2c.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<head>
+ <title>
+ Testcase with only one of [html,body] being scrollable,
+ with their "overflow" styles being dynamically swapped.
+ </title>
+ <style>
+ html {
+ overflow: scroll;
+ }
+ </style>
+ <script>
+ function doTest() {
+ document.documentElement.style.overflow = "visible";
+ document.body.style.overflow = "scroll";
+ document.documentElement.removeAttribute("class");
+ }
+ window.addEventListener("MozReftestInvalidate", doTest);
+ </script>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/propagated-overflow-style-2d.html b/layout/reftests/scrolling/propagated-overflow-style-2d.html
new file mode 100644
index 0000000000..3353a33744
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-2d.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<head>
+ <title>
+ Testcase with only one of [html,body] being scrollable,
+ with their "overflow" styles being dynamically swapped.
+ </title>
+ <style>
+ body {
+ overflow: scroll;
+ }
+ </style>
+ <script>
+ function doTest() {
+ document.documentElement.style.overflow = "scroll";
+ document.body.style.overflow = "visible";
+ document.documentElement.removeAttribute("class");
+ }
+ window.addEventListener("MozReftestInvalidate", doTest);
+ </script>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/propagated-overflow-style-2e.html b/layout/reftests/scrolling/propagated-overflow-style-2e.html
new file mode 100644
index 0000000000..f9105185b1
--- /dev/null
+++ b/layout/reftests/scrolling/propagated-overflow-style-2e.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html>
+<head>
+ <title>
+ Testcase with the root viewport scrollable, via styles on body node.
+ </title>
+ <style>
+ body {
+ overflow: scroll;
+ }
+ </style>
+</head>
+<body>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/reftest.list b/layout/reftests/scrolling/reftest.list
index db1b81db6f..43997ced7d 100644
--- a/layout/reftests/scrolling/reftest.list
+++ b/layout/reftests/scrolling/reftest.list
@@ -85,3 +85,13 @@ fuzzy-if(asyncPan&&!layersGPUAccelerated,102,2420) == frame-scrolling-attr-2.htm
== fractional-scroll-area.html?top=0.4&outerBottom=99.6&innerBottom=200.4&scrollBefore=999 fractional-scroll-area.html?top=0&outerBottom=100&innerBottom=200&scrollBefore=999
== fractional-scroll-area.html?top=0.4&outerBottom=100.4&innerBottom=200.4&scrollBefore=999 fractional-scroll-area.html?top=0&outerBottom=100&innerBottom=200&scrollBefore=999
!= fractional-scroll-area-invalidation.html about:blank
+
+# Tests for "overflow" styles that may be propagated to the viewport:
+== propagated-overflow-style-1a.html propagated-overflow-style-1-ref.html
+== propagated-overflow-style-1b.html propagated-overflow-style-1-ref.html
+== propagated-overflow-style-1c.html propagated-overflow-style-1-ref.html
+== propagated-overflow-style-2a.html propagated-overflow-style-2-ref.html
+== propagated-overflow-style-2b.html propagated-overflow-style-2-ref.html
+== propagated-overflow-style-2c.html propagated-overflow-style-2-ref.html
+== propagated-overflow-style-2d.html propagated-overflow-style-2-ref.html
+== propagated-overflow-style-2e.html propagated-overflow-style-2-ref.html
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index eab11b80c0..553239e0ed 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -1629,28 +1629,11 @@ nsStylePosition::CalcDifference(const nsStylePosition& aNewData,
if (aOldStyleVisibility) {
bool isVertical = WritingMode(aOldStyleVisibility).IsVertical();
if (isVertical ? widthChanged : heightChanged) {
- // Block-size changes can affect descendant intrinsic sizes due to
- // replaced elements with percentage bsizes in descendants which
- // also have percentage bsizes. This is handled via
- // nsChangeHint_UpdateComputedBSize which clears intrinsic sizes
- // for frames that have such replaced elements.
- //
- // We need to use nsChangeHint_ClearAncestorIntrinsics for
- // block-size changes so we clear results of cached CSS Flex
- // measuring reflows.
