remove dist files.

src/api.axis.js

@@ -3,9 +3,9 @@ c3_chart_fn.axis.labels = function (labels) {
     var $$ = this.internal;
     if (arguments.length) {
         Object.keys(labels).forEach(function (axisId) {
-            $$.setAxisLabelText(axisId, labels[axisId]);
+            $$.axis.setLabelText(axisId, labels[axisId]);
         });
-        $$.updateAxisLabels();
+        $$.axis.updateLabels();
     }
     // TODO: return some values?
 };

src/axis.js

-c3_chart_internal_fn.initAxis = function () {
-    var $$ = this, config = $$.config, main = $$.main;
+function Axis(owner) {
+    API.call(this, owner);
+}
+
+inherit(API, Axis);
+
+Axis.prototype.init = function init() {
+
+    var $$ = this.owner, config = $$.config, main = $$.main;
     $$.axes.x = main.append("g")
         .attr("class", CLASS.axis + ' ' + CLASS.axisX)
         .attr("clip-path", $$.clipPathForXAxis)
@@ -8,7 +15,7 @@ c3_chart_internal_fn.initAxis = function () {
     $$.axes.x.append("text")
         .attr("class", CLASS.axisXLabel)
         .attr("transform", config.axis_rotated ? "rotate(-90)" : "")
-        .style("text-anchor", $$.textAnchorForXAxisLabel.bind($$));
+        .style("text-anchor", this.textAnchorForXAxisLabel.bind(this));
 
     $$.axes.y = main.append("g")
         .attr("class", CLASS.axis + ' ' + CLASS.axisY)
@@ -18,7 +25,7 @@ c3_chart_internal_fn.initAxis = function () {
     $$.axes.y.append("text")
         .attr("class", CLASS.axisYLabel)
         .attr("transform", config.axis_rotated ? "" : "rotate(-90)")
-        .style("text-anchor", $$.textAnchorForYAxisLabel.bind($$));
+        .style("text-anchor", this.textAnchorForYAxisLabel.bind(this));
 
     $$.axes.y2 = main.append("g")
         .attr("class", CLASS.axis + ' ' + CLASS.axisY2)
@@ -28,10 +35,10 @@ c3_chart_internal_fn.initAxis = function () {
     $$.axes.y2.append("text")
         .attr("class", CLASS.axisY2Label)
         .attr("transform", config.axis_rotated ? "" : "rotate(-90)")
-        .style("text-anchor", $$.textAnchorForY2AxisLabel.bind($$));
+        .style("text-anchor", this.textAnchorForY2AxisLabel.bind(this));
 };
-c3_chart_internal_fn.getXAxis = function (scale, orient, tickFormat, tickValues, withOuterTick, withoutTransition) {
-    var $$ = this, config = $$.config,
+Axis.prototype.getXAxis = function getXAxis(scale, orient, tickFormat, tickValues, withOuterTick, withoutTransition) {
+    var $$ = this.owner, config = $$.config,
         axisParams = {
             isCategory: $$.isCategorized(),
             withOuterTick: withOuterTick,
@@ -64,10 +71,10 @@ c3_chart_internal_fn.getXAxis = function (scale, orient, tickFormat, tickValues,
 
