# # Titanium.UI.Matrix2D

The 2D Matrix is an object for holding values for an affine transformation matrix.

## # Overview

A 2D matrix is used to rotate, scale, translate, or skew the objects in a two-dimensional space. A 2D affine transformation can be represented by a 3 by 3 matrix:

a | b | 0 |

c | d | 0 |

tx | ty | 1 |

The third column is constant (0,0,1).

On iOS, the matrix terms, `a`

, `b`

, `c`

, `d`

, `tx`

, and `ty`

,
are available as properties. On Android, the matrix terms are not available as properties.

Use the Titanium.UI.createMatrix2D method to create a new 2D matrix. You can pass an optional Matrix2DCreationDict dictionary to the method to initialize the matrix. For example, the following creates a new matrix with a 45 degree rotation.

```
var matrix = Ti.UI.createMatrix2D({
rotate: 45
});
```

If you pass no arguments, `createMatrix2D`

returns an identity matrix.

## # Examples

### # Apply a 2D Matrix to a Label

The following uses a 2D matrix to translate a label in the y direction.

```
var win = Ti.UI.createWindow();
var label = Ti.UI.createLabel({
font: { fontSize: 50 },
text: 'Titanium',
textAlign: 'center',
top: 100
});
win.add(label);
var button = Ti.UI.createButton({
title: 'Animate',
bottom: 20,
width: 200,
height: 40
});
win.add(button);
button.addEventListener('click', function() {
var t1 = Ti.UI.createMatrix2D();
t1 = t1.translate(0, 300);
var a1 = Ti.UI.createAnimation();
a1.transform = t1;
a1.duration = 800;
label.animate(a1);
});
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`

.

### # 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`

### # lifecycleContainer

The Window or TabGroup whose Activity lifecycle should be triggered on the proxy.

If this property is set to a Window or TabGroup, then the corresponding Activity lifecycle event callbacks will also be called on the proxy. Proxies that require the activity lifecycle will need this property set to the appropriate containing Window or TabGroup.

## # Methods

### # 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

### # 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

### # invert

Returns a matrix constructed by inverting this matrix.

#### Returns

- Type
- Titanium.UI.Matrix2D

### # multiply

Returns a matrix constructed by combining two existing matrices.

The argument, `t2`

is concatenated to the matrix instance against which the function is invoked. The
resulting matrix is the result of multiplying this matrix by `t2`

. You might perform several
multiplications in order to create a single matrix that contains the cumulative effects of
several transformations.

Note that matrix operations are not commutative -- the order in which you concatenate matrices
is important. That is, the result of multiplying matrix `t1`

by matrix `t2`

does not necessarily
equal the result of multiplying matrix `t2`

by matrix `t1`

.

#### Parameters

Name | Type | Description |
---|---|---|

`t2` | Titanium.UI.Matrix2D | The second matrix. |

#### Returns

- Type
- Titanium.UI.Matrix2D

### # 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

### # rotate

Returns a matrix constructed by rotating this matrix.

There are two distinct versions of this method, depending on whether one argument or two are specified.

`rotate(angle)`

. The standard`rotate`

method.`rotate(fromAngle, toAngle)`

. Android only. Used for specifying rotation animations.

In both cases, a positive value specifies clockwise rotation and a negative value specifies counter-clockwise rotation.

Details for each version are discussed below.

#### # rotate(angle)

Returns a matrix constructed by rotating this matrix.

Note that the resulting matrix only expresses the final transformation, not the
direction of the rotation. For example, the matrix produced by `m1.rotate(-10)`

is identical to the matrix produced by `m1.rotate(350)`

and `m1.rotate(710)`

.

Note that if you specify a rotation matrix as the `transform`

property of an
animation, the animation animates the view from its current rotation to the
rotation represented by the matrix by its shortest path. So to rotate a view
in a complete circle, the easiest method is to chain together three animations,
rotating 120 degrees each time.

For the purposes of animation, it should be noted that the rotation angle is normalized to the range -180 <= angle < 180. In other words, an angle of 180 degrees is normalized to -180. This makes no difference except when determining which direction an animation rotates. 179 degrees rotates rotate clockwise, but 180 degrees is normalized to -180, so rotates counter-clockwise.

#### # rotate(angle, toAngle) -- Android Only

This is an Android-specific method used for creating rotation animations.
Returns a `Matrix2D`

object that represents a rotation from `angle`

to `toAngle`

.

Angles are specified in degrees. Positive values represent clockwise rotation, and negative values represent counter-clockwise rotation. Values are not normalized, so for example an angle of 720 degrees represents two complete clockwise revolutions.

The resulting object cannot be expressed as an affine transform, but can be used with the Titanium.UI.Animation.transform property to specify a rotation animation.

#### Parameters

Name | Type | Description |
---|---|---|

`angle` | Number | Angle to rotate to, in degrees. On Android, if |

`toAngle` | Number | Ending angle for a rotation animation, in degrees. Android only. |

#### Returns

- Type
- Titanium.UI.Matrix2D

### # scale

Returns a `Matrix2D`

object that specifies a scaling animation from one scale to another.

There are two distinct versions of this method, depending on whether two arguments or four are specified.

`scale(sx, sy)`

. The standard`scale`

method.`scale(fromSx, fromSy, toSx, toSy)`

. Android only. Used for specifying a scaling animation from one size to another.

#### # scale(sx, sy)

Returns a matrix constructed by applying a scale transform to this matrix.
Scaling the current matrix by `sx`

along the X axis and by `sy`

along the Y axis.

#### # scale(sx, sy, toSx, toSy) -- Android Only

This Android-specific method returns a `Matrix2D`

object that can be used to
create a scaling animation from one scale factor to another scale factor.

The resulting object cannot be expressed as an affine transform, but can be used with the transform property to specify a scaling animation.

#### Parameters

Name | Type | Description |
---|---|---|

`sx` | Number | Horizontal scaling factor. If |

`sy` | Number | Vertical scaling factor. If |

`toSx` | Number | Ending horizontal scaling factor, at the end of an animation.
If specified, |

`toSy` | Number | Ending vertical scaling factor, at the end of an animation.
If specified, |

#### Returns

- Type
- Titanium.UI.Matrix2D

### # translate

Returns a matrix constructed by applying a translation transform to this matrix.

#### Parameters

Name | Type | Description |
---|---|---|

`tx` | Number | Horizontal component of the translation. |

`ty` | Number | Vertical component of the translation. |

#### Returns

- Type
- Titanium.UI.Matrix2D