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.IOException;
007import java.io.OutputStream;
008import java.io.OutputStreamWriter;
009import java.nio.charset.StandardCharsets;
010import java.nio.file.Files;
011import java.util.Collection;
012import java.util.HashMap;
013import java.util.List;
014import java.util.Locale;
015import java.util.Map;
016import java.util.Objects;
017import java.util.Set;
018import java.util.stream.Collectors;
019import java.util.zip.ZipEntry;
020import java.util.zip.ZipOutputStream;
021
022import javax.xml.parsers.DocumentBuilder;
023import javax.xml.parsers.ParserConfigurationException;
024import javax.xml.transform.OutputKeys;
025import javax.xml.transform.Transformer;
026import javax.xml.transform.TransformerException;
027import javax.xml.transform.dom.DOMSource;
028import javax.xml.transform.stream.StreamResult;
029
030import org.openstreetmap.josm.data.coor.EastNorth;
031import org.openstreetmap.josm.data.coor.LatLon;
032import org.openstreetmap.josm.data.projection.ProjectionRegistry;
033import org.openstreetmap.josm.gui.MainApplication;
034import org.openstreetmap.josm.gui.MapView;
035import org.openstreetmap.josm.gui.layer.GpxLayer;
036import org.openstreetmap.josm.gui.layer.GpxRouteLayer;
037import org.openstreetmap.josm.gui.layer.Layer;
038import org.openstreetmap.josm.gui.layer.NoteLayer;
039import org.openstreetmap.josm.gui.layer.OsmDataLayer;
040import org.openstreetmap.josm.gui.layer.TMSLayer;
041import org.openstreetmap.josm.gui.layer.WMSLayer;
042import org.openstreetmap.josm.gui.layer.WMTSLayer;
043import org.openstreetmap.josm.gui.layer.geoimage.GeoImageLayer;
044import org.openstreetmap.josm.gui.layer.markerlayer.MarkerLayer;
045import org.openstreetmap.josm.gui.preferences.projection.ProjectionPreference;
046import org.openstreetmap.josm.tools.JosmRuntimeException;
047import org.openstreetmap.josm.tools.Logging;
048import org.openstreetmap.josm.tools.MultiMap;
049import org.openstreetmap.josm.tools.Utils;
050import org.openstreetmap.josm.tools.XmlUtils;
051import org.w3c.dom.Document;
052import org.w3c.dom.Element;
053import org.w3c.dom.Text;
054
055/**
056 * Writes a .jos session file from current supported layers.
057 * @since 4685
058 */
059public class SessionWriter {
060
061    private static final Map<Class<? extends Layer>, Class<? extends SessionLayerExporter>> sessionLayerExporters = new HashMap<>();
062
063    private final List<Layer> layers;
064    private final int active;
065    private final Map<Layer, SessionLayerExporter> exporters;
066    private final MultiMap<Layer, Layer> dependencies;
067    private final boolean zip;
068
069    private ZipOutputStream zipOut;
070
071    static {
072        registerSessionLayerExporter(OsmDataLayer.class, OsmDataSessionExporter.class);
073        registerSessionLayerExporter(TMSLayer.class, ImagerySessionExporter.class);
074        registerSessionLayerExporter(WMSLayer.class, ImagerySessionExporter.class);
075        registerSessionLayerExporter(WMTSLayer.class, ImagerySessionExporter.class);
076        registerSessionLayerExporter(GpxLayer.class, GpxTracksSessionExporter.class);
077        registerSessionLayerExporter(GpxRouteLayer.class, GpxRoutesSessionExporter.class);
078        registerSessionLayerExporter(GeoImageLayer.class, GeoImageSessionExporter.class);
079        registerSessionLayerExporter(MarkerLayer.class, MarkerSessionExporter.class);
080        registerSessionLayerExporter(NoteLayer.class, NoteSessionExporter.class);
081    }
082
083    /**
084     * Register a session layer exporter.
085     *
086     * The exporter class must have a one-argument constructor with layerClass as formal parameter type.
087     * @param layerClass layer class
088     * @param exporter exporter for this layer class
089     */
090    public static void registerSessionLayerExporter(Class<? extends Layer> layerClass, Class<? extends SessionLayerExporter> exporter) {
091        sessionLayerExporters.put(layerClass, exporter);
092    }
093
094    /**
095     * Returns the session layer exporter for the given layer.
