var core = require('../core');
/**
* 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.
*
* @class
* @extends Sprite
* @namespace PIXI
* @param text {string} The copy that you would like the text to display
* @param [style] {object} The style parameters
* @param [style.font] {string} default 'bold 20px Arial' The style and size of the font
* @param [style.fill='black'] {String|Number} A canvas fillstyle that will be used on the text e.g 'red', '#00FF00'
* @param [style.align='left'] {string} Alignment for multiline text ('left', 'center' or 'right'), does not affect single line text
* @param [style.stroke] {String|Number} A canvas fillstyle that will be used on the text stroke e.g 'blue', '#FCFF00'
* @param [style.strokeThickness=0] {number} A number that represents the thickness of the stroke. Default is 0 (no stroke)
* @param [style.wordWrap=false] {boolean} Indicates if word wrap should be used
* @param [style.wordWrapWidth=100] {number} The width at which text will wrap, it needs wordWrap to be set to true
* @param [style.dropShadow=false] {boolean} Set a drop shadow for the text
* @param [style.dropShadowColor='#000000'] {string} A fill style to be used on the dropshadow e.g 'red', '#00FF00'
* @param [style.dropShadowAngle=Math.PI/4] {number} Set a angle of the drop shadow
* @param [style.dropShadowDistance=5] {number} Set a distance of the drop shadow
*/
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 of the canvas.
* @member {number}
*/
this.resolution = resolution || core.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;
core.Sprite.call(this, core.Texture.fromCanvas(this.canvas));
this.text = text;
this.style = style;
}
// constructor
Text.prototype = Object.create(core.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 Text#
*/
width: {
get: function ()
{
if (this.dirty)
{
this.updateText();
}
return this.scale.x * this._texture._frame.width;
},
set: function (value)
{
this.scale.x = value / this._texture._frame.width;
this._width = value;
}
},
/**
* The height of the Text, setting this will actually modify the scale to achieve the value set
*
* @member {number}
* @memberof Text#
*/
height: {
get: function ()
{
if (this.dirty)
{
this.updateText();
}
return this.scale.y * this._texture._frame.height;
},
set: function (value)
{
this.scale.y = value / this._texture._frame.height;
this._height = value;
}
},
/**
* Set the style of the text
*
* @param [style] {object} The style parameters
* @param [style.font='bold 20pt Arial'] {string} The style and size of the font
* @param [style.fill='black'] {object} A canvas fillstyle that will be used on the text eg 'red', '#00FF00'
* @param [style.align='left'] {string} Alignment for multiline text ('left', 'center' or 'right'), does not affect single line text
* @param [style.stroke='black'] {string} A canvas fillstyle that will be used on the text stroke eg 'blue', '#FCFF00'
* @param [style.strokeThickness=0] {number} A number that represents the thickness of the stroke. Default is 0 (no stroke)
* @param [style.wordWrap=false] {boolean} Indicates if word wrap should be used
* @param [style.wordWrapWidth=100] {number} The width at which text will wrap
* @param [style.dropShadow=false] {boolean} Set a drop shadow for the text
* @param [style.dropShadowColor='#000000'] {string} A fill style to be used on the dropshadow e.g 'red', '#00FF00'
* @param [style.dropShadowAngle=Math.PI/6] {number} Set a angle of the drop shadow
* @param [style.dropShadowDistance=5] {number} Set a distance of the drop shadow
* @memberof Text#
*/
style: {
get: function ()
{
return this._style;
},
set: function (style)
{
style = style || {};
style.font = style.font || 'bold 20pt Arial';
style.fill = style.fill || 'black';
style.align = style.align || 'left';
style.stroke = style.stroke || 'black'; //provide a default, see: https://github.com/GoodBoyDigital/pixi.js/issues/136
style.strokeThickness = style.strokeThickness || 0;
style.wordWrap = style.wordWrap || false;
style.wordWrapWidth = style.wordWrapWidth || 100;
style.dropShadow = style.dropShadow || false;
style.dropShadowColor = style.dropShadowColor || '#000000';
style.dropShadowAngle = style.dropShadowAngle || Math.PI / 6;
style.dropShadowDistance = style.dropShadowDistance || 5;
this._style = style;
this.dirty = true;
}
},
/**
* Set the copy for the text object. To split a line you can use '\n'.
