jquery_flot_pie.js

/* Flot plugin for rendering pie charts.

Copyright (c) 2007-2014 IOLA and Ole Laursen.
Licensed under the MIT license.

The plugin assumes that each series has a single data value, and that each
value is a positive integer or zero.  Negative numbers don't make sense for a
pie chart, and have unpredictable results.  The values do NOT need to be
passed in as percentages; the plugin will calculate the total and per-slice
percentages internally.

* Created by Brian Medendorp

* Updated with contributions from btburnett3, Anthony Aragues and Xavi Ivars

The plugin supports these options:

	series: {
		pie: {
			show: true/false
			radius: 0-1 for percentage of fullsize, or a specified pixel length, or 'auto'
			innerRadius: 0-1 for percentage of fullsize or a specified pixel length, for creating a donut effect
			startAngle: 0-2 factor of PI used for starting angle (in radians) i.e 3/2 starts at the top, 0 and 2 have the same result
			tilt: 0-1 for percentage to tilt the pie, where 1 is no tilt, and 0 is completely flat (nothing will show)
			offset: {
				top: integer value to move the pie up or down
				left: integer value to move the pie left or right, or 'auto'
			},
			stroke: {
				color: any hexadecimal color value (other formats may or may not work, so best to stick with something like '#FFF')
				width: integer pixel width of the stroke
			},
			label: {
				show: true/false, or 'auto'
				formatter:  a user-defined function that modifies the text/style of the label text
				radius: 0-1 for percentage of fullsize, or a specified pixel length
				background: {
					color: any hexadecimal color value (other formats may or may not work, so best to stick with something like '#000')
					opacity: 0-1
				},
				threshold: 0-1 for the percentage value at which to hide labels (if they're too small)
			},
			combine: {
				threshold: 0-1 for the percentage value at which to combine slices (if they're too small)
				color: any hexadecimal color value (other formats may or may not work, so best to stick with something like '#CCC'), if null, the plugin will automatically use the color of the first slice to be combined
				label: any text value of what the combined slice should be labeled
			}
			highlight: {
				opacity: 0-1
			}
		}
	}

More detail and specific examples can be found in the included HTML file.

*/

import { i18n } from '@osd/i18n';

(function($) {
	// Maximum redraw attempts when fitting labels within the plot

	var REDRAW_ATTEMPTS = 10;

	// Factor by which to shrink the pie when fitting labels within the plot

	var REDRAW_SHRINK = 0.95;

  function init(plot) {
    let canvas = null;
    let target = null;
    let options = null;
    let maxRadius = null;
    let centerLeft = null;
    let centerTop = null;
    let processed = false;
    let ctx = null;

    // interactive variables

    let highlights = [];

    // add hook to determine if pie plugin in enabled, and then perform necessary operations

    plot.hooks.processOptions.push(function (plot, options) {
      if (options.series.pie.show) {
        options.grid.show = false;

        // set labels.show

        if (options.series.pie.label.show === 'auto') {
          if (options.legend.show) {
            options.series.pie.label.show = false;
          } else {
            options.series.pie.label.show = true;
          }
        }

        // set radius

        if (options.series.pie.radius === 'auto') {
          if (options.series.pie.label.show) {
            options.series.pie.radius = 3 / 4;
          } else {
            options.series.pie.radius = 1;
          }
        }

        // ensure sane tilt

        if (options.series.pie.tilt > 1) {
          options.series.pie.tilt = 1;
        } else if (options.series.pie.tilt < 0) {
          options.series.pie.tilt = 0;
        }
      }
    });

    plot.hooks.bindEvents.push(function (plot, eventHolder) {
      const options = plot.getOptions();
      if (options.series.pie.show) {
        if (options.grid.hoverable) {
          eventHolder.unbind('mousemove').mousemove(onMouseMove);
        }

        if (options.grid.clickable) {
          eventHolder.unbind('click').click(onClick);
        }
      }
    });

    plot.hooks.processDatapoints.push(function (plot, series, data, datapoints) {
      const options = plot.getOptions();
      if (options.series.pie.show) {
        processDatapoints(plot, series, data, datapoints);
      }
    });

    plot.hooks.drawOverlay.push(function (plot, octx) {
      const options = plot.getOptions();
      if (options.series.pie.show) {
        drawOverlay(plot, octx);
      }
    });

    plot.hooks.draw.push(function (plot, newCtx) {
      const options = plot.getOptions();
      if (options.series.pie.show) {
        draw(plot, newCtx);
      }
    });

    function processDatapoints(plot) {
      if (!processed) {
        processed = true;
        canvas = plot.getCanvas();
        target = $(canvas).parent();
        options = plot.getOptions();
        plot.setData(combine(plot.getData()));
      }
    }

    function combine(data) {
      let total = 0;
      let combined = 0;
      let numCombined = 0;
      let color = options.series.pie.combine.color;
      const newdata = [];

