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.server.wm;
18
19import android.graphics.Rect;
20import android.os.Environment;
21import android.util.AtomicFile;
22import android.util.Slog;
23import android.util.Xml;
24import com.android.internal.util.FastXmlSerializer;
25import com.android.internal.util.XmlUtils;
26import org.xmlpull.v1.XmlPullParser;
27import org.xmlpull.v1.XmlPullParserException;
28import org.xmlpull.v1.XmlSerializer;
29
30import java.io.File;
31import java.io.FileInputStream;
32import java.io.FileNotFoundException;
33import java.io.FileOutputStream;
34import java.io.IOException;
35import java.util.HashMap;
36
37/**
38 * Current persistent settings about a display
39 */
40public class DisplaySettings {
41    private static final String TAG = WindowManagerService.TAG;
42
43    private final AtomicFile mFile;
44    private final HashMap<String, Entry> mEntries = new HashMap<String, Entry>();
45
46    public static class Entry {
47        public final String name;
48        public int overscanLeft;
49        public int overscanTop;
50        public int overscanRight;
51        public int overscanBottom;
52
53        public Entry(String _name) {
54            name = _name;
55        }
56    }
57
58    public DisplaySettings() {
59        File dataDir = Environment.getDataDirectory();
60        File systemDir = new File(dataDir, "system");
61        mFile = new AtomicFile(new File(systemDir, "display_settings.xml"));
62    }
63
64    public void getOverscanLocked(String name, String uniqueId, Rect outRect) {
65        // Try to get the entry with the unique if possible.
66        // Else, fall back on the display name.
67        Entry entry;
68        if (uniqueId == null || (entry = mEntries.get(uniqueId)) == null) {
69            entry = mEntries.get(name);
70        }
71        if (entry != null) {
72            outRect.left = entry.overscanLeft;
73            outRect.top = entry.overscanTop;
74            outRect.right = entry.overscanRight;
75            outRect.bottom = entry.overscanBottom;
76        } else {
77            outRect.set(0, 0, 0, 0);
78        }
79    }
80
81    public void setOverscanLocked(String name, int left, int top, int right, int bottom) {
82        if (left == 0 && top == 0 && right == 0 && bottom == 0) {
83            // Right now all we are storing is overscan; if there is no overscan,
84            // we have no need for the entry.
85            mEntries.remove(name);
86            return;
87        }
88        Entry entry = mEntries.get(name);
89        if (entry == null) {
90            entry = new Entry(name);
91            mEntries.put(name, entry);
92        }
93        entry.overscanLeft = left;
94        entry.overscanTop = top;
95        entry.overscanRight = right;
96        entry.overscanBottom = bottom;
97    }
98
99    public void readSettingsLocked() {
100        FileInputStream stream;
101        try {
102            stream = mFile.openRead();
103        } catch (FileNotFoundException e) {
104            Slog.i(TAG, "No existing display settings " + mFile.getBaseFile()
105                    + "; starting empty");
106            return;
107        }
108        boolean success = false;
109        try {
110            XmlPullParser parser = Xml.newPullParser();
111            parser.setInput(stream, null);
112            int type;
113            while ((type = parser.next()) != XmlPullParser.START_TAG
114                    && type != XmlPullParser.END_DOCUMENT) {
115                // Do nothing.
116            }
117
118            if (type != XmlPullParser.START_TAG) {
119                throw new IllegalStateException("no start tag found");
120            }
121
122            int outerDepth = parser.getDepth();
123            while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
124                    && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) {
125                if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
126                    continue;
127                }
128
129                String tagName = parser.getName();
130                if (tagName.equals("display")) {
131                    readDisplay(parser);
132                } else {
133                    Slog.w(TAG, "Unknown element under <display-settings>: "
134                            + parser.getName());
135                    XmlUtils.skipCurrentTag(parser);
136                }
137            }
138            success = true;
139        } catch (IllegalStateException e) {
140            Slog.w(TAG, "Failed parsing " + e);
141        } catch (NullPointerException e) {
142            Slog.w(TAG, "Failed parsing " + e);
143        } catch (NumberFormatException e) {
144            Slog.w(TAG, "Failed parsing " + e);
145        } catch (XmlPullParserException e) {
146            Slog.w(TAG, "Failed parsing " + e);
147        } catch (IOException e) {
148            Slog.w(TAG, "Failed parsing " + e);
149        } catch (IndexOutOfBoundsException e) {
150            Slog.w(TAG, "Failed parsing " + e);
151        } finally {
152            if (!success) {
153                mEntries.clear();
154            }
155            try {
156                stream.close();
157            } catch (IOException e) {
158            }
159        }
160    }
161
162    private int getIntAttribute(XmlPullParser parser, String name) {
163        try {
164            String str = parser.getAttributeValue(null, name);
165            return str != null ? Integer.parseInt(str) : 0;
166        } catch (NumberFormatException e) {
167            return 0;
168        }
169    }
170
171    private void readDisplay(XmlPullParser parser) throws NumberFormatException,
172            XmlPullParserException, IOException {
173        String name = parser.getAttributeValue(null, "name");
174        if (name != null) {
175            Entry entry = new Entry(name);
176            entry.overscanLeft = getIntAttribute(parser, "overscanLeft");
177            entry.overscanTop = getIntAttribute(parser, "overscanTop");
178            entry.overscanRight = getIntAttribute(parser, "overscanRight");
179            entry.overscanBottom = getIntAttribute(parser, "overscanBottom");
180            mEntries.put(name, entry);
181        }
182        XmlUtils.skipCurrentTag(parser);
183    }
184
185    public void writeSettingsLocked() {
186        FileOutputStream stream;
187        try {
188            stream = mFile.startWrite();
189        } catch (IOException e) {
190            Slog.w(TAG, "Failed to write display settings: " + e);
191            return;
192        }
193
194        try {
195            XmlSerializer out = new FastXmlSerializer();
196            out.setOutput(stream, "utf-8");
197            out.startDocument(null, true);
198            out.startTag(null, "display-settings");
199
200            for (Entry entry : mEntries.values()) {
201                out.startTag(null, "display");
202                out.attribute(null, "name", entry.name);
203                if (entry.overscanLeft != 0) {
204                    out.attribute(null, "overscanLeft", Integer.toString(entry.overscanLeft));
205                }
206                if (entry.overscanTop != 0) {
207                    out.attribute(null, "overscanTop", Integer.toString(entry.overscanTop));
208                }
209                if (entry.overscanRight != 0) {
210                    out.attribute(null, "overscanRight", Integer.toString(entry.overscanRight));
211                }
212                if (entry.overscanBottom != 0) {
213                    out.attribute(null, "overscanBottom", Integer.toString(entry.overscanBottom));
214                }
215                out.endTag(null, "display");
216            }
217
218            out.endTag(null, "display-settings");
219            out.endDocument();
220            mFile.finishWrite(stream);
221        } catch (IOException e) {
222            Slog.w(TAG, "Failed to write display settings, restoring backup.", e);
223            mFile.failWrite(stream);
224        }
225    }
226}
227