001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.io.session;
003
004import java.io.BufferedOutputStream;
005import java.io.File;
006import java.io.FileNotFoundException;
007import java.io.FileOutputStream;
008import java.io.IOException;
009import java.io.OutputStream;
010import java.io.OutputStreamWriter;
011import java.lang.reflect.Constructor;
012import java.nio.charset.StandardCharsets;
013import java.util.ArrayList;
014import java.util.HashMap;
015import java.util.List;
016import java.util.Map;
017import java.util.Set;
018import java.util.zip.ZipEntry;
019import java.util.zip.ZipOutputStream;
020
021import javax.xml.parsers.DocumentBuilder;
022import javax.xml.parsers.DocumentBuilderFactory;
023import javax.xml.parsers.ParserConfigurationException;
024import javax.xml.transform.OutputKeys;
025import javax.xml.transform.Transformer;
026import javax.xml.transform.TransformerException;
027import javax.xml.transform.TransformerFactory;
028import javax.xml.transform.dom.DOMSource;
029import javax.xml.transform.stream.StreamResult;
030
031import org.openstreetmap.josm.Main;
032import org.openstreetmap.josm.data.coor.EastNorth;
033import org.openstreetmap.josm.data.coor.LatLon;
034import org.openstreetmap.josm.data.projection.Projections;
035import org.openstreetmap.josm.gui.layer.GpxLayer;
036import org.openstreetmap.josm.gui.layer.Layer;
037import org.openstreetmap.josm.gui.layer.NoteLayer;
038import org.openstreetmap.josm.gui.layer.OsmDataLayer;
039import org.openstreetmap.josm.gui.layer.TMSLayer;
040import org.openstreetmap.josm.gui.layer.WMSLayer;
041import org.openstreetmap.josm.gui.layer.WMTSLayer;
042import org.openstreetmap.josm.gui.layer.geoimage.GeoImageLayer;
043import org.openstreetmap.josm.gui.layer.markerlayer.MarkerLayer;
044import org.openstreetmap.josm.tools.MultiMap;
045import org.openstreetmap.josm.tools.Utils;
046import org.w3c.dom.Document;
047import org.w3c.dom.Element;
048import org.w3c.dom.Text;
049
050/**
051 * Writes a .jos session file from current supported layers.
052 * @since 4685
053 */
054public class SessionWriter {
055
056    private static Map<Class<? extends Layer>, Class<? extends SessionLayerExporter>> sessionLayerExporters = new HashMap<>();
057
058    private final List<Layer> layers;
059    private final int active;
060    private final Map<Layer, SessionLayerExporter> exporters;
061    private final MultiMap<Layer, Layer> dependencies;
062    private final boolean zip;
063
064    private ZipOutputStream zipOut;
065
066    static {
067        registerSessionLayerExporter(OsmDataLayer.class, OsmDataSessionExporter.class);
068        registerSessionLayerExporter(TMSLayer.class, ImagerySessionExporter.class);
069        registerSessionLayerExporter(WMSLayer.class, ImagerySessionExporter.class);
070        registerSessionLayerExporter(WMTSLayer.class, ImagerySessionExporter.class);
071        registerSessionLayerExporter(GpxLayer.class, GpxTracksSessionExporter.class);
072        registerSessionLayerExporter(GeoImageLayer.class, GeoImageSessionExporter.class);
073        registerSessionLayerExporter(MarkerLayer.class, MarkerSessionExporter.class);
074        registerSessionLayerExporter(NoteLayer.class, NoteSessionExporter.class);
075    }
076
077    /**
078     * Register a session layer exporter.
079     *
080     * The exporter class must have a one-argument constructor with layerClass as formal parameter type.
081     * @param layerClass layer class
082     * @param exporter exporter for this layer class
083     */
084    public static void registerSessionLayerExporter(Class<? extends Layer> layerClass, Class<? extends SessionLayerExporter> exporter) {
085        sessionLayerExporters.put(layerClass, exporter);
086    }
087
088    /**
089     * Returns the session layer exporter for the given layer.
