CanvasShape Class
yui3/src/graphics/js/CanvasShape.js:1
<a href="http://www.w3.org/TR/html5/the-canvas-element.html">Canvas</a> implementation of the <a href="Shape.html">Shape
</a> class.
CanvasShape
is not intended to be used directly. Instead, use the <a href="Shape.html">Shape
</a> class.
If the browser lacks <a href="http://www.w3.org/TR/SVG/">SVG</a> capabilities but has
<a href="http://www.w3.org/TR/html5/the-canvas-element.html">Canvas</a> capabilities, the <a href="Shape.html">Shape
</a>
class will point to the CanvasShape
class.
Index
Methods
- _addTransform
- _closePath
- _draw
- _drawDashedLine
- _getContentRect
- _getDefaultFill
- _getDefaultStroke
- _initialize
- _parsePathData
- _setFillProps
- _setGraphic
- _strokeAndFill
- _strokeChangeHandler
- _updateHandler
- _updateTransform
- addClass
- compareTo
- contains
- createNode
- destroy
- destroy
- getBounds
- getXY
- init
- on
- removeClass
- rotate
- scale
- set
- setXY
- skew
- skewX
- skewY
- test
- toFront
- toFront
- translate
- translateX
- translateY
Properties
Methods
_addTransform
-
type
-
args
Adds a transform to the shape.
Parameters:
-
type
StringThe transform being applied.
-
args
ArrayThe arguments for the transform.
_closePath
()
private
Completes a shape or drawing
_draw
()
private
Updates the shape.
_drawDashedLine
-
xStart
-
yStart
-
xEnd
-
yEnd
Draws a dashed line between two points.
_getContentRect
-
w
-
h
-
x
-
y
Calculates the bounding box for the shape.
_getDefaultFill
()
private
Value function for fill attribute
Returns:
Object
_getDefaultStroke
()
private
Value function for stroke attribute
Returns:
Object
_initialize
()
private
Initializes the shape
_parsePathData
-
val
Parses path data string and call mapped methods.
Parameters:
-
val
StringThe path data
_setFillProps
-
fill
Adds a fill to the shape node.
Parameters:
-
fill
ObjectProperties of the
fill
attribute.
_setGraphic
-
render
Set the Graphic instance for the shape.
_strokeAndFill
-
Reference
Completes a stroke and/or fill operation on the context.
Parameters:
-
Reference
Contextto the context element of the canvas instance.
_strokeChangeHandler
-
stroke
Adds a stroke to the shape node.
Parameters:
-
stroke
ObjectProperties of the
stroke
attribute.
_updateHandler
()
private
Updates Shape
based on attribute changes.
_updateTransform
()
private
Applies all transforms.
addClass
-
className
Add a class name to each node.
Parameters:
-
className
Stringthe class name to add to the node's class attribute
compareTo
-
refNode
Compares nodes to determine if they match. Node instances can be compared to each other and/or HTMLElements.
Parameters:
-
refNode
HTMLElement | NodeThe reference node to compare to the node.
Returns:
True if the nodes match, false if they do not.
contains
-
needle
Determines whether the node is an ancestor of another HTML element in the DOM hierarchy.
Parameters:
-
needle
CanvasShape | HTMLElementThe possible node or descendent
Returns:
Boolean Whether or not this shape is the needle or its ancestor.
createNode
()
private
Creates the dom node for the shape.
Returns:
HTMLElement
destroy
()
Destroys the shape instance.
destroy
()
protected
Implementation for shape destruction
getBounds
()
Returns the bounds for a shape.
Calculates the a new bounding box from the original corner coordinates (base on size and position) and the transform matrix. The calculated bounding box is used by the graphic instance to calculate its viewBox.
Returns:
Object
getXY
()
Gets the current position of the node in page coordinates.
Returns:
Array The XY position of the shape.
init
()
protected
Init method, invoked during construction.
Calls initializer
method.
on
-
type
-
callback
Overrides default on
method. Checks to see if its a dom interaction event. If so,
return an event attached to the node
element. If not, return the normal functionality.
Parameters:
-
type
Stringevent type
-
callback
Objectfunction
removeClass
-
className
Removes a class name from each node.
Parameters:
-
className
Stringthe class name to remove from the node's class attribute
rotate
-
deg
Rotates the shape clockwise around it transformOrigin.
Parameters:
-
deg
NumberThe degree of the rotation.
set
-
name
-
value
Sets the value of an attribute.
Parameters:
-
name
String | ObjectThe name of the attribute. Alternatively, an object of key value pairs can be passed in to set multiple attributes at once.
-
value
AnyThe value to set the attribute to. This value is ignored if an object is received as the name param.
setXY
-
Contains
Set the position of the shape in page coordinates, regardless of how the node is positioned.
Parameters:
-
Contains
ArrayX & Y values for new position (coordinates are page-based)
skew
-
x
-
y
Skews the shape around the x-axis and y-axis.
test
-
selector
Test if the supplied node matches the supplied selector.
Parameters:
-
selector
StringThe CSS selector to test against.
Returns:
Boolean Wheter or not the shape matches the selector.
toFront
()
Places the shape above all other shapes.
toFront
()
Places the shape underneath all other shapes.
translate
-
x
-
y
Specifies a 2d translation.
translateX
-
x
Translates the shape along the x-axis. When translating x and y coordinates,
use the translate
method.
Parameters:
-
x
NumberThe value to translate.
translateY
-
y
Performs a translate on the y-coordinate. When translating x and y coordinates,
use the translate
method.
Parameters:
-
y
NumberThe value to translate.
