let util = require('../../../../util');
|
|
|
|
class Label {
|
|
constructor(body,options) {
|
|
this.body = body;
|
|
|
|
this.baseSize = undefined;
|
|
this.setOptions(options);
|
|
this.size = {top: 0, left: 0, width: 0, height: 0, yLine: 0}; // could be cached
|
|
}
|
|
|
|
setOptions(options, allowDeletion = false) {
|
|
this.options = options;
|
|
|
|
if (options.label !== undefined) {
|
|
this.labelDirty = true;
|
|
}
|
|
|
|
if (options.font !== undefined) {
|
|
Label.parseOptions(this.options.font, options, allowDeletion);
|
|
if (typeof options.font === 'string') {
|
|
this.baseSize = this.options.font.size;
|
|
}
|
|
else if (typeof options.font === 'object') {
|
|
if (options.font.size !== undefined) {
|
|
this.baseSize = options.font.size;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static parseOptions(parentOptions, newOptions, allowDeletion = false) {
|
|
if (typeof newOptions.font === 'string') {
|
|
let newOptionsArray = newOptions.font.split(" ");
|
|
parentOptions.size = newOptionsArray[0].replace("px",'');
|
|
parentOptions.face = newOptionsArray[1];
|
|
parentOptions.color = newOptionsArray[2];
|
|
}
|
|
else if (typeof newOptions.font === 'object') {
|
|
util.fillIfDefined(parentOptions, newOptions.font, allowDeletion);
|
|
}
|
|
parentOptions.size = Number(parentOptions.size);
|
|
}
|
|
|
|
|
|
/**
|
|
* Main function. This is called from anything that wants to draw a label.
|
|
* @param ctx
|
|
* @param x
|
|
* @param y
|
|
* @param selected
|
|
* @param baseline
|
|
*/
|
|
draw(ctx, x, y, selected, baseline = 'middle') {
|
|
// if no label, return
|
|
if (this.options.label === undefined)
|
|
return;
|
|
|
|
// check if we have to render the label
|
|
let viewFontSize = this.options.font.size * this.body.view.scale;
|
|
if (this.options.label && viewFontSize < this.options.scaling.label.drawThreshold - 1)
|
|
return;
|
|
|
|
// update the size cache if required
|
|
this.calculateLabelSize(ctx, selected, x, y, baseline);
|
|
|
|
// create the fontfill background
|
|
this._drawBackground(ctx);
|
|
// draw text
|
|
this._drawText(ctx, selected, x, y, baseline);
|
|
}
|
|
|
|
/**
|
|
* Draws the label background
|
|
* @param {CanvasRenderingContext2D} ctx
|
|
* @private
|
|
*/
|
|
_drawBackground(ctx) {
|
|
if (this.options.font.background !== undefined && this.options.font.background !== "none") {
|
|
ctx.fillStyle = this.options.font.background;
|
|
|
|
let lineMargin = 2;
|
|
|
|
switch (this.options.font.align) {
|
|
case 'middle':
|
|
ctx.fillRect(-this.size.width * 0.5, -this.size.height * 0.5, this.size.width, this.size.height);
|
|
break;
|
|
case 'top':
|
|
ctx.fillRect(-this.size.width * 0.5, -(this.size.height + lineMargin), this.size.width, this.size.height);
|
|
break;
|
|
case 'bottom':
|
|
ctx.fillRect(-this.size.width * 0.5, lineMargin, this.size.width, this.size.height);
|
|
break
|
|
default:
|
|
ctx.fillRect(this.size.left, this.size.top, this.size.width, this.size.height);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
*
|
|
* @param ctx
|
|
* @param x
|
|
* @param baseline
|
|
* @private
|
|
*/
|
|
_drawText(ctx, selected, x, y, baseline = 'middle') {
|
|
let fontSize = this.options.font.size;
|
|
let viewFontSize = fontSize * this.body.view.scale;
|
|
// this ensures that there will not be HUGE letters on screen by setting an upper limit on the visible text size (regardless of zoomLevel)
|
|
if (viewFontSize >= this.options.scaling.label.maxVisible) {
|
|
fontSize = Number(this.options.scaling.label.maxVisible) / this.body.view.scale;
|
|
}
|
|
|
|
let yLine = this.size.yLine;
|
|
let [fontColor, strokeColor] = this._getColor(viewFontSize);
|
|
[x, yLine] = this._setAlignment(ctx, x, yLine, baseline);
|
|
|
|
// configure context for drawing the text
|
|
ctx.font = (selected ? 'bold ' : '') + fontSize + "px " + this.options.font.face;
|
|
ctx.fillStyle = fontColor;
|
|
ctx.textAlign = 'center';
|
|
|
|
// set the strokeWidth
|
|
if (this.options.font.strokeWidth > 0) {
