android/camera/Util.java

/*
 * Copyright (C) 2009 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.
 */

package com.android.camera;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.util.Log;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.TranslateAnimation;

import com.android.camera.gallery.IImage;
import com.android.camera.R;

import java.io.Closeable;

/**
 * Collection of utility functions used in this package.
 */
public class Util {
    private static final String TAG = "Util";
    public static final int DIRECTION_LEFT = 0;
    public static final int DIRECTION_RIGHT = 1;
    public static final int DIRECTION_UP = 2;
    public static final int DIRECTION_DOWN = 3;

    public static final String REVIEW_ACTION = "com.cooliris.media.action.REVIEW";

    private Util() {
    }

    // Rotates the bitmap by the specified degree.
    // If a new bitmap is created, the original bitmap is recycled.
    public static Bitmap rotate(Bitmap b, int degrees) {
        if (degrees != 0 && b != null) {
            Matrix m = new Matrix();
            m.setRotate(degrees,
                    (float) b.getWidth() / 2, (float) b.getHeight() / 2);
            try {
                Bitmap b2 = Bitmap.createBitmap(
                        b, 0, 0, b.getWidth(), b.getHeight(), m, true);
                if (b != b2) {
                    b.recycle();
                    b = b2;
                }
            } catch (OutOfMemoryError ex) {
                // We have no memory to rotate. Return the original bitmap.
            }
        }
        return b;
    }

    /*
     * Compute the sample size as a function of minSideLength
     * and maxNumOfPixels.
     * minSideLength is used to specify that minimal width or height of a
     * bitmap.
     * maxNumOfPixels is used to specify the maximal size in pixels that is
     * tolerable in terms of memory usage.
     *
     * The function returns a sample size based on the constraints.
     * Both size and minSideLength can be passed in as IImage.UNCONSTRAINED,
     * which indicates no care of the corresponding constraint.
     * The functions prefers returning a sample size that
     * generates a smaller bitmap, unless minSideLength = IImage.UNCONSTRAINED.
     *
     * Also, the function rounds up the sample size to a power of 2 or multiple
     * of 8 because BitmapFactory only honors sample size this way.
     * For example, BitmapFactory downsamples an image by 2 even though the
     * request is 3. So we round up the sample size to avoid OOM.
     */
    public static int computeSampleSize(BitmapFactory.Options options,
            int minSideLength, int maxNumOfPixels) {
        int initialSize = computeInitialSampleSize(options, minSideLength,
                maxNumOfPixels);

        int roundedSize;
        if (initialSize <= 8) {
            roundedSize = 1;
            while (roundedSize < initialSize) {
                roundedSize <<= 1;
            }
        } else {
            roundedSize = (initialSize + 7) / 8 * 8;
        }

        return roundedSize;
    }

    private static int computeInitialSampleSize(BitmapFactory.Options options,
            int minSideLength, int maxNumOfPixels) {
        double w = options.outWidth;
        double h = options.outHeight;

        int lowerBound = (maxNumOfPixels == IImage.UNCONSTRAINED) ? 1 :
                (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
        int upperBound = (minSideLength == IImage.UNCONSTRAINED) ? 128 :
                (int) Math.min(Math.floor(w / minSideLength),
                Math.floor(h / minSideLength));

        if (upperBound < lowerBound) {
            // return the larger one when there is no overlapping zone.
            return lowerBound;
        }

        if ((maxNumOfPixels == IImage.UNCONSTRAINED) &&
                (minSideLength == IImage.UNCONSTRAINED)) {
            return 1;
        } else if (minSideLength == IImage.UNCONSTRAINED) {
            return lowerBound;
        } else {
            return upperBound;
        }
    }

    public static <T>  int indexOf(T [] array, T s) {
        for (int i = 0; i < array.length; i++) {
            if (array[i].equals(s)) {
                return i;
            }
        }
        return -1;
    }