- hint |= nsChangeHint_NeedReflow |
- nsChangeHint_UpdateComputedBSize |
- nsChangeHint_ReflowChangesSizeOrPosition |
- nsChangeHint_ClearAncestorIntrinsics;
+ hint |= nsChangeHint_ReflowHintsForBSizeChange;
}
if (isVertical ? heightChanged : widthChanged) {
- // None of our inline-size differences can affect descendant
- // intrinsic sizes and none of them need to force children to
- // reflow.
- hint |= nsChangeHint_AllReflowHints &
- ~(nsChangeHint_ClearDescendantIntrinsics |
- nsChangeHint_NeedDirtyReflow);
+ hint |= nsChangeHint_ReflowHintsForISizeChange;
}
} else {
if (widthChanged || heightChanged) {
@@ -3263,8 +3246,6 @@ nsStyleDisplay::CalcDifference(const nsStyleDisplay& aNewData) const
|| mDisplay != aNewData.mDisplay
|| mContain != aNewData.mContain
|| (mFloat == StyleFloat::None) != (aNewData.mFloat == StyleFloat::None)
- || mOverflowX != aNewData.mOverflowX
- || mOverflowY != aNewData.mOverflowY
|| mScrollBehavior != aNewData.mScrollBehavior
|| mScrollSnapTypeX != aNewData.mScrollSnapTypeX
|| mScrollSnapTypeY != aNewData.mScrollSnapTypeY
@@ -3276,6 +3257,11 @@ nsStyleDisplay::CalcDifference(const nsStyleDisplay& aNewData) const
hint |= nsChangeHint_ReconstructFrame;
}
+ if (mOverflowX != aNewData.mOverflowX
+ || mOverflowY != aNewData.mOverflowY) {
+ hint |= nsChangeHint_CSSOverflowChange;
+ }
+
/* Note: When mScrollBehavior, mScrollSnapTypeX, mScrollSnapTypeY,
* mScrollSnapPointsX, mScrollSnapPointsY, or mScrollSnapDestination are
* changed, nsChangeHint_NeutralChange is not sufficient to enter
diff --git a/layout/style/test/mochitest.ini b/layout/style/test/mochitest.ini
index 406c6f9015..8182691ca9 100644
--- a/layout/style/test/mochitest.ini
+++ b/layout/style/test/mochitest.ini
@@ -295,6 +295,7 @@ skip-if = toolkit == 'android'
[test_variables.html]
support-files = support/external-variable-url.css
[test_video_object_fit.html]
+[test_viewport_scrollbar_causing_reflow.html]
[test_viewport_units.html]
[test_visited_image_loading.html]
skip-if = toolkit == 'android' #TIMED_OUT
diff --git a/layout/style/test/test_dynamic_change_causing_reflow.html b/layout/style/test/test_dynamic_change_causing_reflow.html
index a941191f60..a5bb3045c1 100644
--- a/layout/style/test/test_dynamic_change_causing_reflow.html
+++ b/layout/style/test/test_dynamic_change_causing_reflow.html
@@ -95,6 +95,90 @@ const gTestcases = [
expectReflow: true,
},
+ // * Changing 'overflow' on <body> should cause reflow,
+ // but not frame reconstruction
+ {
+ elem: document.body,
+ /* beforeStyle: implicitly 'overflow:visible' */
+ afterStyle: "overflow: hidden",
+ expectConstruction: false,
+ expectReflow: true,
+ },
+ {
+ elem: document.body,
+ /* beforeStyle: implicitly 'overflow:visible' */
+ afterStyle: "overflow: scroll",
+ expectConstruction: false,
+ expectReflow: true,
+ },
+ {
+ elem: document.body,
+ beforeStyle: "overflow: hidden",
+ afterStyle: "overflow: auto",
+ expectConstruction: false,
+ expectReflow: true,
+ },
+ {
+ elem: document.body,
+ beforeStyle: "overflow: hidden",
+ afterStyle: "overflow: scroll",
+ expectConstruction: false,
+ expectReflow: true,
+ },
+ {
+ elem: document.body,
+ beforeStyle: "overflow: hidden",
+ afterStyle: "overflow: visible",
+ expectConstruction: false,
+ expectReflow: true,
+ },
+ {
+ elem: document.body,
+ beforeStyle: "overflow: auto",
+ afterStyle: "overflow: hidden",
+ expectConstruction: false,
+ expectReflow: true,
+ },
+ {
+ elem: document.body,
+ beforeStyle: "overflow: visible",
+ afterStyle: "overflow: hidden",
+ expectConstruction: false,
+ expectReflow: true,
+ },
+
+ // * Changing 'overflow' on <html> should cause reflow,
