Cache legend item text rect - #730

c3js · Nov 21, 2014 · 1c35022 · 1c35022
1 parent a788840
commit 1c35022
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Showing 3 changed files with 23 additions and 7 deletions.
diff --git a/c3.js b/c3.js
@@ -3763,6 +3763,7 @@
             .style('opacity', 0)
             .style('visibility', 'hidden');
     };
+    var legendItemTextBox = {};
     c3_chart_internal_fn.updateLegend = function (targetIds, options, transitions) {
         var $$ = this, config = $$.config;
         var xForLegend, xForLegendText, xForLegendRect, yForLegend, yForLegendText, yForLegendRect;
@@ -3776,9 +3777,16 @@
         withTransition = getOption(options, "withTransition", true);
         withTransitionForTransform = getOption(options, "withTransitionForTransform", true);
 
+        function getTextBox(textElement, id) {
+            if (!legendItemTextBox[id]) {
+                legendItemTextBox[id] = $$.getTextRect(textElement.textContent, CLASS.legendItem);
+            }
+            return legendItemTextBox[id];
+        }
+
         function updatePositions(textElement, id, index) {
             var reset = index === 0, isLast = index === targetIds.length - 1,
-                box = $$.getTextRect(textElement.textContent, CLASS.legendItem),
+                box = getTextBox(textElement, id),
                 itemWidth = box.width + tileWidth + (isLast && !($$.isLegendRight || $$.isLegendInset) ? 0 : paddingRight),
                 itemHeight = box.height + paddingTop,
                 itemLength = $$.isLegendRight || $$.isLegendInset ? itemHeight : itemWidth,