- Qt 5.15
- Qt Graphical Effects
- QML Types
- RectangularGlow QML Type
- Qt 5.15.12 Reference Documentation

# RectangularGlow QML Type

Generates a blurred and colorized rectangle, which gives the impression that the source is glowing. More...

Import Statement: | import QtGraphicalEffects 1.15
Since: | QtGraphicalEffects 1.0

- List of all members, including inherited members

## Properties

- cached : bool
- color : color
- cornerRadius : real
- glowRadius : real
- spread : real

## Detailed Description

This effect is intended to have good performance. The shape of the glow is limited to a rectangle with a custom corner radius. For situations where custom shapes are required, consider Glow effect.

Effect applied

Note: This effect is available when running with OpenGL.

## Example

The following example shows how to apply the effect.

     import QtQuick 2.12
     import QtGraphicalEffects 1.12

     Item {
         width: 300
         height: 300

         Rectangle {
             id: background
             anchors.fill: parent
             color: "black"
         }

         RectangularGlow {
             id: effect
             anchors.fill: rect
             glowRadius: 10
             spread: 0.2
             color: "white"
             cornerRadius: rect.radius + glowRadius
         }

         Rectangle {
             id: rect
             color: "black"
             anchors.centerIn: parent
             width: Math.round(parent.width / 1.5)
             height: Math.round(parent.height / 2)
             radius: 25
         }
     }

## Property Documentation

cached : bool

This property allows the effect output pixels to be cached in order to improve the rendering performance.

Every time the source or effect properties are changed, the pixels in the cache must be updated. Memory consumption is increased, because an extra buffer of memory is required for storing the effect output.

It is recommended to disable the cache when the source or the effect properties are animated.

By default, the property is set to `false`.

color : color

This property defines the RGBA color value which is used for the glow.

By default, the property is set to `"white"`.

Output examples with different color values |  |
--- | --- | ---
color: #ffffff | color: #55ff55 | color: #5555ff
glowRadius: 20 | glowRadius: 20 | glowRadius: 20
spread: 0 | spread: 0 | spread: 0
cornerRadius: 25 | cornerRadius: 25 | cornerRadius: 25

cornerRadius : real

This property defines the corner radius that is used to draw a glow with rounded corners.

The value ranges from 0.0 to half of the effective width or height of the glow, whichever is smaller. This can be calculated with: `min(width, height) / 2.0 + glowRadius`

By default, the property is bound to glowRadius property. The glow behaves as if the rectangle was blurred when adjusting the glowRadius property.

Output examples with different cornerRadius values |  |
--- | --- | ---
cornerRadius: 0 | cornerRadius: 25 | cornerRadius: 50
glowRadius: 20 | glowRadius: 20 | glowRadius: 20
spread: 0 | spread: 0 | spread: 0
color: #ffffff | color: #ffffff | color: #ffffff

glowRadius : real

This property defines how many pixels outside the item area are reached by the glow.

The value ranges from 0.0 (no glow) to inf (infinite glow). By default, the property is set to `0.0`.

Output examples with different glowRadius values |  |
--- | --- | ---
glowRadius: 10 | glowRadius: 20 | glowRadius: 40
spread: 0 | spread: 0 | spread: 0
color: #ffffff | color: #ffffff | color: #ffffff
cornerRadius: 25 | cornerRadius: 25 | cornerRadius: 25

spread : real

This property defines how large part of the glow color is strengthened near the source edges.

The value ranges from 0.0 (no strength increase) to 1.0 (maximum strength increase). By default, the property is set to `0.0`.

Output examples with different spread values |  |
--- | --- | ---
spread: 0.0 | spread: 0.5 | spread: 1.0
glowRadius: 20 | glowRadius: 20 | glowRadius: 20
color: #ffffff | color: #ffffff | color: #ffffff
cornerRadius: 25 | cornerRadius: 25 | cornerRadius: 25