090     * @param layer layer to export
091     * @return session layer exporter for the given layer
092     */
093    public static SessionLayerExporter getSessionLayerExporter(Layer layer) {
094        Class<? extends Layer> layerClass = layer.getClass();
095        Class<? extends SessionLayerExporter> exporterClass = sessionLayerExporters.get(layerClass);
096        if (exporterClass == null)
097            return null;
098        try {
099            Constructor<? extends SessionLayerExporter> constructor = exporterClass.getConstructor(layerClass);
100            return constructor.newInstance(layer);
101        } catch (Exception e) {
102            throw new RuntimeException(e);
103        }
104    }
105
106    /**
107     * Constructs a new {@code SessionWriter}.
108     * @param layers The ordered list of layers to save
109     * @param active The index of active layer in {@code layers} (starts at 0). Ignored if set to -1
110     * @param exporters The exporters to use to save layers
111     * @param dependencies layer dependencies
112     * @param zip {@code true} if a joz archive has to be created, {@code false otherwise}
113     * @since 6271
114     */
115    public SessionWriter(List<Layer> layers, int active, Map<Layer, SessionLayerExporter> exporters,
116                MultiMap<Layer, Layer> dependencies, boolean zip) {
117        this.layers = layers;
118        this.active = active;
119        this.exporters = exporters;
120        this.dependencies = dependencies;
121        this.zip = zip;
122    }
123
124    /**
125     * A class that provides some context for the individual {@link SessionLayerExporter}
126     * when doing the export.
127     */
128    public class ExportSupport {
129        private final Document doc;
130        private final int layerIndex;
131
132        /**
133         * Constructs a new {@code ExportSupport}.
134         * @param doc XML document
135         * @param layerIndex layer index
136         */
137        public ExportSupport(Document doc, int layerIndex) {
138            this.doc = doc;
139            this.layerIndex = layerIndex;
140        }
141
142        /**
143         * Creates an element of the type specified.
144         * @param name The name of the element type to instantiate
145         * @return A new {@code Element} object
146         * @see Document#createElement
147         */
148        public Element createElement(String name) {
149            return doc.createElement(name);
150        }
151
152        /**
153         * Creates a text node given the specified string.
154         * @param text The data for the node.
155         * @return The new {@code Text} object.
156         * @see Document#createTextNode
157         */
158        public Text createTextNode(String text) {
159            return doc.createTextNode(text);
160        }
161
162        /**
163         * Get the index of the layer that is currently exported.
164         * @return the index of the layer that is currently exported
165         */
166        public int getLayerIndex() {
167            return layerIndex;
168        }
169
170        /**
171         * Create a file inside the zip archive.
172         *
173         * @param zipPath the path inside the zip archive, e.g. "layers/03/data.xml"
174         * @return the OutputStream you can write to. Never close the returned
175         * output stream, but make sure to flush buffers.
176         * @throws IOException if any I/O error occurs
177         */
178        public OutputStream getOutputStreamZip(String zipPath) throws IOException {
179            if (!isZip()) throw new RuntimeException();
180            ZipEntry entry = new ZipEntry(zipPath);
181            zipOut.putNextEntry(entry);
182            return zipOut;
183        }
184
185        /**
186         * Check, if the session is exported as a zip archive.
187         *
188         * @return true, if the session is exported as a zip archive (.joz file
189         * extension). It will always return true, if one of the
190         * {@link SessionLayerExporter} returns true for the
191         * {@link SessionLayerExporter#requiresZip()} method. Otherwise, the
192         * user can decide in the file chooser dialog.
193         */
194        public boolean isZip() {
195            return zip;
196        }
197    }
198
199    /**
200     * Creates XML (.jos) session document.
