Don't add extraneous truncation token during kCTLineTruncationMiddle. (…

…#1297) * Don't add extraneous truncation token during kCTLineTruncationMiddle * Expand these comments a little.
TextureGroup · Mar 6, 2019 · 7bb3079 · 7bb3079
1 parent a0012d9
commit 7bb3079
Showing 1 changed file with 7 additions and 3 deletions.
diff --git a/Source/Private/TextExperiment/Component/ASTextLayout.mm b/Source/Private/TextExperiment/Component/ASTextLayout.mm
@@ -834,7 +834,8 @@ + (ASTextLayout *)layoutWithContainer:(ASTextContainer *)container text:(NSAttri
             }
           }
           int i = 0;
-          if (type != kCTLineTruncationStart) { // Middle or End/Tail wants text preceding truncated content.
+          if (type != kCTLineTruncationStart) { // Middle or End/Tail wants to collect some text (at least one line's
+              // worth) preceding the truncated content, with which to construct a "truncated line".
             i = (int)removedLines.count - 1;
             while (atLeastOneLine < truncatedWidth && i >= 0) {
               if (lastLineText.length > 0 && [lastLineText.string characterAtIndex:lastLineText.string.length - 1] == '\n') { // Explicit newlines are always "long enough".
@@ -846,7 +847,8 @@ + (ASTextLayout *)layoutWithContainer:(ASTextContainer *)container text:(NSAttri
             }
             [lastLineText appendAttributedString:truncationToken];
           }
-          if (type != kCTLineTruncationEnd && removedLines.count > 0) { // Middle or Start/Head wants text following truncated content.
+          if (type != kCTLineTruncationEnd && removedLines.count > 0) { // Middle or Start/Head wants to collect some
+              // text following the truncated content.
             i = 0;
             atLeastOneLine = removedLines[i].width;
             while (atLeastOneLine < truncatedWidth && i < removedLines.count) {
@@ -860,7 +862,9 @@ + (ASTextLayout *)layoutWithContainer:(ASTextContainer *)container text:(NSAttri
                 [lastLineText appendAttributedString:nextLine];
               }
             }
-            [lastLineText insertAttributedString:truncationToken atIndex:0];
+            if (type == kCTLineTruncationStart) {
+              [lastLineText insertAttributedString:truncationToken atIndex:0];
+            }
           }
 
           CTLineRef ctLastLineExtend = CTLineCreateWithAttributedString((CFAttributedStringRef) lastLineText);