# Class Effects

java.lang.Object
com.codename1.ui.util.Effects

public final class Effects extends Object
Static utility class useful for simple visual effects that don't quite fit anywhere else in the core API.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `static Image`
  `dropshadow(Image source, int blurRadius, float opacity)`
  Generates a shadow for the source image and returns either the shadow itself or the image merged with the shadow.
  `static Image`
  `dropshadow(Image source, int blurRadius, float opacity, int xDistance, int yDistance)`
  Generates a shadow for the source image and returns a new larger image containing the shadow
  `static Image`
  `gaussianBlurImage(Image image, float radius)`
  Create a blur image from the given image.
  `static void`
  `growShrink(Component c, int duration)`
  Grows or shrinks the given component to its new preferred size, this method essentially takes a component whose preferred size has changed and creates a "growing" effect that lasts for the duration.
  `static boolean`
  `isGaussianBlurSupported()`
  Returns true if gaussian blur is supported on this platform
  `static Image`
  `reflectionImage(Image source)`
  Takes the given image and appends an effect of reflection below it that is similar to the way elements appear in water beneath them.
  `static Image`
  `reflectionImage(Image source, float mirrorRatio, int alphaRatio)`
  Takes the given image and appends an effect of reflection below it that is similar to the way elements appear in water beneath them.
  `static Image`
  `reflectionImage(Image source, float mirrorRatio, int alphaRatio, int spacing)`
  Takes the given image and appends an effect of reflection below it that is similar to the way elements appear in water beneath them.
  `static Image`
  `squareShadow(int width, int height, int blurRadius, float opacity)`
  Generates a square shadow and returns it
  `static Image`
  `verticalPerspective(Image i, float topScaleRatio, float bottomScaleRatio, float verticalShrink)`
  Skews an image in a faux perspective transform on the vertical axis, this is effectively a fast scale algorithm that both shrinks the image vertically and reduces the width

  ### Methods inherited from class Object

  `clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Method Details

  - ### reflectionImage

    public static Image reflectionImage(Image source)

    Takes the given image and appends an effect of reflection below it that is similar to the way elements appear in water beneath them. This method shouldn't be used when numAlpha is very low.

    ###### Parameters

    - `source`: image to add the reflection effect to

    ###### Returns

    new image with a reflection effect for the source image

  - ### reflectionImage

    public static Image reflectionImage(Image source, float mirrorRatio, int alphaRatio)

    Takes the given image and appends an effect of reflection below it that is similar to the way elements appear in water beneath them. This method shouldn't be used when numAlpha is very low.

    ###### Parameters

    - `source`: image to add the reflection effect to

    - `mirrorRatio`: @param mirrorRatio generally less than 1, a mirror ration of 0.5f will create a mirror image half the height of the image, 0.75f will create a 3 quarter height mirror etc.

    - `alphaRatio`: @param alphaRatio starting point for the alpha value in the mirror, this should be a number between 0 - 255 (recommended larger than 0) indicating the opacity of the closest pixel. For a mirror thats completely opaque use 255. A recommended value would be between 128 to 90.

    ###### Returns

    new image with a reflection effect for the source image

  - ### reflectionImage

    public static Image reflectionImage(Image source, float mirrorRatio, int alphaRatio, int spacing)

    Takes the given image and appends an effect of reflection below it that is similar to the way elements appear in water beneath them. This method shouldn't be used when numAlpha is very low.

    ###### Parameters

    - `source`: image to add the reflection effect to

    - `mirrorRatio`: @param mirrorRatio generally less than 1, a mirror ration of 0.5f will create a mirror image half the height of the image, 0.75f will create a 3 quarter height mirror etc.

    - `alphaRatio`: @param alphaRatio starting point for the alpha value in the mirror, this should be a number between 0 - 255 (recommended larger than 0) indicating the opacity of the closest pixel. For a mirror thats completely opaque use 255. A recommended value would be between 128 to 90.

    - `spacing`: the distance in pixels between the image and its reflection

    ###### Returns

    new image with a reflection effect for the source image

  - ### growShrink

    public static void growShrink(Component c, int duration)

    Grows or shrinks the given component to its new preferred size, this method essentially takes a component whose preferred size has changed and creates a "growing" effect that lasts for the duration. Notice that some components (such as text areas) don't report proper preferred size untill they are laid out once. Hence the first time around a text area (or container containing a text area) will not produce the expected effect. This can be solved by invoking revalidate before the call to this method only the first time around!

    ###### Parameters

    - `c`: the component to grow/shrink, its size must be different from its preferred size

    - `duration`: the duration in milliseconds for the grow/shrink animation

    ###### Deprecated

    use Component.growShrink instead

  - ### verticalPerspective

    public static Image verticalPerspective(Image i, float topScaleRatio, float bottomScaleRatio, float verticalShrink)

    Skews an image in a faux perspective transform on the vertical axis, this is effectively a fast scale algorithm that both shrinks the image vertically and reduces the width

    ###### Parameters

    - `topScaleRatio`: the amount by which the top portion should be scaled where 1.0 means none

    - `bottomScaleRatio`: the amount by which the bottom portion should be scaled where 1.0 means none

    - `verticalShrink`: the scale ratio for the image height where 1.0 means none

    ###### Returns

    the perspective translated image

  - ### gaussianBlurImage

    public static Image gaussianBlurImage(Image image, float radius)

    Create a blur image from the given image. The algorithm is gaussian blur - https://en.wikipedia.org/wiki/Gaussian_blur

    ###### Parameters

    - `image`: the image to blur

    - `radius`: the radius to be used in the algorithm

  - ### isGaussianBlurSupported

    public static boolean isGaussianBlurSupported()

    Returns true if gaussian blur is supported on this platform

    ###### Returns

    true if gaussian blur is supported.

  - ### dropshadow

    public static Image dropshadow(Image source, int blurRadius, float opacity, int xDistance, int yDistance)

    Generates a shadow for the source image and returns a new larger image containing the shadow

    ###### Parameters

    - `source`: the source image for whom the shadow should be generated

    - `blurRadius`: a shadow is blurred using a gaussian blur when available, a value of 10 is often satisfactory

    - `opacity`: the opacity of the shadow between 0 - 1 where 1 is completely opaque

    - `xDistance`: the distance on the x axis from the main image body in pixels e.g. a negative value will represent a lightsource from the right (shadow on the left)

    - `yDistance`: the distance on the y axis from the main image body in pixels e.g. a negative value will represent a lightsource from the bottom (shadow on top)

    ###### Returns

    a new image whose size incorporates x/yDistance

  - ### dropshadow

    public static Image dropshadow(Image source, int blurRadius, float opacity)

    Generates a shadow for the source image and returns either the shadow itself or the image merged with the shadow.

    ###### Parameters

    - `source`: the source image for whom the shadow should be generated

    - `blurRadius`: a shadow is blurred using a gaussian blur when available, a value of 10 is often satisfactory

    - `opacity`: the opacity of the shadow between 0 - 1 where 1 is completely opaque

    ###### Returns

    an image containing the shadow for source

  - ### squareShadow

    public static Image squareShadow(int width, int height, int blurRadius, float opacity)

    Generates a square shadow and returns it

    ###### Parameters

    - `width`: the width of the shadow image

    - `height`: the height of the shadow image

    - `blurRadius`: a shadow is blurred using a gaussian blur when available, a value of 10 is often satisfactory

    - `opacity`: the opacity of the shadow between 0 - 1 where 1 is completely opaque

    ###### Returns

    an image containing the shadow for source