     return axis;
 };
-c3_chart_internal_fn.updateXAxisTickValues = function (targets, axis) {
-    var $$ = this, config = $$.config, tickValues;
+Axis.prototype.updateXAxisTickValues = function updateXAxisTickValues(targets, axis) {
+    var $$ = this.owner, config = $$.config, tickValues;
     if (config.axis_x_tick_fit || config.axis_x_tick_count) {
-        tickValues = $$.generateTickValues($$.mapTargetsToUniqueXs(targets), config.axis_x_tick_count, $$.isTimeSeries());
+        tickValues = this.generateTickValues($$.mapTargetsToUniqueXs(targets), config.axis_x_tick_count, $$.isTimeSeries());
     }
     if (axis) {
         axis.tickValues(tickValues);
@@ -77,22 +84,25 @@ c3_chart_internal_fn.updateXAxisTickValues = function (targets, axis) {
     }
     return tickValues;
 };
-c3_chart_internal_fn.getYAxis = function (scale, orient, tickFormat, tickValues, withOuterTick) {
+Axis.prototype.getYAxis = function getYAxis(scale, orient, tickFormat, tickValues, withOuterTick) {
     var axisParams = {withOuterTick: withOuterTick},
-        axis = c3_axis(this.d3, axisParams).scale(scale).orient(orient).tickFormat(tickFormat);
-    if (this.isTimeSeriesY()) {
-        axis.ticks(this.d3.time[this.config.axis_y_tick_time_value], this.config.axis_y_tick_time_interval);
+        $$ = this.owner,
+        d3 = $$.d3,
+        config = $$.config,
+        axis = c3_axis(d3, axisParams).scale(scale).orient(orient).tickFormat(tickFormat);
+    if ($$.isTimeSeriesY()) {
+        axis.ticks(d3.time[config.axis_y_tick_time_value], config.axis_y_tick_time_interval);
     } else {
         axis.tickValues(tickValues);
     }
     return axis;
 };
-c3_chart_internal_fn.getAxisId = function (id) {
-    var config = this.config;
+Axis.prototype.getId = function getId(id) {
+    var config = this.owner.config;
     return id in config.data_axes ? config.data_axes[id] : 'y';
 };
-c3_chart_internal_fn.getXAxisTickFormat = function () {
-    var $$ = this, config = $$.config,
+Axis.prototype.getXAxisTickFormat = function getXAxisTickFormat() {
+    var $$ = this.owner, config = $$.config,
         format = $$.isTimeSeries() ? $$.defaultAxisTimeFormat : $$.isCategorized() ? $$.categoryName : function (v) { return v < 0 ? v.toFixed(0) : v; };
     if (config.axis_x_tick_format) {
         if (isFunction(config.axis_x_tick_format)) {
@@ -105,20 +115,20 @@ c3_chart_internal_fn.getXAxisTickFormat = function () {
     }
     return isFunction(format) ? function (v) { return format.call($$, v); } : format;
 };
-c3_chart_internal_fn.getAxisTickValues = function (tickValues, axis) {
+Axis.prototype.getTickValues = function getTickValues(tickValues, axis) {
     return tickValues ? tickValues : axis ? axis.tickValues() : undefined;
 };
-c3_chart_internal_fn.getXAxisTickValues = function () {
-    return this.getAxisTickValues(this.config.axis_x_tick_values, this.xAxis);
+Axis.prototype.getXAxisTickValues = function getXAxisTickValues() {
+    return this.getTickValues(this.owner.config.axis_x_tick_values, this.owner.xAxis);
 };
-c3_chart_internal_fn.getYAxisTickValues = function () {
-    return this.getAxisTickValues(this.config.axis_y_tick_values, this.yAxis);
+Axis.prototype.getYAxisTickValues = function getYAxisTickValues() {
+    return this.getTickValues(this.owner.config.axis_y_tick_values, this.owner.yAxis);
 };
-c3_chart_internal_fn.getY2AxisTickValues = function () {
-    return this.getAxisTickValues(this.config.axis_y2_tick_values, this.y2Axis);
+Axis.prototype.getY2AxisTickValues = function getY2AxisTickValues() {
+    return this.getTickValues(this.owner.config.axis_y2_tick_values, this.owner.y2Axis);
 };
-c3_chart_internal_fn.getAxisLabelOptionByAxisId = function (axisId) {
-    var $$ = this, config = $$.config, option;
+Axis.prototype.getLabelOptionByAxisId = function getLabelOptionByAxisId(axisId) {
+    var $$ = this.owner, config = $$.config, option;
     if (axisId === 'y') {
         option = config.axis_y_label;
     } else if (axisId === 'y2') {
@@ -128,13 +138,13 @@ c3_chart_internal_fn.getAxisLabelOptionByAxisId = function (axisId) {
     }
     return option;
 };
-c3_chart_internal_fn.getAxisLabelText = function (axisId) {
-    var option = this.getAxisLabelOptionByAxisId(axisId);
+Axis.prototype.getLabelText = function getLabelText(axisId) {
+    var option = this.getLabelOptionByAxisId(axisId);
     return isString(option) ? option : option ? option.text : null;
 };
-c3_chart_internal_fn.setAxisLabelText = function (axisId, text) {
+Axis.prototype.setLabelText = function setLabelText(axisId, text) {
     var $$ = this, config = $$.config,
-        option = $$.getAxisLabelOptionByAxisId(axisId);
+        option = this.getLabelOptionByAxisId(axisId);
     if (isString(option)) {
         if (axisId === 'y') {
             config.axis_y_label = text;
@@ -147,8 +157,8 @@ c3_chart_internal_fn.setAxisLabelText = function (axisId, text) {
         option.text = text;
     }
 };
-c3_chart_internal_fn.getAxisLabelPosition = function (axisId, defaultPosition) {
-    var option = this.getAxisLabelOptionByAxisId(axisId),
+Axis.prototype.getLabelPosition = function getLabelPosition(axisId, defaultPosition) {
+    var option = this.getLabelOptionByAxisId(axisId),
         position = (option && typeof option === 'object' && option.position) ? option.position : defaultPosition;
