RectanglePainterV2 class

A custom painter that draws a semi-transparent overlay with a centered rectangular cutout, typically used as a camera overlay to highlight the area for capturing ID cards or documents.

The RectanglePainterV2 class paints an overlay on the screen with a clear rectangle in the center, allowing users to focus on the content within the rectangle (e.g., for taking ID card photos).

Customization:

  • topMargin: Adjust the vertical position of the rectangle.
  • size: A callback function that takes the screen size as an input and returns a custom size for the rectangle. This allows developers to dynamically control the dimensions of the rectangle based on the screen or parent widget's size.
  • strokeWidth: Customize the stroke thickness around the rectangle.
  • strokeColor: Define the stroke color (default is white).
  • overlayColor: Change the color and opacity of the overlay surrounding the rectangle.
  • borderRadius: Add rounded corners to the rectangle.

Usage Example:

Here's how you can use the RectanglePainterV2 in a camera preview setup:

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      title: const Text("Camera ID Card Page", style: TextStyle(color: Colors.black)),
    ),
    body: Stack(
      children: [
        // Camera preview area
        Container(
          alignment: Alignment.center,
          child: cameraController?.value.isInitialized == true
              ? CameraPreview(cameraController!)
              : Container(),
        ),
        // Overlay rectangle for ID card capture
        IgnorePointer(
          child: CustomPaint(
            painter: RectanglePainterV2(),
            child: Container(),
          ),
        ),
      ],
    ),
  );
}

For more detailed examples, refer to the example.

This class is particularly useful in scenarios where users need guidance on framing specific regions, such as ID card or document scanning.

Inheritance

Constructors

RectanglePainterV2({double? topMargin, double strokeWidth = 2.0, Color strokeColor = Colors.white, Color? overlayColor, Radius? borderRadius})

Properties

borderRadius ↔ Radius?
getter/setter pair
hashCode → int
The hash code for this object.
no setterinherited
overlayColor ↔ 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
size ↔ Size? Function(Size)?
getter/setter pair
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