096     * @param layer layer to export
097     * @return session layer exporter for the given layer
098     * @throws IllegalArgumentException if layer cannot be exported
099     */
100    public static SessionLayerExporter getSessionLayerExporter(Layer layer) {
101        Class<? extends Layer> layerClass = layer.getClass();
102        Class<? extends SessionLayerExporter> exporterClass = sessionLayerExporters.get(layerClass);
103        if (exporterClass == null)
104            return null;
105        try {
106            return exporterClass.getConstructor(layerClass).newInstance(layer);
107        } catch (ReflectiveOperationException e) {
108            throw new JosmRuntimeException(e);
109        }
110    }
111
112    /**
113     * Constructs a new {@code SessionWriter}.
114     * @param layers The ordered list of layers to save
115     * @param active The index of active layer in {@code layers} (starts at 0). Ignored if set to -1
116     * @param exporters The exporters to use to save layers
117     * @param dependencies layer dependencies
118     * @param zip {@code true} if a joz archive has to be created, {@code false otherwise}
119     * @since 6271
120     */
121    public SessionWriter(List<Layer> layers, int active, Map<Layer, SessionLayerExporter> exporters,
122                MultiMap<Layer, Layer> dependencies, boolean zip) {
123        this.layers = layers;
124        this.active = active;
125        this.exporters = exporters;
126        this.dependencies = dependencies;
127        this.zip = zip;
128    }
129
130    /**
131     * A class that provides some context for the individual {@link SessionLayerExporter}
132     * when doing the export.
133     */
134    public class ExportSupport {
135        private final Document doc;
136        private final int layerIndex;
137
138        /**
139         * Constructs a new {@code ExportSupport}.
140         * @param doc XML document
141         * @param layerIndex layer index
142         */
143        public ExportSupport(Document doc, int layerIndex) {
144            this.doc = doc;
145            this.layerIndex = layerIndex;
146        }
147
148        /**
149         * Creates an element of the type specified.
150         * @param name The name of the element type to instantiate
151         * @return A new {@code Element} object
152         * @see Document#createElement
153         */
154        public Element createElement(String name) {
155            return doc.createElement(name);
156        }
157
158        /**
159         * Creates a text node given the specified string.
160         * @param text The data for the node.
161         * @return The new {@code Text} object.
162         * @see Document#createTextNode
163         */
164        public Text createTextNode(String text) {
165            return doc.createTextNode(text);
166        }
167
168        /**
169         * Get the index of the layer that is currently exported.
170         * @return the index of the layer that is currently exported
171         */
172        public int getLayerIndex() {
173            return layerIndex;
174        }
175
176        /**
177         * Create a file inside the zip archive.
178         *
179         * @param zipPath the path inside the zip archive, e.g. "layers/03/data.xml"
180         * @return the OutputStream you can write to. Never close the returned
181         * output stream, but make sure to flush buffers.
182         * @throws IOException if any I/O error occurs
183         */
184        public OutputStream getOutputStreamZip(String zipPath) throws IOException {
185            if (!isZip()) throw new JosmRuntimeException("not zip");
186            ZipEntry entry = new ZipEntry(zipPath);
187            zipOut.putNextEntry(entry);
188            return zipOut;
189        }
190
191        /**
192         * Check, if the session is exported as a zip archive.
193         *
194         * @return true, if the session is exported as a zip archive (.joz file
195         * extension). It will always return true, if one of the
196         * {@link SessionLayerExporter} returns true for the
197         * {@link SessionLayerExporter#requiresZip()} method. Otherwise, the
198         * user can decide in the file chooser dialog.
199         */
200        public boolean isZip() {
201            return zip;
202        }
203    }
204
205    /**
206     * Creates XML (.jos) session document.
