I was using a modified version of flot.pie with the possibility to add gradients as fillstyle.
So i took the version linked by @Gabo Lato and merged the collision check with my own version.
Here is the result:
(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) {
var canvas = null,
target = null,
options = null,
maxRadius = null,
centerLeft = null,
centerTop = null,
processed = false,
ctx = null;
// interactive variables
var 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) {
var 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) {
var options = plot.getOptions();
if (options.series.pie.show) {
processDatapoints(plot, series, data, datapoints);
}
});
plot.hooks.drawOverlay.push(function(plot, octx) {
var options = plot.getOptions();
if (options.series.pie.show) {
drawOverlay(plot, octx);
}
});
plot.hooks.draw.push(function(plot, newCtx) {
var options = plot.getOptions();
if (options.series.pie.show) {
draw(plot, newCtx);
}
});
function processDatapoints(plot, series, datapoints) {
if (!processed) {
processed = true;
canvas = plot.getCanvas();
target = $(canvas).parent();
options = plot.getOptions();
plot.setData(combine(plot.getData()));
}
}
function combine(data) {
var total = 0,
combined = 0,
numCombined = 0,
color = options.series.pie.combine.color,
newdata = [];
// Fix up the raw data from Flot, ensuring the data is numeric
for (var i = 0; i < data.length; ++i) {
var value = data[i].data;
// If the data is an array, we'll assume that it's a standard
// Flot x-y pair, and are concerned only with the second value.
// Note how we use the original array, rather than creating a
// new one; this is more efficient and preserves any extra data
// that the user may have stored in higher indexes.
if ($.isArray(value) && value.length == 1) {
value = value[0];
}
if ($.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 (var 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 (var i = 0; i < data.length; ++i) {
var value = data[i].data[0][1];
if (value / total <= options.series.pie.combine.threshold) {
combined += value;
numCombined++;
if (!color) {
color = data[i].color;
}
}
}
for (var i = 0; i < data.length; ++i) {
var 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
}
var canvasWidth = plot.getPlaceholder().width(),
canvasHeight = plot.getPlaceholder().height(),
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;
}
var slices = plot.getData(),
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();
//target.prepend("<div class='error'>Could not draw pie with labels contained inside canvas</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() {
var shadowLeft = options.series.pie.shadow.left;
var shadowTop = options.series.pie.shadow.top;
var edge = 10;
var alpha = options.series.pie.shadow.alpha;
var 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 (var 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() {
var startAngle = Math.PI * options.series.pie.startAngle;
var 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();
var currentAngle = startAngle;
for (var 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 (var 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;
ctx.fillStyle = getColorOrGradient(options.series.pie.gradient, plot.height(), 0, color, options.series.pie.gradient.radial && radius);
} 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 getColorOrGradient(spec, bottom, top, defaultColor, radius) {
// Most of this code is copied from the function with the
// same name in jquery.flot.js. I therefore believe that
// this (common) code should be restructured to avoid
// duplication of errors and an increase in maintenance
// efforts. However, I hope that one of the project
// maintainers can do that.
if (typeof spec === 'string') {
return spec;
} else if ((spec === null) || (spec.colors === null)) {
return defaultColor;
} else {
// assume this is a gradient spec; IE currently only
// supports a simple vertical gradient properly, so that's
// what we support too
var gradient;
if (radius) {
gradient = ctx.createRadialGradient(0, 0, 0, 0, 0, radius);
} else {
gradient = ctx.createLinearGradient(0, top, 0, bottom);
}
for (var i = 0, l = spec.colors.length; i < l; ++i) {
var c = spec.colors[i];
if (typeof c !== 'string') {
var co = $.color.parse(defaultColor);
if (c.brightness != null)
co = co.scale('rgb', c.brightness);
if (c.opacity != null)
co.a *= c.opacity;
c = co.toString();
}
gradient.addColorStop(i / (l - 1), c);
}
return gradient;
}
}
function drawLabels() {
var labels = [];