Properties
_transform
String
private
Storage for the transform attribute.
Attributes
data
String
Represents an SVG Path string. This will be parsed and added to shape's API to represent the SVG data across all implementations. Note that when using VML or SVG implementations, part of this content will be added to the DOM using respective VML/SVG attributes. If your content comes from an untrusted source, you will need to ensure that no malicious code is included in that content.
fill
Object
Contains information about the fill of the shape.
<dl>
<dt>color</dt><dd>The color of the fill.</dd>
<dt>opacity</dt><dd>Number between 0 and 1 that indicates the opacity of the fill. The default value is 1.</dd>
<dt>type</dt><dd>Type of fill.
<dl>
<dt>solid</dt><dd>Solid single color fill. (default)</dd>
<dt>linear</dt><dd>Linear gradient fill.</dd>
<dt>radial</dt><dd>Radial gradient fill.</dd>
</dl>
</dd>
</dl>
<p>If a linear
or radial
is specified as the fill type. The following additional property is used:
<dl>
<dt>stops</dt><dd>An array of objects containing the following properties:
<dl>
<dt>color</dt><dd>The color of the stop.</dd>
<dt>opacity</dt><dd>Number between 0 and 1 that indicates the opacity of the stop. The default value is 1.
Note: No effect for IE 6 - 8</dd>
<dt>offset</dt><dd>Number between 0 and 1 indicating where the color stop is positioned.</dd>
</dl>
</dd>
<p>Linear gradients also have the following property:</p>
<dt>rotation</dt><dd>Linear gradients flow left to right by default. The rotation property allows you to change the
flow by rotation. (e.g. A rotation of 180 would make the gradient pain from right to left.)</dd>
<p>Radial gradients have the following additional properties:</p>
<dt>r</dt><dd>Radius of the gradient circle.</dd>
<dt>fx</dt><dd>Focal point x-coordinate of the gradient.</dd>
<dt>fy</dt><dd>Focal point y-coordinate of the gradient.</dd>
</dl>
<p>The corresponding SVGShape
class implements the following additional properties.</p>
<dl>
<dt>cx</dt><dd>
<p>The x-coordinate of the center of the gradient circle. Determines where the color stop begins. The default value 0.5.</p>
<p><strong>Note: </strong>Currently, this property is not implemented for corresponding CanvasShape
and
VMLShape
classes which are used on Android or IE 6 - 8.</p>
</dd>
<dt>cy</dt><dd>
<p>The y-coordinate of the center of the gradient circle. Determines where the color stop begins. The default value 0.5.</p>
<p><strong>Note: </strong>Currently, this property is not implemented for corresponding CanvasShape
and VMLShape
classes which are used on Android or IE 6 - 8.</p>
</dd>
</dl>
<p>These properties are not currently implemented in CanvasShape
or VMLShape
.</p>
stroke
Object
Contains information about the stroke of the shape. <dl> <dt>color</dt><dd>The color of the stroke.</dd> <dt>weight</dt><dd>Number that indicates the width of the stroke.</dd> <dt>opacity</dt><dd>Number between 0 and 1 that indicates the opacity of the stroke. The default value is 1.</dd> <dt>dashstyle</dt>Indicates whether to draw a dashed stroke. When set to "none", a solid stroke is drawn. When set to an array, the first index indicates the length of the dash. The second index indicates the length of gap. <dt>linecap</dt><dd>Specifies the linecap for the stroke. The following values can be specified: <dl> <dt>butt (default)</dt><dd>Specifies a butt linecap.</dd> <dt>square</dt><dd>Specifies a sqare linecap.</dd> <dt>round</dt><dd>Specifies a round linecap.</dd> </dl> </dd> <dt>linejoin</dt><dd>Specifies a linejoin for the stroke. The following values can be specified: <dl> <dt>round (default)</dt><dd>Specifies that the linejoin will be round.</dd> <dt>bevel</dt><dd>Specifies a bevel for the linejoin.</dd> <dt>miter limit</dt><dd>An integer specifying the miter limit of a miter linejoin. If you want to specify a linejoin of miter, you simply specify the limit as opposed to having separate miter and miter limit values.</dd> </dl> </dd> </dl>
transform
String
<p>A string containing, in order, transform operations applied to the shape instance. The transform
string can contain the following values:
<dl>
<dt>rotate</dt><dd>Rotates the shape clockwise around it transformOrigin.</dd>
<dt>translate</dt><dd>Specifies a 2d translation.</dd>
<dt>skew</dt><dd>Skews the shape around the x-axis and y-axis.</dd>
<dt>scale</dt><dd>Specifies a 2d scaling operation.</dd>
<dt>translateX</dt><dd>Translates the shape along the x-axis.</dd>
<dt>translateY</dt><dd>Translates the shape along the y-axis.</dd>
<dt>skewX</dt><dd>Skews the shape around the x-axis.</dd>
<dt>skewY</dt><dd>Skews the shape around the y-axis.</dd>
<dt>matrix</dt><dd>Specifies a 2D transformation matrix comprised of the specified six values.</dd>
</dl>
</p>
<p>Applying transforms through the transform attribute will reset the transform matrix and apply a new transform. The shape class also contains
corresponding methods for each transform that will apply the transform to the current matrix. The below code illustrates how you might use the
transform
attribute to instantiate a recangle with a rotation of 45 degrees.</p>
var myRect = new Y.Rect({
type:"rect",
width: 50,
height: 40,
transform: "rotate(45)"
};
<p>The code below would apply translate
and rotate
to an existing shape.</p>
myRect.set("transform", "translate(40, 50) rotate(45)");