      // Fix up the raw data from Flot, ensuring the data is numeric

      for (let i = 0; i < data.length; ++i) {
        let value = data[i].data;

        // If the data is an array, we'll assume that it's a standard
        // Flot x-y pair, and are concerned only with the second value.

        // Note how we use the original array, rather than creating a
        // new one; this is more efficient and preserves any extra data
        // that the user may have stored in higher indexes.

        if (Array.isArray(value) && value.length === 1) {
          value = value[0];
        }

        if (Array.isArray(value)) {
          // Equivalent to $.isNumeric() but compatible with jQuery < 1.7
          if (!isNaN(parseFloat(value[1])) && isFinite(value[1])) {
            value[1] = +value[1];
          } else {
            value[1] = 0;
          }
        } else if (!isNaN(parseFloat(value)) && isFinite(value)) {
          value = [1, +value];
        } else {
          value = [1, 0];
        }

        data[i].data = [value];
      }

      // Sum up all the slices, so we can calculate percentages for each

      for (let i = 0; i < data.length; ++i) {
        total += data[i].data[0][1];
      }

      // Count the number of slices with percentages below the combine
      // threshold; if it turns out to be just one, we won't combine.

      for (let i = 0; i < data.length; ++i) {
        const value = data[i].data[0][1];
        if (value / total <= options.series.pie.combine.threshold) {
          combined += value;
          numCombined++;
          if (!color) {
            color = data[i].color;
          }
        }
      }

      for (let i = 0; i < data.length; ++i) {
        const value = data[i].data[0][1];
        if (numCombined < 2 || value / total > options.series.pie.combine.threshold) {
          newdata.push(
            $.extend(data[i], {
              /* extend to allow keeping all other original data values
                                        and using them e.g. in labelFormatter. */
              data: [[1, value]],
              color: data[i].color,
              label: data[i].label,
              angle: (value * Math.PI * 2) / total,
              percent: value / (total / 100),
            })
          );
        }
      }

      if (numCombined > 1) {
        newdata.push({
          data: [[1, combined]],
          color: color,
          label: options.series.pie.combine.label,
          angle: (combined * Math.PI * 2) / total,
          percent: combined / (total / 100),
        });
      }

      return newdata;
    }

    function draw(plot, newCtx) {
      if (!target) {
        return;
      } // if no series were passed

      const canvasWidth = plot.getPlaceholder().width();
      const canvasHeight = plot.getPlaceholder().height();
      const legendWidth = target.children().filter('.legend').children().width() || 0;

      ctx = newCtx;

      // WARNING: HACK! REWRITE THIS CODE AS SOON AS POSSIBLE!

      // When combining smaller slices into an 'other' slice, we need to
      // add a new series.  Since Flot gives plugins no way to modify the
      // list of series, the pie plugin uses a hack where the first call
      // to processDatapoints results in a call to setData with the new
      // list of series, then subsequent processDatapoints do nothing.

      // The plugin-global 'processed' flag is used to control this hack;
      // it starts out false, and is set to true after the first call to
      // processDatapoints.

      // Unfortunately this turns future setData calls into no-ops; they
      // call processDatapoints, the flag is true, and nothing happens.

