Merge pull request #1779 from olyckne/adds_min_and_max_to_y_axes

Adds min and max setting to axes

docs/01-Scales.md

@@ -46,6 +46,8 @@ display | Boolean | true | If true, show the scale including gridlines, ticks, a
 *ticks*.display | Boolean | true | If true, show the ticks.
 *ticks*.suggestedMin | Number | - | User defined minimum number for the scale, overrides minimum value *except for if* it is higher than the minimum value.
 *ticks*.suggestedMax | Number | - | User defined maximum number for the scale, overrides maximum value *except for if* it is lower than the maximum value.
+*ticks*.min | Number | - | User defined minimum number for the scale, overrides minimum value
+*ticks*.max | Number | - | User defined minimum number for the scale, overrides maximum value
 *ticks*.callback | Function | `function(value) { return '' + value; } ` | Returns the string representation of the tick value as it should be displayed on the chart.
 
 The `callback` method may be used for advanced tick customization. The following callback would display every label in scientific notation

src/scales/scale.linear.js

@@ -181,6 +181,14 @@
 				this.ticks.push(niceMin + (j * spacing));
 			}
 
+			if (this.options.ticks.min !== undefined) {
+				this.ticks[0] = this.options.ticks.min;
+			}
+
+			if (this.options.ticks.max !== undefined) {
+				this.ticks[this.ticks.length - 1] = this.options.ticks.max;
+			}
+
 			if (this.options.position == "left" || this.options.position == "right") {
 				// We are in a vertical orientation. The top value is the highest. So reverse the array
 				this.ticks.reverse();
@@ -191,6 +199,15 @@
 			this.max = helpers.max(this.ticks);
 			this.min = helpers.min(this.ticks);
 
+			if (this.options.ticks.min !== undefined) {
+				this.min = this.options.ticks.min;
+			}
+
+			if (this.options.ticks.max !== undefined) {
+				this.max = this.options.ticks.max;
+			}
+
+
 			if (this.options.ticks.reverse) {
 				this.ticks.reverse();
 

src/scales/scale.logarithmic.js

@@ -90,6 +90,14 @@
 				}, this);
 			}
 
+			if (this.options.ticks.max) {
+				this.max = this.options.ticks.max;
+			}
+
+			if (this.options.ticks.min) {
+				this.min = this.options.ticks.min;
+			}
+
 			if (this.min === this.max) {
 				if (this.min !== 0 && this.min !== null) {
 					this.min = Math.pow(10, Math.floor(helpers.log10(this.min)) - 1);
@@ -121,6 +129,14 @@
 
 			this.tickValues.push(1.0 * Math.pow(10, maxExponent));
 
+			if (this.options.ticks.min) {
+				this.tickValues[0] = this.min;
+			}
+
+			if (this.options.ticks.max) {
+				this.tickValues[this.tickValues.length - 1] = this.max;
+			}
+
 			if (this.options.position == "left" || this.options.position == "right") {
 				// We are in a vertical orientation. The top value is the highest. So reverse the array
 				this.tickValues.reverse();
@@ -131,6 +147,14 @@
 			this.max = helpers.max(this.tickValues);
 			this.min = helpers.min(this.tickValues);
 
+			if (this.options.ticks.min) {
+				this.min = this.options.ticks.min;
+			}
+
+			if (this.options.ticks.max) {
+				this.max = this.options.ticks.max;
+			}
+
 			if (this.options.ticks.reverse) {
 				this.tickValues.reverse();
 

test/scale.linear.tests.js

@@ -374,6 +374,41 @@ describe('Linear Scale', function() {
 		expect(scale.max).toBe(10);
 	});
 
+	it('Should use the min and max options', function() {
+		var scaleID = 'myScale';
+
+		var mockData = {
+			datasets: [{
+				yAxisID: scaleID,
+				data: [1, 1, 1, 2, 1, 0]
+			}]
+		};
+
+		var config = Chart.helpers.clone(Chart.scaleService.getScaleDefaults('linear'));
+		config.ticks.min = -1010;
+		config.ticks.max = 1010;
+
+		var Constructor = Chart.scaleService.getScaleConstructor('linear');
+		var scale = new Constructor({
+			ctx: {},
+			options: config,
+			chart: {
+				data: mockData
+			},
+			id: scaleID
+		});
+
+		// Set arbitrary width and height for now
+		scale.width = 50;
+		scale.height = 400;
+
+		scale.buildTicks();
+		expect(scale.min).toBe(-1010);
+		expect(scale.max).toBe(1010);
+		expect(scale.ticks[0]).toBe(1010);
+		expect(scale.ticks[scale.ticks.length-1]).toBe(-1010);
+	});
+
 	it('should forcibly include 0 in the range if the beginAtZero option is used', function() {
 		var scaleID = 'myScale';
 

test/scale.logarithmic.tests.js

@@ -329,6 +329,41 @@ describe('Logarithmic Scale tests', function() {
 		expect(scale.max).toBe(1);
 	});
 
+
+	it('Should use the min and max options', function() {
+		var scaleID = 'myScale';
+
+		var mockData = {
+			datasets: [{
+				yAxisID: scaleID,
+				data: [1, 1, 1, 2, 1, 0]
+			}]
+		};
+
+		var mockContext = window.createMockContext();
+		var config = Chart.helpers.clone(Chart.scaleService.getScaleDefaults('logarithmic'));
+
+		config.ticks.min = 10;
+		config.ticks.max = 1010;
+
+		var Constructor = Chart.scaleService.getScaleConstructor('logarithmic');
+		var scale = new Constructor({
+			ctx: mockContext,
+			options: config,
+			chart: {
+				data: mockData
+			},
+			id: scaleID
+		});
+
+		scale.update(400, 00);
+		scale.buildTicks();
+		expect(scale.min).toBe(10);
+		expect(scale.max).toBe(1010);
+		expect(scale.ticks[0]).toBe(1010);
+		expect(scale.ticks[scale.ticks.length - 1]).toBe(10);
+	});
+
 	it('Should generate tick marks', function() {
 		var scaleID = 'myScale';