     return {
         isInner: position.indexOf('inner') >= 0,
@@ -161,114 +171,113 @@ c3_chart_internal_fn.getAxisLabelPosition = function (axisId, defaultPosition) {
         isBottom: position.indexOf('bottom') >= 0
     };
 };
-c3_chart_internal_fn.getXAxisLabelPosition = function () {
-    return this.getAxisLabelPosition('x', this.config.axis_rotated ? 'inner-top' : 'inner-right');
+Axis.prototype.getXAxisLabelPosition = function getXAxisLabelPosition() {
+    return this.getLabelPosition('x', this.owner.config.axis_rotated ? 'inner-top' : 'inner-right');
 };
-c3_chart_internal_fn.getYAxisLabelPosition = function () {
-    return this.getAxisLabelPosition('y', this.config.axis_rotated ? 'inner-right' : 'inner-top');
+Axis.prototype.getYAxisLabelPosition = function getYAxisLabelPosition() {
+    return this.getLabelPosition('y', this.owner.config.axis_rotated ? 'inner-right' : 'inner-top');
 };
-c3_chart_internal_fn.getY2AxisLabelPosition = function () {
-    return this.getAxisLabelPosition('y2', this.config.axis_rotated ? 'inner-right' : 'inner-top');
+Axis.prototype.getY2AxisLabelPosition = function getY2AxisLabelPosition() {
+    return this.getLabelPosition('y2', this.owner.config.axis_rotated ? 'inner-right' : 'inner-top');
 };
-c3_chart_internal_fn.getAxisLabelPositionById = function (id) {
+Axis.prototype.getLabelPositionById = function getLabelPositionById(id) {
     return id === 'y2' ? this.getY2AxisLabelPosition() : id === 'y' ? this.getYAxisLabelPosition() : this.getXAxisLabelPosition();
 };
-c3_chart_internal_fn.textForXAxisLabel = function () {
-    return this.getAxisLabelText('x');
+Axis.prototype.textForXAxisLabel = function textForXAxisLabel() {
+    return this.getLabelText('x');
 };
-c3_chart_internal_fn.textForYAxisLabel = function () {
-    return this.getAxisLabelText('y');
+Axis.prototype.textForYAxisLabel = function textForYAxisLabel() {
+    return this.getLabelText('y');
 };
-c3_chart_internal_fn.textForY2AxisLabel = function () {
-    return this.getAxisLabelText('y2');
+Axis.prototype.textForY2AxisLabel = function textForY2AxisLabel() {
+    return this.getLabelText('y2');
 };
-c3_chart_internal_fn.xForAxisLabel = function (forHorizontal, position) {
-    var $$ = this;
+Axis.prototype.xForAxisLabel = function xForAxisLabel(forHorizontal, position) {
+    var $$ = this.owner;
     if (forHorizontal) {
         return position.isLeft ? 0 : position.isCenter ? $$.width / 2 : $$.width;
     } else {
         return position.isBottom ? -$$.height : position.isMiddle ? -$$.height / 2 : 0;
     }
 };
-c3_chart_internal_fn.dxForAxisLabel = function (forHorizontal, position) {
+Axis.prototype.dxForAxisLabel = function dxForAxisLabel(forHorizontal, position) {
     if (forHorizontal) {
         return position.isLeft ? "0.5em" : position.isRight ? "-0.5em" : "0";
     } else {
         return position.isTop ? "-0.5em" : position.isBottom ? "0.5em" : "0";
     }
 };
-c3_chart_internal_fn.textAnchorForAxisLabel = function (forHorizontal, position) {
+Axis.prototype.textAnchorForAxisLabel = function textAnchorForAxisLabel(forHorizontal, position) {
     if (forHorizontal) {
         return position.isLeft ? 'start' : position.isCenter ? 'middle' : 'end';
     } else {
         return position.isBottom ? 'start' : position.isMiddle ? 'middle' : 'end';
     }
 };
-c3_chart_internal_fn.xForXAxisLabel = function () {
-    return this.xForAxisLabel(!this.config.axis_rotated, this.getXAxisLabelPosition());
+Axis.prototype.xForXAxisLabel = function xForXAxisLabel() {
+    return this.xForAxisLabel(!this.owner.config.axis_rotated, this.getXAxisLabelPosition());
 };
-c3_chart_internal_fn.xForYAxisLabel = function () {
-    return this.xForAxisLabel(this.config.axis_rotated, this.getYAxisLabelPosition());
+Axis.prototype.xForYAxisLabel = function xForYAxisLabel() {
+    return this.xForAxisLabel(this.owner.config.axis_rotated, this.getYAxisLabelPosition());
 };
-c3_chart_internal_fn.xForY2AxisLabel = function () {
-    return this.xForAxisLabel(this.config.axis_rotated, this.getY2AxisLabelPosition());
+Axis.prototype.xForY2AxisLabel = function xForY2AxisLabel() {
+    return this.xForAxisLabel(this.owner.config.axis_rotated, this.getY2AxisLabelPosition());
 };
-c3_chart_internal_fn.dxForXAxisLabel = function () {
-    return this.dxForAxisLabel(!this.config.axis_rotated, this.getXAxisLabelPosition());
+Axis.prototype.dxForXAxisLabel = function dxForXAxisLabel() {
+    return this.dxForAxisLabel(!this.owner.config.axis_rotated, this.getXAxisLabelPosition());
 };
-c3_chart_internal_fn.dxForYAxisLabel = function () {
-    return this.dxForAxisLabel(this.config.axis_rotated, this.getYAxisLabelPosition());
+Axis.prototype.dxForYAxisLabel = function dxForYAxisLabel() {
+    return this.dxForAxisLabel(this.owner.config.axis_rotated, this.getYAxisLabelPosition());
 };
-c3_chart_internal_fn.dxForY2AxisLabel = function () {
-    return this.dxForAxisLabel(this.config.axis_rotated, this.getY2AxisLabelPosition());
+Axis.prototype.dxForY2AxisLabel = function dxForY2AxisLabel() {
+    return this.dxForAxisLabel(this.owner.config.axis_rotated, this.getY2AxisLabelPosition());
 };
-c3_chart_internal_fn.dyForXAxisLabel = function () {
-    var $$ = this, config = $$.config,
