Class ShadowFactory
- All Implemented Interfaces:
ShadowRenderer
A shadow factory generates a drop shadow for any given picture, respecting the transparency channel if present. The resulting picture contains the shadow only and to create a drop shadow effect you will need to stack the original picture and the shadow generated by the factory.
Shadow Properties
A shadow is defined by three properties:
- size: The size, in pixels, of the shadow. This property also defines the fuzzyness.
- opacity: The opacity, between 0.0 and 1.0, of the shadow.
- color: The color of the shadow. Shadows are not meant to be black only.
ShadowFactory factory = new ShadowFactory(10, 0.5f, Color.GREEN); // .. factory = new ShadowFactory(); factory.setSize(10); factory.setOpacity(0.5f); factory.setColor(Color.GREEN);The default constructor provides the following default values:
- size: 5 pixels
- opacity: 50%
- color: Black
Shadow Quality
The factory provides two shadow generation algorithms: fast quality blur and high quality blur. You can select your preferred algorithm by setting the appropriate rendering hint:
ShadowFactory factory = new ShadowFactory(); factory.setRenderingHint(ShadowFactory.KEY_BLUR_QUALITY, ShadowFactory.VALUE_BLUR_QUALITY_HIGH);The default rendering algorithm is
VALUE_BLUR_QUALITY_FAST
. The current implementation should provide the same quality with both algorithms but performances are guaranteed to be better (about 30 times faster) with the fast quality blur.
Generating a Shadow
A shadow is generated as a
BufferedImage
from another BufferedImage
. Once the factory is set up, you must call createShadow(java.awt.image.BufferedImage)
to actually generate the shadow:
ShadowFactory factory = new ShadowFactory(); // factory setup BufferedImage shadow = factory.createShadow(bufferedImage);The resulting image is of type
BufferedImage.TYPE_INT_ARGB
. Both dimensions of this image are larger
than original image's: - new width = original width + 2 * shadow size
- new height = original height + 2 * shadow size
Properties Changes
This factory allows to register property change listeners with addPropertyChangeListener(java.beans.PropertyChangeListener)
. Listening to properties changes is very useful when you embed the factory in a graphical
component and give the API user the ability to access the factory. By listening to properties changes, you can easily
repaint the component when needed.
Threading Issues
ShadowFactory
is not guaranteed to
be thread-safe.
- Author:
- Romain Guy <romain.guy@mac.com>, Sebastien Petrucci <sebastien_petrucci@yahoo.fr>
-
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final String
Identifies a change to the color used to render the shadow.static final String
Key for the blur quality rendering hint.static final String
Identifies a change to the opacity used to render the shadow.static final String
Identifies a change to the size used to render the shadow.static final String
Selects the fast rendering algorithm.static final String
Selects the high quality rendering algorithm. -
Constructor Summary
ConstructorsConstructorDescriptionCreates a default good looking shadow generator.ShadowFactory
(int size, float opacity, Color color) A shadow factory needs three properties to generate shadows. -
Method Summary
Modifier and TypeMethodDescriptionvoid
Add a PropertyChangeListener to the listener list.createShadow
(BufferedImage image) Generates the shadow for a given picture and the current properties of the factory.getColor()
Gets the color used by the factory to generate shadows.float
Gets the opacity used by the factory to generate shadows.int
getSize()
Gets the size in pixel used by the factory to generate shadows.void
Remove a PropertyChangeListener from the listener list.void
Sets the color used by the factory to generate shadows.void
setOpacity
(float shadowOpacity) Sets the opacity used by the factory to generate shadows.void
setRenderingHint
(Object key, Object value) Maps the specified rendering hintkey
to the specifiedvalue
in thisSahdowFactory
object.void
setSize
(int shadowSize) Sets the size, in pixels, used by the factory to generate shadows.
-
Field Details
-
KEY_BLUR_QUALITY
Key for the blur quality rendering hint.
- See Also:
-
VALUE_BLUR_QUALITY_FAST
Selects the fast rendering algorithm. This is the default rendering hint for
KEY_BLUR_QUALITY
.- See Also:
-
VALUE_BLUR_QUALITY_HIGH
Selects the high quality rendering algorithm. With current implementation, This algorithm does not guarantee a better rendering quality and should not be used.
- See Also:
-
SIZE_CHANGED_PROPERTY
Identifies a change to the size used to render the shadow.
