var Sprite = require('../sprites/Sprite'),
Texture = require('../textures/Texture'),
math = require('../math'),
utils = require('../utils'),
CONST = require('../const'),
TextStyle = require('./TextStyle');
/**
* 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
* var text = new PIXI.Text('This is a pixi text',{font : '24px Arial', fill : 0xff1010, align : 'center'});
* ```
*
* @class
* @extends PIXI.Sprite
* @memberof PIXI
* @param text {string} The string that you would like the text to display
* @param [style] {object|PIXI.TextStyle} The style parameters
* @param [resolution=1] {number} The current resolution / device pixel ratio of the canvas
*/
function Text(text, style, resolution)
{
/**
* The canvas element that everything is drawn to
*
* @member {HTMLCanvasElement}
*/
this.canvas = document.createElement('canvas');
/**
* The canvas 2d context that everything is drawn with
* @member {HTMLCanvasElement}
*/
this.context = this.canvas.getContext('2d');
/**
* The resolution / device pixel ratio of the canvas
* @member {number}
* @default 1
*/
this.resolution = resolution || CONST.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 = '';
var texture = Texture.fromCanvas(this.canvas);
texture.orig = new math.Rectangle();
texture.trim = new math.Rectangle();
Sprite.call(this, texture);
this.text = text;
this.style = style;
}
// constructor
Text.prototype = Object.create(Sprite.prototype);
Text.prototype.constructor = Text;
module.exports = Text;
Text.fontPropertiesCache = {};
Text.fontPropertiesCanvas = document.createElement('canvas');
Text.fontPropertiesContext = Text.fontPropertiesCanvas.getContext('2d');
Object.defineProperties(Text.prototype, {
/**
* The width of the Text, setting this will actually modify the scale to achieve the value set
*
* @member {number}
* @memberof PIXI.Text#
*/
width: {
get: function ()
{
this.updateText(true);
return Math.abs(this.scale.x) * this.texture.orig.width;
},
set: function (value)
{
this.updateText(true);
var sign = utils.sign(this.scale.x) || 1;
this.scale.x = sign * 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}
* @memberof PIXI.Text#
*/
height: {
get: function ()
{
this.updateText(true);
return Math.abs(this.scale.y) * this._texture.orig.height;
},
set: function (value)
{
this.updateText(true);
var sign = utils.sign(this.scale.x) || 1;
this.scale.x = sign * value / this.texture.orig.width;
this._width = 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}
* @memberof PIXI.Text#
*/
style: {
get: function ()
{
return this._style;
},
set: function (style)
{
if (this._style)
{
this._style.off(CONST.TEXT_STYLE_CHANGED, this._onStyleChange, this);
}
style = style || {};
if (style instanceof TextStyle)
{
this._style = style;
}
else
{
this._style = new TextStyle(style);
}
this._style.on(CONST.TEXT_STYLE_CHANGED, this._onStyleChange, this);
this.dirty = true;
}
},
/**
* Set the copy for the text object. To split a line you can use '\n'.
*
* @member {string}
* @memberof PIXI.Text#
*/
text: {
get: function()
{
return this._text;
},
set: function (text){
text = text || ' ';
text = text.toString();
if (this._text === text)
{
return;
}
this._text = text;
this.dirty = true;
}
}
});
/**
* Renders text and updates it when needed
* @param respectDirty {boolean} Whether to abort updating the text if the Text isn't dirty and the function is called.
* @private
*/
Text.prototype.updateText = function (respectDirty)
{
if (!this.dirty && respectDirty) {
return;
}
var style = this._style;
// build canvas api font setting from invididual components. Convert a numeric style.fontSize to px
var fontSizeString = (typeof style.fontSize === 'number') ? style.fontSize + 'px' : style.fontSize;
this._font = style.fontStyle + ' ' + style.fontVariant + ' ' + style.fontWeight + ' ' + fontSizeString + ' ' + style.fontFamily;
this.context.font = this._font;
// word wrap
// preserve original text
var outputText = style.wordWrap ? this.wordWrap(this._text) : this._text;
// split text into lines
var lines = outputText.split(/(?:\r\n|\r|\n)/);
// calculate text width
var lineWidths = new Array(lines.length);
var maxLineWidth = 0;
var fontProperties = this.determineFontProperties(this._font);
var i;
for (i = 0; i < lines.length; i++)
{
var lineWidth = this.context.measureText(lines[i]).width + ((lines[i].length - 1) * style.letterSpacing);
lineWidths[i] = lineWidth;
maxLineWidth = Math.max(maxLineWidth, lineWidth);
}
var width = maxLineWidth + style.strokeThickness;
if (style.dropShadow)
{
width += style.dropShadowDistance;
}
this.canvas.width = Math.ceil( ( width + this.context.lineWidth ) * this.resolution );
// calculate text height
var lineHeight = this.style.lineHeight || fontProperties.fontSize + style.strokeThickness;
var height = lineHeight * lines.length;
if (style.dropShadow)
{
height += style.dropShadowDistance;
}
this.canvas.height = Math.ceil( ( height + this._style.padding * 2 ) * this.resolution );
this.context.scale( this.resolution, this.resolution);
if (navigator.isCocoonJS)
{
this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
}
//this.context.fillStyle="#FF0000";
//this.context.fillRect(0, 0, this.canvas.width, this.canvas.height);
this.context.font = this._font;
