OnDraw triangle on a button
In a class I created that extends Button
, I redefined the function onDraw
to create a triangle on the right side of the button pointing to the center:
Instead, I get: 
Here's what I wrote:
Paint paint = new Paint();
@Override
public void onDraw(Canvas canvas)
{
Paint paint = new Paint();
paint.setColor(android.graphics.Color.BLACK);
canvas.drawPaint(paint);
paint.setStrokeWidth(4);
paint.setStyle(Paint.Style.FILL_AND_STROKE);
paint.setAntiAlias(true);
Point center = new Point(getWidth()/2, getHeight()/2);
Point a=new Point(getWidth(), 0);;
Point b=new Point(getWidth(), getHeight());;
paint.setColor(Color.RED);
Path path= new Path();
path.setFillType(Path.FillType.EVEN_ODD);
path.lineTo(b.x, b.y);
path.lineTo(center.x, center.y);
path.lineTo(a.x, a.y);
path.close();
canvas.drawPath(path, paint);
}
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1 answer
You forgot to move to the starting point.
Something like
path.moveTo(point1_draw.x,point1_draw.y);
before the first lineTo()
Because it lineTo()
takes a "last point" to start a segment.
void lineTo(float x, float y) // Add a line from the last point to the specified point (x,y).
So in the end, your cod will look like this:
Path path= new Path();
path.setFillType(Path.FillType.EVEN_ODD);
path.moveTo(a.x, a.y); // Move to a
path.lineTo(center.x, center.y); // Segment from a to center
path.lineTo(b.x, b.y); // Segment from center to b
path.close(); // Segment from b to a
canvas.drawPath(path, paint);
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