CanvasDrawing.js revision cff2b8ec796b9316395b305e8867408a6d7c3549
var SHAPE = "canvasShape",
DOCUMENT = Y.config.doc,
Y_LANG = Y.Lang,
AttributeLite = Y.AttributeLite,
CanvasShape,
CanvasPath,
CanvasRect,
CanvasEllipse,
CanvasCircle,
CanvasPieSlice,
TORGB = Y.Color.toRGB;
/**
* Set of drawing apis for canvas based classes.
*
* @class CanvasDrawing
* @constructor
*/
function CanvasDrawing()
{
}
CanvasDrawing.prototype = {
/**
* Regex expression used for converting hex strings to rgb
*
* @property _reHex
* @private
*/
_reHex: /^#?([0-9A-F]{2})([0-9A-F]{2})([0-9A-F]{2})$/i,
/**
* Parses hex color string and alpha value to rgba
*
* @method _2RGBA
* @private
*/
_2RGBA: function(val, alpha) {
alpha = (alpha !== undefined) ? alpha : 1;
if (this._reHex.exec(val)) {
val = 'rgba(' + [
parseInt(RegExp.$1, 16),
parseInt(RegExp.$2, 16),
parseInt(RegExp.$3, 16)
].join(',') + ',' + alpha + ')';
}
return val;
},
/**
* Converts color to rgb format
*
* @method _2RGB
* @private
*/
_2RGB: function(val) {
return TORGB(val);
},
/**
* Sets the size of the graphics object.
*
* @method setSize
* @param w {Number} width to set for the instance.
* @param h {Number} height to set for the instance.
*/
setSize: function(w, h) {
if(this.get("autoSize"))
{
if(w > this.node.getAttribute("width"))
{
this.node.style.width = w + "px";
this.node.setAttribute("width", w);
}
if(h > this.node.getAttribute("height"))
{
this.node.style.height = h + "px";
this.node.setAttribute("height", h);
}
}
},
/**
* @private
*/
_updateCoords: function(x, y)
{
this._xcoords.push(x);
this._ycoords.push(y);
},
/**
* @private
*/
_clearAndUpdateCoords: function()
{
var x = this._xcoords.pop() || 0,
y = this._ycoords.pop() || 0;
this._updateCoords(x, y);
},
/**
* @private
*/
_updateNodePosition: function()
{
var node = this.get("node"),
x = this.get("x"),
y = this.get("y");
node.style.position = "absolute";
node.style.left = (x + this._left) + "px";
node.style.top = (y + this._top) + "px";
},
/**
* Holds queue of properties for the target canvas.
*
* @property _properties
* @type Object
* @private
*/
_properties: null,
/**
* Adds a method to the drawing queue
*/
_updateDrawingQueue: function(val)
{
this._methods.push(val);
},
/**
* Draws a line segment using the current line style from the current drawing position to the specified x and y coordinates.
*
* @method lineTo
* @param {Number} point1 x-coordinate for the end point.
* @param {Number} point2 y-coordinate for the end point.
*/
lineTo: function(point1, point2, etc)
{
var args = arguments,
i = 0,
len,
x,
y,
wt = this._stroke && this._strokeWeight ? this._strokeWeight : 0;
if(!this._lineToMethods)
{
this._lineToMethods = [];
}
if (typeof point1 === 'string' || typeof point1 === 'number') {
args = [[point1, point2]];
}
len = args.length;
for (; i < len; ++i)
{
if(args[i])
{
x = args[i][0];
y = args[i][1];
this._updateDrawingQueue(["lineTo", x, y]);
this._lineToMethods[this._lineToMethods.length] = this._methods[this._methods.length - 1];
this._trackSize(x - wt, y - wt);
this._trackSize(x + wt, y + wt);
this._updateCoords(x, y);
}
}
this._drawingComplete = false;
return this;
},
/**
* Moves the current drawing position to specified x and y coordinates.
*
* @method moveTo
* @param {Number} x x-coordinate for the end point.
* @param {Number} y y-coordinate for the end point.
*/
moveTo: function(x, y) {
var wt = this._stroke && this._strokeWeight ? this._strokeWeight : 0;
this._updateDrawingQueue(["moveTo", x, y]);
this._trackSize(x - wt, y - wt);
this._trackSize(x + wt, y + wt);
this._updateCoords(x, y);
this._drawingComplete = false;
return this;
},
/**
* Draws a bezier curve.
*
* @method curveTo
* @param {Number} cp1x x-coordinate for the first control point.
* @param {Number} cp1y y-coordinate for the first control point.
* @param {Number} cp2x x-coordinate for the second control point.