this.context.strokeStyle = style.stroke;
this.context.lineWidth = style.strokeThickness;
this.context.textBaseline = style.textBaseline;
this.context.lineJoin = style.lineJoin;
this.context.miterLimit = style.miterLimit;
var linePositionX;
var linePositionY;
if (style.dropShadow)
{
if (style.dropShadowBlur > 0) {
this.context.shadowColor = style.dropShadowColor;
this.context.shadowBlur = style.dropShadowBlur;
} else {
this.context.fillStyle = style.dropShadowColor;
}
var xShadowOffset = Math.cos(style.dropShadowAngle) * style.dropShadowDistance;
var yShadowOffset = Math.sin(style.dropShadowAngle) * style.dropShadowDistance;
for (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, linePositionY + yShadowOffset + style.padding);
if (style.stroke && style.strokeThickness)
{
this.context.strokeStyle = style.dropShadowColor;
this.drawLetterSpacing(lines[i], linePositionX + xShadowOffset, linePositionY + yShadowOffset + style.padding, true);
this.context.strokeStyle = style.stroke;
}
}
}
}
//set canvas text styles
this.context.fillStyle = this._generateFillStyle(style, lines);
//draw lines line by line
for (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, linePositionY + style.padding, true);
}
if (style.fill)
{
this.drawLetterSpacing(lines[i], linePositionX, 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 - Is this drawing for the outside stroke of the text? If not, it's for the inside fill
* @private
*/
Text.prototype.drawLetterSpacing = function(text, x, y, isStroke)
{
var style = this._style;
// letterSpacing of 0 means normal
var letterSpacing = style.letterSpacing;
if (letterSpacing === 0)
{
if (isStroke)
{
this.context.strokeText(text, x, y);
}
else
{
this.context.fillText(text, x, y);
}
return;
}
var characters = String.prototype.split.call(text, ''),
index = 0,
current,
currentPosition = x;
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
*/
Text.prototype.updateTexture = function ()
{
var texture = this._texture;
var style = this._style;
texture.baseTexture.hasLoaded = true;
texture.baseTexture.resolution = this.resolution;
texture.baseTexture.realWidth = this.canvas.width;
texture.baseTexture.realHeight = this.canvas.height;
texture.baseTexture.width = this.canvas.width / this.resolution;
texture.baseTexture.height = this.canvas.height / this.resolution;
texture.trim.width = texture._frame.width = this.canvas.width / this.resolution;
texture.trim.height = texture._frame.height = this.canvas.height / this.resolution;
texture.trim.x = 0;
texture.trim.y = -style.padding;
texture.orig.width = texture._frame.width;
texture.orig.height = texture._frame.height - style.padding*2;
//call sprite onTextureUpdate to update scale if _width or _height were set
this._onTextureUpdate();
texture.baseTexture.emit('update', texture.baseTexture);
this.dirty = false;
};
/**
* Renders the object using the WebGL renderer
*
* @param renderer {PIXI.WebGLRenderer} The renderer
*/
Text.prototype.renderWebGL = function (renderer)
{
this.updateText(true);
Sprite.prototype.renderWebGL.call(this, renderer);
};
/**
* Renders the object using the Canvas renderer
*
* @param renderer {PIXI.CanvasRenderer} The renderer
* @private
*/
Text.prototype._renderCanvas = function (renderer)
{
this.updateText(true);
Sprite.prototype._renderCanvas.call(this, renderer);
};
/**
* Calculates the ascent, descent and fontSize of a given fontStyle
*
* @param fontStyle {string} String representing the style of the font
* @return {Object} Font properties object
* @private
*/
Text.prototype.determineFontProperties = function (fontStyle)
{
var properties = Text.fontPropertiesCache[fontStyle];
if (!properties)
{
properties = {};
var canvas = Text.fontPropertiesCanvas;
var context = Text.fontPropertiesContext;
context.font = fontStyle;
var width = Math.ceil(context.measureText('|MÉq').width);
var baseline = Math.ceil(context.measureText('M').width);
var height = 2 * baseline;
baseline = baseline * 1.4 | 0;
canvas.width = width;
canvas.height = height;
context.fillStyle = '#f00';
context.fillRect(0, 0, width, height);
context.font = fontStyle;
context.textBaseline = 'alphabetic';
context.fillStyle = '#000';
context.fillText('|MÉq', 0, baseline);
var imagedata = context.getImageData(0, 0, width, height).data;
var pixels = imagedata.length;
var line = width * 4;
var i, j;
var idx = 0;
var stop = false;
// ascent. scan from top to bottom until we find a non red pixel
for (i = 0; i < baseline; i++)
{
for (j = 0; j < line; j += 4)
{
if (imagedata[idx + j] !== 255)
{
stop = true;
break;
}
}
if (!stop)
{
idx += line;
}
else
{
break;
}
}
properties.ascent = baseline - i;
idx = pixels - line;
stop = false;
// descent. scan from bottom to top until we find a non red pixel
for (i = height; i > baseline; i--)
{
for (j = 0; j < line; j += 4)
{
if (imagedata[idx + j] !== 255)
{
stop = true;
break;
}
}
if (!stop)
{
idx -= line;
}
else
{
break;
}
}
properties.descent = i - baseline;
properties.fontSize = properties.ascent + properties.descent;
Text.fontPropertiesCache[fontStyle] = properties;
}
return properties;
};
/**
* Applies newlines to a string to have it optimally fit into the horizontal
* bounds set by the Text object's wordWrapWidth property.
