Change text size calculation algorithm

src/c3.axis.js

@@ -159,29 +159,6 @@ function c3_axis(d3, params, $$) {
                 var tickPosition = scale(d) + (tickCentered ? 0 : tickOffset);
                 return range[0] < tickPosition && tickPosition < range[1] ? innerTickSize : 0;
             }
-            
-            // Seek a specific value in the stylesheets of a document
-            function getStyleValue(selector, property) {
-                var css, rule, sheet, value;
-                for (var styleId = 0; styleId < document.styleSheets.length; styleId++) {
-                    sheet = document.styleSheets[styleId];
-                    for (var ruleId = 0; ruleId < sheet.cssRules.length; ruleId++) {
-                        rule = sheet.cssRules[ruleId];
-                        css = rule.cssText;
-                        if (css.indexOf(selector) !== -1) {
-                            if (css.indexOf(property) !== -1) {
-                                try {
-                                    value = css.split(property)[1].split(':')[1].split(';')[0];
-                                    return value.trim();
-                                } catch (e) {
-                                    // Error will be caught in case of incorrect CSS
-                                    return undefined;
-                                }
-                            }
-                        }
-                    }
-                }
-            }
 
             text = tick.select("text");
             tspan = text.selectAll('tspan')
@@ -195,14 +172,13 @@ function c3_axis(d3, params, $$) {
             tspan.enter().append('tspan');
             tspan.exit().remove();
 
-            var fontSize;
+            var fontSize = parseFloat(getStyleValue('.c3-axis-y .tick', 'font-size'));
                 
             tspan.text(function (d) {
-                fontSize = parseFloat(getStyleValue('.c3-axis-y .tick', 'font-size'));
                 if (d.splitted.length) {
                     $$.config.maxTickTextWidth = Math.max(
                         $$.config.maxTickTextWidth || 0,
-                        d.splitted.length * fontSize / $$.config.tick_text_h_to_w
+                        d.splitted.length * fontSize / $$.config.text_h_to_w
                     );
                 }
                 return d.splitted;

src/config.js

@@ -196,7 +196,8 @@ c3_chart_internal_fn.getDefaultConfig = function () {
         tooltip_init_position: {top: '0px', left: '50px'},
         // default additional tick padding
         tick_text_padding: 0,
-        tick_text_h_to_w: 1.76,
+        // change this when you change font-family!
+        text_h_to_w: 1.76,
         // used when size is not available yet
         default_tick_width: 30,
         // caching

src/core.js

@@ -43,6 +43,30 @@ c3_chart_fn = c3.chart.fn;
 c3_chart_internal_fn = c3.chart.internal.fn;
 
 
+// Seek a specific value in the stylesheets of a document
+function getStyleValue(selector, property) {
+    var css, rule, sheet, value;
+    for (var styleId = 0; styleId < document.styleSheets.length; styleId++) {
+        sheet = document.styleSheets[styleId];
+        for (var ruleId = 0; ruleId < sheet.cssRules.length; ruleId++) {
+            rule = sheet.cssRules[ruleId];
+            css = rule.cssText;
+            if (css.indexOf(selector) !== -1) {
+                if (css.indexOf(property) !== -1) {
+                    try {
+                        value = css.split(property)[1].split(':')[1].split(';')[0];
+                        return value.trim();
+                    } catch (e) {
+                        // Error will be caught in case of incorrect CSS
+                        return undefined;
+                    }
+                }
+            }
+        }
+    }
+}
+
+
 c3_chart_internal_fn.init = function () {
     var $$ = this, config = $$.config;
 

src/legend.js

@@ -137,6 +137,8 @@ c3_chart_internal_fn.updateLegend = function (targetIds, options, transitions) {
     options = options || {};
     withTransition = getOption(options, "withTransition", true);
     withTransitionForTransform = getOption(options, "withTransitionForTransform", true);
+    
+    $$.clearLegendItemTextBoxCache();
 
     function legendText(id){
         return isDefined(config.data_names[id]) ? config.data_names[id] : isDefined(config.data_names.id) ? config.data_names.id : id; 
@@ -144,7 +146,7 @@ c3_chart_internal_fn.updateLegend = function (targetIds, options, transitions) {
 
     function getTextBox(textElement, id) {
         if (!legendItemTextBox[id]) {
-            legendItemTextBox[id] = $$.getTextRect(textElement.textContent, CLASS.legendItem);
+            legendItemTextBox[id] = $$.getTextRect(textElement.textContent, '.c3-legend-item');
         }
         return legendItemTextBox[id];
     }

src/text.js

@@ -48,25 +48,12 @@ c3_chart_internal_fn.redrawText = function (xForText, yForText, forFlow, withTra
     ];
 };
 c3_chart_internal_fn.getTextRect = function (text, cls) {
-    var body = this.d3.select('body').classed('c3', true),
-        svg = body.append("svg").style('visibility', 'hidden'), rect;
-    svg.selectAll('.dummy')
-        .data([text])
-        .enter().append('text')
-        .classed(cls ? cls : "", true)
-        .text(text)
-        .each(function () { rect = this.getBoundingClientRect(); });
-    svg.remove();
-    body.classed('c3', false);
-    // jsdom can't compute real size of text element
-    // getBoundingClientRect() returns zero-sized rect in jsdom
-    // This is a hack to estimate size depending on text length and average glyph size
-    if(isNode()){
-        // 4 is average glyph size. Warning! This may break on font change.
-        // 8 is size of square near the text.
-        rect.width = text.length * 4 - 8;
-    }
-    return rect;
+    var fontSize = parseFloat(getStyleValue(cls, 'font-size'));
+        
+    return {
+        height: fontSize,
+        width: text.length * fontSize / this.config.text_h_to_w
+    };
 };
 c3_chart_internal_fn.generateXYForText = function (areaIndices, barIndices, lineIndices, forX) {
     var $$ = this,