Make the label tab of WikidataInfoToggleDialog work

src/main/java/org/wikipedia/api/ApiUrl.java

@@ -3,10 +3,6 @@ package org.wikipedia.api;
 
 import java.net.MalformedURLException;
 import java.net.URL;
-import java.util.Arrays;
-import java.util.Objects;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
 import org.openstreetmap.josm.tools.Logging;
 
 public class ApiUrl {

src/main/java/org/wikipedia/gui/WikidataInfoLabelPanel.java

+package org.wikipedia.gui;
+
+import java.awt.BorderLayout;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+import javax.swing.JPanel;
+import javax.swing.JProgressBar;
+import javax.swing.JTable;
+import javax.swing.table.AbstractTableModel;
+import org.openstreetmap.josm.gui.Notification;
+import org.openstreetmap.josm.tools.I18n;
+import org.openstreetmap.josm.tools.Pair;
+import org.wikipedia.WikipediaPlugin;
+import org.wikipedia.api.ApiQueryClient;
+import org.wikipedia.api.wikidata_action.WikidataActionApiQuery;
+
+/**
+ * Panel displaying the labels for a Wikidata item
+ */
+class WikidataInfoLabelPanel extends JPanel {
+
+    private static final JProgressBar downloadProgress = new JProgressBar();
+    private final LabelTableModel tableModel = new LabelTableModel(this);
+
+    static {
+        downloadProgress.setStringPainted(true);
+    }
+
+    WikidataInfoLabelPanel() {
+        setLayout(new BorderLayout());
+        add(new JTable(tableModel), BorderLayout.CENTER);
+    }
+
+    void clear() {
+        tableModel.clear();
+    }
+
+    void downloadLabelsFor(final String qId) {
+        tableModel.downloadLabelsFor(qId);
+    }
+
+    private synchronized void showDownloadProgress(final String qId) {
+        if (!isAncestorOf(downloadProgress)) {
+            add(downloadProgress, BorderLayout.NORTH);
+        }
+        downloadProgress.setIndeterminate(true);
+        downloadProgress.setString(I18n.tr("Download labels for {0}…", qId));
+        revalidate();
+    }
+
+    private synchronized void hideDownloadProgress() {
+        remove(downloadProgress);
+        revalidate();
+    }
+
+    private static class LabelTableModel extends AbstractTableModel {
+        private final WikidataInfoLabelPanel parent;
+        private String qIdBeingDownloaded;
+        private final List<Pair<String, String>> valueMap = new ArrayList<>();
+
+        LabelTableModel(final WikidataInfoLabelPanel parent) {
+            this.parent = parent;
+        }
+
+        void clear() {
+            this.valueMap.clear();
+        }
+
+        void downloadLabelsFor(final String qId) {
+            synchronized (valueMap) {
+                qIdBeingDownloaded = qId;
+                parent.showDownloadProgress(qId);
+            }
+
+            new Thread(() -> {
+                try {
+                    final Map<String, String> newValues = ApiQueryClient.query(WikidataActionApiQuery.wbgetentitiesLabels(qId));
+                    synchronized (valueMap) {
+                        if (qIdBeingDownloaded != null && qIdBeingDownloaded.equals(qId)) {
+                            valueMap.clear();
+                            valueMap.addAll(
+                                newValues.entrySet().stream()
+                                    .map(it -> Pair.create(it.getKey(), it.getValue()))
+                                    .sorted((x, y) -> x.a.compareTo(y.a))
+                                    .collect(Collectors.toList())
+                            );
+                        }
+                    }
+                } catch (IOException e) {
+                    new Notification(I18n.tr("Failed to download labels for {0}!", qId)).setIcon(WikipediaPlugin.W_IMAGE.get()).show();
+                }
+                parent.hideDownloadProgress();
+            }).start();
+
+        }
+
+        @Override
+        public int getRowCount() {
+            return valueMap.size();
+        }
+
+        @Override
+        public int getColumnCount() {
+            return 2;
+        }
+
+        @Override
+        public Object getValueAt(int rowIndex, int columnIndex) {
+            return columnIndex == 0 ? valueMap.get(rowIndex).a : valueMap.get(rowIndex).b;
+        }
+
+        @Override
+        public String getColumnName(int column) {
+            return column == 0 ? "language" : "label";
+        }
+    }
+}

src/main/java/org/wikipedia/gui/WikidataInfoToggleDialog.java

@@ -55,7 +55,7 @@ public class WikidataInfoToggleDialog extends ToggleDialog {
     private final JPanel infoPanel = new JPanel(new BorderLayout());
 
     private final JTabbedPane tabs = new JTabbedPane();
-    private final JPanel labelTab = new JPanel();
+    private final WikidataInfoLabelPanel labelTab = new WikidataInfoLabelPanel();
     private final JPanel statementTab = new JPanel();
     private final JPanel linkTab = new JPanel();
     private final JButton webLinkButton = new JButton();
@@ -190,6 +190,9 @@ public class WikidataInfoToggleDialog extends ToggleDialog {
             descriptionLabel.setText(description);
             setDisplayedItem(qId);
 
+            labelTab.clear();
+            labelTab.downloadLabelsFor(qId);
+
             webLinkButton.setAction(new AbstractAction() {
                 @Override
                 public void actionPerformed(ActionEvent e) {