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