src/com/android/managedprovisioning/LogoUtils.java

/*
 * Copyright 2015, 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.managedprovisioning;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.provider.MediaStore;
import android.view.View;
import android.widget.ImageView;

import com.android.internal.annotations.VisibleForTesting;
import com.android.managedprovisioning.ProvisionLogger;

import java.io.InputStream;
import java.io.IOException;
import java.io.File;
import java.io.FileOutputStream;
import java.lang.Math;

public class LogoUtils {
    public static void saveOrganisationLogo(Context context, Uri uri) {
        final File logoFile = getOrganisationLogoFile(context);
        try {
            final InputStream in = context.getContentResolver().openInputStream(uri);
            final FileOutputStream out = new FileOutputStream(logoFile);
            final byte buffer[] = new byte[1024];
            int bytesReadCount;
            while ((bytesReadCount = in.read(buffer)) != -1) {
                out.write(buffer, 0, bytesReadCount);
            }
            out.close();
            ProvisionLogger.logi("Organisation logo from uri " + uri + " has been successfully"
                    + " copied to " + logoFile);
        } catch (IOException e) {
            ProvisionLogger.logi("Could not write organisation logo from " + uri + " to "
                    + logoFile, e);
            // If the file was only partly written, delete it.
            logoFile.delete();
        }
    }

    public static Drawable getOrganisationLogo(Context context) {
        final File logoFile = getOrganisationLogoFile(context);
        Bitmap bitmap = null;
        int maxWidth = (int) context.getResources().getDimension(R.dimen.max_logo_width);
        int maxHeight = (int) context.getResources().getDimension(R.dimen.max_logo_height);
        if (logoFile.exists()) {
            bitmap = getBitmapPartiallyResized(logoFile.getPath(), maxWidth, maxHeight);
            if (bitmap == null) {
                ProvisionLogger.loge("Could not get organisation logo from " + logoFile);
            }
        }
        // If the app that started ManagedProvisioning didn't specify a logo or we couldn't get a
        // logo from the uri they specified, use the default logo.
        if (bitmap == null) {
            bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.ic_corp_icon);
        }
        return new BitmapDrawable(context.getResources(),
                resizeBitmap(bitmap, maxWidth, maxHeight));
    }

    /**
     * Decodes a bitmap from an input stream.
     * If the actual dimensions of the bitmap are larger than the desired ones, will try to return a
     * subsample.
     * The point of using this method is that the entire image may be too big to fit entirely in
     * memmory. Since we may not need the entire image anyway, it's better to only decode a
     * subsample when possible.
     */
    @VisibleForTesting
    static Bitmap getBitmapPartiallyResized(String filePath, int maxDesiredWidth,
            int maxDesiredHeight) {
        BitmapFactory.Options bounds = new BitmapFactory.Options();
        // Firstly, let's just get the dimensions of the image.
        bounds.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(filePath, bounds);
        int streamWidth = bounds.outWidth;
        int streamHeight = bounds.outHeight;
        int ratio = Math.max(streamWidth / maxDesiredWidth, streamHeight / maxDesiredHeight);
        if (ratio > 1) {
            // Decodes a smaller bitmap. Note that this ratio will be rounded down to the nearest
            // power of 2. The decoded bitmap will not have the expected size, but we'll do another
            // round of scaling.
            bounds.inSampleSize = ratio;
        }
        bounds.inJustDecodeBounds = false;
        // Now, decode the actual bitmap
        return BitmapFactory.decodeFile(filePath, bounds);
    }

    /*
     * Returns a new Bitmap with the specified maximum width and height. Does scaling if
     * necessary. Keeps the ratio of the original image.
     */
    @VisibleForTesting
    static Bitmap resizeBitmap(Bitmap bitmap, int maxWidth, int maxHeight) {
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        double ratio = Math.max((double) width / maxWidth, (double) height / maxHeight);
        // We don't scale up.
        if (ratio > 1) {
            width /= ratio;
            height /= ratio;
            bitmap = Bitmap.createScaledBitmap(bitmap, width, height, false);
        }
        return bitmap;
    }

    public static void cleanUp(Context context) {
        getOrganisationLogoFile(context).delete();
    }

    private static File getOrganisationLogoFile(Context context) {
        return new File(context.getFilesDir() + File.separator + "organisation_logo");
    }
}