FilteringCursorWrapper.java revision 6efba22ce510352bb84910d6efc42fecafd31ed7 
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
17package com.android.documentsui;
18
19import static com.android.documentsui.DocumentsActivity.TAG;
20
21import android.database.AbstractCursor;
22import android.database.Cursor;
23import android.os.Bundle;
24import android.provider.DocumentsContract.Document;
25import android.util.Log;
26
27/**
28 * Cursor wrapper that filters MIME types not matching given list.
29 */
30public class FilteringCursorWrapper extends AbstractCursor {
31    private final Cursor mCursor;
32
33    private final int[] mPosition;
34    private int mCount;
35
36    public FilteringCursorWrapper(Cursor cursor, String[] acceptMimes) {
37        this(cursor, acceptMimes, null, Long.MIN_VALUE);
38    }
39
40    public FilteringCursorWrapper(Cursor cursor, String[] acceptMimes, String[] rejectMimes) {
41        this(cursor, acceptMimes, rejectMimes, Long.MIN_VALUE);
42    }
43
44    public FilteringCursorWrapper(
45            Cursor cursor, String[] acceptMimes, String[] rejectMimes, long rejectBefore) {
46        mCursor = cursor;
47
48        final int count = cursor.getCount();
49        mPosition = new int[count];
50
51        cursor.moveToPosition(-1);
52        while (cursor.moveToNext()) {
53            final String mimeType = cursor.getString(
54                    cursor.getColumnIndex(Document.COLUMN_MIME_TYPE));
55            final long lastModified = cursor.getLong(
56                    cursor.getColumnIndex(Document.COLUMN_LAST_MODIFIED));
57            if (rejectMimes != null && MimePredicate.mimeMatches(rejectMimes, mimeType)) {
58                continue;
59            }
60            if (lastModified < rejectBefore) {
61                continue;
62            }
63            if (MimePredicate.mimeMatches(acceptMimes, mimeType)) {
64                mPosition[mCount++] = cursor.getPosition();
65            }
66        }
67
68        Log.d(TAG, "Before filtering " + cursor.getCount() + ", after " + mCount);
69    }
70
71    @Override
72    public Bundle getExtras() {
73        return mCursor.getExtras();
74    }
75
76    @Override
77    public void close() {
78        super.close();
79        mCursor.close();
80    }
81
82    @Override
83    public boolean onMove(int oldPosition, int newPosition) {
84        return mCursor.moveToPosition(mPosition[newPosition]);
85    }
86
87    @Override
88    public String[] getColumnNames() {
89        return mCursor.getColumnNames();
90    }
91
92    @Override
93    public int getCount() {
94        return mCount;
95    }
96
97    @Override
98    public double getDouble(int column) {
99        return mCursor.getDouble(column);
100    }
101
102    @Override
103    public float getFloat(int column) {
104        return mCursor.getFloat(column);
105    }
106
107    @Override
108    public int getInt(int column) {
109        return mCursor.getInt(column);
110    }
111
112    @Override
113    public long getLong(int column) {
114        return mCursor.getLong(column);
115    }
116
117    @Override
118    public short getShort(int column) {
119        return mCursor.getShort(column);
120    }
121
122    @Override
123    public String getString(int column) {
124        return mCursor.getString(column);
125    }
126
127    @Override
128    public int getType(int column) {
129        return mCursor.getType(column);
130    }
131
132    @Override
133    public boolean isNull(int column) {
134        return mCursor.isNull(column);
135    }
136}
137