-        position = $$.getXAxisLabelPosition();
+Axis.prototype.dyForXAxisLabel = function dyForXAxisLabel() {
+    var $$ = this.owner, config = $$.config,
+        position = this.getXAxisLabelPosition();
     if (config.axis_rotated) {
-        return position.isInner ? "1.2em" : -25 - $$.getMaxTickWidth('x');
+        return position.isInner ? "1.2em" : -25 - this.getMaxTickWidth('x');
     } else {
         return position.isInner ? "-0.5em" : config.axis_x_height ? config.axis_x_height - 10 : "3em";
     }
 };
-c3_chart_internal_fn.dyForYAxisLabel = function () {
-    var $$ = this,
-        position = $$.getYAxisLabelPosition();
+Axis.prototype.dyForYAxisLabel = function dyForYAxisLabel() {
+    var $$ = this.owner,
+        position = this.getYAxisLabelPosition();
     if ($$.config.axis_rotated) {
         return position.isInner ? "-0.5em" : "3em";
     } else {
-        return position.isInner ? "1.2em" : -10 - ($$.config.axis_y_inner ? 0 : ($$.getMaxTickWidth('y') + 10));
+        return position.isInner ? "1.2em" : -10 - ($$.config.axis_y_inner ? 0 : (this.getMaxTickWidth('y') + 10));
     }
 };
-c3_chart_internal_fn.dyForY2AxisLabel = function () {
-    var $$ = this,
-        position = $$.getY2AxisLabelPosition();
+Axis.prototype.dyForY2AxisLabel = function dyForY2AxisLabel() {
+    var $$ = this.owner,
+        position = this.getY2AxisLabelPosition();
     if ($$.config.axis_rotated) {
         return position.isInner ? "1.2em" : "-2.2em";
     } else {
         return position.isInner ? "-0.5em" : 15 + ($$.config.axis_y2_inner ? 0 : (this.getMaxTickWidth('y2') + 15));
     }
 };
-c3_chart_internal_fn.textAnchorForXAxisLabel = function () {
-    var $$ = this;
-    return $$.textAnchorForAxisLabel(!$$.config.axis_rotated, $$.getXAxisLabelPosition());
+Axis.prototype.textAnchorForXAxisLabel = function textAnchorForXAxisLabel() {
+    var $$ = this.owner;
+    return this.textAnchorForAxisLabel(!$$.config.axis_rotated, this.getXAxisLabelPosition());
 };
-c3_chart_internal_fn.textAnchorForYAxisLabel = function () {
-    var $$ = this;
-    return $$.textAnchorForAxisLabel($$.config.axis_rotated, $$.getYAxisLabelPosition());
+Axis.prototype.textAnchorForYAxisLabel = function textAnchorForYAxisLabel() {
+    var $$ = this.owner;
+    return this.textAnchorForAxisLabel($$.config.axis_rotated, this.getYAxisLabelPosition());
 };
-c3_chart_internal_fn.textAnchorForY2AxisLabel = function () {
-    var $$ = this;
-    return $$.textAnchorForAxisLabel($$.config.axis_rotated, $$.getY2AxisLabelPosition());
+Axis.prototype.textAnchorForY2AxisLabel = function textAnchorForY2AxisLabel() {
+    var $$ = this.owner;
+    return this.textAnchorForAxisLabel($$.config.axis_rotated, this.getY2AxisLabelPosition());
 };
-
-c3_chart_internal_fn.xForRotatedTickText = function (r) {
+Axis.prototype.xForRotatedTickText = function xForRotatedTickText(r) {
     return 8 * Math.sin(Math.PI * (r / 180));
 };
-c3_chart_internal_fn.yForRotatedTickText = function (r) {
+Axis.prototype.yForRotatedTickText = function yForRotatedTickText(r) {
     return 11.5 - 2.5 * (r / 15) * (r > 0 ? 1 : -1);
 };
-c3_chart_internal_fn.rotateTickText = function (axis, transition, rotate) {
+Axis.prototype.rotateTickText = function rotateTickText(axis, transition, rotate) {
     axis.selectAll('.tick text')
         .style("text-anchor", rotate > 0 ? "start" : "end");
     transition.selectAll('.tick text')
@@ -277,9 +286,8 @@ c3_chart_internal_fn.rotateTickText = function (axis, transition, rotate) {
       .selectAll('tspan')
         .attr('dx', this.xForRotatedTickText(rotate));
 };
-
-c3_chart_internal_fn.getMaxTickWidth = function (id, withoutRecompute) {
-    var $$ = this, config = $$.config,
+Axis.prototype.getMaxTickWidth = function getMaxTickWidth(id, withoutRecompute) {
+    var $$ = this.owner, config = $$.config,
         maxWidth = 0, targetsToShow, scale, axis, body, svg;
     if (withoutRecompute && $$.currentMaxTickWidths[id]) {
         return $$.currentMaxTickWidths[id];
@@ -288,16 +296,16 @@ c3_chart_internal_fn.getMaxTickWidth = function (id, withoutRecompute) {
         targetsToShow = $$.filterTargetsToShow($$.data.targets);
         if (id === 'y') {
             scale = $$.y.copy().domain($$.getYDomain(targetsToShow, 'y'));
-            axis = $$.getYAxis(scale, $$.yOrient, config.axis_y_tick_format, $$.yAxisTickValues);
+            axis = this.getYAxis(scale, $$.yOrient, config.axis_y_tick_format, $$.yAxisTickValues);
         } else if (id === 'y2') {
             scale = $$.y2.copy().domain($$.getYDomain(targetsToShow, 'y2'));
-            axis = $$.getYAxis(scale, $$.y2Orient, config.axis_y2_tick_format, $$.y2AxisTickValues);
+            axis = this.getYAxis(scale, $$.y2Orient, config.axis_y2_tick_format, $$.y2AxisTickValues);
         } else {
             scale = $$.x.copy().domain($$.getXDomain(targetsToShow));
-            axis = $$.getXAxis(scale, $$.xOrient, $$.xAxisTickFormat, $$.xAxisTickValues);
-            $$.updateXAxisTickValues(targetsToShow, axis);
+            axis = this.getXAxis(scale, $$.xOrient, $$.xAxisTickFormat, $$.xAxisTickValues);
+            this.updateXAxisTickValues(targetsToShow, axis);
         }
-        body = this.d3.select('body').classed('c3', true);
+        body = $$.d3.select('body').classed('c3', true);
