/* eslint max-depth: [2, 8] */
import Sprite from '../sprites/Sprite';
import Texture from '../textures/Texture';
import { Rectangle } from '../math';
import { sign } from '../utils';
import { TEXT_GRADIENT } from '../const';
import settings from '../settings';
import TextStyle from './TextStyle';
import TextMetrics from './TextMetrics';
import trimCanvas from '../utils/trimCanvas';
const defaultDestroyOptions = {
texture: true,
children: false,
baseTexture: true,
};
/**
* A Text Object will create a line or multiple lines of text. To split a line you can use '\n' in your text string,
* or add a wordWrap property set to true and and wordWrapWidth property with a value in the style object.
*
* A Text can be created directly from a string and a style object
*
* ```js
* let text = new PIXI.Text('This is a PixiJS text',{fontFamily : 'Arial', fontSize: 24, fill : 0xff1010, align : 'center'});
* ```
*
* @class
* @extends PIXI.Sprite
* @memberof PIXI
*/
export default class Text extends Sprite
{
/**
* @param {string} text - The string that you would like the text to display
* @param {object|PIXI.TextStyle} [style] - The style parameters
* @param {HTMLCanvasElement} [canvas] - The canvas element for drawing text
*/
constructor(text, style, canvas)
{
canvas = canvas || document.createElement('canvas');
canvas.width = 3;
canvas.height = 3;
const texture = Texture.from(canvas, settings.SCALE_MODE, 'text');
texture.orig = new Rectangle();
texture.trim = new Rectangle();
super(texture);
// base texture is already automatically added to the cache, now adding the actual texture
Texture.addToCache(this._texture, this._texture.baseTexture.textureCacheIds[0]);
/**
* The canvas element that everything is drawn to
*
* @member {HTMLCanvasElement}
*/
this.canvas = canvas;
/**
* The canvas 2d context that everything is drawn with
* @member {CanvasRenderingContext2D}
*/
this.context = this.canvas.getContext('2d');
/**
* The resolution / device pixel ratio of the canvas. This is set automatically by the renderer.
* @member {number}
* @default 1
*/
this.resolution = settings.RESOLUTION;
/**
* Private tracker for the current text.
*
* @member {string}
* @private
*/
this._text = null;
/**
* Private tracker for the current style.
*
* @member {object}
* @private
*/
this._style = null;
/**
* Private listener to track style changes.
*
* @member {Function}
* @private
*/
this._styleListener = null;
/**
* Private tracker for the current font.
*
* @member {string}
* @private
*/
this._font = '';
this.text = text;
this.style = style;
this.localStyleID = -1;
}
/**
* Renders text and updates it when needed.
*
* @private
* @param {boolean} respectDirty - Whether to abort updating the text if the Text isn't dirty and the function is called.
*/
updateText(respectDirty)
{
const style = this._style;
// check if style has changed..
