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.OsmDataLayer;
038import org.openstreetmap.josm.gui.layer.TMSLayer;
039import org.openstreetmap.josm.gui.layer.WMSLayer;
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
048public class SessionWriter {
049
050    private static Map<Class<? extends Layer>, Class<? extends SessionLayerExporter>> sessionLayerExporters = new HashMap<>();
051    static {
052        registerSessionLayerExporter(OsmDataLayer.class , OsmDataSessionExporter.class);
053        registerSessionLayerExporter(TMSLayer.class , ImagerySessionExporter.class);
054        registerSessionLayerExporter(WMSLayer.class , ImagerySessionExporter.class);
055        registerSessionLayerExporter(GpxLayer.class , GpxTracksSessionExporter.class);
056        registerSessionLayerExporter(GeoImageLayer.class , GeoImageSessionExporter.class);
057        registerSessionLayerExporter(MarkerLayer.class, MarkerSessionExporter.class);
058    }
059
060    /**
061     * Register a session layer exporter.
062     *
063     * The exporter class must have an one-argument constructor with layerClass as formal parameter type.
064     */
065    public static void registerSessionLayerExporter(Class<? extends Layer> layerClass, Class<? extends SessionLayerExporter> exporter) {
066        sessionLayerExporters.put(layerClass, exporter);
067    }
068
069    public static SessionLayerExporter getSessionLayerExporter(Layer layer) {
070        Class<? extends Layer> layerClass = layer.getClass();
071        Class<? extends SessionLayerExporter> exporterClass = sessionLayerExporters.get(layerClass);
072        if (exporterClass == null) return null;
073        try {
074            Constructor<? extends SessionLayerExporter> constructor = exporterClass.getConstructor(layerClass);
075            return constructor.newInstance(layer);
076        } catch (Exception e) {
077            throw new RuntimeException(e);
078        }
079    }
080
081    private final List<Layer> layers;
082    private final int active;
083    private final Map<Layer, SessionLayerExporter> exporters;
084    private final MultiMap<Layer, Layer> dependencies;
085    private final boolean zip;
086
087    private ZipOutputStream zipOut;
088
089    /**
090     * Constructs a new {@code SessionWriter}.
091     * @param layers The ordered list of layers to save
092     * @param active The index of active layer in {@code layers} (starts to 0). Ignored if set to -1
093     * @param exporters The exporters to use to save layers
094     * @param zip {@code true} if a joz archive has to be created, {@code false otherwise}
095     * @since 6271
096     */
097    public SessionWriter(List<Layer> layers, int active, Map<Layer, SessionLayerExporter> exporters,
098                MultiMap<Layer, Layer> dependencies, boolean zip) {
099        this.layers = layers;
100        this.active = active;
101        this.exporters = exporters;
102        this.dependencies = dependencies;
103        this.zip = zip;
104    }
105
106    /**
107     * A class that provides some context for the individual {@link SessionLayerExporter}
108     * when doing the export.
109     */
110    public class ExportSupport {
111        private Document doc;
112        private int layerIndex;
113
114        public ExportSupport(Document doc, int layerIndex) {
115            this.doc = doc;
116            this.layerIndex = layerIndex;
117        }
118
119        public Element createElement(String name) {
120            return doc.createElement(name);
121        }
122
123        public Text createTextNode(String text) {
124            return doc.createTextNode(text);
125        }
126
127        /**
128         * Get the index of the layer that is currently exported.
129         * @return the index of the layer that is currently exported
130         */
131        public int getLayerIndex() {
132            return layerIndex;
133        }
134
135        /**
136         * Create a file inside the zip archive.
137         *
138         * @param zipPath the path inside the zip archive, e.g. "layers/03/data.xml"
139         * @return the OutputStream you can write to. Never close the returned
140         * output stream, but make sure to flush buffers.
141         */
142        public OutputStream getOutputStreamZip(String zipPath) throws IOException {
143            if (!isZip()) throw new RuntimeException();
144            ZipEntry entry = new ZipEntry(zipPath);
145            zipOut.putNextEntry(entry);
146            return zipOut;
147        }
148
149        /**
150         * Check, if the session is exported as a zip archive.
