# Titanium.UI.iOS.PushBehavior

Continuous or instantaneous force to apply to an item.

Availability
3.2.0
9.2.0

# Overview

A push behavior configures the continuous or instaneous force to apply to one or more items. To define a push behavior:

  1. Use the Titanium.UI.iOS.createPushBehavior method to create and define the behavior.
  2. To define a force vector, either set the Titanium.UI.iOS.PushBehavior.angle and Titanium.UI.iOS.PushBehavior.magnitude properties, or set the Titanium.UI.iOS.PushBehavior.pushDirection property.
  3. Use the Titanium.UI.iOS.PushBehavior.addItem method to add items to the behavior.
  4. Add the behavior to an Titanium.UI.iOS.Animator.

# Examples

# Simple Example

The following example generates a random push force on the block when it stops.

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});

var block = Ti.UI.createView({
    width: 100,
    height: 100,
    backgroundColor: 'blue',
    transform: Ti.UI.createMatrix2D({ rotate: 45 })
});

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

// Push the block down when the application first starts
var push = Ti.UI.iOS.createPushBehavior({
    pushDirection: {x: 0.0, y: 1.0},
    pushMode: Ti.UI.iOS.PUSH_MODE_INSTANTANEOUS
});
push.addItem(block);
animator.addBehavior(push);

// Apply a new push behavior when the item stops
animator.addEventListener('pause', function(e){
    push.angle = 2 * Math.PI * Math.random();
    push.magnitude = Math.random() * 5 + 5;
    push.active = true;
});

animator.addEventListener('resume', function(e){
    Ti.API.info(JSON.stringify(
        'push force: ' + push.magnitude * 100 + " points/s^2 @ "
        + (push.angle * 360 / (2 * Math.PI)) + " degrees")
    );
});

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

win.add(block);
win.open();

# Properties

# active

Availability
3.2.0
9.2.0
active :Boolean

State of the push behavior's force.

Set to true to activate the force or false to deactivate it. Use this property rather than removing and re-adding the behavior to the animator.

Default: true


# angle

Availability
3.2.0
9.2.0
angle :Number

Specifies the angle of the force vector in radians.

To configure the force vector, you need to also specify the magnitude property.

Default: 0


# items READONLY

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

Items added to this behavior.


# magnitude

Availability
3.2.0
9.2.0
magnitude :Number

Specifies the magnitude of the force vector.

A value of 1.0 represents an acceleration of 100 points per second squared if the item is 100 x 100 points with a density of 1.0.

To configure the push vector, you need to also specify the angle property.

Default: 0


# pushDirection

Availability
3.2.0
9.2.0
pushDirection :Point

Specifies the direction of the force vector as an x, y pair.

For example, specifiying {x: 0.0, y: 1.0} indicates a positive upward force of 100 points per second squared if the item is 100 x 100 points with a density of 1.0.

Specifiying a negative value reverses the direction of the force.

Default: (0,0)


# pushMode

Availability
3.2.0
9.2.0
pushMode :Number

Specifies the push mode.

This API can be assigned the following constants:

Default: Titanium.UI.iOS.PUSH_MODE_CONTINUOUS

# Methods

# 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

# 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