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