Reduce size of on-canvas legend

This commit is contained in:
Evert Timberg 2016-05-04 19:28:22 -04:00
parent eb126fdd27
commit eeae8a6a16

View File

@ -3,6 +3,7 @@
module.exports = function(Chart) {
var helpers = Chart.helpers;
var noop = helpers.noop;
Chart.defaults.global.legend = {
@ -14,13 +15,14 @@ module.exports = function(Chart) {
// a callback that will handle
onClick: function(e, legendItem) {
var index = legendItem.datasetIndex;
var meta = this.chart.getDatasetMeta(index);
var ci = this.chart;
var meta = ci.getDatasetMeta(index);
// See controller.isDatasetVisible comment
meta.hidden = meta.hidden === null? !this.chart.data.datasets[index].hidden : null;
meta.hidden = meta.hidden === null? !ci.data.datasets[index].hidden : null;
// We hid a dataset ... rerender the chart
this.chart.update();
ci.update();
},
labels: {
@ -75,7 +77,7 @@ module.exports = function(Chart) {
// Any function defined here is inherited by all legend types.
// Any function can be extended by the legend type
beforeUpdate: helpers.noop,
beforeUpdate: noop,
update: function(maxWidth, maxHeight, margins) {
// Update Lifecycle - Probably don't want to ever extend or overwrite this function ;)
@ -104,11 +106,11 @@ module.exports = function(Chart) {
return this.minSize;
},
afterUpdate: helpers.noop,
afterUpdate: noop,
//
beforeSetDimensions: helpers.noop,
beforeSetDimensions: noop,
setDimensions: function() {
// Set the unconstrained dimension before label rotation
if (this.isHorizontal()) {
@ -136,90 +138,92 @@ module.exports = function(Chart) {
height: 0
};
},
afterSetDimensions: helpers.noop,
afterSetDimensions: noop,
//
beforeBuildLabels: helpers.noop,
beforeBuildLabels: noop,
buildLabels: function() {
this.legendItems = this.options.labels.generateLabels.call(this, this.chart);
if(this.options.reverse){
this.legendItems.reverse();
}
},
afterBuildLabels: helpers.noop,
afterBuildLabels: noop,
//
beforeFit: helpers.noop,
beforeFit: noop,
fit: function() {
var opts = this.options;
var labelOpts = opts.labels;
var display = opts.display;
var ctx = this.ctx;
var fontSize = helpers.getValueOrDefault(this.options.labels.fontSize, Chart.defaults.global.defaultFontSize);
var fontStyle = helpers.getValueOrDefault(this.options.labels.fontStyle, Chart.defaults.global.defaultFontStyle);
var fontFamily = helpers.getValueOrDefault(this.options.labels.fontFamily, Chart.defaults.global.defaultFontFamily);
var labelFont = helpers.fontString(fontSize, fontStyle, fontFamily);
var globalDefault = Chart.defaults.global,
itemOrDefault = helpers.getValueOrDefault,
fontSize = itemOrDefault(labelOpts.fontSize, globalDefault.defaultFontSize),
fontStyle = itemOrDefault(labelOpts.fontStyle, globalDefault.defaultFontStyle),
fontFamily = itemOrDefault(labelOpts.fontFamily, globalDefault.defaultFontFamily),
labelFont = helpers.fontString(fontSize, fontStyle, fontFamily);
// Reset hit boxes
this.legendHitBoxes = [];
var hitboxes = this.legendHitBoxes = [];
// Width
if (this.isHorizontal()) {
this.minSize.width = this.maxWidth; // fill all the width
} else {
this.minSize.width = this.options.display ? 10 : 0;
}
var minSize = this.minSize;
var isHorizontal = this.isHorizontal();
// height
if (this.isHorizontal()) {
this.minSize.height = this.options.display ? 10 : 0;
if (isHorizontal) {
minSize.width = this.maxWidth; // fill all the width
minSize.height = display ? 10 : 0;
} else {
this.minSize.height = this.maxHeight; // fill all the height
minSize.width = display ? 10 : 0;
minSize.height = this.maxHeight; // fill all the height
}
// Increase sizes here
if (this.options.display) {
if (this.isHorizontal()) {
if (display) {
if (isHorizontal) {
// Labels
// Width of each line of legend boxes. Labels wrap onto multiple lines when there are too many to fit on one
this.lineWidths = [0];
var totalHeight = this.legendItems.length ? fontSize + (this.options.labels.padding) : 0;