      // To fix this we'll set the flag back to false here in draw, when
      // all series have been processed, so the next sequence of calls to
      // processDatapoints once again starts out with a slice-combine.
      // This is really a hack; in 0.9 we need to give plugins a proper
      // way to modify series before any processing begins.

      processed = false;

      // calculate maximum radius and center point

      maxRadius = Math.min(canvasWidth, canvasHeight / options.series.pie.tilt) / 2;
      centerTop = canvasHeight / 2 + options.series.pie.offset.top;
      centerLeft = canvasWidth / 2;

      if (options.series.pie.offset.left === 'auto') {
        if (options.legend.position.match('w')) {
          centerLeft += legendWidth / 2;
        } else {
          centerLeft -= legendWidth / 2;
        }

        if (centerLeft < maxRadius) {
          centerLeft = maxRadius;
        } else if (centerLeft > canvasWidth - maxRadius) {
          centerLeft = canvasWidth - maxRadius;
        }
      } else {
        centerLeft += options.series.pie.offset.left;
      }

      const slices = plot.getData();
      let attempts = 0;

      // Keep shrinking the pie's radius until drawPie returns true,
      // indicating that all the labels fit, or we try too many times.

      do {
        if (attempts > 0) {
          maxRadius *= REDRAW_SHRINK;
        }

        attempts += 1;
        clear();
        if (options.series.pie.tilt <= 0.8) {
          drawShadow();
        }
      } while (!drawPie() && attempts < REDRAW_ATTEMPTS);

      if (attempts >= REDRAW_ATTEMPTS) {
        clear();
        const errorMessage = i18n.translate('flot.pie.unableToDrawLabelsInsideCanvasErrorMessage', {
					defaultMessage: 'Could not draw pie with labels contained inside canvas',
				});
        target.prepend(
          `<div class='error'>${errorMessage}</div>`
        );
      }

      if (plot.setSeries && plot.insertLegend) {
        plot.setSeries(slices);
        plot.insertLegend();
      }

      // we're actually done at this point, just defining internal functions at this point

      function clear() {
        ctx.clearRect(0, 0, canvasWidth, canvasHeight);
        target.children().filter('.pieLabel, .pieLabelBackground').remove();
      }

      function drawShadow() {
        const shadowLeft = options.series.pie.shadow.left;
        const shadowTop = options.series.pie.shadow.top;
        const edge = 10;
        const alpha = options.series.pie.shadow.alpha;
        let radius =
          options.series.pie.radius > 1
            ? options.series.pie.radius
            : maxRadius * options.series.pie.radius;

        if (
          radius >= canvasWidth / 2 - shadowLeft ||
          radius * options.series.pie.tilt >= canvasHeight / 2 - shadowTop ||
          radius <= edge
        ) {
          return;
        } // shadow would be outside canvas, so don't draw it

        ctx.save();
        ctx.translate(shadowLeft, shadowTop);
        ctx.globalAlpha = alpha;
        ctx.fillStyle = '#000';

        // center and rotate to starting position

        ctx.translate(centerLeft, centerTop);
        ctx.scale(1, options.series.pie.tilt);

        //radius -= edge;

        for (let i = 1; i <= edge; i++) {
          ctx.beginPath();
          ctx.arc(0, 0, radius, 0, Math.PI * 2, false);
          ctx.fill();
          radius -= i;
        }

        ctx.restore();
      }

      function drawPie() {
        const startAngle = Math.PI * options.series.pie.startAngle;
        const radius =
          options.series.pie.radius > 1
            ? options.series.pie.radius
            : maxRadius * options.series.pie.radius;

        // center and rotate to starting position

        ctx.save();
        ctx.translate(centerLeft, centerTop);
        ctx.scale(1, options.series.pie.tilt);
        //ctx.rotate(startAngle); // start at top; -- This doesn't work properly in Opera

        // draw slices

        ctx.save();
        let currentAngle = startAngle;
        for (let i = 0; i < slices.length; ++i) {
          slices[i].startAngle = currentAngle;
          drawSlice(slices[i].angle, slices[i].color, true);
        }
        ctx.restore();

        // draw slice outlines

        if (options.series.pie.stroke.width > 0) {
          ctx.save();
          ctx.lineWidth = options.series.pie.stroke.width;
          currentAngle = startAngle;
          for (let i = 0; i < slices.length; ++i) {
            drawSlice(slices[i].angle, options.series.pie.stroke.color, false);
          }

          ctx.restore();
        }

        // draw donut hole

        drawDonutHole(ctx);

        ctx.restore();