When the property change event is fired, the old value and the new value are provided as
Integer
instances.- See Also:
-
OPACITY_CHANGED_PROPERTY
Identifies a change to the opacity used to render the shadow.
When the property change event is fired, the old value and the new value are provided as
Float
instances.- See Also:
-
COLOR_CHANGED_PROPERTY
Identifies a change to the color used to render the shadow.
- See Also:
-
-
Constructor Details
-
ShadowFactory
public ShadowFactory()Creates a default good looking shadow generator. The default shadow factory provides the following default values:
- size: 5 pixels
- opacity: 50%
- color: Black
- rendering quality: VALUE_BLUR_QUALITY_FAST
These properties provide a regular, good looking shadow.
-
ShadowFactory
A shadow factory needs three properties to generate shadows. These properties are:
- size: The size, in pixels, of the shadow. This property also defines the fuzzyness.
- opacity: The opacity, between 0.0 and 1.0, of the shadow.
- color: The color of the shadow. Shadows are not meant to be black only.
Besides these properties you can set rendering hints to control the rendering process. The default rendering hints let the factory use the fastest shadow generation algorithm.
- Parameters:
size
- The size of the shadow in pixels. Defines the fuzziness.opacity
- The opacity of the shadow.color
- The color of the shadow.- See Also:
-
-
Method Details
-
addPropertyChangeListener
Add a PropertyChangeListener to the listener list. The listener is registered for all properties. The same listener object may be added more than once, and will be called as many times as it is added. If
listener
is null, no exception is thrown and no action is taken.- Parameters:
listener
- the PropertyChangeListener to be added
-
removePropertyChangeListener
Remove a PropertyChangeListener from the listener list. This removes a PropertyChangeListener that was registered for all properties. If
listener
was added more than once to the same event source, it will be notified one less time after being removed. Iflistener
is null, or was never added, no exception is thrown and no action is taken.- Parameters:
listener
-
-
setRenderingHint
Maps the specified rendering hint
key
to the specifiedvalue
in thisSahdowFactory
object.- Parameters:
key
- The rendering hint keyvalue
- The rendering hint value
-
getColor
Gets the color used by the factory to generate shadows.
- Returns:
- this factory's shadow color
-
setColor
Sets the color used by the factory to generate shadows.
Consecutive calls to
createShadow(java.awt.image.BufferedImage)
will all use this color until it is set again.If the color provided is null, the previous color will be retained.
- Parameters:
shadowColor
- the generated shadows color
-
getOpacity
public float getOpacity()Gets the opacity used by the factory to generate shadows.
The opacity is comprised between 0.0f and 1.0f; 0.0f being fully transparent and 1.0f fully opaque.
- Returns:
- this factory's shadow opacity
-
setOpacity
public void setOpacity(float shadowOpacity) Sets the opacity used by the factory to generate shadows.
Consecutive calls to
createShadow(java.awt.image.BufferedImage)
will all use this color until it is set again.The opacity is comprised between 0.0f and 1.0f; 0.0f being fully transparent and 1.0f fully opaque. If you provide a value out of these boundaries, it will be restrained to the closest boundary.
- Parameters:
shadowOpacity
- the generated shadows opacity
-
getSize
public int getSize()Gets the size in pixel used by the factory to generate shadows.
- Returns:
- this factory's shadow size
-
setSize
public void setSize(int shadowSize) Sets the size, in pixels, used by the factory to generate shadows.
The size defines the blur radius applied to the shadow to create the fuzziness.
There is virtually no limit to the size but it has an impact on shadow generation performances. The greater this value, the longer it will take to generate the shadow. Remember the generated shadow image dimensions are computed as follow:
- new width = original width + 2 * shadow size
- new height = original height + 2 * shadow size
- Parameters:
shadowSize
- the generated shadows size in pixels (fuzziness)
-
createShadow
Generates the shadow for a given picture and the current properties of the factory.
The generated shadow image dimensions are computed as follow:
- new width = original width + 2 * shadow size
- new height = original height + 2 * shadow size
The time taken by a call to this method depends on the size of the shadow, the larger the longer it takes, and on the selected rendering algorithm.
- Specified by:
createShadow
in interfaceShadowRenderer
- Parameters:
image
- the picture from which the shadow must be cast- Returns:
- the picture containing the shadow of
image
-