if (this.localStyleID !== style.styleID)
{
this.dirty = true;
this.localStyleID = style.styleID;
}
if (!this.dirty && respectDirty)
{
return;
}
this._font = this._style.toFontString();
const context = this.context;
const measured = TextMetrics.measureText(this._text, this._style, this._style.wordWrap, this.canvas);
const width = measured.width;
const height = measured.height;
const lines = measured.lines;
const lineHeight = measured.lineHeight;
const lineWidths = measured.lineWidths;
const maxLineWidth = measured.maxLineWidth;
const fontProperties = measured.fontProperties;
this.canvas.width = Math.ceil((width + (style.padding * 2)) * this.resolution);
this.canvas.height = Math.ceil((height + (style.padding * 2)) * this.resolution);
context.scale(this.resolution, this.resolution);
context.clearRect(0, 0, this.canvas.width, this.canvas.height);
context.font = this._font;
context.strokeStyle = style.stroke;
context.lineWidth = style.strokeThickness;
context.textBaseline = style.textBaseline;
context.lineJoin = style.lineJoin;
context.miterLimit = style.miterLimit;
let linePositionX;
let linePositionY;
if (style.dropShadow)
{
context.fillStyle = style.dropShadowColor;
context.globalAlpha = style.dropShadowAlpha;
context.shadowBlur = style.dropShadowBlur;
if (style.dropShadowBlur > 0)
{
context.shadowColor = style.dropShadowColor;
}
const xShadowOffset = Math.cos(style.dropShadowAngle) * style.dropShadowDistance;
const yShadowOffset = Math.sin(style.dropShadowAngle) * style.dropShadowDistance;
for (let i = 0; i < lines.length; i++)
{
linePositionX = style.strokeThickness / 2;
linePositionY = ((style.strokeThickness / 2) + (i * lineHeight)) + fontProperties.ascent;
if (style.align === 'right')
{
linePositionX += maxLineWidth - lineWidths[i];
}
else if (style.align === 'center')
{
linePositionX += (maxLineWidth - lineWidths[i]) / 2;
}
if (style.fill)
{
this.drawLetterSpacing(
lines[i],
linePositionX + xShadowOffset + style.padding, linePositionY + yShadowOffset + style.padding
);
if (style.stroke && style.strokeThickness)
{
context.strokeStyle = style.dropShadowColor;
this.drawLetterSpacing(
lines[i],
linePositionX + xShadowOffset + style.padding, linePositionY + yShadowOffset + style.padding,
true
);
context.strokeStyle = style.stroke;
}
}
}
}
// reset the shadow blur and alpha that was set by the drop shadow, for the regular text
context.shadowBlur = 0;
context.globalAlpha = 1;
// set canvas text styles
context.fillStyle = this._generateFillStyle(style, lines);
// draw lines line by line
for (let i = 0; i < lines.length; i++)
{
linePositionX = style.strokeThickness / 2;
linePositionY = ((style.strokeThickness / 2) + (i * lineHeight)) + fontProperties.ascent;
if (style.align === 'right')
{
linePositionX += maxLineWidth - lineWidths[i];
}
else if (style.align === 'center')
{
linePositionX += (maxLineWidth - lineWidths[i]) / 2;
}
if (style.stroke && style.strokeThickness)
{
this.drawLetterSpacing(
lines[i],
linePositionX + style.padding,
linePositionY + style.padding,
true
);
}
if (style.fill)
{
this.drawLetterSpacing(
lines[i],
linePositionX + style.padding,
linePositionY + style.padding
);
}
}
this.updateTexture();
}
/**
* Render the text with letter-spacing.
* @param {string} text - The text to draw
* @param {number} x - Horizontal position to draw the text
* @param {number} y - Vertical position to draw the text
* @param {boolean} [isStroke=false] - Is this drawing for the outside stroke of the
* text? If not, it's for the inside fill
* @private
*/
drawLetterSpacing(text, x, y, isStroke = false)
{
const style = this._style;
// letterSpacing of 0 means normal
const letterSpacing = style.letterSpacing;
if (letterSpacing === 0)
{
if (isStroke)
{
this.context.strokeText(text, x, y);
}
else
{
this.context.fillText(text, x, y);
}
return;
}
const characters = String.prototype.split.call(text, '');
let currentPosition = x;
let index = 0;
let current = '';
while (index < text.length)
{
current = characters[index++];
if (isStroke)
{
this.context.strokeText(current, currentPosition, y);
}
else
{
this.context.fillText(current, currentPosition, y);
