How to set text and color of multiple ListView items when clicked - javafx

Question

I know there are many related questions about this but maybe I'm missing something because I can't get the behavior I'm expecting, to work.
#FXML
private ListView<String> guiList;
void performAction(Actions action) {
try {
Task<String> task = new Task<>() {
#Override
public String call() {
String mySelection = Context.getInstance().getSelected();
ArrayList<String> selectedList = Context.getInstance().getItemsClicked();
if (selectedList == null) {
selectedList = new ArrayList<>();
}
selectedList.add(mySelection);
Context.getInstance().setItemsClicked(selectedList);
guiList.setCellFactory(new Callback<ListView<String>, ListCell<String>>() {
#Override
public ListCell<String> call(ListView<String> param) {
ListCell<String> cell = new ListCell<String>() {
#Override
protected void updateItem(String item, boolean empty) {
super.updateItem(item, empty);
if(item != null && item.matches(mySelection)) {
setText(mySelection + " [" + action + "]");
setFont(Font.font(Font.getDefault().getFamily(), FontWeight.BOLD, Font.getDefault().getSize()));
setStyle("-fx-text-fill: green;");
} else {
setText(item);
}
}
};
return cell;
}
});
return "";
}
};
} catch (Exception e) {
}
}
When I click in an item of guiList, the text is changed, gets bold and shows in green color but I don't understand why I need the else statement. If I don't use it, all the other items of the list disappear.
I ask this because I want to change ALL of the items I click and in the current behavior, the changes are only made in the last one clicked.

Answer 1

Here is on approach. Use an object that has a Boolean variable to keeps up with if the item has been selected.
KeyCode 1
lvMain.getSelectionModel().selectedItemProperty().addListener(((ov, t, t1) - > {
if (t1 != null) {
t1.setSelected(true);
}
}));
Key Code 2
lvMain.setCellFactory(lv - > new ListCell < MyItem > () {
#Override
public void updateItem(MyItem item, boolean empty) {
super.updateItem(item, empty);
if (empty) {
setText(null);
setGraphic(null);
} else {
setText(item.getText());
if (item.isSelected()) {
setTextFill(Color.RED);
}
}
}
});
Main
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.ListCell;
import javafx.scene.control.ListView;
import javafx.scene.control.SelectionMode;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
/**
*
* #author blj0011
*/
public class App extends Application {
#Override
public void start(Stage primaryStage) {
ListView<MyItem> lvMain = new ListView();//Create ListView
lvMain.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);//Change ListView selection mode to multiple
ObservableList<MyItem> items = FXCollections.observableArrayList(new MyItem("Julia"), new MyItem("Ian"), new MyItem("Sue"), new MyItem("Matthew"), new MyItem("Hannah"));//ObseravableList that will be used to set the ListView
lvMain.setItems(items);//Set the ListView's items
lvMain.setCellFactory(lv -> new ListCell<MyItem>()
{
#Override
public void updateItem(MyItem item, boolean empty)
{
super.updateItem(item, empty);
if (empty) {
setText(null);
setGraphic(null);
}
else {
setText(item.getText());
if(item.isSelected())
{
setTextFill(Color.RED);
}
}
}
});
lvMain.getSelectionModel().selectedItemProperty().addListener(((ov, t, t1) -> {
if(t1 != null)
{
t1.setSelected(true);
}
}));
VBox vbox = new VBox();
vbox.getChildren().addAll(lvMain);
StackPane root = new StackPane();
root.getChildren().add(vbox);
Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Hello World!");
primaryStage.setScene(scene);
primaryStage.show();
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
MyItem
/**
*
* #author Sed
*/
public class MyItem {
private String text;
private boolean selected;
public MyItem(String text) {
this.text = text;
this.selected = false;
}
public boolean isSelected() {
return selected;
}
public void setSelected(boolean isSelected) {
this.selected = isSelected;
}
public String getText() {
return text;
}
public void setText(String text) {
this.text = text;
}
}
Output
I think a better solution would be to use the ListView's built in multiple selection or have your cells have a ToggleButton. When the ToggleButton is on, change the color of the text. When it is off, change the color back to it's original state.