var lineWidths = this.lineWidths = [0];
var totalHeight = this.legendItems.length ? fontSize + (labelOpts.padding) : 0;
ctx.textAlign = "left";
ctx.textBaseline = 'top';
ctx.font = labelFont;
helpers.each(this.legendItems, function(legendItem, i) {
var width = this.options.labels.boxWidth + (fontSize / 2) + ctx.measureText(legendItem.text).width;
if (this.lineWidths[this.lineWidths.length - 1] + width + this.options.labels.padding >= this.width) {
totalHeight += fontSize + (this.options.labels.padding);
this.lineWidths[this.lineWidths.length] = this.left;
var width = labelOpts.boxWidth + (fontSize / 2) + ctx.measureText(legendItem.text).width;
if (lineWidths[lineWidths.length - 1] + width + labelOpts.padding >= this.width) {
totalHeight += fontSize + (labelOpts.padding);
lineWidths[lineWidths.length] = this.left;
}
// Store the hitbox width and height here. Final position will be updated in `draw`
this.legendHitBoxes[i] = {
hitboxes[i] = {
left: 0,
top: 0,
width: width,
height: fontSize
};
this.lineWidths[this.lineWidths.length - 1] += width + this.options.labels.padding;
lineWidths[lineWidths.length - 1] += width + labelOpts.padding;
}, this);
this.minSize.height += totalHeight;
minSize.height += totalHeight;
} else {
// TODO vertical
}
}
this.width = this.minSize.width;
this.height = this.minSize.height;
this.width = minSize.width;
this.height = minSize.height;
},
afterFit: helpers.noop,
afterFit: noop,
// Shared Methods
isHorizontal: function() {
@ -228,19 +232,26 @@ module.exports = function(Chart) {
// Actualy draw the legend on the canvas
draw: function() {
if (this.options.display) {
var ctx = this.ctx;
var cursor = {
x: this.left + ((this.width - this.lineWidths[0]) / 2),
y: this.top + this.options.labels.padding,
line: 0
};
var opts = this.options;
var labelOpts = opts.labels;
var globalDefault = Chart.defaults.global,
lineDefault = globalDefault.elements.line,
legendWidth = this.width,
lineWidths = this.lineWidths;
var fontColor = helpers.getValueOrDefault(this.options.labels.fontColor, Chart.defaults.global.defaultFontColor);
var fontSize = helpers.getValueOrDefault(this.options.labels.fontSize, Chart.defaults.global.defaultFontSize);
var fontStyle = helpers.getValueOrDefault(this.options.labels.fontStyle, Chart.defaults.global.defaultFontStyle);
var fontFamily = helpers.getValueOrDefault(this.options.labels.fontFamily, Chart.defaults.global.defaultFontFamily);
var labelFont = helpers.fontString(fontSize, fontStyle, fontFamily);
if (opts.display) {
var ctx = this.ctx,
cursor = {
x: this.left + ((legendWidth - lineWidths[0]) / 2),
y: this.top + labelOpts.padding,
line: 0
},
itemOrDefault = helpers.getValueOrDefault,
fontColor = itemOrDefault(labelOpts.fontColor, globalDefault.defaultFontColor),
fontSize = itemOrDefault(labelOpts.fontSize, globalDefault.defaultFontSize),
fontStyle = itemOrDefault(labelOpts.fontStyle, globalDefault.defaultFontStyle),
fontFamily = itemOrDefault(labelOpts.fontFamily, globalDefault.defaultFontFamily),
labelFont = helpers.fontString(fontSize, fontStyle, fontFamily);
// Horizontal
if (this.isHorizontal()) {
@ -252,57 +263,58 @@ module.exports = function(Chart) {
ctx.fillStyle = fontColor; // render in correct colour
ctx.font = labelFont;
helpers.each(this.legendItems, function(legendItem, i) {
var textWidth = ctx.measureText(legendItem.text).width;
var width = this.options.labels.boxWidth + (fontSize / 2) + textWidth;
var boxWidth = labelOpts.boxWidth,
hitboxes = this.legendHitBoxes;
if (cursor.x + width >= this.width) {
cursor.y += fontSize + (this.options.labels.padding);
helpers.each(this.legendItems, function(legendItem, i) {
var textWidth = ctx.measureText(legendItem.text).width,
width = boxWidth + (fontSize / 2) + textWidth,
x = cursor.x,
y = cursor.y;
if (x + width >= legendWidth) {
cursor.y += fontSize + (labelOpts.padding);
cursor.line++;
