| /* |
| * Copyright (C) 2010 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.videoeditor; |
| |
| import java.util.ArrayList; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| |
| import android.content.Context; |
| import android.graphics.Bitmap; |
| import android.graphics.drawable.BitmapDrawable; |
| import android.os.AsyncTask; |
| import android.view.View; |
| import android.view.ViewGroup; |
| import android.widget.AbsListView; |
| import android.widget.BaseAdapter; |
| import android.widget.ImageView; |
| import android.widget.TextView; |
| |
| /** |
| * Base class for BaseAdapters which load images. |
| */ |
| public abstract class BaseAdapterWithImages<K> extends BaseAdapter { |
| protected final Context mContext; |
| private final List<ImageViewHolder<K>> mViewHolders; |
| // For recording keys of images that are being loaded |
| private final Set<K> mLoadingImages; |
| private final AbsListView mListView; |
| |
| /** |
| * View holder class |
| */ |
| protected static class ImageViewHolder<K> { |
| private final ImageView mImageView; |
| private K mKey; |
| |
| public ImageViewHolder(View rowView) { |
| mImageView = (ImageView) rowView.findViewById(R.id.item_preview); |
| } |
| |
| public void setKey(K key) { |
| mKey = key; |
| } |
| } |
| |
| /** |
| * View holder class |
| */ |
| protected static class ImageTextViewHolder<K> extends ImageViewHolder<K> { |
| protected final TextView mNameView; |
| |
| public ImageTextViewHolder(View rowView) { |
| super(rowView); |
| mNameView = (TextView) rowView.findViewById(R.id.item_name); |
| } |
| } |
| |
| /** |
| * Image loader class |
| */ |
| protected class ImageLoaderAsyncTask extends AsyncTask<Void, Void, Bitmap> { |
| private final K mKey; |
| private final Object mData; |
| |
| /** |
| * Constructor |
| * |
| * @param key The bitmap key |
| * @param data The data |
| */ |
| public ImageLoaderAsyncTask(K key, Object data) { |
| mKey = key; |
| mData = data; |
| } |
| |
| @Override |
| protected Bitmap doInBackground(Void... zzz) { |
| return loadImage(mData); |
| } |
| |
| @Override |
| protected void onPostExecute(Bitmap bitmap) { |
| mLoadingImages.remove(mKey); |
| if (bitmap == null) { |
| return; |
| } |
| |
| for (ImageViewHolder<K> viewHolder : mViewHolders) { |
| if (mKey.equals(viewHolder.mKey)) { |
| viewHolder.mImageView.setImageBitmap(bitmap); |
| return; |
| } |
| } |
| |
| bitmap.recycle(); |
| } |
| } |
| |
| /** |
| * Constructor |
| * |
| * @param context The context |
| * @param listView The list view |
| */ |
| public BaseAdapterWithImages(Context context, AbsListView listView) { |
| mContext = context; |
| mListView = listView; |
| mLoadingImages = new HashSet<K>(); |
| mViewHolders = new ArrayList<ImageViewHolder<K>>(); |
| |
| mListView.setRecyclerListener(new AbsListView.RecyclerListener() { |
| @Override |
| @SuppressWarnings("unchecked") |
| public void onMovedToScrapHeap(View view) { |
| final ImageViewHolder<K> viewHolder = (ImageViewHolder<K>)view.getTag(); |
| |
| mViewHolders.remove(viewHolder); |
| viewHolder.setKey(null); |
| |
| final BitmapDrawable drawable |
| = (BitmapDrawable)viewHolder.mImageView.getDrawable(); |
| if (drawable != null && drawable.getBitmap() != null) { |
| viewHolder.mImageView.setImageDrawable(null); |
| drawable.getBitmap().recycle(); |
| } |
| } |
| }); |
| } |
| |
| public void onPause() { |
| mViewHolders.clear(); |
| } |
| |
| /** |
| * Upon destroy, recycle all images and then remove all child views in the list view. |
| */ |
| public void onDestroy() { |
| final int count = mListView.getChildCount(); |
| for (int i = 0; i < count; i++) { |
| final View rowView = mListView.getChildAt(i); |
| final ImageView imageView = (ImageView)rowView.findViewById(R.id.item_preview); |
| final BitmapDrawable drawable = (BitmapDrawable)imageView.getDrawable(); |
| if (drawable != null && drawable.getBitmap() != null) { |
| drawable.getBitmap().recycle(); |
| } |
| } |
| |
| mListView.removeViews(0, count); |
| System.gc(); |
| } |
| |
| /** |
| * Starts the AsyncTask which loads the bitmap. |
| * |
| * @param key The bitmap key |
| * @param data The data |
| * @param viewHolder The view holder |
| */ |
| protected void initiateLoad(K key, Object data, ImageViewHolder<K> viewHolder) { |
| // The adapter may recycle a view and then reuse it. |
| if (!mViewHolders.contains(viewHolder)) { |
| mViewHolders.add(viewHolder); |
| } |
| viewHolder.setKey(key); |
| |
| if (!mLoadingImages.contains(key)) { |
| mLoadingImages.add(key); |
| new ImageLoaderAsyncTask(key, data).execute(); |
| } |
| } |
| |
| @Override |
| public long getItemId(int position) { |
| return position; |
| } |
| |
| @Override |
| public abstract int getCount(); |
| |
| @Override |
| public abstract Object getItem(int position); |
| |
| @Override |
| public abstract View getView(int position, View convertView, ViewGroup parent); |
| |
| /** |
| * Loads an image based on its key. |
| * |
| * @param data The data required to load the image |
| * |
| * @return The loaded bitmap |
| */ |
| protected abstract Bitmap loadImage(Object data); |
| } |