java.lang.Object
- org.eclipse.swt.graphics.Resource
- - org.eclipse.swt.graphics.Transform

```
public class Transform
extends Resource
```
Instances of this class represent transformation matrices for points expressed as (x, y) pairs of floating point numbers.
Application code must explicitly invoke the Transform.dispose() method to release the operating system resources managed by each instance when those instances are no longer required.

This class requires the operating system's advanced graphics subsystem which may not be available on some platforms.

Since:

3.1

See Also:

SWT Example: GraphicsExample, Sample code and further information

Field Summary

Fields
Modifier and Type Field Description

long handle
the OS resource for the Transform (Warning: This field is platform dependent)

Constructor Summary

Constructors
Constructor	Description
`Transform(Device device)`	Constructs a new identity Transform.
`Transform(Device device, float[] elements)`	Constructs a new Transform given an array of elements that represent the matrix that describes the transformation.
`Transform(Device device, float m11, float m12, float m21, float m22, float dx, float dy)`	Constructs a new Transform given all of the elements that represent the matrix that describes the transformation.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`getElements(float[] elements)`	Fills the parameter with the values of the transformation matrix that the receiver represents, in the order {m11, m12, m21, m22, dx, dy}.
`void`	`identity()`	Modifies the receiver such that the matrix it represents becomes the identity matrix.
`void`	`invert()`	Modifies the receiver such that the matrix it represents becomes the mathematical inverse of the matrix it previously represented.
`boolean`	`isDisposed()`	Returns `true` if the Transform has been disposed, and `false` otherwise.
`boolean`	`isIdentity()`	Returns `true` if the Transform represents the identity matrix and false otherwise.
`void`	`multiply(Transform matrix)`	Modifies the receiver such that the matrix it represents becomes the the result of multiplying the matrix it previously represented by the argument.
`void`	`rotate(float angle)`	Modifies the receiver so that it represents a transformation that is equivalent to its previous transformation rotated by the specified angle.
`void`	`scale(float scaleX, float scaleY)`	Modifies the receiver so that it represents a transformation that is equivalent to its previous transformation scaled by (scaleX, scaleY).
`void`	`setElements(float m11, float m12, float m21, float m22, float dx, float dy)`	Modifies the receiver to represent a new transformation given all of the elements that represent the matrix that describes that transformation.
`void`	`shear(float shearX, float shearY)`	Modifies the receiver so that it represents a transformation that is equivalent to its previous transformation sheared by (shearX, shearY).
`String`	`toString()`	Returns a string containing a concise, human-readable description of the receiver.
`void`	`transform(float[] pointArray)`	Given an array containing points described by alternating x and y values, modify that array such that each point has been replaced with the result of applying the transformation represented by the receiver to that point.
`void`	`translate(float offsetX, float offsetY)`	Modifies the receiver so that it represents a transformation that is equivalent to its previous transformation translated by (offsetX, offsetY).

Methods inherited from class org.eclipse.swt.graphics.Resource
dispose, getDevice, setNonDisposeHandler

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - handle
```
public long handle
```
    the OS resource for the Transform (Warning: This field is platform dependent)
    IMPORTANT: This field is not part of the SWT public API. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms and should never be accessed from application code.
    
    Restriction:
    
    This field is not intended to be referenced by clients.
- Constructor Detail
  - Transform
```
public Transform(Device device)
```
    Constructs a new identity Transform.
    This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.
    
    You must dispose the transform when it is no longer required.
    Parameters:
    
    device - the device on which to allocate the Transform
    
    Throws:
    
    IllegalArgumentException -
    
    ERROR_NULL_ARGUMENT - if device is null and there is no current device
    
    SWTException -
    
    ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
    
    SWTError -
    
    ERROR_NO_HANDLES if a handle for the Transform could not be obtained
    
    See Also:
    
    Resource.dispose()
  - Transform
```
public Transform(Device device,
                 float[] elements)
```
    Constructs a new Transform given an array of elements that represent the matrix that describes the transformation.
    This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.
    
    You must dispose the transform when it is no longer required.
    Parameters:
    
    device - the device on which to allocate the Transform
    
    elements - an array of floats that describe the transformation matrix
    
    Throws:
    
    IllegalArgumentException -
    
    ERROR_NULL_ARGUMENT - if device is null and there is no current device, or the elements array is null
    
    ERROR_INVALID_ARGUMENT - if the elements array is too small to hold the matrix values
    
    SWTException -
    
    ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
    
    SWTError -
    
    ERROR_NO_HANDLES if a handle for the Transform could not be obtained
    
    See Also:
    
    Resource.dispose()
  - Transform
```
public Transform(Device device,
                 float m11,
                 float m12,
                 float m21,
                 float m22,
                 float dx,
                 float dy)
```
    Constructs a new Transform given all of the elements that represent the matrix that describes the transformation.
    This operation requires the operating system's advanced graphics subsystem which may not be available on some platforms.
    