         svg = body.append('svg').style('visibility', 'hidden');
         svg.append('g').call(axis).each(function () {
             $$.d3.select(this).selectAll('text tspan').each(function () {
@@ -314,30 +322,28 @@ c3_chart_internal_fn.getMaxTickWidth = function (id, withoutRecompute) {
     $$.currentMaxTickWidths[id] = maxWidth <= 0 ? $$.currentMaxTickWidths[id] : maxWidth;
     return $$.currentMaxTickWidths[id];
 };
-
-c3_chart_internal_fn.updateAxisLabels = function (withTransition) {
-    var $$ = this;
+Axis.prototype.updateLabels = function updateLabels(withTransition) {
+    var $$ = this.owner;
     var axisXLabel = $$.main.select('.' + CLASS.axisX + ' .' + CLASS.axisXLabel),
         axisYLabel = $$.main.select('.' + CLASS.axisY + ' .' + CLASS.axisYLabel),
         axisY2Label = $$.main.select('.' + CLASS.axisY2 + ' .' + CLASS.axisY2Label);
     (withTransition ? axisXLabel.transition() : axisXLabel)
-        .attr("x", $$.xForXAxisLabel.bind($$))
-        .attr("dx", $$.dxForXAxisLabel.bind($$))
-        .attr("dy", $$.dyForXAxisLabel.bind($$))
-        .text($$.textForXAxisLabel.bind($$));
+        .attr("x", this.xForXAxisLabel.bind(this))
+        .attr("dx", this.dxForXAxisLabel.bind(this))
+        .attr("dy", this.dyForXAxisLabel.bind(this))
+        .text(this.textForXAxisLabel.bind(this));
     (withTransition ? axisYLabel.transition() : axisYLabel)
-        .attr("x", $$.xForYAxisLabel.bind($$))
-        .attr("dx", $$.dxForYAxisLabel.bind($$))
-        .attr("dy", $$.dyForYAxisLabel.bind($$))
-        .text($$.textForYAxisLabel.bind($$));
+        .attr("x", this.xForYAxisLabel.bind(this))
+        .attr("dx", this.dxForYAxisLabel.bind(this))
+        .attr("dy", this.dyForYAxisLabel.bind(this))
+        .text(this.textForYAxisLabel.bind(this));
     (withTransition ? axisY2Label.transition() : axisY2Label)
-        .attr("x", $$.xForY2AxisLabel.bind($$))
-        .attr("dx", $$.dxForY2AxisLabel.bind($$))
-        .attr("dy", $$.dyForY2AxisLabel.bind($$))
-        .text($$.textForY2AxisLabel.bind($$));
+        .attr("x", this.xForY2AxisLabel.bind(this))
+        .attr("dx", this.dxForY2AxisLabel.bind(this))
+        .attr("dy", this.dyForY2AxisLabel.bind(this))
+        .text(this.textForY2AxisLabel.bind(this));
 };
-
-c3_chart_internal_fn.getAxisPadding = function (padding, key, defaultValue, domainLength) {
+Axis.prototype.getPadding = function getPadding(padding, key, defaultValue, domainLength) {
     if (!isValue(padding[key])) {
         return defaultValue;
     }
@@ -347,12 +353,12 @@ c3_chart_internal_fn.getAxisPadding = function (padding, key, defaultValue, doma
     // assume padding is pixels if unit is not specified
     return this.convertPixelsToAxisPadding(padding[key], domainLength);
 };
-c3_chart_internal_fn.convertPixelsToAxisPadding = function (pixels, domainLength) {
-    var length = this.config.axis_rotated ? this.width : this.height;
+Axis.prototype.convertPixelsToAxisPadding = function convertPixelsToAxisPadding(pixels, domainLength) {
+    var $$ = this.owner,
+        length = $$.config.axis_rotated ? $$.width : $$.height;
     return domainLength * (pixels / length);
 };
-
-c3_chart_internal_fn.generateTickValues = function (values, tickCount, forTimeSeries) {
+Axis.prototype.generateTickValues = function generateTickValues(values, tickCount, forTimeSeries) {
     var tickValues = values, targetCount, start, end, count, interval, i, tickValue;
     if (tickCount) {
         targetCount = isFunction(tickCount) ? tickCount() : tickCount;
@@ -378,8 +384,8 @@ c3_chart_internal_fn.generateTickValues = function (values, tickCount, forTimeSe
     if (!forTimeSeries) { tickValues = tickValues.sort(function (a, b) { return a - b; }); }
     return tickValues;
 };
-c3_chart_internal_fn.generateAxisTransitions = function (duration) {
-    var $$ = this, axes = $$.axes;
+Axis.prototype.generateTransitions = function generateTransitions(duration) {
+    var $$ = this.owner, axes = $$.axes;
     return {
         axisX: duration ? axes.x.transition().duration(duration) : axes.x,
         axisY: duration ? axes.y.transition().duration(duration) : axes.y,
@@ -387,8 +393,8 @@ c3_chart_internal_fn.generateAxisTransitions = function (duration) {
         axisSubX: duration ? axes.subx.transition().duration(duration) : axes.subx
     };
 };
-c3_chart_internal_fn.redrawAxis = function (transitions, isHidden) {
-    var $$ = this, config = $$.config;
+Axis.prototype.redraw = function redraw(transitions, isHidden) {
+    var $$ = this.owner, config = $$.config;
     $$.axes.x.style("opacity", isHidden ? 0 : 1);
     $$.axes.y.style("opacity", isHidden ? 0 : 1);
     $$.axes.y2.style("opacity", isHidden ? 0 : 1);
@@ -399,7 +405,7 @@ c3_chart_internal_fn.redrawAxis = function (transitions, isHidden) {
     transitions.axisSubX.call($$.subXAxis);
     // rotate tick text if needed
     if (!config.axis_rotated && config.axis_x_tick_rotate) {
-        $$.rotateTickText($$.axes.x, transitions.axisX, config.axis_x_tick_rotate);
-        $$.rotateTickText($$.axes.subx, transitions.axisSubX, config.axis_x_tick_rotate);
+        this.rotateTickText($$.axes.x, transitions.axisX, config.axis_x_tick_rotate);
+        this.rotateTickText($$.axes.subx, transitions.axisSubX, config.axis_x_tick_rotate);
     }
 };

