helpers.canvas.tests.js

'use strict';

describe('Chart.helpers.canvas', function() {
  describe('auto', jasmine.fixture.specs('helpers'));

  var helpers = Chart.helpers;

  describe('clearCanvas', function() {
    it('should clear the chart canvas', function() {
      var chart = acquireChart({}, {
        canvas: {
          style: 'width: 150px; height: 245px'
        }
      });

      spyOn(chart.ctx, 'clearRect');

      helpers.clearCanvas(chart.canvas, chart.ctx);

      expect(chart.ctx.clearRect.calls.count()).toBe(1);
      expect(chart.ctx.clearRect.calls.first().object).toBe(chart.ctx);
      expect(chart.ctx.clearRect.calls.first().args).toEqual([0, 0, 150, 245]);
    });
  });

  describe('isPointInArea', function() {
    it('should return true when no area is provided', function() {
      expect(helpers._isPointInArea({x: 1, y: 1})).toBe(true);
    });
    it('should determine if a point is in the area', function() {
      var isPointInArea = helpers._isPointInArea;
      var area = {left: 0, top: 0, right: 512, bottom: 256};

      expect(isPointInArea({x: 0, y: 0}, area)).toBe(true);
      expect(isPointInArea({x: -1e-12, y: -1e-12}, area)).toBe(true);
      expect(isPointInArea({x: 512, y: 256}, area)).toBe(true);
      expect(isPointInArea({x: 512 + 1e-12, y: 256 + 1e-12}, area)).toBe(true);
      expect(isPointInArea({x: -0.5, y: 0}, area)).toBe(false);
      expect(isPointInArea({x: 0, y: 256.5}, area)).toBe(false);
    });
  });

  it('should return the width of the longest text in an Array and 2D Array', function() {
    var context = window.createMockContext();
    var font = "normal 12px 'Helvetica Neue', 'Helvetica', 'Arial', sans-serif";
    var arrayOfThings1D = ['FooBar', 'Bar'];
    var arrayOfThings2D = [['FooBar_1', 'Bar_2'], 'Foo_1'];


    // Regardless 'FooBar' is the longest label it should return (characters * 10)
    expect(helpers._longestText(context, font, arrayOfThings1D, {})).toEqual(60);
    expect(helpers._longestText(context, font, arrayOfThings2D, {})).toEqual(80);
    // We check to make sure we made the right calls to the canvas.
    expect(context.getCalls()).toEqual([{
      name: 'save',
      args: []
    }, {
      name: 'setFont',
      args: ["normal 12px 'Helvetica Neue', 'Helvetica', 'Arial', sans-serif"],
    }, {
      name: 'measureText',
      args: ['FooBar']
    }, {
      name: 'measureText',
      args: ['Bar']
    }, {
      name: 'restore',
      args: []
    }, {
      name: 'save',
      args: []
    }, {
      name: 'setFont',
      args: ["normal 12px 'Helvetica Neue', 'Helvetica', 'Arial', sans-serif"],
    }, {
      name: 'measureText',
      args: ['FooBar_1']
    }, {
      name: 'measureText',
      args: ['Bar_2']
    }, {
      name: 'measureText',
      args: ['Foo_1']
    }, {
      name: 'restore',
      args: []
    }]);
  });

  it('compare text with current longest and update', function() {
    var context = window.createMockContext();
    var data = {};
    var gc = [];
    var longest = 70;

    expect(helpers._measureText(context, data, gc, longest, 'foobar')).toEqual(70);
    expect(helpers._measureText(context, data, gc, longest, 'foobar_')).toEqual(70);
    expect(helpers._measureText(context, data, gc, longest, 'foobar_1')).toEqual(80);
    // We check to make sure we made the right calls to the canvas.
    expect(context.getCalls()).toEqual([{
      name: 'measureText',
      args: ['foobar']
    }, {
      name: 'measureText',
      args: ['foobar_']
    }, {
      name: 'measureText',
      args: ['foobar_1']
    }]);
  });

  describe('renderText', function() {
    it('should render multiple lines of text', function() {
      var context = window.createMockContext();
      var font = {string: '12px arial', lineHeight: 20};
      helpers.renderText(context, ['foo', 'foo2'], 0, 0, font);

      expect(context.getCalls()).toEqual([{
        name: 'save',
        args: [],
      }, {
        name: 'setFont',
        args: ['12px arial'],
      }, {
        name: 'fillText',
        args: ['foo', 0, 0, undefined],
      }, {
        name: 'fillText',
        args: ['foo2', 0, 20, undefined],
      }, {
        name: 'restore',
        args: [],
      }]);
    });

    it('should accept the text maxWidth', function() {
      var context = window.createMockContext();
      var font = {string: '12px arial', lineHeight: 20};
      helpers.renderText(context, 'foo', 0, 0, font, {maxWidth: 30});
      expect(context.getCalls()).toEqual([{
        name: 'save',
        args: [],
      }, {
        name: 'setFont',
        args: ['12px arial'],
      }, {
        name: 'fillText',
        args: ['foo', 0, 0, 30],
      }, {
        name: 'restore',
        args: [],
      }]);
    });