        // Draw the labels, returning true if they fit within the plot

        if (options.series.pie.label.show) {
          return drawLabels();
        } else {
          return true;
        }

        function drawSlice(angle, color, fill) {
          if (angle <= 0 || isNaN(angle)) {
            return;
          }

          if (fill) {
            ctx.fillStyle = color;
          } else {
            ctx.strokeStyle = color;
            ctx.lineJoin = 'round';
          }

          ctx.beginPath();
          if (Math.abs(angle - Math.PI * 2) > 0.000000001) {
            ctx.moveTo(0, 0);
          } // Center of the pie

          //ctx.arc(0, 0, radius, 0, angle, false); // This doesn't work properly in Opera
          ctx.arc(0, 0, radius, currentAngle, currentAngle + angle / 2, false);
          ctx.arc(0, 0, radius, currentAngle + angle / 2, currentAngle + angle, false);
          ctx.closePath();
          //ctx.rotate(angle); // This doesn't work properly in Opera
          currentAngle += angle;

          if (fill) {
            ctx.fill();
          } else {
            ctx.stroke();
          }
        }

        function drawLabels() {
          let currentAngle = startAngle;
          const radius =
            options.series.pie.label.radius > 1
              ? options.series.pie.label.radius
              : maxRadius * options.series.pie.label.radius;

          for (let i = 0; i < slices.length; ++i) {
            if (slices[i].percent >= options.series.pie.label.threshold * 100) {
              if (!drawLabel(slices[i], currentAngle, i)) {
                return false;
              }
            }

            currentAngle += slices[i].angle;
          }

          return true;

          function drawLabel(slice, startAngle, index) {
            if (slice.data[0][1] === 0) {
              return true;
            }

            // format label text

            const lf = options.legend.labelFormatter;
            let text;
            const plf = options.series.pie.label.formatter;

            if (lf) {
              text = lf(slice.label, slice);
            } else {
              text = slice.label;
            }

            if (plf) {
              text = plf(text, slice);
            }

            const halfAngle = (startAngle + slice.angle + startAngle) / 2;
            const x = centerLeft + Math.round(Math.cos(halfAngle) * radius);
            const y = centerTop + Math.round(Math.sin(halfAngle) * radius) * options.series.pie.tilt;

            const html =
              "<span class='pieLabel' id='pieLabel" +
              index +
              "' style='position:absolute;top:" +
              y +
              'px;left:' +
              x +
              "px;'>" +
              text +
              '</span>';
            target.append(html);

            const label = target.children('#pieLabel' + index);
            const labelTop = y - label.height() / 2;
            const labelLeft = x - label.width() / 2;

            label.css('top', labelTop);
            label.css('left', labelLeft);

            // check to make sure that the label is not outside the canvas

            if (
              0 - labelTop > 0 ||
              0 - labelLeft > 0 ||
              canvasHeight - (labelTop + label.height()) < 0 ||
              canvasWidth - (labelLeft + label.width()) < 0
            ) {
              return false;
            }

            if (options.series.pie.label.background.opacity !== 0) {
              // put in the transparent background separately to avoid blended labels and label boxes

              let c = options.series.pie.label.background.color;

              if (c == null) {
                c = slice.color;
              }

              const pos = 'top:' + labelTop + 'px;left:' + labelLeft + 'px;';
              $(
                "<div class='pieLabelBackground' style='position:absolute;width:" +
                  label.width() +
                  'px;height:' +
                  label.height() +
                  'px;' +
                  pos +
                  'background-color:' +
                  c +
                  ";'></div>"
              )
                .css('opacity', options.series.pie.label.background.opacity)
                .insertBefore(label);
            }

            return true;
          } // end individual label function
        } // end drawLabels function
      } // end drawPie function
    } // end draw function

    // Placed here because it needs to be accessed from multiple locations

    function drawDonutHole(layer) {
      if (options.series.pie.innerRadius > 0) {
        // subtract the center

        layer.save();
        const innerRadius =
          options.series.pie.innerRadius > 1
            ? options.series.pie.innerRadius
            : maxRadius * options.series.pie.innerRadius;
        layer.globalCompositeOperation = 'destination-out'; // this does not work with excanvas, but it will fall back to using the stroke color
        layer.beginPath();
        layer.fillStyle = options.series.pie.stroke.color;
        layer.arc(0, 0, innerRadius, 0, Math.PI * 2, false);
        layer.fill();
        layer.closePath();
        layer.restore();

