001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.gui.dialogs.relation;
003
004import static org.openstreetmap.josm.tools.I18n.tr;
005
006import java.awt.Component;
007import java.awt.Dialog;
008import java.io.IOException;
009
010import javax.swing.JTree;
011import javax.swing.SwingUtilities;
012import javax.swing.event.TreeExpansionEvent;
013import javax.swing.event.TreeWillExpandListener;
014import javax.swing.tree.ExpandVetoException;
015import javax.swing.tree.TreePath;
016
017import org.openstreetmap.josm.Main;
018import org.openstreetmap.josm.data.osm.DataSet;
019import org.openstreetmap.josm.data.osm.DataSetMerger;
020import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
021import org.openstreetmap.josm.data.osm.Relation;
022import org.openstreetmap.josm.gui.PleaseWaitRunnable;
023import org.openstreetmap.josm.gui.progress.PleaseWaitProgressMonitor;
024import org.openstreetmap.josm.gui.progress.ProgressMonitor;
025import org.openstreetmap.josm.io.OsmApi;
026import org.openstreetmap.josm.io.OsmServerObjectReader;
027import org.openstreetmap.josm.io.OsmTransferException;
028import org.xml.sax.SAXException;
029
030/**
031 * This is a {@link JTree} rendering the hierarchical structure of {@link Relation}s.
032 *
033 * @see RelationTreeModel
034 */
035public class RelationTree extends JTree {
036    /**
037     * builds the UI
038     */
039    protected void build() {
040        setRootVisible(false);
041        setCellRenderer(new RelationTreeCellRenderer());
042        addTreeWillExpandListener(new LazyRelationLoader());
043    }
044
045    /**
046     * constructor
047     */
048    public RelationTree(){
049        super();
050        build();
051    }
052
053    /**
054     * constructor
055     * @param model the tree model
056     */
057    public RelationTree(RelationTreeModel model) {
058        super(model);
059        build();
060    }
061
062    /**
063     * replies the parent dialog this tree is embedded in.
064     *
065     * @return the parent dialog; null, if there is no parent dialog
066     */
067    protected Dialog getParentDialog() {
068        Component c = RelationTree.this;
069        while(c != null && ! (c instanceof Dialog)) {
070            c = c.getParent();
071        }
072        return (Dialog)c;
073    }
074
075    /**
076     * An adapter for TreeWillExpand-events. If a node is to be expanded which is
077     * not loaded yet this will trigger asynchronous loading of the respective
078     * relation.
079     *
080     */
081    class LazyRelationLoader implements TreeWillExpandListener {
082
083        @Override
084        public void treeWillCollapse(TreeExpansionEvent event) throws ExpandVetoException {
085            // do nothing
086        }
087
088        @Override
089        public void treeWillExpand(TreeExpansionEvent event) throws ExpandVetoException {
090            TreePath path  = event.getPath();
091            Relation parent = (Relation)event.getPath().getLastPathComponent();
092            if (! parent.isIncomplete() || parent.isNew())
093                // we don't load complete  or new relations
094                return;
095            // launch the download task
096            //
097            Main.worker.submit(new RelationLoader(getParentDialog(),parent, path));
098        }
099    }
100
101    /**
102     * Asynchronous download task for a specific relation
103     *
104     */
105    class RelationLoader extends PleaseWaitRunnable {
106        private boolean canceled;
107        private Exception lastException;
108        private Relation relation;
109        private DataSet ds;
110        private TreePath path;
111
112        public RelationLoader(Dialog dialog, Relation relation, TreePath path) {
113            super(
114                    tr("Load relation"),
115                    new PleaseWaitProgressMonitor(
116                            dialog
117                    ),
118                    false /* don't ignore exceptions */
119            );
120            this.relation = relation;
121            this.path = path;
122        }
123        @Override
124        protected void cancel() {
125            OsmApi.getOsmApi().cancel();
126            this.canceled = true;
127        }
128
129        @Override
130        protected void finish() {
131            if (canceled)
132                return;
133            if (lastException != null) {
134                Main.error(lastException);
135                return;
136            }
137            DataSetMerger visitor = new DataSetMerger(Main.main.getEditLayer().data, ds);
138            visitor.merge();
139            if (! visitor.getConflicts().isEmpty()) {
140                Main.main.getEditLayer().getConflicts().add(visitor.getConflicts());
141            }
142            final RelationTreeModel model = (RelationTreeModel)getModel();
143            SwingUtilities.invokeLater(
144                    new Runnable() {
145                        @Override
146                        public void run() {
147                            model.refreshNode(path);
148                        }
149                    }
150            );
151        }
152
153        @Override
154        protected void realRun() throws SAXException, IOException, OsmTransferException {
155            try {
156                OsmServerObjectReader reader = new OsmServerObjectReader(relation.getId(), OsmPrimitiveType.from(relation), true /* full load */);
157                ds = reader.parseOsm(progressMonitor
158                        .createSubTaskMonitor(ProgressMonitor.ALL_TICKS, false));
159            } catch(Exception e) {
160                if (canceled) {
161                    Main.warn(tr("Ignoring exception because task was canceled. Exception: {0}", e.toString()));
162                    return;
163                }
164                this.lastException = e;
165            }
166        }
167    }
168}