*
* @param text {string} The copy that you would like the text to display
*/
text: {
get: function()
{
return this._text;
},
set: function (text){
text = text.toString() || ' ';
if (this._text === text)
{
return;
}
this._text = text;
this.dirty = true;
}
}
});
/**
* Renders text and updates it when needed
*
* @private
*/
Text.prototype.updateText = function ()
{
var style = this._style;
this.context.font = style.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(style.font);
for (var i = 0; i < lines.length; i++)
{
var lineWidth = this.context.measureText(lines[i]).width;
lineWidths[i] = lineWidth;
maxLineWidth = Math.max(maxLineWidth, lineWidth);
}
var width = maxLineWidth + style.strokeThickness;
if (style.dropShadow)
{
width += style.dropShadowDistance;
}
this.canvas.width = ( width + this.context.lineWidth ) * this.resolution;
//calculate text height
var lineHeight = fontProperties.fontSize + style.strokeThickness;
var height = lineHeight * lines.length;
if (style.dropShadow)
{
height += style.dropShadowDistance;
}
this.canvas.height = height * 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.font = style.font;
this.context.strokeStyle = style.stroke;
this.context.lineWidth = style.strokeThickness;
this.context.textBaseline = 'alphabetic';
//this.context.lineJoin = 'round';
var linePositionX;
var linePositionY;
if (style.dropShadow)
{
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.context.fillText(lines[i], linePositionX + xShadowOffset, linePositionY + yShadowOffset);
}
}
}
//set canvas text styles
this.context.fillStyle = style.fill;
//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.context.strokeText(lines[i], linePositionX, linePositionY);
}
if (style.fill)
{
this.context.fillText(lines[i], linePositionX, linePositionY);
}
}
this.updateTexture();
};
/**
* Updates texture size based on canvas size
*
* @private
*/
Text.prototype.updateTexture = function ()
{
this._texture.baseTexture.hasLoaded = true;
this._texture.baseTexture.resolution = this.resolution;
this._texture.baseTexture.width = this.canvas.width / this.resolution;
this._texture.baseTexture.height = this.canvas.height / this.resolution;
this._texture.crop.width = this._texture._frame.width = this.canvas.width / this.resolution;
this._texture.crop.height = this._texture._frame.height = this.canvas.height / this.resolution;
this._width = this.canvas.width / this.resolution;
this._height = this.canvas.height / this.resolution;
this._texture.update();
this.dirty = false;
};
/**
* Renders the object using the WebGL renderer
*
* @param renderer {WebGLRenderer}
*/
Text.prototype.renderWebGL = function (renderer)
{
if (this.dirty)
{
this.resolution = renderer.resolution;
this.updateText();
}
core.Sprite.prototype.renderWebGL.call(this, renderer);
};
/**
* Renders the object using the Canvas renderer
*
* @param renderer {CanvasRenderer}
*/
Text.prototype.renderCanvas = function (renderer)
{
if (this.dirty)
{
this.resolution = renderer.resolution;
this.updateText();
}
core.Sprite.prototype.renderCanvas.call(this, renderer);
};
/**
* Calculates the ascent, descent and fontSize of a given fontStyle
*
* @param fontStyle {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('|Mq').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;
//TODO might need a tweak. kind of a temp fix!
properties.descent += 6;
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}
* @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;
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 {Matrix} the transformation matrix of the Text
* @return {Rectangle} the framing rectangle
*/
Text.prototype.getBounds = function (matrix)
{
if (this.dirty)
{
this.updateText();
}
return core.Sprite.prototype.getBounds.call(this, matrix);
};
/**
* Destroys this text object.
*
* @param destroyBaseTexture {boolean} whether to destroy the base texture as well
*/
Text.prototype.destroy = function (destroyBaseTexture)
{
// make sure to reset the the context and canvas.. dont want this hanging around in memory!
this.context = null;
this.canvas = null;
this._texture.destroy(destroyBaseTexture === undefined ? true : destroyBaseTexture);
};
