touchable 👆🏻 #

Flutter library to add various gesture callbacks to each Shape you draw on your canvas in your CustomPainter

Why Use Touchable ? #

• The CustomPainter lets you only draw shapes on the canvas. But most would want to let user interact with the drawings.

• With touchable , you get what the normal canvas always missed : touchability 😉

• With this , its possible to add all kinds of gesture callbacks to each drawing and thus interaction capability to each Shape you draw on the canvas.

• Animating individual shapes becomes so much easier than ever before.

• Automatically handles the painting style of your drawing. So , when your paint is filled ▮ it registers touch on the entire shape else when its stroke ▯ , it looks for gesture only on the borders.

• Takes the painting stroke width also into account. So if your shapes are painted thick , we still got it covered ✓

• Supports and handles clipping and different clipping modes. So, You can have any kind of complex clipping and drawing combinations while getting full interactive capability.

• Simple and Easy API. Just wrap your CustomPaint with CanvasTouchDetector and use the TouchCanvas in your painter.

Usage : #

• Just Wrap your CustomPaint widget with CanvasTouchDetector. It takes a builder function as argument that expects your CustomPaint widget as shown below.

CanvasTouchDetector(
    builder: (context) => 
        CustomPaint(
            painter: MyPainter(context)
        )
)

• Inside your CustomPainter class's paint method , create and use the TouchyCanvas object (using the context obtained from the CanvasTouchDetector and canvas) to draw any shape with different gesture callbacks.

var myCanvas = TouchyCanvas(context,canvas);
myCanvas.drawRect( rect , Paint() , onTapDown: (tapDetail){
    //Do stuff here. Probably change your state and animate
});

MyPainter example : #

class MyPainter extends CustomPainter {

  final BuildContext context ;
  MyPainter(this.context); // context from CanvasTouchDetector

  @override
  void paint(Canvas canvas, Size size) {
    var myCanvas = TouchyCanvas(context,canvas); 

    myCanvas.drawCircle(Offset(10, 10), 60, Paint()..color=Colors.orange ,
        onTapDown: (_) {
      print("orange Circle touched");
    });

    myCanvas.drawLine(
        Offset(0, 0),
        Offset(size.width - 100, size.height - 100),
        Paint()
          ..color = Colors.black
          ..strokeWidth = 50, 
        onPanUpdate: (detail) {
            print('Black line Swiped'); //do cooler things here. Probably change app state or animate
    });
  }
}