    You must dispose the transform when it is no longer required.
    Parameters:
    
    device - the device on which to allocate the Transform
    
    m11 - the first element of the first row of the matrix
    
    m12 - the second element of the first row of the matrix
    
    m21 - the first element of the second row of the matrix
    
    m22 - the second element of the second row of the matrix
    
    dx - the third element of the first row of the matrix
    
    dy - the third element of the second row of the matrix
    
    Throws:
    
    IllegalArgumentException -
    
    ERROR_NULL_ARGUMENT - if device is null and there is no current device
    
    SWTException -
    
    ERROR_NO_GRAPHICS_LIBRARY - if advanced graphics are not available
    
    SWTError -
    
    ERROR_NO_HANDLES if a handle for the Transform could not be obtained
    
    See Also:
    
    Resource.dispose()
- Method Detail
  - getElements
```
public void getElements(float[] elements)
```
    Fills the parameter with the values of the transformation matrix that the receiver represents, in the order {m11, m12, m21, m22, dx, dy}.
    Parameters:
    
    elements - array to hold the matrix values
    
    Throws:
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
    
    IllegalArgumentException -
    
    ERROR_NULL_ARGUMENT - if the parameter is null
    
    ERROR_INVALID_ARGUMENT - if the parameter is too small to hold the matrix values
  - identity
```
public void identity()
```
    Modifies the receiver such that the matrix it represents becomes the identity matrix.
    Throws:
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
    
    Since:
    
    3.4
  - invert
```
public void invert()
```
    Modifies the receiver such that the matrix it represents becomes the mathematical inverse of the matrix it previously represented.
    Throws:
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
    
    ERROR_CANNOT_INVERT_MATRIX - if the matrix is not invertible
  - isDisposed
```
public boolean isDisposed()
```
    Returns true if the Transform has been disposed, and false otherwise.
    This method gets the dispose state for the Transform. When a Transform has been disposed, it is an error to invoke any other method (except Resource.dispose()) using the Transform.
    
    Specified by:
    
    isDisposed in class Resource
    
    Returns:
    
    true when the Transform is disposed, and false otherwise
  - isIdentity
```
public boolean isIdentity()
```
    Returns true if the Transform represents the identity matrix and false otherwise.
    
    Returns:
    
    true if the receiver is an identity Transform, and false otherwise
  - multiply
```
public void multiply(Transform matrix)
```
    Modifies the receiver such that the matrix it represents becomes the the result of multiplying the matrix it previously represented by the argument.
    Parameters:
    
    matrix - the matrix to multiply the receiver by
    
    Throws:
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
    
    IllegalArgumentException -
    
    ERROR_NULL_ARGUMENT - if the parameter is null
    
    ERROR_INVALID_ARGUMENT - if the parameter has been disposed
  - rotate
```
public void rotate(float angle)
```
    Modifies the receiver so that it represents a transformation that is equivalent to its previous transformation rotated by the specified angle. The angle is specified in degrees and for the identity transform 0 degrees is at the 3 o'clock position. A positive value indicates a clockwise rotation while a negative value indicates a counter-clockwise rotation.
    Parameters:
    
    angle - the angle to rotate the transformation by
    
    Throws:
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
  - scale
```
public void scale(float scaleX,
                  float scaleY)
```
    Modifies the receiver so that it represents a transformation that is equivalent to its previous transformation scaled by (scaleX, scaleY).
    Parameters:
    
    scaleX - the amount to scale in the X direction
    
    scaleY - the amount to scale in the Y direction
    
    Throws:
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
  - setElements
```
public void setElements(float m11,
                        float m12,
                        float m21,
                        float m22,
                        float dx,
                        float dy)
```
    Modifies the receiver to represent a new transformation given all of the elements that represent the matrix that describes that transformation.
    Parameters:
    
    m11 - the first element of the first row of the matrix
    
    m12 - the second element of the first row of the matrix
    
    m21 - the first element of the second row of the matrix
    
    m22 - the second element of the second row of the matrix
    
    dx - the third element of the first row of the matrix
    
    dy - the third element of the second row of the matrix
    
    Throws:
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
  - shear
```
public void shear(float shearX,
                  float shearY)
```
    Modifies the receiver so that it represents a transformation that is equivalent to its previous transformation sheared by (shearX, shearY).
    Parameters:
    
    shearX - the shear factor in the X direction
    
    shearY - the shear factor in the Y direction
    
    Throws:
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
    
    Since:
    
    3.4
  - transform
```
public void transform(float[] pointArray)
```
    Given an array containing points described by alternating x and y values, modify that array such that each point has been replaced with the result of applying the transformation represented by the receiver to that point.
    Parameters:
    
    pointArray - an array of alternating x and y values to be transformed
    
    Throws:
    
    IllegalArgumentException -
    
    ERROR_NULL_ARGUMENT - if the point array is null
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
  - translate
```
public void translate(float offsetX,
                      float offsetY)
```
    Modifies the receiver so that it represents a transformation that is equivalent to its previous transformation translated by (offsetX, offsetY).
    Parameters:
    
    offsetX - the distance to translate in the X direction
    
    offsetY - the distance to translate in the Y direction
    
    Throws:
    
    SWTException -
    
    ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
  - toString
```
public String toString()
```
    Returns a string containing a concise, human-readable description of the receiver.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    a string representation of the receiver

Class Transform

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.eclipse.swt.graphics.Resource

Methods inherited from class java.lang.Object

Field Detail

handle

Constructor Detail

Transform

Transform

Transform

Method Detail

getElements

identity

invert

isDisposed

isIdentity

multiply

rotate

scale

setElements

shear

transform

translate

toString