Populate TableView with ObservableMap JavaFX - javafx

Question

I wanted to know if it is possible to use a ObservableMap to populate a TableView ?
I use ObservableMap instead of ObservableList because I need to add and delete often, so I need to minimize the cost.
My hashMap use an BigInteger as key field and a type with many properties as value field.
In my tableView I just want to display the values with a column per properties. I hope that is clear
Thanks

Answer 1

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.

Answer 2

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