独自ビューを用意して、三角形を描く
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int height = getContext().getResources().getDimensionPixelSize(
R.dimen.change_list_mark_height);
int width = getContext().getResources().getDimensionPixelSize(
R.dimen.change_list_mark_width);
setMeasuredDimension(width, height);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.TRANSPARENT);
Paint paint = new Paint();
paint.setAntiAlias(true);
// 三角形を描く
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.FILL_AND_STROKE);
Path path = new Path();
path.moveTo(getWidth(), 0);
path.lineTo(getWidth(), getHeight());
path.lineTo(0, 0);
path.lineTo(getWidth(), 0);
canvas.drawPath(path, paint);
}