Group

Group

Represents a collection of graphical elements that can be acted on together.

Constructor

new Group(…elements)

Source:
Constructs a new Group.
Example
const group = new Group(new Circle(20), new Rectangle(20, 20));
add(group);
Parameters:
Name Type Attributes Description
elements Thing <repeatable>
 Any number of elements to initialize the group with.

Extends

Members

height :number

Source:
Height of the group, meaning the difference between bottom and top bounds.
Type:
  • number

layer

Source:
Overrides:
Sets the layer of the Thing and marks the sortInvalidated flag so any Graphics instances drawing it know to re-sort.

width :number

Source:
Width of the group, meaning the difference between right and left bounds.
Type:
  • number

x :number

Source:
X position of the group, indicated by its left bound.
Type:
  • number

y :number

Source:
X position of the group, indicated by its top bound.
Type:
  • number

Methods

add(element)

Source:
Add an element to the group. This will cause the group's bounds to recalculate to include this element.
Example
const g = new Group();
g.add(new Circle(10));
Parameters:
Name Type Description
element Thing

containsPoint(x, y) → {boolean}

Source:
Overrides:
Return whether this group contains the point, which is true if any element in this group contains it.
Parameters:
Name Type Description
x number
y number
Returns:
Type
boolean

describe()

Source:
Overrides:
Describe the element for screen readers.

draw(context)

Source:
Overrides:
Draws the group, which draws all of its elements.
Parameters:
Name Type Description
context CanvasRenderingContext2D

focus()

Source:
Overrides:
Focuses the element for use with screen readers. This isn't something you should need to call manually, but you can if you'd like to provide focus to an element even if it wasn't navigated to with the keyboard.

getAnchor() → {Object}

Source:
Overrides:
Gets the element's anchor.
Returns:
Type
Object

getBorderColor() → {Color}

Source:
Overrides:
Gets the border color of a Thing.
Example
// this method is on every Shape
let thing = new Thing();
thing.getBorderColor();
Returns:
The color of the Thing's border.
Type
Color

getBorderWidth() → {number}

Source:
Overrides:
Gets the width of the Thing's border.
Example
// this method is on every Shape
let thing = new Thing();
thing.getBorderWidth();
Returns:
The width of the Thing's border.
Type
number

getBounds() → {Object}

Source:
Overrides:
Get the elements bounds. This is an internal property that you shouldn't need to use, but it can be useful for doing quick calculations for the bounding box of a shape.
Example
// this method is on every Shape
let thing = new Thing();
let height = thing.getBounds().bottom - this.getBounds().top;
Returns:
Type
Object

getColor() → {Color}

Source:
Overrides:
Gets the color of a Thing.
Example
// this method is on every Shape
let thing = new Thing();
thing.getColor(); // #000000, by default
Returns:
The destination y coordinate of this Thing.
Type
Color

getElements() → {Array.<Thing>}

Source:
Get all elements in the group.
Returns:
Type
Array.<Thing>

getType() → {string}

Source:
Overrides:
Get the .type of the Thing
Returns:
Type
string

getX() → {number}

Source:
Overrides:
Gets the x position of the Thing.
Example
thing.x === thing.getX();
Returns:
The x position of the Thing.
Type
number

getY() → {number}

Source:
Overrides:
Gets the y position of the Thing.
Example
thing.y === thing.getY();
Returns:
The y position of the Thing.
Type
number

hasBorder() → {boolean}

Source:
Overrides:
Returns if a Thing has a border.
Example
// this method is on every Shape
let thing = new Thing();
thing.hasBorder();
Returns:
True if the Thing has a border.
Type
boolean

isFilled() → {boolean}

Source:
Overrides:
Returns if a Thing is filled.
Example
// this method is on every Shape
let thing = new Thing();
thing.isFilled();
Returns:
True if the Thing is filled.
Type
boolean

move(dx, dy)

Source:
Overrides:
Moves all elements in the group by dx, dy. The .move method of each element in the group will be called with dx, dy.
Parameters:
Name Type Description
dx number
dy number

remove(element)

