I have a JavaFX table column which I would like to display a comma-separated list of strings, unless the text does not fit within the current bounds of the cell, at which point it would display, for example, "Foo and 3 others...", or "3 Bars", i.e. reflecting the number of elements in the list.
Is there a way to check, when building a CellValueFactory for a table column, whether the text would overrun the cell, so I could switch between these two behaviors?
You can specify an overrun style for Labeled controls like TableCells.
Overrun style ELLIPSIS will automatically add these ellipses as needed to indicate if the content would have extended outside of the label.
I recommend doing this in a cell factory, like so:
column.setCellFactory(() -> {
TableCell<?, ?> cell = new TableCell<>();
cell.setTextOverrun(OverrunStyle.ELLIPSIS);
return cell;
});
So you would need to use the cell factory instead of the cell value factory. The reason I recommend cell factory is because the table creates and destroys cells on its own as needed, so you'd have a hard time getting all those instances and setting their overrun behavior if you didn't have control of those cells creation like you do with the cell factory.
Try something along these lines, you might need to tweak the method to get the length of your string, and you might want to try to figure out the current length of the table cell whenever you update it, but this should get you started. Think it's a decent approach?
public class TestApplication extends Application {
public static void main(String[] args) {
Application.launch(args);
}
public void start(final Stage stage) {
stage.setResizable(true);
TestTableView table = new TestTableView();
ObservableList<String> items = table.getItems();
items.add("this,is,short,list");
items.add("this,is,long,list,it,just,keeps,going,on,and,on,and,on");
Scene scene = new Scene(table, 400, 200);
stage.setScene(scene);
stage.show();
}
/**
* Note: this does not take into account font or any styles.
* <p>
* You might want to modify this to put the text in a label, apply fonts and css, layout the label,
* then get the width.
*/
private static double calculatePixelWidthOfString(String str) {
return new Text(str).getBoundsInLocal().getWidth();
}
public class TestTableView extends TableView<String> {
public TestTableView() {
final TableColumn<String, CsvString> column = new TableColumn<>("COL1");
column.setCellValueFactory(cdf -> {
return new ReadOnlyObjectWrapper<>(new CsvString(cdf.getValue()));
});
column.setCellFactory(col -> {
return new TableCell<String, CsvString>() {
@Override
protected void updateItem(CsvString item, boolean empty) {
super.updateItem(item, empty);
if (item == null || empty) {
setText(null);
} else {
String text = item.getText();
// get the width, might need to tweak this.
double textWidth = calculatePixelWidthOfString(text);
// might want to compare against current cell width
if (textWidth > 100) {
// modify the text here
text = item.getNumElements() + " elements";
}
setText(text);
}
}
};
});
this.getColumns().add(column);
}
}
private static class CsvString {
private final String text;
private final String[] elements;
public CsvString(String string) {
Objects.requireNonNull(string);
this.text = string;
this.elements = string.split(" *, *");
}
public int getNumElements() {
return elements.length;
}
public String getText() {
return text;
}
}
}
