CutoutTicketView.java

package app.pasaporte.ui.widget;

import android.content.Context;
import android.graphics.Path;
import android.graphics.RectF;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.util.AttributeSet;

import app.pasaporte.ui.widget.shapeofview.ClipPathManager;
import app.pasaporte.ui.widget.shapeofview.ShapeOfView;

public class CutoutTicketView extends ShapeOfView {

    private static final int DEFAULT_SCALLOP_RADIUS = 10;       //dp
    private static final int DEFAULT_CORNER_RADIUS = 4;         //dp
    private static final float DEFAULT_SHADOW_BLUR_RADIUS = 6f; //dp

    private RectF roundedCornerArc = new RectF();
    private RectF scallopCornerArc = new RectF();

    private int mScallopRadius;
    private int mCornerRadius;
    private float mShadowBlurRadius;

    public CutoutTicketView(@NonNull Context context) {
        this(context, null);
    }

    public CutoutTicketView(@NonNull Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public CutoutTicketView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        final int density = (int) context.getResources().getDisplayMetrics().density;

        mScallopRadius = DEFAULT_SCALLOP_RADIUS * density;
        mCornerRadius = DEFAULT_CORNER_RADIUS * density;
        setShadowBlurRadius(DEFAULT_SHADOW_BLUR_RADIUS * density);

        super.setClipPathCreator(new ClipPathManager.ClipPathCreator() {
            @Override
            public Path createClipPath(int width, int height) {
                float left = getPaddingLeft() + mShadowBlurRadius;
                float right = getWidth() - getPaddingRight() - mShadowBlurRadius;
                float top = getPaddingTop() + (mShadowBlurRadius / 2);
                float bottom = getHeight() - getPaddingBottom();
                return generatePath(left, right, top, bottom);
            }

            @Override
            public boolean requiresBitmap() {
                return false;
            }
        });
    }

    private Path generatePath(float left, float right, float top, float bottom) {
        final Path path = new Path();
        //top rounded corners
        path.arcTo(getTopLeftCornerRoundedArc(top, left), 180.0f, 90.0f, false);
        path.lineTo(left + mCornerRadius, top);

        path.lineTo(right - mCornerRadius, top);
        path.arcTo(getTopRightCornerRoundedArc(top, right), -90.0f, 90.0f, false);

        //bottom scallop corners
        path.arcTo(getBottomRightCornerScallopArc(bottom, right), 270.0f, -90.0f, false);
        path.lineTo(right - mScallopRadius, bottom);

        path.lineTo(left + mScallopRadius, bottom);
        path.arcTo(getBottomLeftCornerScallopArc(left, bottom), 0.0f, -90.0f, false);

        path.close();
        return path;
    }

    private RectF getTopLeftCornerRoundedArc(float top, float left) {
        roundedCornerArc.set(left, top, left + mCornerRadius * 2, top + mCornerRadius * 2);
        return roundedCornerArc;
    }

    private RectF getTopRightCornerRoundedArc(float top, float right) {
        roundedCornerArc.set(right - mCornerRadius * 2, top, right, top + mCornerRadius * 2);
        return roundedCornerArc;
    }

    private RectF getBottomLeftCornerScallopArc(float left, float bottom) {
        scallopCornerArc.set(left - mScallopRadius, bottom - mScallopRadius, left + mScallopRadius, bottom + mScallopRadius);
        return scallopCornerArc;
    }

    private RectF getBottomRightCornerScallopArc(float bottom, float right) {
        scallopCornerArc.set(right - mScallopRadius, bottom - mScallopRadius, right + mScallopRadius, bottom + mScallopRadius);
        return scallopCornerArc;
    }

    private void setShadowBlurRadius(float elevation) {
        float maxElevation = dpToPx(24f);
        mShadowBlurRadius = Math.min(25f * (elevation / maxElevation), 25f);
    }
}