# Titanium.UI.iOS.CollisionBehavior
Dynamic behavior to support collisions between items and boundaries.
# Overview
A collision behavior specifies the behavior when items collide with each other and boundaries. To define a collision behavior:
- Use the Titanium.UI.iOS.createCollisionBehavior method to create and define the behavior.
- Use the Titanium.UI.iOS.CollisionBehavior.addItem method to add items to the behavior.
- 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.
- 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
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
Boundary identfiers added to this behavior.
# bubbleParent
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
Specifies the collision behavior.
Default: Titanium.UI.iOS.COLLISION_MODE_ALL
# referenceInsets
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
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
Adds a boundary to this behavior.
Parameters
Name | Type | Description |
---|---|---|
boundary | BoundaryIdentifier | Boundary to add to the behavior. |
Returns
- Type
- void
# addEventListener
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
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
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
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
Removes all boundaries from this behavior.
Returns
- Type
- void
# removeBoundary
Removes the specified boundary from this behavior.
Parameters
Name | Type | Description |
---|---|---|
boundary | BoundaryIdentifier | Boundary to remove. |
Returns
- Type
- void
# removeEventListener
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 |
Returns
- Type
- void
# removeItem
Removes the specified item from this behavior.
Parameters
Name | Type | Description |
---|---|---|
item | Titanium.UI.View | Item to remove. |
Returns
- Type
- void
# Events
# boundarycollision
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 | Boolean | Returns |
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
Fired when two items collide.
Properties
Name | Type | Description |
---|---|---|
item1 | Titanium.UI.View | Item that collided with |
item2 | Titanium.UI.View | Item that collided with |
point | Point | Point of the collision when it started. Only returned when |
start | Boolean | Returns |
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. |