* @param {Number} cp2y y-coordinate for the second control point.
* @param {Number} x x-coordinate for the end point.
* @param {Number} y y-coordinate for the end point.
*/
curveTo: function(cp1x, cp1y, cp2x, cp2y, x, y) {
var hiX,
hiY,
loX,
loY;
this._updateDrawingQueue(["bezierCurveTo", cp1x, cp1y, cp2x, cp2y, x, y]);
this._drawingComplete = false;
hiX = Math.max(x, Math.max(cp1x, cp2x));
hiY = Math.max(y, Math.max(cp1y, cp2y));
loX = Math.min(x, Math.min(cp1x, cp2x));
loY = Math.min(y, Math.min(cp1y, cp2y));
this._trackSize(hiX, hiY);
this._trackSize(loX, loY);
this._updateCoords(hiX, hiY);
return this;
},
/**
* Draws a quadratic bezier curve.
*
* @method quadraticCurveTo
* @param {Number} cpx x-coordinate for the control point.
* @param {Number} cpy y-coordinate for the control point.
* @param {Number} x x-coordinate for the end point.
* @param {Number} y y-coordinate for the end point.
*/
quadraticCurveTo: function(cpx, cpy, x, y) {
var hiX,
hiY,
loX,
loY,
wt = this._stroke && this._strokeWeight ? this._strokeWeight : 0;
this._updateDrawingQueue(["quadraticCurveTo", cpx, cpy, x, y]);
this._drawingComplete = false;
hiX = Math.max(x, cpx);
hiY = Math.max(y, cpy);
loX = Math.min(x, cpx);
loY = Math.min(y, cpy);
this._trackSize(hiX + wt, hiY + wt);
this._trackSize(loX - wt, loY - wt);
this._updateCoords(hiX, hiY);
return this;
},
/**
* Draws a circle.
*
* @method drawCircle
* @param {Number} x y-coordinate
* @param {Number} y x-coordinate
* @param {Number} r radius
*/
drawCircle: function(x, y, radius) {
var startAngle = 0,
endAngle = 2 * Math.PI,
wt = this._stroke & this._strokeWeight ? this._strokeWeight : 0,
circum = radius * 2;
circum += wt;
this._drawingComplete = false;
this._trackSize(x + circum, y + circum);
this._trackSize(x - wt, y - wt);
this._updateCoords(x, y);
this._updateDrawingQueue(["arc", x + radius, y + radius, radius, startAngle, endAngle, false]);
return this;
},
/**
* Draws an ellipse.
*
* @method drawEllipse
* @param {Number} x x-coordinate
* @param {Number} y y-coordinate
* @param {Number} w width
* @param {Number} h height
*/
drawEllipse: function(x, y, w, h) {
var l = 8,
theta = -(45/180) * Math.PI,
angle = 0,
angleMid,
radius = w/2,
yRadius = h/2,
i = 0,
centerX = x + radius,
centerY = y + yRadius,
ax, ay, bx, by, cx, cy,
wt = this._stroke && this._strokeWeight ? this._strokeWeight : 0;
ax = centerX + Math.cos(0) * radius;
ay = centerY + Math.sin(0) * yRadius;
this.moveTo(ax, ay);
for(; i < l; i++)
{
angle += theta;
angleMid = angle - (theta / 2);
bx = centerX + Math.cos(angle) * radius;
by = centerY + Math.sin(angle) * yRadius;
cx = centerX + Math.cos(angleMid) * (radius / Math.cos(theta / 2));
cy = centerY + Math.sin(angleMid) * (yRadius / Math.cos(theta / 2));
this._updateDrawingQueue(["quadraticCurveTo", cx, cy, bx, by]);
}
this._trackSize(x + w + wt, y + h + wt);
this._trackSize(x - wt, y - wt);
this._updateCoords(x, y);
return this;
},
/**
* Draws a rectangle.
*
* @method drawRect
* @param {Number} x x-coordinate
* @param {Number} y y-coordinate
* @param {Number} w width
* @param {Number} h height
*/
drawRect: function(x, y, w, h) {
var wt = this._stroke && this._strokeWeight ? this._strokeWeight : 0;
this._drawingComplete = false;
this._updateDrawingQueue(["moveTo", x, y]);
this._updateDrawingQueue(["lineTo", x + w, y]);
this._updateDrawingQueue(["lineTo", x + w, y + h]);
this._updateDrawingQueue(["lineTo", x, y + h]);
this._updateDrawingQueue(["lineTo", x, y]);
this._trackSize(x - wt, y - wt);
this._trackSize(x + w + wt, y + h + wt);
return this;
},
/**
* Draws a rectangle with rounded corners.
