ImageViewUtil.java

package com.aitorvs.android.rsspace.util;

/*
 * Copyright (C) 21/08/16 aitorvs
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License 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.Matrix;
import android.graphics.drawable.Drawable;
import android.widget.ImageView;

public class ImageViewUtil {

    /**
     * Returns the bitmap position inside an imageView.
     *
     * @param imageView source ImageView
     * @return 0: left, 1: top, 2: width, 3: height
     */
    public static int[] getDisplayedImageLocation(ImageView imageView) {
        int[] ret = new int[4];

        if (imageView == null || imageView.getDrawable() == null)
            return ret;

        // Get image dimensions
        // Get image matrix values and place them in an array
        float[] f = new float[9];
        imageView.getImageMatrix().getValues(f);

        // Extract the scale values using the constants (if aspect ratio maintained, scaleX == scaleY)
        final float scaleX = f[Matrix.MSCALE_X];
        final float scaleY = f[Matrix.MSCALE_Y];

        // Get the drawable (could also get the bitmap behind the drawable and getWidth/getHeight)
        final Drawable d = imageView.getDrawable();
        final int origW = d.getIntrinsicWidth();
        final int origH = d.getIntrinsicHeight();

        // Calculate the actual dimensions
        final int actW = Math.round(origW * scaleX);
        final int actH = Math.round(origH * scaleY);

        ret[2] = actW;
        ret[3] = actH;

        // Get image position
        // We assume that the image is centered into ImageView
        int imgViewW = imageView.getWidth();
        int imgViewH = imageView.getHeight();

        int[] imgViewScreenLoc = new int[2];
        imageView.getLocationOnScreen(imgViewScreenLoc);

        // get the actual image location inside its image view
        int left = imgViewScreenLoc[0] + (imgViewW - actW) / 2;
        int top = imgViewScreenLoc[1] + (imgViewH - actH) / 2;

        ret[0] = left;
        ret[1] = top;

        return ret;
    }
}