CirclePainterV2 class

A custom painter that draws a semi-transparent overlay with a circular cutout and optional progress arc, typically used as an overlay for selfie cameras to focus on the subject in the center of the screen.

The CirclePainterV2 class is designed to paint an overlay on the screen with a clear circle in the center, making it suitable for use in selfie camera applications, or any use case that requires a circular overlay. Additionally, it supports drawing a progress arc around the circle, which can be useful for indicating capture progress.

Customization:

  • topMargin: Adjust the vertical position of the circle.
  • circleRadius: A callback function that determines the radius of the circle based on the screen size.
  • progress: A value between 0.0 and 1.0 that controls the portion of the progress arc to be drawn around the circle. For example, 0.25 represents a quarter circle, 0.5 represents half, and 1.0 represents a full circle.
  • strokeWidth: Customize the thickness of the circle stroke and progress arc.
  • strokeColor: Define the color of the circle's stroke (default is white).
  • overlayColor: Change the color and opacity of the overlay surrounding the circle.
  • progressColor: Set the color of the progress arc (default is green).

Usage Example:

Here's how you can use the CirclePainterV2 in a camera preview setup, typically for selfies:

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      title: const Text("Camera Selfie Page", style: TextStyle(color: Colors.black)),
    ),
    body: Stack(
      children: [
        // Camera preview area
        Container(
          alignment: Alignment.center,
          child: cameraController?.value.isInitialized == true
              ? CameraPreview(cameraController!)
              : Container(),
        ),
        // Circular overlay for selfie capture
        IgnorePointer(
          child: CustomPaint(
            painter: CirclePainterV2(
              progress: 0.5, // Draw half of the progress arc (optional)
            ),
            child: Container(),
          ),
        ),
      ],
    ),
  );
}

This painter is useful for creating a focused circular overlay for selfie or face-related captures, and the progress arc can be used for visual feedback during actions like countdowns or photo captures.

For more detailed examples, refer to the example.

Inheritance

Constructors

CirclePainterV2({double? topMargin, double? circleRadius(Size size)?, double progress = 0.0, double strokeWidth = 2.0, Color strokeColor = Colors.white, Color? overlayColor, Color progressColor = Colors.green})

Properties

circleRadius ↔ double? Function(Size size)?
getter/setter pair
hashCode → int
The hash code for this object.
no setterinherited
overlayColor ↔ Color?
getter/setter pair
progress ↔ double
getter/setter pair
progressColor ↔ Color
getter/setter pair
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
semanticsBuilder → SemanticsBuilderCallback?
Returns a function that builds semantic information for the picture drawn by this painter.
no setterinherited
strokeColor ↔ Color
getter/setter pair
strokeWidth ↔ double
getter/setter pair
topMargin ↔ double?
getter/setter pair

Methods

addListener(VoidCallback listener) → void
Register a closure to be notified when it is time to repaint.
inherited
hitTest(Offset position) → bool?
Called whenever a hit test is being performed on an object that is using this custom paint delegate.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
paint(Canvas canvas, Size size) → void
Called whenever the object needs to paint. The given Canvas has its coordinate space configured such that the origin is at the top left of the box. The area of the box is the size of the size argument.
override
removeListener(VoidCallback listener) → void
Remove a previously registered closure from the list of closures that the object notifies when it is time to repaint.
inherited
shouldRebuildSemantics(covariant CustomPainter oldDelegate) → bool
Called whenever a new instance of the custom painter delegate class is provided to the RenderCustomPaint object, or any time that a new CustomPaint object is created with a new instance of the custom painter delegate class (which amounts to the same thing, because the latter is implemented in terms of the former).
inherited
shouldRepaint(covariant CustomPainter oldDelegate) → bool
Called whenever a new instance of the custom painter delegate class is provided to the RenderCustomPaint object, or any time that a new CustomPaint object is created with a new instance of the custom painter delegate class (which amounts to the same thing, because the latter is implemented in terms of the former).
override
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited