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