var currentAngle = startAngle;
var radius = options.series.pie.label.radius > 1 ? options.series.pie.label.radius : maxRadius * options.series.pie.label.radius;
for (var 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
var lf = options.legend.labelFormatter, text, plf = options.series.pie.label.formatter;
if (lf) {
text = lf(slice.label, slice);
} else {
text = slice.label;
}
if (plf) {
text = plf(text, slice);
}
var halfAngle = ((startAngle + slice.angle) + startAngle) / 2;
var x = centerLeft + Math.round(Math.cos(halfAngle) * radius);
var y = centerTop + Math.round(Math.sin(halfAngle) * radius) * options.series.pie.tilt;
var html = "<span class='pieLabel' id='pieLabel" + index + "' style='position:absolute;top:" + y + "px;left:" + x + "px;'>" + text + "</span>";
target.append(html);
var label = target.children("#pieLabel" + index);
var labelTop = (y - label.height() / 2);
var labelLeft = (x - label.width() / 2);
label.css("top", labelTop);
label.css("left", labelLeft);
// check to make sure that the label doesn't overlap one of the other labels
var label_pos = getPositions(label);
for(var j=0; j<labels.length; j++)
{
var tmpPos = getPositions(labels[j]);
var horizontalMatch = comparePositions(label_pos[0], tmpPos[0]);
var verticalMatch = comparePositions(label_pos[1], tmpPos[1]);
var match = horizontalMatch && verticalMatch;
if(match)
{
var newTop = tmpPos[1][0] - (label.height() +1 );
label.css('top', newTop);
labelTop = newTop;
}
}
function getPositions(box) {
var $box = $(box);
var pos = $box.position();
var width = $box.width();
var height = $box.height();
return [ [ pos.left, pos.left + width ], [ pos.top, pos.top + height ] ];
}
function comparePositions(p1, p2) {
var x1 = p1[0] < p2[0] ? p1 : p2;
var x2 = p1[0] < p2[0] ? p2 : p1;
return x1[1] > x2[0] || x1[0] === x2[0] ? true : false;
}
labels.push(label);
// 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
var c = options.series.pie.label.background.color;
if (c == null) {
c = slice.color;
}
var 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();
var 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
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) {
for(var c = false, i = -1, l = poly.length, j = l - 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) {
var slices = plot.getData(),
options = plot.getOptions(),
radius = options.series.pie.radius > 1 ? options.series.pie.radius : maxRadius * options.series.pie.radius,
x, y;
for (var i = 0; i < slices.length; ++i) {
var 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.
var p1X = radius * Math.cos(s.startAngle),
p1Y = radius * Math.sin(s.startAngle),
p2X = radius * Math.cos(s.startAngle + s.angle / 4),
p2Y = radius * Math.sin(s.startAngle + s.angle / 4),
p3X = radius * Math.cos(s.startAngle + s.angle / 2),
p3Y = radius * Math.sin(s.startAngle + s.angle / 2),
p4X = radius * Math.cos(s.startAngle + s.angle / 1.5),
p4Y = radius * Math.sin(s.startAngle + s.angle / 1.5),
p5X = radius * Math.cos(s.startAngle + s.angle),
p5Y = radius * Math.sin(s.startAngle + s.angle),
arrPoly = [[0, 0], [p1X, p1Y], [p2X, p2Y], [p3X, p3Y], [p4X, p4Y], [p5X, p5Y]],
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) {
var offset = plot.offset();
var canvasX = parseInt(e.pageX - offset.left);
var canvasY = parseInt(e.pageY - offset.top);
var item = findNearbySlice(canvasX, canvasY);
if (options.grid.autoHighlight) {
// clear auto-highlights
for (var i = 0; i < highlights.length; ++i) {
var 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
var pos = { pageX: e.pageX, pageY: e.pageY };
target.trigger(eventname, [pos, item]);
}
function highlight(s, auto) {
//if (typeof s == "number") {
// s = series[s];
//}
var 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];
//}
var i = indexOfHighlight(s);
if (i != -1) {
highlights.splice(i, 1);
plot.triggerRedrawOverlay();
}
}
function indexOfHighlight(s) {
for (var i = 0; i < highlights.length; ++i) {
var h = highlights[i];
if (h.series == s)
return i;
}
return -1;
}
function drawOverlay(plot, octx) {
var options = plot.getOptions();
var 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 (var 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
var 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
},
gradient: {
radial: true, // boolean, indicating radial or linear gradient
colors: null // e.g., [{opacity: 0.1, brightness: 1.0}, {opacity: 1.0, brightness: 1.0}]
}
}
}
};
$.plot.plugins.push({
init: init,
options: options,
name: "pie",
version: "1.1"
});
})(jQuery);
full Code in fiddle
