Changeset 213733 in webkit

Timestamp:

Mar 10, 2017 4:33:18 PM (7 years ago)

Author:

Alan Bujtas

Message:

Simple line layout: Check how many orphans needed on the current page before breaking.
​https://bugs.webkit.org/show_bug.cgi?id=169477

Reviewed by Antti Koivisto.

Source/WebCore:

Before breaking for the widows we actually need to check for orphans first.

Test: fast/multicol/simple-line-layout-orphans-and-widows.html

• rendering/SimpleLineLayoutPagination.cpp:

(WebCore::SimpleLineLayout::computeLineBreakIndex):
(WebCore::SimpleLineLayout::adjustLinePositionsForPagination):

LayoutTests:

• fast/multicol/simple-line-layout-orphans-and-widows-expected.html: Added.
• fast/multicol/simple-line-layout-orphans-and-widows.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/multicol/simple-line-layout-orphans-and-widows-expected.html (added)
• LayoutTests/fast/multicol/simple-line-layout-orphans-and-widows.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/SimpleLineLayoutPagination.cpp (modified) (5 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2017-03-10  Zalan Bujtas  <zalan@apple.com>
+
+        Simple line layout: Check how many orphans needed on the current page before breaking.
+        https://bugs.webkit.org/show_bug.cgi?id=169477
+
+        Reviewed by Antti Koivisto.
+
+        * fast/multicol/simple-line-layout-orphans-and-widows-expected.html: Added.
+        * fast/multicol/simple-line-layout-orphans-and-widows.html: Added.
+
 2017-03-10  Ryan Haddad  <ryanhaddad@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2017-03-10  Zalan Bujtas  <zalan@apple.com>
+
+        Simple line layout: Check how many orphans needed on the current page before breaking.
+        https://bugs.webkit.org/show_bug.cgi?id=169477
+
+        Reviewed by Antti Koivisto.
+
+        Before breaking for the widows we actually need to check for orphans first.
+
+        Test: fast/multicol/simple-line-layout-orphans-and-widows.html
+
+        * rendering/SimpleLineLayoutPagination.cpp:
+        (WebCore::SimpleLineLayout::computeLineBreakIndex):
+        (WebCore::SimpleLineLayout::adjustLinePositionsForPagination):
+
 2017-03-10  Dean Jackson  <dino@apple.com>
 

trunk/Source/WebCore/rendering/SimpleLineLayoutPagination.cpp

@@ -64 +64 @@
 }
 
-static unsigned computeLineBreakIndex(unsigned breakCandidate, unsigned lineCount, unsigned widows, const Layout::SimpleLineStruts& struts)
+static unsigned computeLineBreakIndex(unsigned breakCandidate, unsigned lineCount, int orphansNeeded, int widowsNeeded,
+    const Layout::SimpleLineStruts& struts)
 {
     // First line does not fit the current page.
@@ -70 +71 @@
         return breakCandidate;
     
-    auto remainingLineCount = lineCount - breakCandidate;
-    if (widows <= remainingLineCount)
+    int widowsOnTheNextPage = lineCount - breakCandidate;
+    if (widowsNeeded <= widowsOnTheNextPage)
         return breakCandidate;
-    
     // Only break after the first line with widows.
-    auto lineBreak = std::max<int>(lineCount - widows, 1);
+    auto lineBreak = std::max<int>(lineCount - widowsNeeded, 1);
+    if (orphansNeeded > lineBreak)
+        return breakCandidate;
     // Break on current page only.
     if (struts.isEmpty())
@@ -98 +100 @@
     auto remainingLogicalHeight = flow.pageRemainingLogicalHeightForOffset(line.top, RenderBlockFlow::ExcludePageBoundary);
     auto& style = flow.style();
-    auto firstLineWithDoesNotFit = !lineBreakIndex && line.height < flow.pageLogicalHeightForOffset(line.top);
+    auto firstLineDoesNotFit = !lineBreakIndex && line.height < flow.pageLogicalHeightForOffset(line.top);
     auto orphanDoesNotFit = !style.hasAutoOrphans() && style.orphans() > (short)lineBreakIndex;
-    if (firstLineWithDoesNotFit || orphanDoesNotFit) {
+    if (firstLineDoesNotFit || orphanDoesNotFit) {
         auto firstLine = lines.first();
         auto firstLineOverflowRect = computeOverflow(flow, LayoutRect(0, firstLine.top, 0, firstLine.height));
@@ -133 +135 @@
     unsigned lineIndex = 0;
     auto widows = flow.style().hasAutoWidows() ? 1 : std::max<int>(flow.style().widows(), 1);
+    auto orphans = flow.style().hasAutoOrphans() ? 1 : std::max<int>(flow.style().orphans(), 1);
     PaginatedLines lines;
     for (unsigned runIndex = 0; runIndex < simpleLines.runCount(); ++runIndex) {
@@ -144 +147 @@
         auto atTheTopOfColumnOrPage = flow.pageLogicalHeightForOffset(line.top) == remainingHeight;
         if (line.height > remainingHeight || (atTheTopOfColumnOrPage && lineIndex)) {
-            auto lineBreakIndex = computeLineBreakIndex(lineIndex, lineCount, widows, struts);
+            auto lineBreakIndex = computeLineBreakIndex(lineIndex, lineCount, orphans, widows, struts);
             // Are we still at the top of the column/page?
             atTheTopOfColumnOrPage = atTheTopOfColumnOrPage ? lineIndex == lineBreakIndex : false;
             setPageBreakForLine(lineBreakIndex, lines, flow, struts, atTheTopOfColumnOrPage);
-            // Recompute line positions that we already visited but window break pushed them to a new page.
+            // Recompute line positions that we already visited but widow break pushed them to a new page.
             for (auto i = lineBreakIndex; i < lines.size(); ++i)
                 lines.at(i) = computeLineTopAndBottomWithOverflow(flow, i, struts);