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