+ // but not frame reconstruction
+ {
+ elem: document.documentElement,
+ /* beforeStyle: implicitly 'overflow:visible' */
+ afterStyle: "overflow: auto",
+ expectConstruction: false,
+ expectReflow: true,
+ },
+ {
+ elem: document.documentElement,
+ beforeStyle: "overflow: visible",
+ afterStyle: "overflow: auto",
+ expectConstruction: false,
+ expectReflow: true,
+ },
+
+ // * Setting 'overflow' on arbitrary node should cause reflow as well as
+ // frame reconstruction
+ {
+ /* beforeStyle: implicitly 'overflow:visible' */
+ afterStyle: "overflow: auto",
+ expectConstruction: true,
+ expectReflow: true,
+ },
+ {
+ beforeStyle: "overflow: auto",
+ afterStyle: "overflow: visible",
+ expectConstruction: true,
+ expectReflow: true,
+ },
+
// * Changing 'display' should cause frame construction and reflow.
{
beforeStyle: "display: inline",
@@ -135,23 +219,34 @@ function runOneTest(aTestcase)
return;
}
+ // Figure out which element we'll be tweaking (defaulting to gElem)
+ let elem = aTestcase.elem ?
+ aTestcase.elem : gElem;
+
+ // Verify that 'style' attribute is unset (avoid causing ourselves trouble):
+ if (elem.hasAttribute("style")) {
+ ok(false,
+ "test element has 'style' attribute already set! We're going to stomp " +
+ "on whatever's there when we clean up...");
+ }
+
// Set the "before" style, and compose the first part of the message
// to be used in our "is"/"isnot" invocations:
let msgPrefix = "Changing style ";
if (aTestcase.beforeStyle) {
- gElem.setAttribute("style", aTestcase.beforeStyle);
+ elem.setAttribute("style", aTestcase.beforeStyle);
msgPrefix += "from '" + aTestcase.beforeStyle + "' ";
}
- msgPrefix += "to '" + aTestcase.afterStyle + "' ";
+ msgPrefix += "on " + elem.nodeName + " ";
// Establish initial counts:
- let unusedVal = gElem.offsetHeight; // flush layout
+ let unusedVal = elem.offsetHeight; // flush layout
let origFramesConstructed = gUtils.framesConstructed;
let origFramesReflowed = gUtils.framesReflowed;
// Make the change and flush:
- gElem.setAttribute("style", aTestcase.afterStyle);
- unusedVal = gElem.offsetHeight; // flush layout
+ elem.setAttribute("style", aTestcase.afterStyle);
+ unusedVal = elem.offsetHeight; // flush layout
// Make our is/isnot assertions about whether things should have changed:
checkFinalCount(gUtils.framesConstructed, origFramesConstructed,
@@ -162,7 +257,7 @@ function runOneTest(aTestcase)
"reflow");
// Clean up!
- gElem.removeAttribute("style");
+ elem.removeAttribute("style");
}
gTestcases.forEach(runOneTest);
diff --git a/layout/style/test/test_viewport_scrollbar_causing_reflow.html b/layout/style/test/test_viewport_scrollbar_causing_reflow.html
new file mode 100644
index 0000000000..dfd7ec450d
--- /dev/null
+++ b/layout/style/test/test_viewport_scrollbar_causing_reflow.html
@@ -0,0 +1,125 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1367568
+-->
+<head>
+ <meta charset="utf-8">
+ <title>Test for Bug 1367568</title>
+ <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.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=">Mozilla Bug 1367568</a>
+<div id="content">
+ <!-- Some fixed-width divs that we shouldn't have to reflow when the viewport
+ changes: -->
+ <div style="width: 100px">
+ fixed-width
+ <div>(child)</div>
+ </div>
+ <div style="position: absolute; width: 150px">
+ abs-fixed-width
+ <div>(child)</div>
+ </div>
+</div>
+<pre id="test">
+<script type="application/javascript">
+"use strict";
+
+/** Test for Bug 1367568 **/
+
+/**
+ * This test verifies that "overflow" changes on the <body> don't cause
+ * an unnecessarily large amount of reflow.
