# Titanium.UI.iOS.CollisionBehavior

Dynamic behavior to support collisions between items and boundaries.

Availability
3.2.0
9.2.0

# Overview

A collision behavior specifies the behavior when items collide with each other and boundaries. To define a collision behavior:

  1. Use the Titanium.UI.iOS.createCollisionBehavior method to create and define the behavior.
  2. Use the Titanium.UI.iOS.CollisionBehavior.addItem method to add items to the behavior.
  3. Use the Titanium.UI.iOS.CollisionBehavior.addBoundary method to add custom boundaries for the item to collide with. By default, the behavior uses the Animator object's reference view as the boundary.
  4. Add the behavior to an Titanium.UI.iOS.Animator.

# Examples

# Simple Example

The following example creates many blocks scattered across the top of the window, which start falling after the window opens. The item and boundary collisions are reported to the console.

var win = Ti.UI.createWindow({backgroundColor: 'white', fullscreen: true});

// Create an Animator object using the window as the coordinate system
var animator = Ti.UI.iOS.createAnimator({referenceView: win});

// Create a default collision behavior, using the window edges as boundaries
var collision = Ti.UI.iOS.createCollisionBehavior();

// Listen for collisions
function report(e) {
    Ti.API.info(JSON.stringify(e.type));
};
collision.addEventListener('itemcollision', report);
collision.addEventListener('boundarycollision', report);

// Simulate Earth's gravity
var gravity = Ti.UI.iOS.createGravityBehavior({
    gravityDirection: {x: 0.0, y: 1.0}
});

var WIDTH = Ti.Platform.displayCaps.platformWidth;
var HEIGHT = Ti.Platform.displayCaps.platformHeight;

// Create a bunch of random blocks; add to the window and behaviors
var blocks = [];   
for (var i = 0; i < 25; i++) {
    var r = Math.round(Math.random() * 255);
    var g = Math.round(Math.random() * 255);
    var b = Math.round(Math.random() * 255);
    var rgb = 'rgb(' + r +"," + g + "," + b + ")";

    blocks[i] = Ti.UI.createView({
        width: 25,
        height: 25,
        top: Math.round(Math.random() * (HEIGHT / 4) + 25),
        left: Math.round(Math.random() * (WIDTH - 25) + 25),
        backgroundColor: rgb
    });
    win.add(blocks[i]);
    collision.addItem(blocks[i]);
    gravity.addItem(blocks[i]);
}

animator.addBehavior(collision);
animator.addBehavior(gravity);

// Start the animation when the window opens
win.addEventListener('open', function(e){
    animator.startAnimator();
});

win.open();

# Properties

# apiName READONLY

Availability
3.2.0
9.2.0
apiName :String

The name of the API that this proxy corresponds to.

The value of this property is the fully qualified name of the API. For example, Titanium.UI.Button returns Ti.UI.Button.


# boundaryIdentifiers READONLY

Availability
3.2.0
9.2.0
boundaryIdentifiers :Array<BoundaryIdentifier>

Boundary identfiers added to this behavior.


# bubbleParent

Availability
3.2.0
9.2.0
bubbleParent :Boolean

Indicates if the proxy will bubble an event to its parent.

Some proxies (most commonly views) have a relationship to other proxies, often established by the add() method. For example, for a button added to a window, a click event on the button would bubble up to the window. Other common parents are table sections to their rows, table views to their sections, and scrollable views to their views. Set this property to false to disable the bubbling to the proxy's parent.

Default: true


# collisionMode

Availability
3.2.0
9.2.0
collisionMode :Number

Specifies the collision behavior.

Default: Titanium.UI.iOS.COLLISION_MODE_ALL


# items READONLY

Availability
3.2.0
9.2.0
items :Array<Titanium.UI.View>

Items added to this behavior.


# referenceInsets

Availability
3.2.0
9.2.0
referenceInsets :Padding

Insets to apply when using the animator's reference view as the boundary.

The treatReferenceAsBoundary property needs to be set to true to use this property.

Default: All insets are zero.


