Minimized memory use in load of bitmaps for thumbnails generated from local files

This commit is contained in:
David A. Velasco 2014-09-23 13:34:25 +02:00
parent 7a345cf83b
commit 63de8e9229
2 changed files with 102 additions and 19 deletions

View file

@ -18,14 +18,10 @@
package com.owncloud.android.ui.adapter;
import java.io.File;
import java.io.IOException;
import java.lang.ref.WeakReference;
//import java.net.URLEncoder;
import java.util.Vector;
import android.accounts.Account;
import android.accounts.AuthenticatorException;
import android.accounts.OperationCanceledException;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
@ -51,23 +47,10 @@ import com.owncloud.android.datamodel.FileDataStorageManager;
import com.owncloud.android.datamodel.OCFile;
import com.owncloud.android.files.services.FileDownloader.FileDownloaderBinder;
import com.owncloud.android.files.services.FileUploader.FileUploaderBinder;
import com.owncloud.android.lib.common.OwnCloudAccount;
import com.owncloud.android.lib.common.OwnCloudClient;
import com.owncloud.android.lib.common.OwnCloudClientManagerFactory;
import com.owncloud.android.lib.common.accounts.AccountUtils.AccountNotFoundException;
import com.owncloud.android.ui.activity.ComponentsGetter;
import com.owncloud.android.utils.BitmapUtils;
import com.owncloud.android.utils.DisplayUtils;
/*
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
*/
/**
* This Adapter populates a ListView with all files and folders in an ownCloud
@ -171,7 +154,8 @@ public class FileListListAdapter extends BaseAdapter implements ListAdapter {
));
if (file.isDown()){
Bitmap bitmap = BitmapFactory.decodeFile(file.getStoragePath());
Bitmap bitmap = BitmapUtils.decodeSampledBitmapFromFile(
file.getStoragePath(), px, px);
if (bitmap != null) {
thumbnail = ThumbnailUtils.extractThumbnail(bitmap, px, px);

View file

@ -0,0 +1,99 @@
/* ownCloud Android client application
* Copyright (C) 2012-2014 ownCloud Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package com.owncloud.android.utils;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
/**
* Utility class with methods for decoding Bitmaps.
*
* @author David A. Velasco
*/
public class BitmapUtils {
/**
* Decodes a bitmap from a file containing it minimizing the memory use, known that the bitmap
* will be drawn in a surface of reqWidth x reqHeight
*
* @param srcPath Absolute path to the file containing the image.
* @param reqWidth Width of the surface where the Bitmap will be drawn on, in pixels.
* @param reqHeight Height of the surface where the Bitmap will be drawn on, in pixels.
* @return
*/
public static Bitmap decodeSampledBitmapFromFile(String srcPath, int reqWidth, int reqHeight) {
// set desired options that will affect the size of the bitmap
final Options options = new Options();
options.inScaled = true;
options.inPurgeable = true;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.GINGERBREAD_MR1) {
options.inPreferQualityOverSpeed = false;
}
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB) {
options.inMutable = false;
}
// make a false load of the bitmap to get its dimensions
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(srcPath, options);
// calculate factor to subsample the bitmap
options.inSampleSize = calculateSampleFactor(options, reqWidth, reqHeight);
// decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(srcPath, options);
}
/**
* Calculates a proper value for options.inSampleSize in order to decode a Bitmap minimizing
* the memory overload and covering a target surface of reqWidth x reqHeight if the original
* image is big enough.
*
* @param options Bitmap decoding options; options.outHeight and options.inHeight should
* be set.
* @param reqWidth Width of the surface where the Bitmap will be drawn on, in pixels.
* @param reqHeight Height of the surface where the Bitmap will be drawn on, in pixels.
* @return The largest inSampleSize value that is a power of 2 and keeps both
* height and width larger than reqWidth and reqHeight.
*/
private static int calculateSampleFactor(Options options, int reqWidth, int reqHeight) {
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
while ((halfHeight / inSampleSize) > reqHeight
&& (halfWidth / inSampleSize) > reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
}