*
* @method drawRect
* @param {Number} x x-coordinate
* @param {Number} y y-coordinate
* @param {Number} w width
* @param {Number} h height
* @param {Number} ew width of the ellipse used to draw the rounded corners
* @param {Number} eh height of the ellipse used to draw the rounded corners
*/
drawRoundRect: function(x, y, w, h, ew, eh) {
var wt = this._stroke && this._strokeWeight ? this._strokeWeight : 0;
this._drawingComplete = false;
this._updateDrawingQueue(["moveTo", x, y + eh]);
this._updateDrawingQueue(["lineTo", x, y + h - eh]);
this._updateDrawingQueue(["quadraticCurveTo", x, y + h, x + ew, y + h]);
this._updateDrawingQueue(["lineTo", x + w - ew, y + h]);
this._updateDrawingQueue(["quadraticCurveTo", x + w, y + h, x + w, y + h - eh]);
this._updateDrawingQueue(["lineTo", x + w, y + eh]);
this._updateDrawingQueue(["quadraticCurveTo", x + w, y, x + w - ew, y]);
this._updateDrawingQueue(["lineTo", x + ew, y]);
this._updateDrawingQueue(["quadraticCurveTo", x, y, x, y + eh]);
this._trackSize(x - wt, y - wt);
this._trackSize(x + w + wt, y + h + wt);
this._updateCoords(w, h);
return this;
},
/**
* @private
* Draws a wedge.
*
* @param x x component of the wedge's center point
* @param y y component of the wedge's center point
* @param startAngle starting angle in degrees
* @param arc sweep of the wedge. Negative values draw clockwise.
* @param radius radius of wedge. If [optional] yRadius is defined, then radius is the x radius.
* @param yRadius [optional] y radius for wedge.
*/
drawWedge: function(x, y, startAngle, arc, radius, yRadius)
{
var segs,
segAngle,
theta,
angle,
angleMid,
ax,
ay,
bx,
by,
cx,
cy,
i = 0;
yRadius = yRadius || radius;
this._drawingComplete = false;
// move to x,y position
this._updateDrawingQueue(["moveTo", x, y]);
yRadius = yRadius || radius;
// limit sweep to reasonable numbers
if(Math.abs(arc) > 360)
{
arc = 360;
}
// First we calculate how many segments are needed
// for a smooth arc.
segs = Math.ceil(Math.abs(arc) / 45);
// Now calculate the sweep of each segment.
segAngle = arc / segs;
// The math requires radians rather than degrees. To convert from degrees
// use the formula (degrees/180)*Math.PI to get radians.
theta = -(segAngle / 180) * Math.PI;
// convert angle startAngle to radians
angle = (startAngle / 180) * Math.PI;
// draw the curve in segments no larger than 45 degrees.
if(segs > 0)
{
// draw a line from the center to the start of the curve
ax = x + Math.cos(startAngle / 180 * Math.PI) * radius;
ay = y + Math.sin(startAngle / 180 * Math.PI) * yRadius;
this.lineTo(ax, ay);
// Loop for drawing curve segments
for(; i < segs; ++i)
{
angle += theta;
angleMid = angle - (theta / 2);
bx = x + Math.cos(angle) * radius;
by = y + Math.sin(angle) * yRadius;
cx = x + Math.cos(angleMid) * (radius / Math.cos(theta / 2));
cy = y + Math.sin(angleMid) * (yRadius / Math.cos(theta / 2));
this._updateDrawingQueue(["quadraticCurveTo", cx, cy, bx, by]);
}
// close the wedge by drawing a line to the center
this._updateDrawingQueue(["lineTo", x, y]);
}
this._trackSize(0 , 0);
this._trackSize(radius * 2, radius * 2);
return this;
},
/**
* Completes a drawing operation.