src/core.js

 var c3 = { version: "0.4.9" };
 
-var c3_chart_fn, c3_chart_internal_fn;
+var c3_chart_fn,
+    c3_chart_internal_fn,
+    c3_chart_internal_axis_fn;
+
+function API(owner) {
+    this.owner = owner;
+}
+
+function inherit(base, derived) {
+
+    if (Object.create) {
+        derived.prototype = Object.create(base.prototype);
+    } else {
+        var f = function f() {};
+        f.prototype = base.prototype;
+        derived.prototype = new f();
+    }
+
+    derived.prototype.constructor = derived;
+
+    return derived;
+}
 
 function Chart(config) {
     var $$ = this.internal = new ChartInternal(this);
@@ -35,12 +56,15 @@ c3.generate = function (config) {
 c3.chart = {
     fn: Chart.prototype,
     internal: {
-        fn: ChartInternal.prototype
+        fn: ChartInternal.prototype,
+        axis: {
+            fn: Axis.prototype
+        }
     }
 };
 c3_chart_fn = c3.chart.fn;
 c3_chart_internal_fn = c3.chart.internal.fn;
-
+c3_chart_internal_axis_fn = c3.chart.internal.axis.fn;
 
 c3_chart_internal_fn.init = function () {
     var $$ = this, config = $$.config;
@@ -149,6 +173,8 @@ c3_chart_internal_fn.initWithData = function (data) {
     var $$ = this, d3 = $$.d3, config = $$.config;
     var defs, main, binding = true;
 
+    $$.axis = new Axis($$);
+
     if ($$.initPie) { $$.initPie(); }
     if ($$.initBrush) { $$.initBrush(); }
     if ($$.initZoom) { $$.initZoom(); }
@@ -266,7 +292,7 @@ c3_chart_internal_fn.initWithData = function (data) {
     if (config.axis_x_extent) { $$.brush.extent($$.getDefaultExtent()); }
 
     // Add Axis
-    $$.initAxis();
+    $$.axis.init();
 
     // Set targets
     $$.updateTargets($$.data.targets);
@@ -456,7 +482,7 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
     durationForExit = withTransitionForExit ? duration : 0;
     durationForAxis = withTransitionForAxis ? duration : 0;
 
-    transitions = transitions || $$.generateAxisTransitions(durationForAxis);
+    transitions = transitions || $$.axis.generateTransitions(durationForAxis);
 
     // update legend and transform each g
     if (withLegend && config.legend_show) {
@@ -475,7 +501,7 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
     if (targetsToShow.length) {
         $$.updateXDomain(targetsToShow, withUpdateXDomain, withUpdateOrgXDomain, withTrimXDomain);
         if (!config.axis_x_tick_values) {
-            tickValues = $$.updateXAxisTickValues(targetsToShow);
+            tickValues = $$.axis.updateXAxisTickValues(targetsToShow);
         }
     } else {
         $$.xAxis.tickValues([]);
@@ -490,17 +516,17 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
     $$.y2.domain($$.getYDomain(targetsToShow, 'y2', xDomainForZoom));
 
     if (!config.axis_y_tick_values && config.axis_y_tick_count) {
-        $$.yAxis.tickValues($$.generateTickValues($$.y.domain(), config.axis_y_tick_count));
+        $$.yAxis.tickValues($$.axis.generateTickValues($$.y.domain(), config.axis_y_tick_count));
     }
     if (!config.axis_y2_tick_values && config.axis_y2_tick_count) {
-        $$.y2Axis.tickValues($$.generateTickValues($$.y2.domain(), config.axis_y2_tick_count));
+        $$.y2Axis.tickValues($$.axis.generateTickValues($$.y2.domain(), config.axis_y2_tick_count));
     }
 
     // axes
-    $$.redrawAxis(transitions, hideAxis);
+    $$.axis.redraw(transitions, hideAxis);
 
     // Update axis label
-    $$.updateAxisLabels(withTransition);
+    $$.axis.updateLabels(withTransition);
 
     // show/hide if manual culling needed
     if ((withUpdateXDomain || withUpdateXAxis) && targetsToShow.length) {
@@ -681,7 +707,7 @@ c3_chart_internal_fn.updateAndRedraw = function (options) {
     $$.updateSizes();
     // MEMO: called in updateLegend in redraw if withLegend
     if (!(options.withLegend && config.legend_show)) {
-        transitions = $$.generateAxisTransitions(options.withTransitionForAxis ? config.transition_duration : 0);
+        transitions = $$.axis.generateTransitions(options.withTransitionForAxis ? config.transition_duration : 0);
         // Update scales
         $$.updateScales();
         $$.updateSvgSize();