151         *
152         * @return true, if the session is exported as a zip archive (.joz file
153         * extension). It will always return true, if one of the
154         * {@link SessionLayerExporter} returns true for the
155         * {@link SessionLayerExporter#requiresZip()} method. Otherwise, the
156         * user can decide in the file chooser dialog.
157         */
158        public boolean isZip() {
159            return zip;
160        }
161    }
162
163    public Document createJosDocument() throws IOException {
164        DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
165        builderFactory.setValidating(false);
166        builderFactory.setNamespaceAware(true);
167        DocumentBuilder builder = null;
168        try {
169            builder = builderFactory.newDocumentBuilder();
170        } catch (ParserConfigurationException e) {
171            throw new RuntimeException(e);
172        }
173        Document doc = builder.newDocument();
174
175        Element root = doc.createElement("josm-session");
176        root.setAttribute("version", "0.1");
177        doc.appendChild(root);
178
179        Element viewportEl = doc.createElement("viewport");
180        root.appendChild(viewportEl);
181        Element centerEl = doc.createElement("center");
182        viewportEl.appendChild(centerEl);
183        EastNorth center = Main.map.mapView.getCenter();
184        LatLon centerLL = Projections.inverseProject(center);
185        centerEl.setAttribute("lat", Double.toString(centerLL.lat()));
186        centerEl.setAttribute("lon", Double.toString(centerLL.lon()));
187        Element scale = doc.createElement("scale");
188        viewportEl.appendChild(scale);
189        double dist100px = Main.map.mapView.getDist100Pixel();
190        scale.setAttribute("meter-per-pixel", Double.toString(dist100px / 100));
191
192        Element layersEl = doc.createElement("layers");
193        if (active >= 0) {
194            layersEl.setAttribute("active", Integer.toString(active+1));
195        }
196        root.appendChild(layersEl);
197
198        for (int index=0; index<layers.size(); ++index) {
199            Layer layer = layers.get(index);
200            SessionLayerExporter exporter = exporters.get(layer);
201            ExportSupport support = new ExportSupport(doc, index+1);
202            Element el = exporter.export(support);
203            el.setAttribute("index", Integer.toString(index+1));
204            el.setAttribute("name", layer.getName());
205            el.setAttribute("visible", Boolean.toString(layer.isVisible()));
206            if (layer.getOpacity() != 1.0) {
207                el.setAttribute("opacity", Double.toString(layer.getOpacity()));
208            }
209            Set<Layer> deps = dependencies.get(layer);
210            if (deps != null && !deps.isEmpty()) {
211                List<Integer> depsInt = new ArrayList<>();
212                for (Layer depLayer : deps) {
213                    int depIndex = layers.indexOf(depLayer);
214                    if (depIndex == -1) throw new AssertionError();
215                    depsInt.add(depIndex+1);
216                }
217                el.setAttribute("depends", Utils.join(",", depsInt));
218            }
219            layersEl.appendChild(el);
220        }
221        return doc;
222    }
223
224    public void writeJos(Document doc, OutputStream out) throws IOException {
225        try {
226            OutputStreamWriter writer = new OutputStreamWriter(out, StandardCharsets.UTF_8);
227            writer.write("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
228            TransformerFactory transfac = TransformerFactory.newInstance();
229            Transformer trans = transfac.newTransformer();
230            trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
231            trans.setOutputProperty(OutputKeys.INDENT, "yes");
232            trans.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
233            StreamResult result = new StreamResult(writer);
234            DOMSource source = new DOMSource(doc);
235            trans.transform(source, result);
236        } catch (TransformerException e) {
237            throw new RuntimeException(e);
238        }
239    }
240
241    public void write(File f) throws IOException {
242        try (OutputStream out = new FileOutputStream(f)) {
243            write(out);
244        } catch (FileNotFoundException e) {
245            throw new IOException(e);
246        }
247    }
248
249    public void write(OutputStream out) throws IOException {
250        if (zip) {
251            zipOut = new ZipOutputStream(new BufferedOutputStream(out), StandardCharsets.UTF_8);
252        }
253        Document doc = createJosDocument(); // as side effect, files may be added to zipOut
254        if (zip) {
255            ZipEntry entry = new ZipEntry("session.jos");
256            zipOut.putNextEntry(entry);
257            writeJos(doc, zipOut);
258            Utils.close(zipOut);
259        } else {
260            writeJos(doc, new BufferedOutputStream(out));
261        }
262    }
263}