Source:
Removes `element` from the group. This will cause the group's bounds to recalculate to remove this element.
Parameters:
Name Type Description
element Thing

rotate(degrees, angleUnit)

Source:
Overrides:
Rotates a Thing an additional amount of degrees.
Example
// this method is on every Shape
let thing = new Thing();
thing.rotate(90);
thing.rotate(Math.PI / 2, Thing.RADIANS);
Parameters:
Name Type Description
degrees number The degrees to rotate degrees.
angleUnit number Whether it is degrees or radians. Defaults to degrees.

setAnchor(anchor)

Source:
Overrides:
Sets the Anchor for the object. This alters how the shape will draw relative to its position. An anchor of 0, 0 will cause the shape to draw with its position at its top left corner. An anchor of 1, 1 will cause the shape to draw with its position at its bottom right corner.
Example
// this method is on every Shape
let thing = new Thing();
// center the object around its position
thing.setPosition({vertical: 0.5, horizontal: 0.5});
Parameters:
Name Type Description
anchor Object

setBorder(hasBorder)

Source:
Overrides:
Sets a Thing object to filled. Throws an error if an argument is not passed.
Example
// this method is on every Shape
let thing = new Thing();
thing.setBorder(true);
Parameters:
Name Type Description
hasBorder bool A boolean of whether or not Thing has a border.

setBorderColor(color)

Source:
Overrides:
Sets the border color of a Thing. Throws an error if there are fewer than 1 params or if the param is undefined. This will automatically give the Thing a border, as if you had called thing.setBorder(true);
Example
// this method is on every Shape
let thing = new Thing();
thing.setBorderColor('orange');
Parameters:
Name Type Description
color Color The resulting color of the Thing's border.

setBorderWidth(width)

Source:
Overrides:
Sets the width of a Thing's border. Throws an error if there is not 1 argument. This will automatically set the Thing to draw with a border, as if you had called thing.setBorder(true);
Example
// this method is on every Shape
let thing = new Thing();
thing.setBorderWidth(5);
Parameters:
Name Type Description
width number The resulting width of the Thing's border.

setColor(color)

Source:
Overrides:
Sets the color of a Thing. Throws an error if there are fewer than 1 params or if the param is undefined.
Example
// this method is on every Shape
let thing = new Thing();
thing.setColor('red');
thing.setColor(Color.orange);
thing.setColor('#ff0000');
Parameters:
Name Type Description
color Color The resulting color of Thing.

setFilled(filled)

Source:
Overrides:
Sets a Thing object to filled. Throws an error if an argument is not passed.
Example
// this method is on every Shape
let thing = new Thing();
thing.setFilled(false);
Parameters:
Name Type Description
filled bool A boolean of whether or not Thing is filled.

setOpacity(opacity)

Source:
Overrides:
Set the opacity of the Thing.
Example
// this method is on every Shape
let thing = new Thing();
thing.setOpacity(0.5);
Parameters:
Name Type Description
opacity number

setPosition(x, y)

Source:
Overrides:
Set the position of the group. This will calculate the difference between the current and desired position and .move() the group and all its elements by that distance.
Parameters:
Name Type Description
x number
y number

setRotation(degrees, angleUnit)

Source:
Overrides:
Sets the rotation of a Thing in degrees. Throws an error if there are fewer than 1 params or if they are not numbers.
Example
// this method is on every Shape
let thing = new Thing();
thing.setRotation(90);
thing.setRotation(Math.PI / 2, Thing.RADIANS);
Parameters:
Name Type Description
degrees number The degrees to rotate degrees.
angleUnit number Whether it is degrees or radians. Defaults to degrees.

setType(type)

Source:
Overrides:
Set the .type of the Thing
Parameters:
Name Type Description
type string new type

unfocus()

Source:
Overrides:
Unfocuses the element for use with screen readers. This isn't something you should need to call manually, but you can if you'd like to unfocus to an element even if it wasn't navigated from with the keyboard.