    it('should underline the text', function() {
      var context = window.createMockContext();
      var font = {string: '12px arial', lineHeight: 20};
      helpers.renderText(context, 'foo', 0, 0, font, {decorationWidth: 3, underline: true});

      expect(context.getCalls()).toEqual([{
        name: 'save',
        args: [],
      }, {
        name: 'setFont',
        args: ['12px arial'],
      }, {
        name: 'fillText',
        args: ['foo', 0, 0, undefined],
      }, {
        name: 'measureText',
        args: ['foo'],
      }, {
        name: 'setStrokeStyle',
        args: [null],
      }, {
        name: 'beginPath',
        args: [],
      }, {
        name: 'setLineWidth',
        args: [3],
      }, {
        name: 'moveTo',
        args: [-15, 8],
      }, {
        name: 'lineTo',
        args: [25, 8],
      }, {
        name: 'stroke',
        args: [],
      }, {
        name: 'restore',
        args: [],
      }]);
    });

    it('should strikethrough the text', function() {
      var context = window.createMockContext();
      var font = {string: '12px arial', lineHeight: 20};
      helpers.renderText(context, 'foo', 0, 0, font, {strikethrough: true});

      expect(context.getCalls()).toEqual([{
        name: 'save',
        args: [],
      }, {
        name: 'setFont',
        args: ['12px arial'],
      }, {
        name: 'fillText',
        args: ['foo', 0, 0, undefined],
      }, {
        name: 'measureText',
        args: ['foo'],
      }, {
        name: 'setStrokeStyle',
        args: [null],
      }, {
        name: 'beginPath',
        args: [],
      }, {
        name: 'setLineWidth',
        args: [2],
      }, {
        name: 'moveTo',
        args: [-15, 2],
      }, {
        name: 'lineTo',
        args: [25, 2],
      }, {
        name: 'stroke',
        args: [],
      }, {
        name: 'restore',
        args: [],
      }]);
    });

    it('should set the fill style if supplied', function() {
      var context = window.createMockContext();
      var font = {string: '12px arial', lineHeight: 20};
      helpers.renderText(context, 'foo', 0, 0, font, {color: 'red'});

      expect(context.getCalls()).toEqual([{
        name: 'save',
        args: [],
      }, {
        name: 'setFont',
        args: ['12px arial'],
      }, {
        name: 'setFillStyle',
        args: ['red'],
      }, {
        name: 'fillText',
        args: ['foo', 0, 0, undefined],
      }, {
        name: 'restore',
        args: [],
      }]);
    });

    it('should set the stroke style if supplied', function() {
      var context = window.createMockContext();
      var font = {string: '12px arial', lineHeight: 20};
      helpers.renderText(context, 'foo', 0, 0, font, {strokeColor: 'red', strokeWidth: 2});
      expect(context.getCalls()).toEqual([{
        name: 'save',
        args: [],
      }, {
        name: 'setFont',
        args: ['12px arial'],
      }, {
        name: 'setStrokeStyle',
        args: ['red'],
      }, {
        name: 'setLineWidth',
        args: [2],
      }, {
        name: 'strokeText',
        args: ['foo', 0, 0, undefined],
      }, {
        name: 'fillText',
        args: ['foo', 0, 0, undefined],
      }, {
        name: 'restore',
        args: [],
      }]);
    });

    it('should set the text alignment', function() {
      var context = window.createMockContext();
      var font = {string: '12px arial', lineHeight: 20};
      helpers.renderText(context, 'foo', 0, 0, font, {textAlign: 'left', textBaseline: 'middle'});

      expect(context.getCalls()).toEqual([{
        name: 'save',
        args: [],
      }, {
        name: 'setFont',
        args: ['12px arial'],
      }, {
        name: 'setTextAlign',
        args: ['left'],
      }, {
        name: 'setTextBaseline',
        args: ['middle'],
      }, {
        name: 'fillText',
        args: ['foo', 0, 0, undefined],
      }, {
        name: 'restore',
        args: [],
      }]);
    });

    it('should translate and rotate text', function() {
      var context = window.createMockContext();
      var font = {string: '12px arial', lineHeight: 20};
      helpers.renderText(context, 'foo', 0, 0, font, {rotation: 90, translation: [10, 20]});

      expect(context.getCalls()).toEqual([{
        name: 'save',
        args: [],
      }, {
        name: 'setFont',
        args: ['12px arial'],
      }, {
        name: 'translate',
        args: [10, 20],
      }, {
        name: 'rotate',
        args: [90],
      }, {
        name: 'fillText',
        args: ['foo', 0, 0, undefined],
      }, {
        name: 'restore',
        args: [],
      }]);
    });
  });
});