Returns a new Bitmap copy with a crop effect depending on the crop anchor given. - Android Graphics

Android examples for Graphics:Bitmap Effect

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Description

Returns a new Bitmap copy with a crop effect depending on the crop anchor given.

Demo Code

/*/*from   w w w .ja  va  2 s.co m*/
 * Copyright (C) 2012 The Android Open Source Project
 *
 * 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.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import com.android.mail.utils.LogUtils;

public class Main{
    private static final boolean DEBUG = false;
    /**
     * Returns a new Bitmap copy with a crop effect depending on the crop anchor given. 0.5f is like
     * {@link android.widget.ImageView.ScaleType#CENTER_CROP}. The crop anchor will be be nudged
     * so the entire cropped bitmap will fit inside the src. May return the input bitmap if no
     * scaling is necessary.
     *
     *
     * Example of changing verticalCenterPercent:
     *   _________            _________
     *  |         |          |         |
     *  |         |          |_________|
     *  |         |          |         |/___0.3f
     *  |---------|          |_________|\
     *  |         |<---0.5f  |         |
     *  |---------|          |         |
     *  |         |          |         |
     *  |         |          |         |
     *  |_________|          |_________|
     *
     * @param src original bitmap of any size
     * @param w desired width in px
     * @param h desired height in px
     * @param horizontalCenterPercent determines which part of the src to crop from. Range from 0
     *                                .0f to 1.0f. The value determines which part of the src
     *                                maps to the horizontal center of the resulting bitmap.
     * @param verticalCenterPercent determines which part of the src to crop from. Range from 0
     *                              .0f to 1.0f. The value determines which part of the src maps
     *                              to the vertical center of the resulting bitmap.
     * @return a copy of src conforming to the given width and height, or src itself if it already
     *         matches the given width and height
     */
    public static Bitmap crop(final Bitmap src, final int w, final int h,
            final float horizontalCenterPercent,
            final float verticalCenterPercent) {
        if (horizontalCenterPercent < 0 || horizontalCenterPercent > 1
                || verticalCenterPercent < 0 || verticalCenterPercent > 1) {
            throw new IllegalArgumentException(
                    "horizontalCenterPercent and verticalCenterPercent must be between 0.0f and "
                            + "1.0f, inclusive.");
        }
        final int srcWidth = src.getWidth();
        final int srcHeight = src.getHeight();

        // exit early if no resize/crop needed
        if (w == srcWidth && h == srcHeight) {
            return src;
        }

        final Matrix m = new Matrix();
        final float scale = Math.max((float) w / srcWidth, (float) h
                / srcHeight);
        m.setScale(scale, scale);

        final int srcCroppedW, srcCroppedH;
        int srcX, srcY;

        srcCroppedW = Math.round(w / scale);
        srcCroppedH = Math.round(h / scale);
        srcX = (int) (srcWidth * horizontalCenterPercent - srcCroppedW / 2);
        srcY = (int) (srcHeight * verticalCenterPercent - srcCroppedH / 2);

        // Nudge srcX and srcY to be within the bounds of src
        srcX = Math.max(Math.min(srcX, srcWidth - srcCroppedW), 0);
        srcY = Math.max(Math.min(srcY, srcHeight - srcCroppedH), 0);

        final Bitmap cropped = Bitmap.createBitmap(src, srcX, srcY,
                srcCroppedW, srcCroppedH, m, true /* filter */);

        if (DEBUG)
            LogUtils.i(PhotoManager.TAG,
                    "IN centerCrop, srcW/H=%s/%s desiredW/H=%s/%s srcX/Y=%s/%s"
                            + " innerW/H=%s/%s scale=%s resultW/H=%s/%s",
                    srcWidth, srcHeight, w, h, srcX, srcY, srcCroppedW,
                    srcCroppedH, scale, cropped.getWidth(),
                    cropped.getHeight());
        if (DEBUG && (w != cropped.getWidth() || h != cropped.getHeight())) {
            LogUtils.e(PhotoManager.TAG, new Error(),
                    "last center crop violated assumptions.");
        }

        return cropped;
    }
}

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