Populate TableView with ObservableMap JavaFX

Question

I wanted to know if it is possible to use a ObservableMap to populate a TableView ? I use ObservableMap instead of ObservableLis

Answer 1

I packaged up my Map Table listeners in a subclass of TableView.

package tablemap;

import java.util.AbstractMap;
import java.util.Map;
import javafx.collections.FXCollections;
import javafx.collections.ListChangeListener;
import javafx.collections.MapChangeListener;
import javafx.collections.ObservableList;
import javafx.collections.ObservableMap;
import javafx.scene.control.TableView;

public class MapTableView<K,V> extends TableView<Map.Entry<K,V>>{
    private final ObservableList<Map.Entry<K,V>> obsList;
    private final ObservableMap<K,V> map;
    private final MapChangeListener<K,V> mapChange;
    private final ListChangeListener<Map.Entry<K,V>> listChange;

    public MapTableView(ObservableMap<K,V> map) {
        this.map = map;
        obsList = FXCollections.observableArrayList(map.entrySet());
        setItems(obsList);

        mapChange = new MapChangeListener<K, V>() {
            @Override
            public void onChanged(MapChangeListener.Change<? extends K, ? extends V> change) {
                obsList.removeListener(listChange);
                if (change.wasAdded())
                    obsList.add(new AbstractMap.SimpleEntry(change.getKey(),change.getValueAdded()));
                if (change.wasRemoved()){
                    //obsList.remove(new AbstractMap.SimpleEntry(change.getKey(),change.getValueRemoved()));
                    // ^ doesn't work always, use loop instead
                    for (Map.Entry<K,V> me : obsList){
                        if (me.getKey().equals(change.getKey())){
                            obsList.remove(me);
                            break;
                        }
                    }
                }
                obsList.addListener(listChange);
            }
        };

        listChange = (ListChangeListener.Change<? extends Map.Entry<K, V>> change) -> {
            map.removeListener(mapChange);
            while (change.next()){
                //maybe check for uniqueness here
                if (change.wasAdded()) for (Map.Entry<K, V> me: change.getAddedSubList())
                    map.put(me.getKey(),me.getValue());
                if (change.wasRemoved()) for (Map.Entry<K, V> me: change.getRemoved())
                    map.remove(me.getKey());
            }
            map.addListener(mapChange);
        };

        map.addListener(mapChange);
        obsList.addListener(listChange);
    }

    //adding to list should be unique
    public void addUnique(K key, V value){
        boolean isFound = false;
        //if a duplicate key just change the value
        for (Map.Entry<K,V> me : getItems()){
            if (me.getKey().equals(key)){
                isFound = true;
                me.setValue(value);
                break;//only first match 
            }
        }
        if (!isFound) // add new entry
            getItems().add(new AbstractMap.SimpleEntry<>(key,value));
    }

    //for doing lenghty map operations
    public void removeMapListener(){
        map.removeListener(mapChange);
    }

    //for resyncing list to map after many changes
    public void resetMapListener(){
        obsList.removeListener(listChange);
          obsList.clear();
          obsList.addAll(map.entrySet());
        obsList.addListener(listChange);
        map.addListener(mapChange);
    }

}

It seems to work so far. I create with the following code :

final ObservableMap<String, LineItem> obsMap = FXCollections.observableHashMap();
final MapTableView<String,LineItem> mtv = new MapTableView(obsMap);

You can even edit the keys.

final TableColumn<Map.Entry<String,LineItem>,String> keyCol = new TableColumn("Key");
keyCol.setCellValueFactory(
    (TableColumn.CellDataFeatures<Map.Entry<String,LineItem>, String> p) -> 
        new SimpleStringProperty(p.getValue().getKey()));
keyCol.setCellFactory(TextFieldTableCell.forTableColumn());
keyCol.setOnEditCommit((CellEditEvent<Map.Entry<String,LineItem>, String> t) -> {
    final String oldKey = t.getOldValue();
    final LineItem oldLineItem = obsMap.get(oldKey);
    obsMap.remove(oldKey);//should remove from list but maybe doesn't always
    obsMap.put(t.getNewValue(),oldLineItem);
});

You can see I added a method to remove and re add the map listeners. To add and remove 100k entries takes .65 secs w/out listeners and 5.2 secs with them.

