Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
/**
 * Copyright 2015-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *     http://aws.amazon.com/apache2.0/
 *
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;

import android.graphics.RadialGradient;
import android.graphics.Rect;
import android.graphics.Shader;

public class Main {
    /**
     * Create a Bitmap that will be used as a mask to create the preview window in the background.
     * The Bitmap will be the given width and height. The Bitmap will be transparent except for a
     * gradient on the left and bottom sides.
     *
     * @param width Width of the mask.
     * @param height Height of the mask.
     * @param gradientSize Size of the gradient.
     * @return Bitmap mask that will be used to create a preview window.
     */
    private static Bitmap createPreviewWindowMask(int width, int height, int gradientSize) {

        // Do nothing if the size is invalid
        if (width <= 0 || height <= 0) {
            return null;
        }

        // Initialize the mask
        Bitmap mask = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(mask);
        canvas.drawColor(Color.TRANSPARENT);

        // If the gradient size is zero, don't draw the gradients
        if (gradientSize <= 0) {
            return mask;
        }

        // Calculate gradient rects
        Rect leftGradientRect = new Rect(0, 0, gradientSize, height - gradientSize);
        Rect bottomGradientRect = new Rect(leftGradientRect.right, height - gradientSize, width, height);
        Rect cornerGradientRect = new Rect(leftGradientRect.left, leftGradientRect.bottom, bottomGradientRect.left,
                bottomGradientRect.bottom);

        // Create left gradient
        Paint leftGradientPaint = new Paint();
        leftGradientPaint.setDither(true);
        leftGradientPaint.setShader(new LinearGradient(leftGradientRect.left, 0, leftGradientRect.right, 0,
                Color.BLACK, Color.TRANSPARENT, Shader.TileMode.CLAMP));

        // Create right gradient
        Paint bottomGradientPaint = new Paint();
        bottomGradientPaint.setDither(true);
        bottomGradientPaint.setShader(
                new LinearGradient(leftGradientRect.right, bottomGradientRect.bottom, leftGradientRect.right,
                        bottomGradientRect.top, Color.BLACK, Color.TRANSPARENT, Shader.TileMode.CLAMP));

        // Create corner gradient
        Paint cornerGradientPaint = new Paint();
        cornerGradientPaint.setDither(true);
        cornerGradientPaint.setShader(new RadialGradient(cornerGradientRect.right, cornerGradientRect.top,
                gradientSize, Color.TRANSPARENT, Color.BLACK, Shader.TileMode.CLAMP));

        // Draw the gradients
        canvas.drawRect(leftGradientRect, leftGradientPaint);
        canvas.drawRect(bottomGradientRect, bottomGradientPaint);
        canvas.drawRect(cornerGradientRect, cornerGradientPaint);

        return mask;
    }
}