207     * @return new document
208     * @throws IOException if any I/O error occurs
209     */
210    public Document createJosDocument() throws IOException {
211        DocumentBuilder builder = null;
212        try {
213            builder = XmlUtils.newSafeDOMBuilder();
214        } catch (ParserConfigurationException e) {
215            throw new IOException(e);
216        }
217        Document doc = builder.newDocument();
218
219        Element root = doc.createElement("josm-session");
220        root.setAttribute("version", "0.1");
221        doc.appendChild(root);
222
223        writeViewPort(root);
224        writeProjection(root);
225
226        Element layersEl = doc.createElement("layers");
227        if (active >= 0) {
228            layersEl.setAttribute("active", Integer.toString(active+1));
229        }
230        root.appendChild(layersEl);
231
232        for (int index = 0; index < layers.size(); ++index) {
233            Layer layer = layers.get(index);
234            SessionLayerExporter exporter = exporters.get(layer);
235            ExportSupport support = new ExportSupport(doc, index+1);
236            Element el = exporter.export(support);
237            el.setAttribute("index", Integer.toString(index+1));
238            el.setAttribute("name", layer.getName());
239            el.setAttribute("visible", Boolean.toString(layer.isVisible()));
240            if (!Utils.equalsEpsilon(layer.getOpacity(), 1.0)) {
241                el.setAttribute("opacity", Double.toString(layer.getOpacity()));
242            }
243            Set<Layer> deps = dependencies.get(layer);
244            final String depends = deps == null ? "" : deps.stream().map(depLayer -> {
245                int depIndex = layers.indexOf(depLayer);
246                if (depIndex == -1) {
247                    Logging.warn("Unable to find " + depLayer);
248                    return null;
249                } else {
250                    return Integer.toString(depIndex+1);
251                }
252            }).filter(Objects::nonNull).collect(Collectors.joining(","));
253            if (!depends.isEmpty()) {
254                el.setAttribute("depends", depends);
255            }
256            layersEl.appendChild(el);
257        }
258        return doc;
259    }
260
261    private static void writeViewPort(Element root) {
262        Document doc = root.getOwnerDocument();
263        Element viewportEl = doc.createElement("viewport");
264        root.appendChild(viewportEl);
265        Element centerEl = doc.createElement("center");
266        viewportEl.appendChild(centerEl);
267        MapView mapView = MainApplication.getMap().mapView;
268        EastNorth center = mapView.getCenter();
269        LatLon centerLL = ProjectionRegistry.getProjection().eastNorth2latlon(center);
270        centerEl.setAttribute("lat", Double.toString(centerLL.lat()));
271        centerEl.setAttribute("lon", Double.toString(centerLL.lon()));
272        Element scale = doc.createElement("scale");
273        viewportEl.appendChild(scale);
274        double dist100px = mapView.getDist100Pixel();
275        scale.setAttribute("meter-per-pixel", String.format(Locale.ROOT, "%6f", dist100px / 100));
276    }
277
278    private static void writeProjection(Element root) {
279        Document doc = root.getOwnerDocument();
280        Element projectionEl = doc.createElement("projection");
281        root.appendChild(projectionEl);
282        String pcId = ProjectionPreference.getCurrentProjectionChoiceId();
283        Element projectionChoiceEl = doc.createElement("projection-choice");
284        projectionEl.appendChild(projectionChoiceEl);
285        Element idEl = doc.createElement("id");
286        projectionChoiceEl.appendChild(idEl);
287        idEl.setTextContent(pcId);
288        Collection<String> parameters = ProjectionPreference.getSubprojectionPreference(pcId);
289        Element parametersEl = doc.createElement("parameters");
290        projectionChoiceEl.appendChild(parametersEl);
291        if (parameters != null) {
292            for (String param : parameters) {
293                Element paramEl = doc.createElement("param");
294                parametersEl.appendChild(paramEl);
295                paramEl.setTextContent(param);
296            }
297        }
298        String code = ProjectionRegistry.getProjection().toCode();
299        if (code != null) {
300            Element codeEl = doc.createElement("code");
301            projectionEl.appendChild(codeEl);
302            codeEl.setTextContent(code);
303        }
304    }
305
306    /**
307     * Writes given .jos document to an output stream.
308     * @param doc session document
309     * @param out output stream
310     * @throws IOException if any I/O error occurs
311     */
312    public void writeJos(Document doc, OutputStream out) throws IOException {
313        try {
314            OutputStreamWriter writer = new OutputStreamWriter(out, StandardCharsets.UTF_8);
315            writer.write("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
316            Transformer trans = XmlUtils.newSafeTransformerFactory().newTransformer();
317            trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
318            trans.setOutputProperty(OutputKeys.INDENT, "yes");
319            trans.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
320            StreamResult result = new StreamResult(writer);
321            DOMSource source = new DOMSource(doc);
322            trans.transform(source, result);
323        } catch (TransformerException e) {
324            throw new JosmRuntimeException(e);
325        }
326    }
327
328    /**
329     * Writes session to given file.
330     * @param f output file
331     * @throws IOException if any I/O error occurs
332     */
333    public void write(File f) throws IOException {
334        try (OutputStream out = Files.newOutputStream(f.toPath())) {
335            write(out);
336        }
337    }
338
339    /**
340     * Writes session to given output stream.
341     * @param out output stream
342     * @throws IOException if any I/O error occurs
343     */
344    public void write(OutputStream out) throws IOException {
345        if (zip) {
346            zipOut = new ZipOutputStream(new BufferedOutputStream(out), StandardCharsets.UTF_8);
347        }
348        Document doc = createJosDocument(); // as side effect, files may be added to zipOut
349        if (zip) {
350            ZipEntry entry = new ZipEntry("session.jos");
351            zipOut.putNextEntry(entry);
352            writeJos(doc, zipOut);
353            Utils.close(zipOut);
354        } else {
355            writeJos(doc, new BufferedOutputStream(out));
356        }
357    }
358}