201     * @return new document
202     * @throws IOException if any I/O error occurs
203     */
204    public Document createJosDocument() throws IOException {
205        DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
206        builderFactory.setValidating(false);
207        builderFactory.setNamespaceAware(true);
208        DocumentBuilder builder = null;
209        try {
210            builder = builderFactory.newDocumentBuilder();
211        } catch (ParserConfigurationException e) {
212            throw new RuntimeException(e);
213        }
214        Document doc = builder.newDocument();
215
216        Element root = doc.createElement("josm-session");
217        root.setAttribute("version", "0.1");
218        doc.appendChild(root);
219
220        Element viewportEl = doc.createElement("viewport");
221        root.appendChild(viewportEl);
222        Element centerEl = doc.createElement("center");
223        viewportEl.appendChild(centerEl);
224        EastNorth center = Main.map.mapView.getCenter();
225        LatLon centerLL = Projections.inverseProject(center);
226        centerEl.setAttribute("lat", Double.toString(centerLL.lat()));
227        centerEl.setAttribute("lon", Double.toString(centerLL.lon()));
228        Element scale = doc.createElement("scale");
229        viewportEl.appendChild(scale);
230        double dist100px = Main.map.mapView.getDist100Pixel();
231        scale.setAttribute("meter-per-pixel", Double.toString(dist100px / 100));
232
233        Element layersEl = doc.createElement("layers");
234        if (active >= 0) {
235            layersEl.setAttribute("active", Integer.toString(active+1));
236        }
237        root.appendChild(layersEl);
238
239        for (int index = 0; index < layers.size(); ++index) {
240            Layer layer = layers.get(index);
241            SessionLayerExporter exporter = exporters.get(layer);
242            ExportSupport support = new ExportSupport(doc, index+1);
243            Element el = exporter.export(support);
244            el.setAttribute("index", Integer.toString(index+1));
245            el.setAttribute("name", layer.getName());
246            el.setAttribute("visible", Boolean.toString(layer.isVisible()));
247            if (!Utils.equalsEpsilon(layer.getOpacity(), 1.0)) {
248                el.setAttribute("opacity", Double.toString(layer.getOpacity()));
249            }
250            Set<Layer> deps = dependencies.get(layer);
251            if (deps != null && !deps.isEmpty()) {
252                List<Integer> depsInt = new ArrayList<>();
253                for (Layer depLayer : deps) {
254                    int depIndex = layers.indexOf(depLayer);
255                    if (depIndex == -1)
256                        throw new AssertionError();
257                    depsInt.add(depIndex+1);
258                }
259                el.setAttribute("depends", Utils.join(",", depsInt));
260            }
261            layersEl.appendChild(el);
262        }
263        return doc;
264    }
265
266    /**
267     * Writes given .jos document to an output stream.
268     * @param doc session document
269     * @param out output stream
270     * @throws IOException if any I/O error occurs
271     */
272    public void writeJos(Document doc, OutputStream out) throws IOException {
273        try {
274            OutputStreamWriter writer = new OutputStreamWriter(out, StandardCharsets.UTF_8);
275            writer.write("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
276            TransformerFactory transfac = TransformerFactory.newInstance();
277            Transformer trans = transfac.newTransformer();
278            trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
279            trans.setOutputProperty(OutputKeys.INDENT, "yes");
280            trans.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
281            StreamResult result = new StreamResult(writer);
282            DOMSource source = new DOMSource(doc);
283            trans.transform(source, result);
284        } catch (TransformerException e) {
285            throw new RuntimeException(e);
286        }
287    }
288
289    /**
290     * Writes session to given file.
291     * @param f output file
292     * @throws IOException if any I/O error occurs
293     */
294    public void write(File f) throws IOException {
295        try (OutputStream out = new FileOutputStream(f)) {
296            write(out);
297        } catch (FileNotFoundException e) {
298            throw new IOException(e);
299        }
300    }
301
302    /**
303     * Writes session to given output stream.
304     * @param out output stream
305     * @throws IOException if any I/O error occurs
306     */
307    public void write(OutputStream out) throws IOException {
308        if (zip) {
309            zipOut = new ZipOutputStream(new BufferedOutputStream(out), StandardCharsets.UTF_8);
310        }
311        Document doc = createJosDocument(); // as side effect, files may be added to zipOut
312        if (zip) {
313            ZipEntry entry = new ZipEntry("session.jos");
314            zipOut.putNextEntry(entry);
315            writeJos(doc, zipOut);
316            Utils.close(zipOut);
317        } else {
318            writeJos(doc, new BufferedOutputStream(out));
319        }
320    }
321}