1 /* 2 * Copyright (C) 2013 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.example.android.bitmapscaling; 18 19 import android.app.Activity; 20 import android.graphics.Bitmap; 21 import android.graphics.BitmapFactory; 22 import android.os.Bundle; 23 import android.widget.ImageView; 24 import android.widget.LinearLayout; 25 import android.widget.LinearLayout.LayoutParams; 26 27 /** 28 * This example shows how the use of BitmapOptions affects the resulting size of a loaded 29 * bitmap. Sub-sampling can speed up load times and reduce the need for large bitmaps 30 * in memory if your target bitmap size is much smaller, although it's good to understand 31 * that you can't get specific Bitmap sizes, but rather power-of-two reductions in sizes. 32 * 33 * Watch the associated video for this demo on the DevBytes channel of developer.android.com 34 * or on YouTube at https://www.youtube.com/watch?v=12cB7gnL6po. 35 */ 36 public class BitmapScaling extends Activity { 37 38 @Override 39 public void onCreate(Bundle savedInstanceState) { 40 super.onCreate(savedInstanceState); 41 setContentView(R.layout.activity_bitmap_scaling); 42 43 LinearLayout container = (LinearLayout) findViewById(R.id.scaledImageContainer); 44 ImageView originalImageView = (ImageView) findViewById(R.id.originalImageHolder); 45 46 Bitmap bitmap = BitmapFactory.decodeResource(getResources(), 47 R.drawable.jellybean_statue); 48 originalImageView.setImageBitmap(bitmap); 49 50 for (int i = 2; i < 10; ++i) { 51 addScaledImageView(bitmap, i, container); 52 } 53 } 54 55 private void addScaledImageView(Bitmap original, int sampleSize, LinearLayout container) { 56 57 // inSampleSize tells the loader how much to scale the final image, which it does at 58 // load time by simply reading less pixels for every pixel value in the final bitmap. 59 // Note that it only scales by powers of two, so a value of two results in a bitmap 60 // 1/2 the size of the original and a value of four results in a bitmap 1/4 the original 61 // size. Intermediate values are rounded down, so a value of three results in a bitmap 1/2 62 // the original size. 63 64 BitmapFactory.Options bitmapOptions = new BitmapFactory.Options(); 65 bitmapOptions.inSampleSize = sampleSize; 66 67 Bitmap scaledBitmap = BitmapFactory.decodeResource(getResources(), 68 R.drawable.jellybean_statue, bitmapOptions); 69 ImageView scaledImageView = new ImageView(this); 70 scaledImageView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, 71 LayoutParams.WRAP_CONTENT)); 72 scaledImageView.setImageBitmap(scaledBitmap); 73 container.addView(scaledImageView); 74 } 75 } 76