cursor.x = this.left + ((this.width - this.lineWidths[cursor.line]) / 2);
cursor.x = this.left + ((legendWidth - lineWidths[cursor.line]) / 2);
}
// Set the ctx for the box
ctx.save();
var itemOrDefault = function(item, defaulVal) {
return item !== undefined ? item : defaulVal;
};
ctx.fillStyle = itemOrDefault(legendItem.fillStyle, Chart.defaults.global.defaultColor);
ctx.lineCap = itemOrDefault(legendItem.lineCap, Chart.defaults.global.elements.line.borderCapStyle);
ctx.lineDashOffset = itemOrDefault(legendItem.lineDashOffset, Chart.defaults.global.elements.line.borderDashOffset);
ctx.lineJoin = itemOrDefault(legendItem.lineJoin, Chart.defaults.global.elements.line.borderJoinStyle);
ctx.lineWidth = itemOrDefault(legendItem.lineWidth, Chart.defaults.global.elements.line.borderWidth);
ctx.strokeStyle = itemOrDefault(legendItem.strokeStyle, Chart.defaults.global.defaultColor);
ctx.fillStyle = itemOrDefault(legendItem.fillStyle, globalDefault.defaultColor);
ctx.lineCap = itemOrDefault(legendItem.lineCap, lineDefault.borderCapStyle);
ctx.lineDashOffset = itemOrDefault(legendItem.lineDashOffset, lineDefault.borderDashOffset);
ctx.lineJoin = itemOrDefault(legendItem.lineJoin, lineDefault.borderJoinStyle);
ctx.lineWidth = itemOrDefault(legendItem.lineWidth, lineDefault.borderWidth);
ctx.strokeStyle = itemOrDefault(legendItem.strokeStyle, globalDefault.defaultColor);
if (ctx.setLineDash) {
// IE 9 and 10 do not support line dash
ctx.setLineDash(itemOrDefault(legendItem.lineDash, Chart.defaults.global.elements.line.borderDash));
ctx.setLineDash(itemOrDefault(legendItem.lineDash, lineDefault.borderDash));
}
// Draw the box
ctx.strokeRect(cursor.x, cursor.y, this.options.labels.boxWidth, fontSize);
ctx.fillRect(cursor.x, cursor.y, this.options.labels.boxWidth, fontSize);
ctx.strokeRect(x, y, boxWidth, fontSize);
ctx.fillRect(x, y, boxWidth, fontSize);
ctx.restore();
this.legendHitBoxes[i].left = cursor.x;
this.legendHitBoxes[i].top = cursor.y;
hitboxes[i].left = x;
hitboxes[i].top = y;
// Fill the actual label
ctx.fillText(legendItem.text, this.options.labels.boxWidth + (fontSize / 2) + cursor.x, cursor.y);
ctx.fillText(legendItem.text, boxWidth + (fontSize / 2) + x, y);
if (legendItem.hidden) {
// Strikethrough the text if hidden
ctx.beginPath();
ctx.lineWidth = 2;
ctx.moveTo(this.options.labels.boxWidth + (fontSize / 2) + cursor.x, cursor.y + (fontSize / 2));
ctx.lineTo(this.options.labels.boxWidth + (fontSize / 2) + cursor.x + textWidth, cursor.y + (fontSize / 2));
ctx.moveTo(boxWidth + (fontSize / 2) + x, y + (fontSize / 2));
ctx.lineTo(boxWidth + (fontSize / 2) + x + textWidth, y + (fontSize / 2));
ctx.stroke();
}
cursor.x += width + (this.options.labels.padding);
cursor.x += width + (labelOpts.padding);
}, this);
} else {
@ -312,17 +324,21 @@ module.exports = function(Chart) {
// Handle an event
handleEvent: function(e) {
var position = helpers.getRelativePosition(e, this.chart.chart);
var position = helpers.getRelativePosition(e, this.chart.chart),
x = position.x,
y = position.y,
opts = this.options;
if (position.x >= this.left && position.x <= this.right && position.y >= this.top && position.y <= this.bottom) {
if (x >= this.left && x <= this.right && y >= this.top && y <= this.bottom) {
// See if we are touching one of the dataset boxes
for (var i = 0; i < this.legendHitBoxes.length; ++i) {
var hitBox = this.legendHitBoxes[i];
var lh = this.legendHitBoxes;
for (var i = 0; i < lh.length; ++i) {
var hitBox = lh[i];
if (position.x >= hitBox.left && position.x <= hitBox.left + hitBox.width && position.y >= hitBox.top && position.y <= hitBox.top + hitBox.height) {
if (x >= hitBox.left && x <= hitBox.left + hitBox.width && y >= hitBox.top && y <= hitBox.top + hitBox.height) {
// Touching an element
if (this.options.onClick) {
this.options.onClick.call(this, e, this.legendItems[i]);
if (opts.onClick) {
opts.onClick.call(this, e, this.legendItems[i]);
}
break;
}