Java tutorial
/* * Copyright (C) 2014 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.murati.oszk.audiobook.utils; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.drawable.BitmapDrawable; import android.net.Uri; import android.support.v4.media.MediaMetadataCompat; import com.murati.oszk.audiobook.AlbumArtCache; import com.murati.oszk.audiobook.R; import java.io.BufferedInputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; public class BitmapHelper { private static final String TAG = LogHelper.makeLogTag(BitmapHelper.class); //TODO: remove static packagename private static final String packageName = "com.murati.oszk.audiobook"; // Max read limit that we allow our input stream to mark/reset. private static final int MAX_READ_LIMIT_PER_IMG = 1024 * 1024; public static Bitmap scaleBitmap(Bitmap src, int maxWidth, int maxHeight) { double scaleFactor = Math.min(((double) maxWidth) / src.getWidth(), ((double) maxHeight) / src.getHeight()); return Bitmap.createScaledBitmap(src, (int) (src.getWidth() * scaleFactor), (int) (src.getHeight() * scaleFactor), false); } public static Bitmap scaleBitmap(int scaleFactor, InputStream is) { // Get the dimensions of the bitmap BitmapFactory.Options bmOptions = new BitmapFactory.Options(); // Decode the image file into a Bitmap sized to fill the View bmOptions.inJustDecodeBounds = false; bmOptions.inSampleSize = scaleFactor; return BitmapFactory.decodeStream(is, null, bmOptions); } public static int findScaleFactor(int targetW, int targetH, InputStream is) { // Get the dimensions of the bitmap BitmapFactory.Options bmOptions = new BitmapFactory.Options(); bmOptions.inJustDecodeBounds = true; BitmapFactory.decodeStream(is, null, bmOptions); int actualW = bmOptions.outWidth; int actualH = bmOptions.outHeight; // Determine how much to scale down the image return Math.min(actualW / targetW, actualH / targetH); } @SuppressWarnings("SameParameterValue") public static Bitmap fetchAndRescaleBitmap(String uri, int width, int height) throws IOException { URL url = new URL(uri); BufferedInputStream is = null; try { HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); is = new BufferedInputStream(urlConnection.getInputStream()); is.mark(MAX_READ_LIMIT_PER_IMG); int scaleFactor = findScaleFactor(width, height, is); LogHelper.d(TAG, "Scaling bitmap ", uri, " by factor ", scaleFactor, " to support ", width, "x", height, "requested dimension"); is.reset(); return scaleBitmap(scaleFactor, is); } finally { if (is != null) { is.close(); } } } public static Uri convertDrawabletoUri(int resourceId) { return Uri.parse(String.format("android.resource://%s/%d", packageName, resourceId)); } }