        // add inner stroke
        // TODO: Canvas forked flot here!
        if (options.series.pie.stroke.width > 0) {
          layer.save();
          layer.beginPath();
          layer.strokeStyle = options.series.pie.stroke.color;
          layer.arc(0, 0, innerRadius, 0, Math.PI * 2, false);
          layer.stroke();
          layer.closePath();
          layer.restore();
        }

        // TODO: add extra shadow inside hole (with a mask) if the pie is tilted.
      }
    }

    //-- Additional Interactive related functions --

    function isPointInPoly(poly, pt) {
      let c = false;
      const l = poly.length;
      let j = l - 1;
      for (let i = -1; ++i < l; j = i) {
        ((poly[i][1] <= pt[1] && pt[1] < poly[j][1]) ||
          (poly[j][1] <= pt[1] && pt[1] < poly[i][1])) &&
          pt[0] <
            ((poly[j][0] - poly[i][0]) * (pt[1] - poly[i][1])) / (poly[j][1] - poly[i][1]) +
              poly[i][0] &&
          (c = !c);
      }
      return c;
    }

    function findNearbySlice(mouseX, mouseY) {
      const slices = plot.getData();
      const options = plot.getOptions();
      const radius =
        options.series.pie.radius > 1
          ? options.series.pie.radius
          : maxRadius * options.series.pie.radius;
      let x;
      let y;

      for (let i = 0; i < slices.length; ++i) {
        const s = slices[i];

        if (s.pie.show) {
          ctx.save();
          ctx.beginPath();
          ctx.moveTo(0, 0); // Center of the pie
          //ctx.scale(1, options.series.pie.tilt);	// this actually seems to break everything when here.
          ctx.arc(0, 0, radius, s.startAngle, s.startAngle + s.angle / 2, false);
          ctx.arc(0, 0, radius, s.startAngle + s.angle / 2, s.startAngle + s.angle, false);
          ctx.closePath();
          x = mouseX - centerLeft;
          y = mouseY - centerTop;

          if (ctx.isPointInPath) {
            if (ctx.isPointInPath(mouseX - centerLeft, mouseY - centerTop)) {
              ctx.restore();
              return {
                datapoint: [s.percent, s.data],
                dataIndex: 0,
                series: s,
                seriesIndex: i,
              };
            }
          } else {
            // excanvas for IE doesn;t support isPointInPath, this is a workaround.

            const p1X = radius * Math.cos(s.startAngle);
            const p1Y = radius * Math.sin(s.startAngle);
            const p2X = radius * Math.cos(s.startAngle + s.angle / 4);
            const p2Y = radius * Math.sin(s.startAngle + s.angle / 4);
            const p3X = radius * Math.cos(s.startAngle + s.angle / 2);
            const p3Y = radius * Math.sin(s.startAngle + s.angle / 2);
            const p4X = radius * Math.cos(s.startAngle + s.angle / 1.5);
            const p4Y = radius * Math.sin(s.startAngle + s.angle / 1.5);
            const p5X = radius * Math.cos(s.startAngle + s.angle);
            const p5Y = radius * Math.sin(s.startAngle + s.angle);
            const arrPoly = [
              [0, 0],
              [p1X, p1Y],
              [p2X, p2Y],
              [p3X, p3Y],
              [p4X, p4Y],
              [p5X, p5Y],
            ];
            const arrPoint = [x, y];

            // TODO: perhaps do some mathmatical trickery here with the Y-coordinate to compensate for pie tilt?

            if (isPointInPoly(arrPoly, arrPoint)) {
              ctx.restore();
              return {
                datapoint: [s.percent, s.data],
                dataIndex: 0,
                series: s,
                seriesIndex: i,
              };
            }
          }

          ctx.restore();
        }
      }

      return null;
    }

    function onMouseMove(e) {
      triggerClickHoverEvent('plothover', e);
    }

    function onClick(e) {
      triggerClickHoverEvent('plotclick', e);
    }

    // trigger click or hover event (they send the same parameters so we share their code)

    function triggerClickHoverEvent(eventname, e) {
      const offset = plot.offset();
      const canvasX = parseInt(e.pageX - offset.left, 10);
      const canvasY = parseInt(e.pageY - offset.top, 10);
      const item = findNearbySlice(canvasX, canvasY);

      if (options.grid.autoHighlight) {
        // clear auto-highlights

        for (let i = 0; i < highlights.length; ++i) {
          const h = highlights[i];
          if (h.auto === eventname && !(item && h.series === item.series)) {
            unhighlight(h.series);
          }
        }
      }