src/domain.js

@@ -20,7 +20,7 @@ c3_chart_internal_fn.getYDomainMin = function (targets) {
                 id = idsInGroup[k];
                 if (! ys[id]) { continue; }
                 ys[id].forEach(function (v, i) {
-                    if ($$.getAxisId(id) === $$.getAxisId(baseId) && ys[baseId] && !(hasNegativeValue && +v > 0)) {
+                    if ($$.axis.getId(id) === $$.axis.getId(baseId) && ys[baseId] && !(hasNegativeValue && +v > 0)) {
                         ys[baseId][i] += +v;
                     }
                 });
@@ -51,7 +51,7 @@ c3_chart_internal_fn.getYDomainMax = function (targets) {
                 id = idsInGroup[k];
                 if (! ys[id]) { continue; }
                 ys[id].forEach(function (v, i) {
-                    if ($$.getAxisId(id) === $$.getAxisId(baseId) && ys[baseId] && !(hasPositiveValue && +v < 0)) {
+                    if ($$.axis.getId(id) === $$.axis.getId(baseId) && ys[baseId] && !(hasPositiveValue && +v < 0)) {
                         ys[baseId][i] += +v;
                     }
                 });
@@ -62,7 +62,7 @@ c3_chart_internal_fn.getYDomainMax = function (targets) {
 };
 c3_chart_internal_fn.getYDomain = function (targets, axisId, xDomain) {
     var $$ = this, config = $$.config,
-        targetsByAxisId = targets.filter(function (t) { return $$.getAxisId(t.id) === axisId; }),
+        targetsByAxisId = targets.filter(function (t) { return $$.axis.getId(t.id) === axisId; }),
         yTargets = xDomain ? $$.filterByXDomain(targetsByAxisId, xDomain) : targetsByAxisId,
         yMin = axisId === 'y2' ? config.axis_y2_min : config.axis_y_min,
         yMax = axisId === 'y2' ? config.axis_y2_max : config.axis_y_max,
@@ -123,16 +123,16 @@ c3_chart_internal_fn.getYDomain = function (targets, axisId, xDomain) {
         padding_bottom += domainLength * (ratio[0] / (1 - ratio[0] - ratio[1]));
     } else if (showVerticalDataLabel) {
         lengths = $$.getDataLabelLength(yDomainMin, yDomainMax, 'height');
-        padding_top += this.convertPixelsToAxisPadding(lengths[1], domainLength);
-        padding_bottom += this.convertPixelsToAxisPadding(lengths[0], domainLength);
+        padding_top += $$.axis.convertPixelsToAxisPadding(lengths[1], domainLength);
+        padding_bottom += $$.axis.convertPixelsToAxisPadding(lengths[0], domainLength);
     }
     if (axisId === 'y' && notEmpty(config.axis_y_padding)) {
-        padding_top = $$.getAxisPadding(config.axis_y_padding, 'top', padding_top, domainLength);
-        padding_bottom = $$.getAxisPadding(config.axis_y_padding, 'bottom', padding_bottom, domainLength);
+        padding_top = $$.axis.getPadding(config.axis_y_padding, 'top', padding_top, domainLength);
+        padding_bottom = $$.axis.getPadding(config.axis_y_padding, 'bottom', padding_bottom, domainLength);
     }
     if (axisId === 'y2' && notEmpty(config.axis_y2_padding)) {
-        padding_top = $$.getAxisPadding(config.axis_y2_padding, 'top', padding_top, domainLength);
-        padding_bottom = $$.getAxisPadding(config.axis_y2_padding, 'bottom', padding_bottom, domainLength);
+        padding_top = $$.axis.getPadding(config.axis_y2_padding, 'top', padding_top, domainLength);
+        padding_bottom = $$.axis.getPadding(config.axis_y2_padding, 'bottom', padding_bottom, domainLength);
     }
     // Bar/Area chart should be 0-based if all positive|negative
     if (isZeroBased) {

src/format.js

@@ -3,7 +3,7 @@ c3_chart_internal_fn.getYFormat = function (forArc) {
         formatForY = forArc && !$$.hasType('gauge') ? $$.defaultArcValueFormat : $$.yFormat,
         formatForY2 = forArc && !$$.hasType('gauge') ? $$.defaultArcValueFormat : $$.y2Format;
     return function (v, ratio, id) {
-        var format = $$.getAxisId(id) === 'y2' ? formatForY2 : formatForY;
+        var format = $$.axis.getId(id) === 'y2' ? formatForY2 : formatForY;
         return format.call($$, v, ratio);
     };
 };

src/scale.js

@@ -44,10 +44,10 @@ c3_chart_internal_fn.getY = function (min, max, domain) {
     return scale;
 };
 c3_chart_internal_fn.getYScale = function (id) {
-    return this.getAxisId(id) === 'y2' ? this.y2 : this.y;
+    return this.axis.getId(id) === 'y2' ? this.y2 : this.y;
 };
 c3_chart_internal_fn.getSubYScale = function (id) {
-    return this.getAxisId(id) === 'y2' ? this.subY2 : this.subY;
+    return this.axis.getId(id) === 'y2' ? this.subY2 : this.subY;
 };
 c3_chart_internal_fn.updateScales = function () {
     var $$ = this, config = $$.config,
@@ -69,15 +69,15 @@ c3_chart_internal_fn.updateScales = function () {
     $$.subY = $$.getY($$.subYMin, $$.subYMax, forInit ? config.axis_y_default : $$.subY.domain());
     $$.subY2 = $$.getY($$.subYMin, $$.subYMax, forInit ? config.axis_y2_default : $$.subY2.domain());
     // update axes
-    $$.xAxisTickFormat = $$.getXAxisTickFormat();
-    $$.xAxisTickValues = $$.getXAxisTickValues();
-    $$.yAxisTickValues = $$.getYAxisTickValues();
-    $$.y2AxisTickValues = $$.getY2AxisTickValues();
+    $$.xAxisTickFormat = $$.axis.getXAxisTickFormat();
+    $$.xAxisTickValues = $$.axis.getXAxisTickValues();
+    $$.yAxisTickValues = $$.axis.getYAxisTickValues();
+    $$.y2AxisTickValues = $$.axis.getY2AxisTickValues();
 
