| /* |
| * Copyright (C) 2009 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.camera.gallery; |
| |
| import com.android.camera.ImageManager; |
| import com.android.camera.Util; |
| |
| import android.content.ContentResolver; |
| import android.content.ContentUris; |
| import android.database.Cursor; |
| import android.net.Uri; |
| import android.util.Log; |
| |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| /** |
| * A collection of <code>BaseImage</code>s. |
| */ |
| public abstract class BaseImageList implements IImageList { |
| private static final String TAG = "BaseImageList"; |
| private static final int CACHE_CAPACITY = 512; |
| private final LruCache<Integer, BaseImage> mCache = |
| new LruCache<Integer, BaseImage>(CACHE_CAPACITY); |
| |
| protected ContentResolver mContentResolver; |
| protected int mSort; |
| |
| protected Uri mBaseUri; |
| protected Cursor mCursor; |
| protected String mBucketId; |
| protected boolean mCursorDeactivated = false; |
| |
| public BaseImageList(ContentResolver resolver, Uri uri, int sort, |
| String bucketId) { |
| mSort = sort; |
| mBaseUri = uri; |
| mBucketId = bucketId; |
| mContentResolver = resolver; |
| mCursor = createCursor(); |
| |
| if (mCursor == null) { |
| Log.w(TAG, "createCursor returns null."); |
| } |
| |
| // TODO: We need to clear the cache because we may "reopen" the image |
| // list. After we implement the image list state, we can remove this |
| // kind of usage. |
| mCache.clear(); |
| } |
| |
| public void close() { |
| try { |
| invalidateCursor(); |
| } catch (IllegalStateException e) { |
| // IllegalStateException may be thrown if the cursor is stale. |
| Log.e(TAG, "Caught exception while deactivating cursor.", e); |
| } |
| mContentResolver = null; |
| if (mCursor != null) { |
| mCursor.close(); |
| mCursor = null; |
| } |
| } |
| |
| // TODO: Change public to protected |
| public Uri contentUri(long id) { |
| // TODO: avoid using exception for most cases |
| try { |
| // does our uri already have an id (single image query)? |
| // if so just return it |
| long existingId = ContentUris.parseId(mBaseUri); |
| if (existingId != id) Log.e(TAG, "id mismatch"); |
| return mBaseUri; |
| } catch (NumberFormatException ex) { |
| // otherwise tack on the id |
| return ContentUris.withAppendedId(mBaseUri, id); |
| } |
| } |
| |
| public int getCount() { |
| Cursor cursor = getCursor(); |
| if (cursor == null) return 0; |
| synchronized (this) { |
| return cursor.getCount(); |
| } |
| } |
| |
| public boolean isEmpty() { |
| return getCount() == 0; |
| } |
| |
| private Cursor getCursor() { |
| synchronized (this) { |
| if (mCursor == null) return null; |
| if (mCursorDeactivated) { |
| mCursor.requery(); |
| mCursorDeactivated = false; |
| } |
| return mCursor; |
| } |
| } |
| |
| public IImage getImageAt(int i) { |
| BaseImage result = mCache.get(i); |
| if (result == null) { |
| Cursor cursor = getCursor(); |
| if (cursor == null) return null; |
| synchronized (this) { |
| result = cursor.moveToPosition(i) |
| ? loadImageFromCursor(cursor) |
| : null; |
| mCache.put(i, result); |
| } |
| } |
| return result; |
| } |
| |
| public boolean removeImage(IImage image) { |
| // TODO: need to delete the thumbnails as well |
| if (mContentResolver.delete(image.fullSizeImageUri(), null, null) > 0) { |
| ((BaseImage) image).onRemove(); |
| invalidateCursor(); |
| invalidateCache(); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| public boolean removeImageAt(int i) { |
| // TODO: need to delete the thumbnails as well |
| return removeImage(getImageAt(i)); |
| } |
| |
| protected abstract Cursor createCursor(); |
| |
| protected abstract BaseImage loadImageFromCursor(Cursor cursor); |
| |
| protected abstract long getImageId(Cursor cursor); |
| |
| protected void invalidateCursor() { |
| if (mCursor == null) return; |
| mCursor.deactivate(); |
| mCursorDeactivated = true; |
| } |
| |
| protected void invalidateCache() { |
| mCache.clear(); |
| } |
| |
| private static final Pattern sPathWithId = Pattern.compile("(.*)/\\d+"); |
| |
| private static String getPathWithoutId(Uri uri) { |
| String path = uri.getPath(); |
| Matcher matcher = sPathWithId.matcher(path); |
| return matcher.matches() ? matcher.group(1) : path; |
| } |
| |
| private boolean isChildImageUri(Uri uri) { |
| // Sometimes, the URI of an image contains a query string with key |
| // "bucketId" inorder to restore the image list. However, the query |
| // string is not part of the mBaseUri. So, we check only other parts |
| // of the two Uri to see if they are the same. |
| Uri base = mBaseUri; |
| return Util.equals(base.getScheme(), uri.getScheme()) |
| && Util.equals(base.getHost(), uri.getHost()) |
| && Util.equals(base.getAuthority(), uri.getAuthority()) |
| && Util.equals(base.getPath(), getPathWithoutId(uri)); |
| } |
| |
| public IImage getImageForUri(Uri uri) { |
| if (!isChildImageUri(uri)) return null; |
| // Find the id of the input URI. |
| long matchId; |
| try { |
| matchId = ContentUris.parseId(uri); |
| } catch (NumberFormatException ex) { |
| Log.i(TAG, "fail to get id in: " + uri, ex); |
| return null; |
| } |
| // TODO: design a better method to get URI of specified ID |
| Cursor cursor = getCursor(); |
| if (cursor == null) return null; |
| synchronized (this) { |
| cursor.moveToPosition(-1); // before first |
| for (int i = 0; cursor.moveToNext(); ++i) { |
| if (getImageId(cursor) == matchId) { |
| BaseImage image = mCache.get(i); |
| if (image == null) { |
| image = loadImageFromCursor(cursor); |
| mCache.put(i, image); |
| } |
| return image; |
| } |
| } |
| return null; |
| } |
| } |
| |
| public int getImageIndex(IImage image) { |
| return ((BaseImage) image).mIndex; |
| } |
| |
| // This provides a default sorting order string for subclasses. |
| // The list is first sorted by date, then by id. The order can be ascending |
| // or descending, depending on the mSort variable. |
| // The date is obtained from the "datetaken" column. But if it is null, |
| // the "date_modified" column is used instead. |
| protected String sortOrder() { |
| String ascending = |
| (mSort == ImageManager.SORT_ASCENDING) |
| ? " ASC" |
| : " DESC"; |
| |
| // Use DATE_TAKEN if it's non-null, otherwise use DATE_MODIFIED. |
| // DATE_TAKEN is in milliseconds, but DATE_MODIFIED is in seconds. |
| String dateExpr = |
| "case ifnull(datetaken,0)" + |
| " when 0 then date_modified*1000" + |
| " else datetaken" + |
| " end"; |
| |
| // Add id to the end so that we don't ever get random sorting |
| // which could happen, I suppose, if the date values are the same. |
| return dateExpr + ascending + ", _id" + ascending; |
| } |
| } |