added configurable domain trimming

Gruntfile.coffee

@@ -65,6 +65,7 @@ module.exports = (grunt) ->
               'src/api.color.js',
               'src/api.x.js',
               'src/api.axis.js',
+              'src/api.domain.js',
               'src/api.legend.js',
               'src/api.chart.js',
               'src/api.tooltip.js',

c3.js

@@ -965,6 +965,8 @@
             axis_x_height: undefined,
             axis_x_extent: undefined,
             axis_x_label: {},
+            axis_x_domain_min: undefined,
+            axis_x_domain_max: undefined,
             axis_y_show: true,
             axis_y_max: undefined,
             axis_y_min: undefined,
@@ -1382,14 +1384,16 @@
         return $$.x.domain();
     };
     c3_chart_internal_fn.trimXDomain = function (domain) {
-        var $$ = this;
-        if (domain[0] <= $$.orgXDomain[0]) {
-            domain[1] = +domain[1] + ($$.orgXDomain[0] - domain[0]);
-            domain[0] = $$.orgXDomain[0];
+        var $$ = this, config = $$.config, d3 = $$.d3;
+        var min = d3.min([$$.orgXDomain[0], config.axis_x_domain_min]);
+        var max = d3.max([$$.orgXDomain[1], config.axis_x_domain_max]);
+        if (domain[0] <= min) {
+            domain[1] = +domain[1] + (min - domain[0]);
+            domain[0] = min;
         }
-        if ($$.orgXDomain[1] <= domain[1]) {
-            domain[0] = +domain[0] - (domain[1] - $$.orgXDomain[1]);
-            domain[1] = $$.orgXDomain[1];
+        if (max <= domain[1]) {
+            domain[0] = +domain[0] - (domain[1] - max);
+            domain[1] = max;
         }
         return domain;
     };
@@ -6095,6 +6099,39 @@
         }
     };
 
+    c3_chart_fn.domain = function () {};
+
+    c3_chart_fn.domain.max = function (max) {
+        var $$ = this.internal, config = $$.config, d3 = $$.d3;
+        if (max === 0 || max) {
+            config.axis_x_domain_max = d3.max([$$.orgXDomain[1], max]);
+        }
+        else {
+            return config.axis_x_domain_max;
+        }
+    };
+
+    c3_chart_fn.domain.min = function (min) {
+        var $$ = this.internal, config = $$.config, d3 = $$.d3;
+        if (min === 0 || min) {
+            config.axis_x_domain_min = d3.min([$$.orgXDomain[0], min]);
+        }
+        else {
+            return config.axis_x_domain_min;
+        }
+    };
+
+    c3_chart_fn.domain.range = function (range) {
+        if (arguments.length) {
+            if (isDefined(range.max)) { this.domain.max(range.max); }
+            if (isDefined(range.min)) { this.domain.min(range.min); }
+        } else {
+            return {
+                max: this.domain.max(),
+                min: this.domain.min()
+            };
+        }
+    };
     c3_chart_fn.legend = function () {};
     c3_chart_fn.legend.show = function (targetIds) {
         var $$ = this.internal;

src/api.domain.js

@@ -0,0 +1,33 @@
+c3_chart_fn.domain = function () {};
+
+c3_chart_fn.domain.max = function (max) {
+    var $$ = this.internal, config = $$.config, d3 = $$.d3;
+    if (max === 0 || max) {
+        config.axis_x_domain_max = d3.max([$$.orgXDomain[1], max]);
+    }
+    else {
+        return config.axis_x_domain_max;
+    }
+};
+
+c3_chart_fn.domain.min = function (min) {
+    var $$ = this.internal, config = $$.config, d3 = $$.d3;
+    if (min === 0 || min) {
+        config.axis_x_domain_min = d3.min([$$.orgXDomain[0], min]);
+    }
+    else {
+        return config.axis_x_domain_min;
+    }
+};
+
+c3_chart_fn.domain.range = function (range) {
+    if (arguments.length) {
+        if (isDefined(range.max)) { this.domain.max(range.max); }
+        if (isDefined(range.min)) { this.domain.min(range.min); }
+    } else {
+        return {
+            max: this.domain.max(),
+            min: this.domain.min()
+        };
+    }
+};

src/config.js

@@ -95,6 +95,8 @@ c3_chart_internal_fn.getDefaultConfig = function () {
         axis_x_height: undefined,
         axis_x_extent: undefined,
         axis_x_label: {},
+        axis_x_domain_min: undefined,
+        axis_x_domain_max: undefined,
         axis_y_show: true,
         axis_y_max: undefined,
         axis_y_min: undefined,

src/domain.js

@@ -213,14 +213,16 @@ c3_chart_internal_fn.updateXDomain = function (targets, withUpdateXDomain, withU
     return $$.x.domain();
 };
 c3_chart_internal_fn.trimXDomain = function (domain) {
-    var $$ = this;
-    if (domain[0] <= $$.orgXDomain[0]) {
-        domain[1] = +domain[1] + ($$.orgXDomain[0] - domain[0]);
-        domain[0] = $$.orgXDomain[0];
-    }
-    if ($$.orgXDomain[1] <= domain[1]) {
-        domain[0] = +domain[0] - (domain[1] - $$.orgXDomain[1]);
-        domain[1] = $$.orgXDomain[1];
+    var $$ = this, config = $$.config, d3 = $$.d3;
+    var min = d3.min([$$.orgXDomain[0], config.axis_x_domain_min]);
+    var max = d3.max([$$.orgXDomain[1], config.axis_x_domain_max]);
+    if (domain[0] <= min) {
+        domain[1] = +domain[1] + (min - domain[0]);
+        domain[0] = min;
+    }
+    if (max <= domain[1]) {
+        domain[0] = +domain[0] - (domain[1] - max);
+        domain[1] = max;
     }
     return domain;
 };