}
currentPosition += this.context.measureText(current).width + letterSpacing;
}
}
/**
* Updates texture size based on canvas size
*
* @private
*/
updateTexture()
{
const canvas = this.canvas;
if (this._style.trim)
{
const trimmed = trimCanvas(canvas);
canvas.width = trimmed.width;
canvas.height = trimmed.height;
this.context.putImageData(trimmed.data, 0, 0);
}
const texture = this._texture;
const style = this._style;
const padding = style.trim ? 0 : style.padding;
const baseTexture = texture.baseTexture;
baseTexture.hasLoaded = true;
baseTexture.resolution = this.resolution;
baseTexture.width = canvas.width / this.resolution;
baseTexture.height = canvas.height / this.resolution;
texture.trim.width = texture._frame.width = canvas.width / this.resolution;
texture.trim.height = texture._frame.height = canvas.height / this.resolution;
texture.trim.x = -padding;
texture.trim.y = -padding;
texture.orig.width = texture._frame.width - (padding * 2);
texture.orig.height = texture._frame.height - (padding * 2);
// call sprite onTextureUpdate to update scale if _width or _height were set
this._onTextureUpdate();
texture.baseTexture.update();// emit('update', texture.baseTexture);
this.dirty = false;
}
/**
* Renders the object using the WebGL renderer
*
* @param {PIXI.WebGLRenderer} renderer - The renderer
*/
renderWebGL(renderer)
{
if (this.resolution !== renderer.resolution)
{
this.resolution = renderer.resolution;
this.dirty = true;
}
this.updateText(true);
super.renderWebGL(renderer);
}
/**
* Renders the object using the Canvas renderer
*
* @private
* @param {PIXI.CanvasRenderer} renderer - The renderer
*/
_renderCanvas(renderer)
{
if (this.resolution !== renderer.resolution)
{
this.resolution = renderer.resolution;
this.dirty = true;
}
this.updateText(true);
super._renderCanvas(renderer);
}
/**
* Gets the local bounds of the text object.
*
* @param {Rectangle} rect - The output rectangle.
* @return {Rectangle} The bounds.
*/
getLocalBounds(rect)
{
this.updateText(true);
return super.getLocalBounds.call(this, rect);
}
/**
* calculates the bounds of the Text as a rectangle. The bounds calculation takes the worldTransform into account.
*/
_calculateBounds()
{
this.updateText(true);
this.calculateVertices();
// if we have already done this on THIS frame.
this._bounds.addQuad(this.vertexData);
}
/**
* Method to be called upon a TextStyle change.
* @private
*/
_onStyleChange()
{
this.dirty = true;
}
/**
* Generates the fill style. Can automatically generate a gradient based on the fill style being an array
*
* @private
* @param {object} style - The style.
* @param {string[]} lines - The lines of text.
* @return {string|number|CanvasGradient} The fill style
*/
_generateFillStyle(style, lines)
{
if (!Array.isArray(style.fill))
{
return style.fill;
}
// cocoon on canvas+ cannot generate textures, so use the first colour instead
if (navigator.isCocoonJS)
{
return style.fill[0];
}
// the gradient will be evenly spaced out according to how large the array is.
// ['#FF0000', '#00FF00', '#0000FF'] would created stops at 0.25, 0.5 and 0.75
let gradient;
let totalIterations;
let currentIteration;
let stop;
const width = this.canvas.width / this.resolution;
const height = this.canvas.height / this.resolution;
// make a copy of the style settings, so we can manipulate them later
const fill = style.fill.slice();
const fillGradientStops = style.fillGradientStops.slice();
// wanting to evenly distribute the fills. So an array of 4 colours should give fills of 0.25, 0.5 and 0.75
if (!fillGradientStops.length)
{
const lengthPlus1 = fill.length + 1;
for (let i = 1; i < lengthPlus1; ++i)
{
fillGradientStops.push(i / lengthPlus1);
}
}
// stop the bleeding of the last gradient on the line above to the top gradient of the this line
// by hard defining the first gradient colour at point 0, and last gradient colour at point 1
fill.unshift(style.fill[0]);
fillGradientStops.unshift(0);
fill.push(style.fill[style.fill.length - 1]);
fillGradientStops.push(1);
if (style.fillGradientType === TEXT_GRADIENT.LINEAR_VERTICAL)
{
