Operator (java-gnome 4.1.3 API Documentation)

Object
- org.freedesktop.bindings.Constant
- - org.freedesktop.cairo.Operator

```
public class Operator
extends org.freedesktop.bindings.Constant
```
Constants specifying the compositing operating mode in effect. These are set for a drawing Context using setOperator(), and take effect when commands like paint() are invoked.
The Context should be created using a cairo Surface. The operators don't seem to work correctly when a Drawable is used instead of a cairo Surface.
The example images shown below were generated with the following code:
```
 cr.rectangle(0, 0, 75, 75);
 cr.setSource(0.7, 0, 0, 0.8);
 cr.fill();
 
 cr.setOperator(Operator.FOO);
 
 cr.rectangle(40, 40, 75, 75);
 cr.setSource(0, 0, 0.9, 0.4);
 cr.fill();
 
```
The drawing operations in cairo are said to be bounded and unbounded with reguards to the Surface to be drawn to.
When an operator is said to be bounded any cairo mask present determines where the operation is applied.
When an operator is said to be unbounded the operation is applied ignoring any present mask. Note: Clipping can still limit an unbounded operator.
Since:

4.0.7

Author:

Andrew Cowie, Kenneth Prugh, Zak Fenton

Field Summary

Fields
Modifier and Type	Field and Description
`static Operator`	`ADD` Add the colors of the overlapping region.
`static Operator`	`ATOP` Draw only where existing pixels are, mixing the color of the overlapping region.
`static Operator`	`CLEAR` Clear a surface to all transparent.
`static Operator`	`DEST` Any existing pixels are left untouched, while the current drawing is discarded.
`static Operator`	`DEST_ATOP` Draw and clear any existing pixels outside the overlapping region, the color of the overlapping region is mixed similar to the `ATOP` Operator.
`static Operator`	`DEST_IN` Draw below the overlapping region, clearing everything outside the region similar to the `IN` Operator.
`static Operator`	`DEST_OUT` Reduce the visibility of the overlapping region.
`static Operator`	`DEST_OVER` Draw below any existing pixels with similar results to the `OVER` operator.
`static Operator`	`IN` Draw only where existing pixels are, clearing the rest of the surface.
`static Operator`	`OUT` Draw only where existing pixels are not present, leaving a shadow behind where the two overlapped due to transparency.
`static Operator`	`OVER` Draws the specified source object over the underlying object as if both objects were two overlapping panels of transparent glass.
`static Operator`	`SATURATE` Saturate the colors of the overlapping region.
`static Operator`	`SOURCE` Draw over existing pixels as if they were not present.
`static Operator`	`XOR` XOR the colors of the overlapping region.

Method Summary
- Methods inherited from class org.freedesktop.bindings.Constant
  toString
- Methods inherited from class Object
  equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - ADD
```
public static final Operator ADD
```
    Add the colors of the overlapping region.
    This operator has the same effect for bounded and unbounded.
    
    Since:
    
    4.0.16
  - ATOP
```
public static final Operator ATOP
```
    Draw only where existing pixels are, mixing the color of the overlapping region.
    This operator has the same effect for bounded and unbounded.
    
    Since:
    
    4.0.16
  - CLEAR
```
public static final Operator CLEAR
```
    Clear a surface to all transparent.
    This operator is bounded.
    
    Since:
    
    4.0.7
  - DEST
```
public static final Operator DEST
```
    Any existing pixels are left untouched, while the current drawing is discarded.
    This operator has the same effect for bounded and unbounded.
    
    Since:
    
    4.0.16
  - DEST_ATOP
```
public static final Operator DEST_ATOP
```
    Draw and clear any existing pixels outside the overlapping region, the color of the overlapping region is mixed similar to the ATOP Operator.
    This operator is unbounded.
    
    Since:
    
    4.0.16
  - DEST_IN
```
public static final Operator DEST_IN
```
    Draw below the overlapping region, clearing everything outside the region similar to the IN Operator.
    This operator is unbounded.
    
    Since:
    
    4.0.16
  - DEST_OUT
```
public static final Operator DEST_OUT
```
    Reduce the visibility of the overlapping region.
    This operator has the same effect for bounded and unbounded.
    
    Since:
    
    4.0.16
  - DEST_OVER
```
public static final Operator DEST_OVER
```
    Draw below any existing pixels with similar results to the OVER operator.
    This operator has the same effect for bounded and unbounded.
    
    Since:
    
    4.0.16
  - IN
```
public static final Operator IN
```
    Draw only where existing pixels are, clearing the rest of the surface.
    This operator is unbounded.
    
    Since:
    
    4.0.16
  - OUT
```
public static final Operator OUT
```
    Draw only where existing pixels are not present, leaving a shadow behind where the two overlapped due to transparency.
    This operator is unbounded.
    
    Since:
    
    4.0.16
  - OVER
```
public static final Operator OVER
```
    Draws the specified source object over the underlying object as if both objects were two overlapping panels of transparent glass. This only applies to objects that have an alpha channel; if the objects do not have an alpha channel, the source object simply paints over the underlying object.
    This is the default operator.
    This operator has the same effect for bounded and unbounded.
    
    Since:
    
    4.0.10
  - SATURATE
```
public static final Operator SATURATE
```
    Saturate the colors of the overlapping region.
    This operator has the same effect for bounded and unbounded.
    
    Since:
    
    4.0.16
  - SOURCE
```
public static final Operator SOURCE
```
    Draw over existing pixels as if they were not present.
    This operator is bounded.
    As an example, you could set up the object to be drawn over:
```
 cr.setSource(0.7, 0, 0, 0.8);
 cr.rectangle(15, 10, 50, 50);
 cr.fill();
 
```
    Now set up the source object that will draw over the area beneath it:
```
 cr.setSource(0, 0, 0.9, 0.4);
 cr.rectangle(35, 35, 50, 50);
 cr.setOperator(Operator.SOURCE);
 cr.fill();
 
```
    Since:
    
    4.0.16
  - XOR
```
public static final Operator XOR
```
    XOR the colors of the overlapping region.
    This operator has the same effect for bounded and unbounded.
    
    Since:
    
    4.0.16

Class Operator

Field Summary

Method Summary

Methods inherited from class org.freedesktop.bindings.Constant

Methods inherited from class Object

Field Detail

ADD

ATOP

CLEAR

DEST

DEST_ATOP

DEST_IN

DEST_OUT

DEST_OVER

IN

OUT

OVER

SATURATE

SOURCE

XOR