|
|
ctx.lineWidth = this.options.font.strokeWidth;
|
|
ctx.strokeStyle = strokeColor;
|
|
ctx.lineJoin = 'round';
|
|
}
|
|
|
|
// draw the text
|
|
for (let i = 0; i < this.lineCount; i++) {
|
|
if (this.options.font.strokeWidth > 0) {
|
|
ctx.strokeText(this.lines[i], x, yLine);
|
|
}
|
|
ctx.fillText(this.lines[i], x, yLine);
|
|
yLine += fontSize;
|
|
}
|
|
}
|
|
|
|
_setAlignment(ctx, x, yLine, baseline) {
|
|
// check for label alignment (for edges)
|
|
// TODO: make alignment for nodes
|
|
if (this.options.font.align !== 'horizontal') {
|
|
x = 0;
|
|
yLine = 0;
|
|
|
|
let lineMargin = 2;
|
|
if (this.options.font.align === 'top') {
|
|
ctx.textBaseline = 'alphabetic';
|
|
yLine -= 2 * lineMargin; // distance from edge, required because we use alphabetic. Alphabetic has less difference between browsers
|
|
}
|
|
else if (this.options.font.align === 'bottom') {
|
|
ctx.textBaseline = 'hanging';
|
|
yLine += 2 * lineMargin;// distance from edge, required because we use hanging. Hanging has less difference between browsers
|
|
}
|
|
else {
|
|
ctx.textBaseline = 'middle';
|
|
}
|
|
}
|
|
else {
|
|
ctx.textBaseline = baseline;
|
|
}
|
|
|
|
return [x,yLine];
|
|
}
|
|
|
|
/**
|
|
* fade in when relative scale is between threshold and threshold - 1.
|
|
* If the relative scale would be smaller than threshold -1 the draw function would have returned before coming here.
|
|
*
|
|
* @param viewFontSize
|
|
* @returns {*[]}
|
|
* @private
|
|
*/
|
|
_getColor(viewFontSize) {
|
|
let fontColor = this.options.font.color || '#000000';
|
|
let strokeColor = this.options.font.strokeColor || '#ffffff';
|
|
if (viewFontSize <= this.options.scaling.label.drawThreshold) {
|
|
let opacity = Math.max(0, Math.min(1, 1 - (this.options.scaling.label.drawThreshold - viewFontSize)));
|
|
fontColor = util.overrideOpacity(fontColor, opacity);
|
|
strokeColor = util.overrideOpacity(strokeColor, opacity);
|
|
}
|
|
return [fontColor, strokeColor];
|
|
}
|
|
|
|
|
|
/**
|
|
*
|
|
* @param ctx
|
|
* @param selected
|
|
* @returns {{width: number, height: number}}
|
|
*/
|
|
getTextSize(ctx, selected = false) {
|
|
let size = {
|
|
width: this._processLabel(ctx,selected),
|
|
height: this.options.font.size * this.lineCount,
|
|
lineCount: this.lineCount
|
|
};
|
|
return size;
|
|
}
|
|
|
|
|
|
/**
|
|
*
|
|
* @param ctx
|
|
* @param selected
|
|
* @param x
|
|
* @param y
|
|
* @param baseline
|
|
*/
|
|
calculateLabelSize(ctx, selected, x = 0, y = 0, baseline = 'middle') {
|
|
if (this.labelDirty === true) {
|
|
this.size.width = this._processLabel(ctx,selected);
|
|
}
|
|
this.size.height = this.options.font.size * this.lineCount;
|
|
this.size.left = x - this.size.width * 0.5;
|
|
this.size.top = y - this.size.height * 0.5;
|
|
this.size.yLine = y + (1 - this.lineCount) * 0.5 * this.options.font.size;
|
|
if (baseline === "hanging") {
|
|
this.size.top += 0.5 * this.options.font.size;
|
|
this.size.top += 4; // distance from node, required because we use hanging. Hanging has less difference between browsers
|
|
this.size.yLine += 4; // distance from node
|
|
}
|
|
|
|
this.labelDirty = false;
|
|
}
|
|
|
|
|
|
/**
|
|
* This calculates the width as well as explodes the label string and calculates the amount of lines.
|
|
* @param ctx
|
|
* @param selected
|
|
* @returns {number}
|
|
* @private
|
|
*/
|
|
_processLabel(ctx,selected) {
|
|
let width = 0;
|
|
let lines = [''];
|
|
let lineCount = 0;
|
|
if (this.options.label !== undefined) {
|
|
lines = String(this.options.label).split('\n');
|
|
lineCount = lines.length;
|
|
ctx.font = (selected ? 'bold ' : '') + this.options.font.size + "px " + this.options.font.face;
|
|
width = ctx.measureText(lines[0]).width;
|
|
for (let i = 1; i < lineCount; i++) {
|
|
let lineWidth = ctx.measureText(lines[i]).width;
|
|
width = lineWidth > width ? lineWidth : width;
|
|
}
|
|
}
|
|
this.lines = lines;
|
|
this.lineCount = lineCount;
|
|
|
|
return width;
|
|
}
|
|
}
|
|
|
|
export default Label;
|