import android.database.CursorJoiner; //导入依赖的package包/类
/**
 * todo:
 *
 * @param newCursor
 * @param oldCursor
 * @return
 */
@NonNull
@SuppressWarnings("ConstantConditions")
public Result processCursors(@Nullable Cursor newCursor, @Nullable Cursor oldCursor) {
	if (newCursor == null && oldCursor == null) return new Result();
	Result result;
	if ((result = processCursorsTotalChange(oldCursor, newCursor)) != null) {
		return result;
	}

	final CursorJoiner joiner = new CursorJoiner(
			oldCursor, COMPARABLE_COLUMN_NAMES,
			newCursor, COMPARABLE_COLUMN_NAMES
	);

	mInsertHandler.clear();
	mRemoveHandler.clear();
	result = new Result();

	DataSetChange[] dataSetChanges;
	for (CursorJoiner.Result joinerResult : joiner) {
		switch (joinerResult) {
			// Row has been removed.
			case LEFT:
				this.resolvePendingChange(mInsertHandler, result);

				dataSetChanges = mRemoveHandler.handleChange(oldCursor.getPosition());
				if (dataSetChanges != null) {
					if (dataSetChanges.length == 1) {
						result.addDataSetChange(dataSetChanges[0]);
					} else {
						result.addDataSetChange(dataSetChanges[1]);
					}
				}
				break;
			// Row has been inserted.
			case RIGHT:
				this.resolvePendingChange(mRemoveHandler, result);

				dataSetChanges = mInsertHandler.handleChange(newCursor.getPosition());
				if (dataSetChanges != null) {
					if (dataSetChanges.length == 1) {
						result.addDataSetChange(dataSetChanges[0]);
					} else {
						result.addDataSetChange(dataSetChanges[1]);
					}
				}
				break;
			// Row has been possibly changed.
			case BOTH:
				if (mItemChangeHandler != null && mFirstVisibleItemPosition != NO_POSITION && mLastVisibleItemPosition != NO_POSITION) {
					final int cursorPosition = newCursor.getPosition();
					if (cursorPosition >= mFirstVisibleItemPosition && cursorPosition <= mLastVisibleItemPosition &&
							mItemChangeHandler.hasChanged(newCursor)) {
						this.resolvePendingChange(mInsertHandler, result);
						this.resolvePendingChange(mRemoveHandler, result);

						// Item at the current processing position is visible and its data has
						// changed so its UI should be re-bound with the new data.
						result.addDataSetChange(new ItemChanged(cursorPosition));
						// todo: handle item range changes
					}
				}
				break;
		}
	}
	return result;
}
 

import android.database.CursorJoiner; //导入依赖的package包/类
@Override
protected void onCreateCallback(Bundle savedInstanceState) {
    Cursor medias = getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null, null, null, MediaStore.Images.Media._ID);
    String[] colunsMedia = new String[]{MediaStore.Images.Media._ID};

    int idIdx = medias.getColumnIndex(MediaStore.Images.Media._ID);
    int displayIdx = medias.getColumnIndex(MediaStore.Images.Media.DISPLAY_NAME);
    int pathIdx = medias.getColumnIndex(MediaStore.Images.Media.DATA);

    Cursor thumbnail = getContentResolver().query(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, null, null, null, MediaStore.Images.Thumbnails.IMAGE_ID);
    String[] columnsThumbnail = new String[]{MediaStore.Images.Thumbnails.IMAGE_ID};

    int thumbIdx = thumbnail.getColumnIndex(MediaStore.Images.Thumbnails.DATA);

    CursorJoiner joiner = new CursorJoiner(medias, colunsMedia, thumbnail, columnsThumbnail);

    mList = new ArrayList<ImageEntity>();
    mFilters = new ArrayList<ImageFilter>();
    for (CursorJoiner.Result joinerResult : joiner) {
        ImageEntity entity = new ImageEntity();
        switch (joinerResult) {
            case LEFT:
                entity.id = medias.getInt(idIdx);
                entity.displayName = medias.getString(displayIdx);
                entity.data = medias.getString(pathIdx);
                break;
            case RIGHT:
                Logs.i(TAG, "RIGHT ............");
                continue;
            case BOTH:
                entity.id = medias.getInt(idIdx);
                entity.displayName = medias.getString(displayIdx);
                entity.data = medias.getString(pathIdx);
                entity.thumb = thumbnail.getString(thumbIdx);
                break;
        }
        setToFilter(entity);
        mList.add(entity);
    }

    mGridView = (GridView) findViewById(R.id.gridview);
    mAdapter = new ImageAdapter();
    mGridView.setAdapter(mAdapter);
    medias.close();
    thumbnail.close();
    setBaseToolBarTitle("选择图片(" + 0 + "/" + mList.size() + ")");