      // highlight the slice

      if (item) {
        highlight(item.series, eventname);
      }

      // trigger any hover bind events

      const pos = { pageX: e.pageX, pageY: e.pageY };
      target.trigger(eventname, [pos, item]);
    }

    function highlight(s, auto) {
      //if (typeof s == "number") {
      //	s = series[s];
      //}

      const i = indexOfHighlight(s);

      if (i === -1) {
        highlights.push({ series: s, auto: auto });
        plot.triggerRedrawOverlay();
      } else if (!auto) {
        highlights[i].auto = false;
      }
    }

    function unhighlight(s) {
      if (s == null) {
        highlights = [];
        plot.triggerRedrawOverlay();
      }

      //if (typeof s == "number") {
      //	s = series[s];
      //}

      const i = indexOfHighlight(s);

      if (i !== -1) {
        highlights.splice(i, 1);
        plot.triggerRedrawOverlay();
      }
    }

    function indexOfHighlight(s) {
      for (let i = 0; i < highlights.length; ++i) {
        const h = highlights[i];
        if (h.series === s) {
          return i;
        }
      }
      return -1;
    }

    function drawOverlay(plot, octx) {
      const options = plot.getOptions();

      const radius =
        options.series.pie.radius > 1
          ? options.series.pie.radius
          : maxRadius * options.series.pie.radius;

      octx.save();
      octx.translate(centerLeft, centerTop);
      octx.scale(1, options.series.pie.tilt);

      for (let i = 0; i < highlights.length; ++i) {
        drawHighlight(highlights[i].series);
      }

      drawDonutHole(octx);

      octx.restore();

      function drawHighlight(series) {
        if (series.angle <= 0 || isNaN(series.angle)) {
          return;
        }

        //octx.fillStyle = parseColor(options.series.pie.highlight.color).scale(null, null, null, options.series.pie.highlight.opacity).toString();
        octx.fillStyle = 'rgba(255, 255, 255, ' + options.series.pie.highlight.opacity + ')'; // this is temporary until we have access to parseColor
        octx.beginPath();
        if (Math.abs(series.angle - Math.PI * 2) > 0.000000001) {
          octx.moveTo(0, 0);
        } // Center of the pie

        octx.arc(0, 0, radius, series.startAngle, series.startAngle + series.angle / 2, false);
        octx.arc(
          0,
          0,
          radius,
          series.startAngle + series.angle / 2,
          series.startAngle + series.angle,
          false
        );
        octx.closePath();
        octx.fill();
      }
    }
  } // end init (plugin body)

  // define pie specific options and their default values

  const options = {
    series: {
      pie: {
        show: false,
        radius: 'auto', // actual radius of the visible pie (based on full calculated radius if <=1, or hard pixel value)
        innerRadius: 0 /* for donut */,
        startAngle: 3 / 2,
        tilt: 1,
        shadow: {
          left: 5, // shadow left offset
          top: 15, // shadow top offset
          alpha: 0.02, // shadow alpha
        },
        offset: {
          top: 0,
          left: 'auto',
        },
        stroke: {
          color: '#fff',
          width: 1,
        },
        label: {
          show: 'auto',
          formatter: function (label, slice) {
            return (
              "<div style='font-size:x-small;text-align:center;padding:2px;color:" +
              slice.color +
              ";'>" +
              label +
              '<br/>' +
              Math.round(slice.percent) +
              '%</div>'
            );
          }, // formatter function
          radius: 1, // radius at which to place the labels (based on full calculated radius if <=1, or hard pixel value)
          background: {
            color: null,
            opacity: 0,
          },
          threshold: 0, // percentage at which to hide the label (i.e. the slice is too narrow)
        },
        combine: {
          threshold: -1, // percentage at which to combine little slices into one larger slice
          color: null, // color to give the new slice (auto-generated if null)
          label: 'Other', // label to give the new slice
        },
        highlight: {
          //color: "#fff",		// will add this functionality once parseColor is available
          opacity: 0.5,
        },
      },
    },
  };

	$.plot.plugins.push({
		init: init,
		options: options,
		name: "pie",
		version: "1.1"
	});

})(jQuery);