*
* @param text {string} String to apply word wrapping to
* @return {string} New string with new lines applied where required
* @private
*/
Text.prototype.wordWrap = function (text)
{
// Greedy wrapping algorithm that will wrap words as the line grows longer
// than its horizontal bounds.
var result = '';
var lines = text.split('\n');
var wordWrapWidth = this._style.wordWrapWidth;
for (var i = 0; i < lines.length; i++)
{
var spaceLeft = wordWrapWidth;
var words = lines[i].split(' ');
for (var j = 0; j < words.length; j++)
{
var wordWidth = this.context.measureText(words[j]).width;
if (this._style.breakWords && wordWidth > wordWrapWidth)
{
// Word should be split in the middle
var characters = words[j].split('');
for (var c = 0; c < characters.length; c++)
{
var characterWidth = this.context.measureText(characters[c]).width;
if (characterWidth > spaceLeft)
{
result += '\n' + characters[c];
spaceLeft = wordWrapWidth - characterWidth;
}
else
{
if (c === 0)
{
result += ' ';
}
result += characters[c];
spaceLeft -= characterWidth;
}
}
}
else
{
var wordWidthWithSpace = wordWidth + this.context.measureText(' ').width;
if (j === 0 || wordWidthWithSpace > spaceLeft)
{
// Skip printing the newline if it's the first word of the line that is
// greater than the word wrap width.
if (j > 0)
{
result += '\n';
}
result += words[j];
spaceLeft = wordWrapWidth - wordWidth;
}
else
{
spaceLeft -= wordWidthWithSpace;
result += ' ' + words[j];
}
}
}
if (i < lines.length-1)
{
result += '\n';
}
}
return result;
};
/**
* Returns the bounds of the Text as a rectangle. The bounds calculation takes the worldTransform into account.
*
* @param matrix {PIXI.Matrix} the transformation matrix of the Text
* @return {PIXI.Rectangle} the framing rectangle
*/
Text.prototype.getBounds = function (matrix)
{
this.updateText(true);
return Sprite.prototype.getBounds.call(this, matrix);
};
/**
* Method to be called upon a TextStyle change.
* @private
*/
Text.prototype._onStyleChange = function ()
{
this.dirty = true;
};
/**
* Generates the fill style. Can automatically generate a gradient based on the fill style being an array
* @return string|Number|CanvasGradient
* @private
*/
Text.prototype._generateFillStyle = function (style, lines)
{
if (!Array.isArray(style.fill))
{
return style.fill;
}
else
{
// 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
var i;
var gradient;
var totalIterations;
var currentIteration;
var stop;
if (style.fillGradientType === CONST.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(this.canvas.width / 2, 0, this.canvas.width / 2, this.canvas.height);
// we need to repeat the gradient so that each invididual 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 = ( style.fill.length + 1 ) * lines.length;
currentIteration = 0;
for (i = 0; i < lines.length; i++)
{
currentIteration += 1;
for (var j = 0; j < style.fill.length; j++)
{
stop = (currentIteration / totalIterations);
gradient.addColorStop(stop, style.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, this.canvas.height / 2, this.canvas.width, this.canvas.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 = style.fill.length + 1;
currentIteration = 1;
for (i = 0; i < style.fill.length; i++)
{
stop = currentIteration / totalIterations;
gradient.addColorStop(stop, style.fill[i]);
currentIteration++;
}
}
return gradient;
}
};
/**
* Destroys this text object.
*
* @param [options] {object|boolean} Options parameter. A boolean will act as if all options have been set to that value
* @param [options.children=false] {boolean} if set to true, all the children will have their destroy
* method called as well. 'options' will be passed on to those calls.
* @param [options.texture=false] {boolean} Should it destroy the current texture of the sprite as well
* @param [options.baseTexture=false] {boolean} Should it destroy the base texture of the sprite as well
*/
Text.prototype.destroy = function (options)
{
Sprite.prototype.destroy.call(this, 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.off(CONST.TEXT_STYLE_CHANGED, this._onStyleChange, this);
this._style = null;
};