Here's the whole thing in one file on pastebin. http://pastebin.com/NmdTURFt

Answer 2

I've been trying to do this. I guess the post is old but I don't see any answers anywhere on the net. The examples use the map key for columns and then a list of maps for every row. I'd like to see the rows as keys and their associated values. It's a long example.

package tablemap;

import static java.lang.Math.random;
import java.util.Map;
import java.util.TreeMap;
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableColumn.CellEditEvent;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class TableMap extends Application {

    @Override
    public void start(Stage primaryStage) {
        VBox root = new VBox();
        Map<String,LineItem> mapData = new TreeMap<>();
        for (int i = 0; i < 3; i++)
            mapData.put(String.valueOf(random()), new LineItem(String.valueOf(i),"i"));

        ObservableList<Map.Entry<String,LineItem>> listData = 
                FXCollections.observableArrayList(mapData.entrySet());
        TableView<Map.Entry<String,LineItem>> tv = new TableView(listData);

        TableColumn<Map.Entry<String,LineItem>,String> keyCol = new TableColumn("Key");
        keyCol.setCellValueFactory(
            (TableColumn.CellDataFeatures<Map.Entry<String,LineItem>, String> p) -> 
                new SimpleStringProperty(p.getValue().getKey()));

        TableColumn<Map.Entry<String,LineItem>,String> lineNoCol = new TableColumn("Line No");
        lineNoCol.setCellValueFactory(
            (TableColumn.CellDataFeatures<Map.Entry<String,LineItem>, String> p) -> 
                new SimpleStringProperty(p.getValue().getValue().getLineNo()));

        TableColumn<Map.Entry<String,LineItem>,String> descCol = new TableColumn("Desc");
        descCol.setCellValueFactory(
            (TableColumn.CellDataFeatures<Map.Entry<String,LineItem>, String> p) -> 
                new SimpleStringProperty(p.getValue().getValue().getDesc()));

        descCol.setCellFactory(TextFieldTableCell.forTableColumn());

        descCol.setOnEditCommit((CellEditEvent<Map.Entry<String,LineItem>, String> t) -> {
             t.getTableView().getItems().get(t.getTablePosition().getRow())
                     .getValue().setDesc(t.getNewValue());
        });

        tv.getColumns().addAll(keyCol,lineNoCol, descCol);
        tv.setEditable(true);
        tv.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);

        Button btnOut = new Button("out");
        btnOut.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent t) {
                for (Map.Entry<String,LineItem> me : mapData.entrySet()){
                    System.out.println("key "+me.getKey()+" entry "+me.getValue().toCSVString());
                }
                for (Map.Entry<String,LineItem> me : listData){
                    System.out.println("key "+me.getKey()+" entry "+me.getValue().toCSVString());
                }
            }
        });

        root.getChildren().addAll(tv,btnOut);
        Scene scene = new Scene(root, 300, 200);

        primaryStage.setTitle("Map Table Test");
        primaryStage.setScene(scene);
        primaryStage.show();
    }
}

And the LineItem Class Code

package tablemap;

import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;

/* LineItem class */

public class LineItem {
    private final StringProperty lineNo = new SimpleStringProperty();
    private final StringProperty desc = new SimpleStringProperty();

    public LineItem(String ln, String dsc) {
        lineNo.set(ln); desc.set(dsc);
    }

    public String getLineNo() {return (lineNo.getValue() != null) ?lineNo.get():"";}
    public void setLineNo(String lineNo) {this.lineNo.set(lineNo);}
    public StringProperty lineNoProperty() {return lineNo;}

    public String getDesc() {return (desc.getValue() != null) ?desc.get():"";}
    public void setDesc(String desc) {this.desc.set(desc);}
    public StringProperty descProperty() {return desc;}

    public String toCSVString(){
        return lineNo.getValueSafe()+","+
                desc.getValueSafe()+"\n"; 
    }
}

You can see after editing data and clicking out that changes in the list are reflected in the map. I still have to check the other way and handle insertions and deletions but that shouldn't be to hard.