RFR: 8092102: Labeled: truncated property [v11]

[Kevin Rushforth]

On Thu, 2 May 2024 22:10:24 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> Adds **Labeled.textTruncated** property which indicates when the text is visually truncated (and the ellipsis string is inserted) in order to fit the available width.
>> 
>> The new property reacts to changes in the following properties:
>> - ellipsisString
>> - font
>> - height
>> - text
>> - width
>> - wrapText
>> 
>> I don't think it's worth creating a headful test (headless won't work) due to relative simplicity of the code.
>> 
>> **Alternative**
>> 
>> The desired functionality can be just as easily achieved on an application level, by adding a similar property to a subclass.  What is the benefit of adding this functionality to the core?
>> 
>> UPDATE 2024/03/07: turns out Labeled in a TableView (in a TreeTableView as well) lives by different rules (TableCellSkinBase:152, TreeTableCellSkin:126).  The consequence of this is that the new functionality **cannot** be fully implemented with the public APIs alone.
>> 
>> **See Also**
>> 
>> * [JDK-8327483](https://bugs.openjdk.org/browse/JDK-8327483) TreeView: Allow for tooltip when cell text is truncated
>> * [JDK-8205211](https://bugs.openjdk.org/browse/JDK-8205211) Ability to show Tooltip only when text is shown with ellipsis (...)
>
> Andy Goryachev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   using properties

Here is a test showing the failure to detect truncated text.


import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.HBox;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.stage.Stage;

public class TruncatedTest extends Application {

    private static final String clickMe = "Click me";
    private static final String clickMeAgain = "Click me again, please";

    @Override public void start(Stage stage) {
        stage.setTitle("Truncated Button Text (fails)");

        var root = new HBox(10);
        Scene scene = new Scene(root, 600, 450);

        var button = new Button(clickMe);
        button.setPrefWidth(100);
        button.setOnAction(e -> {
            button.setText(clickMe.equals(button.getText()) ? clickMeAgain : clickMe);
            //System.err.println("truncated: " + button.isTextTruncated());
        });
        root.getChildren().add(button);

        var label = new Label();
        label.textProperty().bind(button.textTruncatedProperty().asString());
        root.getChildren().add(label);

        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        Application.launch(args);
    }
}

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PR Comment: https://git.openjdk.org/jfx/pull/1389#issuecomment-2093024810