-    $$.xAxis = $$.getXAxis($$.x, $$.xOrient, $$.xAxisTickFormat, $$.xAxisTickValues, config.axis_x_tick_outer);
-    $$.subXAxis = $$.getXAxis($$.subX, $$.subXOrient, $$.xAxisTickFormat, $$.xAxisTickValues, config.axis_x_tick_outer);
-    $$.yAxis = $$.getYAxis($$.y, $$.yOrient, config.axis_y_tick_format, $$.yAxisTickValues, config.axis_y_tick_outer);
-    $$.y2Axis = $$.getYAxis($$.y2, $$.y2Orient, config.axis_y2_tick_format, $$.y2AxisTickValues, config.axis_y2_tick_outer);
+    $$.xAxis = $$.axis.getXAxis($$.x, $$.xOrient, $$.xAxisTickFormat, $$.xAxisTickValues, config.axis_x_tick_outer);
+    $$.subXAxis = $$.axis.getXAxis($$.subX, $$.subXOrient, $$.xAxisTickFormat, $$.xAxisTickValues, config.axis_x_tick_outer);
+    $$.yAxis = $$.axis.getYAxis($$.y, $$.yOrient, config.axis_y_tick_format, $$.yAxisTickValues, config.axis_y_tick_outer);
+    $$.y2Axis = $$.axis.getYAxis($$.y2, $$.y2Orient, config.axis_y2_tick_format, $$.y2AxisTickValues, config.axis_y2_tick_outer);
 
     // Set initialized scales to brush and zoom
     if (!forInit) {

src/size.js

@@ -22,7 +22,7 @@ c3_chart_internal_fn.getCurrentPaddingLeft = function (withoutRecompute) {
     } else if (config.axis_rotated) {
         return !config.axis_x_show ? 1 : Math.max(ceil10($$.getAxisWidthByAxisId('x', withoutRecompute)), 40);
     } else if (!config.axis_y_show || config.axis_y_inner) { // && !config.axis_rotated
-        return $$.getYAxisLabelPosition().isOuter ? 30 : 1;
+        return $$.axis.getYAxisLabelPosition().isOuter ? 30 : 1;
     } else {
         return ceil10($$.getAxisWidthByAxisId('y', withoutRecompute));
     }
@@ -35,7 +35,7 @@ c3_chart_internal_fn.getCurrentPaddingRight = function () {
     } else if (config.axis_rotated) {
         return defaultPadding + legendWidthOnRight;
     } else if (!config.axis_y2_show || config.axis_y2_inner) { // && !config.axis_rotated
-        return 2 + legendWidthOnRight + ($$.getY2AxisLabelPosition().isOuter ? 20 : 0);
+        return 2 + legendWidthOnRight + ($$.axis.getY2AxisLabelPosition().isOuter ? 20 : 0);
     } else {
         return ceil10($$.getAxisWidthByAxisId('y2')) + legendWidthOnRight;
     }
@@ -75,8 +75,8 @@ c3_chart_internal_fn.getSvgLeft = function (withoutRecompute) {
 
 
 c3_chart_internal_fn.getAxisWidthByAxisId = function (id, withoutRecompute) {
-    var $$ = this, position = $$.getAxisLabelPositionById(id);
-    return $$.getMaxTickWidth(id, withoutRecompute) + (position.isInner ? 20 : 40);
+    var $$ = this, position = $$.axis.getLabelPositionById(id);
+    return $$.axis.getMaxTickWidth(id, withoutRecompute) + (position.isInner ? 20 : 40);
 };
 c3_chart_internal_fn.getHorizontalAxisHeight = function (axisId) {
     var $$ = this, config = $$.config, h = 30;
@@ -86,9 +86,9 @@ c3_chart_internal_fn.getHorizontalAxisHeight = function (axisId) {
     if (axisId === 'y2' && !config.axis_y2_show) { return $$.rotated_padding_top; }
     // Calculate x axis height when tick rotated
     if (axisId === 'x' && !config.axis_rotated && config.axis_x_tick_rotate) {
-        h = $$.getMaxTickWidth(axisId) * Math.cos(Math.PI * (90 - config.axis_x_tick_rotate) / 180);
+        h = $$.axis.getMaxTickWidth(axisId) * Math.cos(Math.PI * (90 - config.axis_x_tick_rotate) / 180);
     }
-    return h + ($$.getAxisLabelPositionById(axisId).isInner ? 0 : 10) + (axisId === 'y2' ? -10 : 0);
+    return h + ($$.axis.getLabelPositionById(axisId).isInner ? 0 : 10) + (axisId === 'y2' ? -10 : 0);
 };
 
 c3_chart_internal_fn.getEventRectWidth = function () {

src/tooltip.js

@@ -18,7 +18,7 @@ c3_chart_internal_fn.initTooltip = function () {
         }
         $$.tooltip.html(config.tooltip_contents.call($$, $$.data.targets.map(function (d) {
             return $$.addName(d.values[config.tooltip_init_x]);
-        }), $$.getXAxisTickFormat(), $$.getYFormat($$.hasArcType()), $$.color));
+        }), $$.axis.getXAxisTickFormat(), $$.getYFormat($$.hasArcType()), $$.color));
         $$.tooltip.style("top", config.tooltip_init_position.top)
             .style("left", config.tooltip_init_position.left)
             .style("display", "block");
@@ -95,7 +95,7 @@ c3_chart_internal_fn.showTooltip = function (selectedData, element) {
     if (dataToShow.length === 0 || !config.tooltip_show) {
         return;
     }
-    $$.tooltip.html(config.tooltip_contents.call($$, selectedData, $$.getXAxisTickFormat(), $$.getYFormat(forArc), $$.color)).style("display", "block");
+    $$.tooltip.html(config.tooltip_contents.call($$, selectedData, $$.axis.getXAxisTickFormat(), $$.getYFormat(forArc), $$.color)).style("display", "block");
 
     // Get tooltip dimensions
     tWidth = $$.tooltip.property('offsetWidth');