+ */
+
+// Vars used in setStyleAndMeasure that we really only have to look up once:
+const gUtils = SpecialPowers.getDOMWindowUtils(window);
+
+function setStyleAndMeasure(initialStyle, finalStyle) {
+ is(document.body.style.length, 0,
+ "Bug in test - body should start with empty style");
+ let unusedVal = document.body.offsetHeight; // flush layout
+ let constructCount = gUtils.framesConstructed;
+
+ document.body.style = initialStyle;
+ unusedVal = document.body.offsetHeight; // flush layout
+ let reflowCountBeforeTweak = gUtils.framesReflowed;
+
+ document.body.style = finalStyle;
+ unusedVal = document.body.offsetHeight; // flush layout
+ let reflowCountAfterTweak = gUtils.framesReflowed;
+
+ // Clean up:
+ document.body.style = "";
+
+ is(gUtils.framesConstructed, constructCount,
+ "Style tweak shouldn't have triggered frame construction");
+
+ // ...and return the delta:
+ return reflowCountAfterTweak - reflowCountBeforeTweak;
+}
+
+function main() {
+ // First, we sanity-check that our measurement make sense -- if we leave
+ // styles unchanged, we should measure no frames being reflowed:
+ let count = setStyleAndMeasure("width: 50px; height: 80px",
+ "width: 50px; height: 80px");
+ is(count, 0,
+ "Shouldn't reflow anything when we leave 'width' & 'height' unchanged");
+
+ // Now: see how many frames are reflowed when the "width" & "height" change.
+ // We'll use this as the reference when measuring reflow counts for various
+ // changes to "overflow" below.
+ count = setStyleAndMeasure("width: 50px; height: 80px",
+ "width: 90px; height: 60px");
+ ok(count > 0,
+ "Should reflow some frames when 'width' & 'height' change");
+
+ // Expected maximum number of frames reflowed for "overflow" changes
+ // (+2 is to allow for reflowing scrollbars themselves):
+ const expectedMax = count + 2;
+
+ // Shared ending for messages in all ok() checks below:
+ const messageSuffix =
+ " shouldn't be greater than count for tweaking width/height on body (" +
+ expectedMax + ")";
+
+ // OK, here is where the relevant tests actually begin!!
+ // See how many frames we reflow for various tweaks to "overflow" on
+ // the body -- we expect the count to be no larger than |expectedMax|.
+ count = setStyleAndMeasure("", "overflow: scroll");
+ ok(count <= expectedMax,
+ "Reflow count when setting 'overflow: scroll' on body (" + count + ")" +
+ messageSuffix);
+
+ count = setStyleAndMeasure("", "overflow: hidden");
+ ok(count <= expectedMax,
+ "Reflow count when setting 'overflow: hidden' on body (" + count + ")" +
+ messageSuffix);
+
+ // Test removal of "overflow: scroll":
+ count = setStyleAndMeasure("overflow: scroll", "");
+ ok(count <= expectedMax,
+ "Reflow count when removing 'overflow: scroll' from body (" + count + ")" +
+ messageSuffix);
+
+ count = setStyleAndMeasure("overflow: hidden", "");
+ ok(count <= expectedMax,
+ "Reflow count when removing 'overflow: hidden' from body (" + count + ")" +
+ messageSuffix);
+
+ // Test change between two non-'visible' overflow values:
+ count = setStyleAndMeasure("overflow: scroll", "overflow: hidden");
+ ok(count <= expectedMax,
+ "Reflow count when changing 'overflow' on body (" + count + ")" +
+ messageSuffix);
+}
+
+main();
+
+</script>
+</pre>
+</body>
+</html>