    public static void closeSilently(Closeable c) {
        if (c == null) return;
        try {
            c.close();
        } catch (Throwable t) {
            // do nothing
        }
    }

    public static Bitmap makeBitmap(byte[] jpegData, int maxNumOfPixels) {
        try {
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            BitmapFactory.decodeByteArray(jpegData, 0, jpegData.length,
                    options);
            if (options.mCancel || options.outWidth == -1
                    || options.outHeight == -1) {
                return null;
            }
            options.inSampleSize = computeSampleSize(
                    options, IImage.UNCONSTRAINED, maxNumOfPixels);
            options.inJustDecodeBounds = false;

            options.inDither = false;
            options.inPreferredConfig = Bitmap.Config.ARGB_8888;
            return BitmapFactory.decodeByteArray(jpegData, 0, jpegData.length,
                    options);
        } catch (OutOfMemoryError ex) {
            Log.e(TAG, "Got oom exception ", ex);
            return null;
        }
    }

    public static void Assert(boolean cond) {
        if (!cond) {
            throw new AssertionError();
        }
    }

    public static void showFatalErrorAndFinish(
            final Activity activity, String title, String message) {
        DialogInterface.OnClickListener buttonListener =
                new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                activity.finish();
            }
        };
        new AlertDialog.Builder(activity)
                .setCancelable(false)
                .setIcon(android.R.drawable.ic_dialog_alert)
                .setTitle(title)
                .setMessage(message)
                .setNeutralButton(R.string.details_ok, buttonListener)
                .show();
    }

    public static Animation slideOut(View view, int to) {
        view.setVisibility(View.INVISIBLE);
        Animation anim;
        switch (to) {
            case DIRECTION_LEFT:
                anim = new TranslateAnimation(0, -view.getWidth(), 0, 0);
                break;
            case DIRECTION_RIGHT:
                anim = new TranslateAnimation(0, view.getWidth(), 0, 0);
                break;
            case DIRECTION_UP:
                anim = new TranslateAnimation(0, 0, 0, -view.getHeight());
                break;
            case DIRECTION_DOWN:
                anim = new TranslateAnimation(0, 0, 0, view.getHeight());
                break;
            default:
                throw new IllegalArgumentException(Integer.toString(to));
        }
        anim.setDuration(500);
        view.startAnimation(anim);
        return anim;
    }

    public static Animation slideIn(View view, int from) {
        view.setVisibility(View.VISIBLE);
        Animation anim;
        switch (from) {
            case DIRECTION_LEFT:
                anim = new TranslateAnimation(-view.getWidth(), 0, 0, 0);
                break;
            case DIRECTION_RIGHT:
                anim = new TranslateAnimation(view.getWidth(), 0, 0, 0);
                break;
            case DIRECTION_UP:
                anim = new TranslateAnimation(0, 0, -view.getHeight(), 0);
                break;
            case DIRECTION_DOWN:
                anim = new TranslateAnimation(0, 0, view.getHeight(), 0);
                break;
            default:
                throw new IllegalArgumentException(Integer.toString(from));
        }
        anim.setDuration(500);
        view.startAnimation(anim);
        return anim;
    }

    public static <T> T checkNotNull(T object) {
        if (object == null) throw new NullPointerException();
        return object;
    }

    public static boolean equals(Object a, Object b) {
        return (a == b) || (a == null ? false : a.equals(b));
    }

    public static boolean isPowerOf2(int n) {
        return (n & -n) == n;
    }

    public static int nextPowerOf2(int n) {
        n -= 1;
        n |= n >>> 16;
        n |= n >>> 8;
        n |= n >>> 4;
        n |= n >>> 2;
        n |= n >>> 1;
        return n + 1;
    }

    public static float distance(float x, float y, float sx, float sy) {
        float dx = x - sx;
        float dy = y - sy;
        return (float) Math.sqrt(dx * dx + dy * dy);
    }

    public static int clamp(int x, int min, int max) {
        if (x > max) return max;
        if (x < min) return min;
        return x;
    }
}