diff options
Diffstat (limited to 'layout/style')
| -rw-r--r-- | layout/style/nsStyleStruct.cpp | 23 | ||||
| -rw-r--r-- | layout/style/test/mochitest.ini | 1 | ||||
| -rw-r--r-- | layout/style/test/test_dynamic_change_causing_reflow.html | 107 | ||||
| -rw-r--r-- | layout/style/test/test_viewport_scrollbar_causing_reflow.html | 125 |
4 files changed, 234 insertions, 22 deletions
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp index 2f12d6201..553239e0e 100644 --- a/layout/style/nsStyleStruct.cpp +++ b/layout/style/nsStyleStruct.cpp @@ -1629,23 +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. - hint |= nsChangeHint_NeedReflow | - nsChangeHint_UpdateComputedBSize | - nsChangeHint_ReflowChangesSizeOrPosition; + 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) { @@ -3258,8 +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 @@ -3271,6 +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 406c6f901..8182691ca 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 a941191f6..a5bb3045c 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 000000000..dfd7ec450 --- /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> |