// start the gradient at the top center of the canvas, and end at the bottom middle of the canvas
gradient = this.context.createLinearGradient(width / 2, 0, width / 2, height);
// we need to repeat the gradient so that each individual line of text has the same vertical gradient effect
// ['#FF0000', '#00FF00', '#0000FF'] over 2 lines would create stops at 0.125, 0.25, 0.375, 0.625, 0.75, 0.875
totalIterations = (fill.length + 1) * lines.length;
currentIteration = 0;
for (let i = 0; i < lines.length; i++)
{
currentIteration += 1;
for (let j = 0; j < fill.length; j++)
{
if (typeof fillGradientStops[j] === 'number')
{
stop = (fillGradientStops[j] / lines.length) + (i / lines.length);
}
else
{
stop = currentIteration / totalIterations;
}
gradient.addColorStop(stop, fill[j]);
currentIteration++;
}
}
}
else
{
// start the gradient at the center left of the canvas, and end at the center right of the canvas
gradient = this.context.createLinearGradient(0, height / 2, width, height / 2);
// can just evenly space out the gradients in this case, as multiple lines makes no difference
// to an even left to right gradient
totalIterations = fill.length + 1;
currentIteration = 1;
for (let i = 0; i < fill.length; i++)
{
if (typeof fillGradientStops[i] === 'number')
{
stop = fillGradientStops[i];
}
else
{
stop = currentIteration / totalIterations;
}
gradient.addColorStop(stop, fill[i]);
currentIteration++;
}
}
return gradient;
}
/**
* Destroys this text object.
* Note* Unlike a Sprite, a Text object will automatically destroy its baseTexture and texture as
* the majority of the time the texture will not be shared with any other Sprites.
*
* @param {object|boolean} [options] - Options parameter. A boolean will act as if all options
* have been set to that value
* @param {boolean} [options.children=false] - if set to true, all the children will have their
* destroy method called as well. 'options' will be passed on to those calls.
* @param {boolean} [options.texture=true] - Should it destroy the current texture of the sprite as well
* @param {boolean} [options.baseTexture=true] - Should it destroy the base texture of the sprite as well
*/
destroy(options)
{
if (typeof options === 'boolean')
{
options = { children: options };
}
options = Object.assign({}, defaultDestroyOptions, options);
super.destroy(options);
// make sure to reset the the context and canvas.. dont want this hanging around in memory!
this.context = null;
this.canvas = null;
this._style = null;
}
/**
* The width of the Text, setting this will actually modify the scale to achieve the value set
*
* @member {number}
*/
get width()
{
this.updateText(true);
return Math.abs(this.scale.x) * this._texture.orig.width;
}
set width(value) // eslint-disable-line require-jsdoc
{
this.updateText(true);
const s = sign(this.scale.x) || 1;
this.scale.x = s * value / this._texture.orig.width;
this._width = value;
}
/**
* The height of the Text, setting this will actually modify the scale to achieve the value set
*
* @member {number}
*/
get height()
{
this.updateText(true);
return Math.abs(this.scale.y) * this._texture.orig.height;
}
set height(value) // eslint-disable-line require-jsdoc
{
this.updateText(true);
const s = sign(this.scale.y) || 1;
this.scale.y = s * value / this._texture.orig.height;
this._height = value;
}
/**
* Set the style of the text. Set up an event listener to listen for changes on the style
* object and mark the text as dirty.
*
* @member {object|PIXI.TextStyle}
*/
get style()
{
return this._style;
}
set style(style) // eslint-disable-line require-jsdoc
{
style = style || {};
if (style instanceof TextStyle)
{
this._style = style;
}
else
{
this._style = new TextStyle(style);
}
this.localStyleID = -1;
this.dirty = true;
}
/**
* Set the copy for the text object. To split a line you can use '\n'.
*
* @member {string}
*/
get text()
{
return this._text;
}
set text(text) // eslint-disable-line require-jsdoc
{
text = String(text === '' || text === null || text === undefined ? ' ' : text);
if (this._text === text)
{
return;
}
this._text = text;
this.dirty = true;
}
}