    mFilterName = (TextView) findViewById(R.id.filter_name);
    mFilterLayout = findViewById(R.id.filter_layout);
    mFilterListView = (ListView) findViewById(R.id.filter_listview);
    mFilterAdapter = new FilterAdapter();
    mFilterListView.setAdapter(mFilterAdapter);
    mFilterListView.setOnItemClickListener(mFilterAdapter);
    mFilterName.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mFilterLayout.getVisibility() == View.VISIBLE) {
                mFilterLayout.setVisibility(View.GONE);
            } else {
                mFilterLayout.setVisibility(View.VISIBLE);
            }
        }
    });
}
 

import android.database.CursorJoiner; //导入依赖的package包/类
/**
 * Conditionally adds a flow event if no flow event exists in the current upload blob.
 */
private void conditionallyAddFlowEvent()
{
    /*
     * Creating a flow "event" is required to act as a placeholder so that the uploader will know that an upload needs to
     * occur. A flow event should only be created if there isn't already a flow event that hasn't been associated with an
     * upload blob.
     */
    boolean foundUnassociatedFlowEvent = false;

    Cursor eventsCursor = null;
    Cursor blob_eventsCursor = null;
    try
    {
        eventsCursor = mProvider.query(EventsDbColumns.TABLE_NAME, PROJECTION_FLOW_EVENTS, SELECTION_FLOW_EVENTS, SELECTION_ARGS_FLOW_EVENTS, EVENTS_SORT_ORDER);

        blob_eventsCursor = mProvider.query(UploadBlobEventsDbColumns.TABLE_NAME, PROJECTION_FLOW_BLOBS, null, null, UPLOAD_BLOBS_EVENTS_SORT_ORDER);

        final CursorJoiner joiner = new CursorJoiner(eventsCursor, PROJECTION_FLOW_EVENTS, blob_eventsCursor, PROJECTION_FLOW_BLOBS);
        for (final CursorJoiner.Result joinerResult : joiner)
        {
            switch (joinerResult)
            {
                case LEFT:
                {
                    foundUnassociatedFlowEvent = true;
                    break;
                }
                case BOTH:
                    break;
                case RIGHT:
                    break;
            }
        }
    }
    finally
    {
        if (null != eventsCursor)
        {
            eventsCursor.close();
            eventsCursor = null;
        }

        if (null != blob_eventsCursor)
        {
            blob_eventsCursor.close();
            blob_eventsCursor = null;
        }
    }

    if (!foundUnassociatedFlowEvent)
    {
        tagEvent(FLOW_EVENT, null);
    }
}
 

import android.database.CursorJoiner; //导入依赖的package包/类
/**
 * Conditionally adds a flow event if no flow event exists in the current upload blob.
 */
private void conditionallyAddFlowEvent()
{
    /*
     * Creating a flow "event" is required to act as a placeholder so that the uploader will know that an upload needs to
     * occur. A flow event should only be created if there isn't already a flow event that hasn't been associated with an
     * upload blob.
     */
    boolean foundUnassociatedFlowEvent = false;

    Cursor eventsCursor = null;
    Cursor blob_eventsCursor = null;
    try
    {
        eventsCursor = mProvider.query(EventsDbColumns.TABLE_NAME, new String[]
            { EventsDbColumns._ID }, String.format("%s = ?", EventsDbColumns.EVENT_NAME), new String[] //$NON-NLS-1$
            { FLOW_EVENT }, EVENTS_SORT_ORDER);

        blob_eventsCursor = mProvider.query(UploadBlobEventsDbColumns.TABLE_NAME, new String[]
            { UploadBlobEventsDbColumns.EVENTS_KEY_REF }, null, null, UPLOAD_BLOBS_EVENTS_SORT_ORDER);

        final CursorJoiner joiner = new CursorJoiner(eventsCursor, new String[]
            { EventsDbColumns._ID }, blob_eventsCursor, new String[]
            { UploadBlobEventsDbColumns.EVENTS_KEY_REF });
        for (final CursorJoiner.Result joinerResult : joiner)
        {
            switch (joinerResult)
            {
                case LEFT:
                {
                    foundUnassociatedFlowEvent = true;
                    break;
                }
                case BOTH:
                    break;
                case RIGHT:
                    break;
            }
        }
    }
    finally
    {
        if (eventsCursor != null)
        {
            eventsCursor.close();
            eventsCursor = null;
        }

        if (blob_eventsCursor != null)
        {
            blob_eventsCursor.close();
            blob_eventsCursor = null;
        }
    }

    if (!foundUnassociatedFlowEvent)
    {
        tagEvent(FLOW_EVENT, null);
    }
}