*
* @method end
*/
end: function() {
this._paint();
return this;
},
/**
* Returns a linear gradient fill
*
* @method _getLinearGradient
* @private
*/
_getLinearGradient: function() {
var isNumber = Y.Lang.isNumber,
fill = this.get("fill"),
stops = fill.stops,
opacity,
color,
stop,
i = 0,
len = stops.length,
gradient,
x = 0,
y = 0,
w = this.get("width"),
h = this.get("height"),
r = fill.rotation,
x1, x2, y1, y2,
cx = x + w/2,
cy = y + h/2,
offset,
radCon = Math.PI/180,
tanRadians = parseFloat(parseFloat(Math.tan(r * radCon)).toFixed(8));
if(Math.abs(tanRadians) * w/2 >= h/2)
{
if(r < 180)
{
y1 = y;
y2 = y + h;
}
else
{
y1 = y + h;
y2 = y;
}
x1 = cx - ((cy - y1)/tanRadians);
x2 = cx - ((cy - y2)/tanRadians);
}
else
{
if(r > 90 && r < 270)
{
x1 = x + w;
x2 = x;
}
else
{
x1 = x;
x2 = x + w;
}
y1 = ((tanRadians * (cx - x1)) - cy) * -1;
y2 = ((tanRadians * (cx - x2)) - cy) * -1;
}
gradient = this._context.createLinearGradient(x1, y1, x2, y2);
for(; i < len; ++i)
{
stop = stops[i];
opacity = stop.opacity;
color = stop.color;
offset = stop.offset;
if(isNumber(opacity))
{
opacity = Math.max(0, Math.min(1, opacity));
color = this._2RGBA(color, opacity);
}
else
{
color = this._2RGB(color);
}
offset = stop.offset || i/(len - 1);
gradient.addColorStop(offset, color);
}
return gradient;
},
/**
* Returns a radial gradient fill
*
* @method _getRadialGradient
* @private
*/
_getRadialGradient: function() {
var isNumber = Y.Lang.isNumber,
fill = this.get("fill"),
r = fill.r,
fx = fill.fx,
fy = fill.fy,
stops = fill.stops,
opacity,
color,
stop,
i = 0,
len = stops.length,
gradient,
x = 0,
y = 0,
w = this.get("width"),
h = this.get("height"),
x1, x2, y1, y2, r2,
xc, yc, xn, yn, d,
offset,
ratio,
stopMultiplier;
xc = x + w/2;
yc = y + h/2;
x1 = w * fx;
y1 = h * fy;
x2 = x + w/2;
y2 = y + h/2;
r2 = w * r;
d = Math.sqrt( Math.pow(Math.abs(xc - x1), 2) + Math.pow(Math.abs(yc - y1), 2) );
if(d >= r2)
{
ratio = d/r2;
//hack. gradient won't show if it is exactly on the edge of the arc
if(ratio === 1)
{
ratio = 1.01;
}
xn = (x1 - xc)/ratio;
yn = (y1 - yc)/ratio;
xn = xn > 0 ? Math.floor(xn) : Math.ceil(xn);
yn = yn > 0 ? Math.floor(yn) : Math.ceil(yn);
x1 = xc + xn;
y1 = yc + yn;
}
//If the gradient radius is greater than the circle's, adjusting the radius stretches the gradient properly.
//If the gradient radius is less than the circle's, adjusting the radius of the gradient will not work.
//Instead, adjust the color stops to reflect the smaller radius.
if(r >= 0.5)
{
gradient = this._context.createRadialGradient(x1, y1, r, x2, y2, r * w);
stopMultiplier = 1;
}
else
{
gradient = this._context.createRadialGradient(x1, y1, r, x2, y2, w/2);
stopMultiplier = r * 2;
}
for(; i < len; ++i)
{
stop = stops[i];
opacity = stop.opacity;
color = stop.color;
offset = stop.offset;
if(isNumber(opacity))
{
opacity = Math.max(0, Math.min(1, opacity));
color = this._2RGBA(color, opacity);
}
else
{
color = this._2RGB(color);
}
offset = stop.offset || i/(len - 1);
offset *= stopMultiplier;
if(offset <= 1)
{
gradient.addColorStop(offset, color);
}
}
return gradient;
},
/**
* Clears all values
*
* @method _initProps
* @private
*/
_initProps: function() {
this._methods = [];
this._lineToMethods = [];
this._xcoords = [0];
this._ycoords = [0];
this._width = 0;
this._height = 0;
this._left = 0;
this._top = 0;
this._right = 0;
this._bottom = 0;
},
/**
* @private
*/
_drawingComplete: false,
/**
* Creates canvas element
*
* @method _createGraphic
* @private
*/
_createGraphic: function(config) {
var graphic = Y.config.doc.createElement('canvas');
return graphic;
},
/**
* Updates the size of the graphics object
*
* @method _trackSize
* @param {Number} w width
* @param {Number} h height
* @private
*/
_trackSize: function(w, h) {
if (w > this._right) {
this._right = w;
}
if(w < this._left)
{
this._left = w;
}
if (h < this._top)
{
this._top = h;
}
if (h > this._bottom)
{
this._bottom = h;
}
this._width = this._right - this._left;
this._height = this._bottom - this._top;
}
};
Y.CanvasDrawing = CanvasDrawing;