# treatReferenceAsBoundary

Availability
3.2.0
9.2.0
treatReferenceAsBoundary :Boolean

Use the animator's reference view as the boundary.

Set to true to enable this behavior or false to disable it.

Default: true

# Methods

# addBoundary

Availability
3.2.0
9.2.0
addBoundary(boundary) void

Adds a boundary to this behavior.

Parameters

Name Type Description
boundary BoundaryIdentifier

Boundary to add to the behavior.

Returns

Type
void

# addEventListener

Availability
3.2.0
9.2.0
addEventListener(name, callback) void

Adds the specified callback as an event listener for the named event.

Parameters

Name Type Description
name String

Name of the event.

callback Callback<Titanium.Event>

Callback function to invoke when the event is fired.

Returns

Type
void

# addItem

Availability
3.2.0
9.2.0
addItem(item) void

Adds an item to this behavior.

Parameters

Name Type Description
item Titanium.UI.View

View object to add to the behavior.

Returns

Type
void

# applyProperties

Availability
3.2.0
9.2.0
applyProperties(props) void

Applies the properties to the proxy.

Properties are supplied as a dictionary. Each key-value pair in the object is applied to the proxy such that myproxy[key] = value.

Parameters

Name Type Description
props Dictionary

A dictionary of properties to apply.

Returns

Type
void

# fireEvent

Availability
3.2.0
9.2.0
fireEvent(name[, event]) void

Fires a synthesized event to any registered listeners.

Parameters

Name Type Description
name String

Name of the event.

event Dictionary

A dictionary of keys and values to add to the Titanium.Event object sent to the listeners.

Returns

Type
void

# removeAllBoundaries

Availability
3.2.0
9.2.0
removeAllBoundaries() void

Removes all boundaries from this behavior.

Returns

Type
void

# removeBoundary

Availability
3.2.0
9.2.0
removeBoundary(boundary) void

Removes the specified boundary from this behavior.

Parameters

Name Type Description
boundary BoundaryIdentifier

Boundary to remove.

Returns

Type
void

# removeEventListener

Availability
3.2.0
9.2.0
removeEventListener(name, callback) void

Removes the specified callback as an event listener for the named event.

Multiple listeners can be registered for the same event, so the callback parameter is used to determine which listener to remove.

When adding a listener, you must save a reference to the callback function in order to remove the listener later:

var listener = function() { Ti.API.info("Event listener called."); }
window.addEventListener('click', listener);

To remove the listener, pass in a reference to the callback function:

window.removeEventListener('click', listener);

Parameters

Name Type Description
name String

Name of the event.

callback Callback<Titanium.Event>

Callback function to remove. Must be the same function passed to addEventListener.

Returns

Type
void

# removeItem

Availability
3.2.0
9.2.0
removeItem(item) void

Removes the specified item from this behavior.

Parameters

Name Type Description
item Titanium.UI.View

Item to remove.

Returns

Type
void

# Events

# boundarycollision

Availability
3.2.0
9.2.0

Fired when an item collides with a boundary.

Properties

Name Type Description
item Titanium.UI.View

Item that collided with the boundary.

identifier String

Identifier of the boundary the item collided with.

point Point

Point of the collision when it started. Only returned when start is true.

start Boolean

Returns true if the collision started else false.

source Object

Source object that fired the event.

type String

Name of the event fired.

bubbles Boolean

True if the event will try to bubble up if possible.

cancelBubble Boolean

Set to true to stop the event from bubbling.


# itemcollision

Availability
3.2.0
9.2.0

Fired when two items collide.

Properties

Name Type Description
item1 Titanium.UI.View

Item that collided with item2.

item2 Titanium.UI.View

Item that collided with item1.

point Point

Point of the collision when it started. Only returned when start is true.

start Boolean

Returns true if the collision started else false.

source Object

Source object that fired the event.

type String

Name of the event fired.

bubbles Boolean

True if the event will try to bubble up if possible.

cancelBubble Boolean

Set to true to stop the event from bubbling.