user interface - Javafx textfield resize to text length?

Question

Hello guys I am building a chat server where I use a textfield on the screen to type in the chat message that the user writes, the idea is that it works like a bubble over a persons head when he types a message.

my question is in order to not make a textbox that is too large or too small is there a way to make the textbox resize (trim if you will) so it adjust to the text written in the textfield?

P.S. I'm using JavaFx scenebuilder to do all of this.

Answer 1

You can use computeTextWidth method in the com.sun.javafx.scene.control.skin.Utils. the method is used in javafx.scene.control.Label class to calculate the minimum width for label content.

I solved my problem as below:

field.textProperty().addListener(new ChangeListener<String>() {
        @Override
        public void changed(ObservableValue<? extends String> ob, String o,
                String n) {
            // expand the textfield
            field.setPrefWidth(TextUtils.computeTextWidth(field.getFont(),
                    field.getText(), 0.0D) + 10);
        }
    });

I have added a listener to textProperty, and with every text change i change the prefWidth of textfield.

Note: as long as the Utils.computeTextWidth() is not public, I have copied the source code to a new class (TextUtils).

Here is the full source code:

package me.jone30rw.fxcontrol;

import javafx.scene.text.Font;
import javafx.scene.text.Text;
import javafx.scene.text.TextBoundsType;

public class TextUtils {

    static final Text helper;
    static final double DEFAULT_WRAPPING_WIDTH;
    static final double DEFAULT_LINE_SPACING;
    static final String DEFAULT_TEXT;
    static final TextBoundsType DEFAULT_BOUNDS_TYPE;
    static {
        helper = new Text();
        DEFAULT_WRAPPING_WIDTH = helper.getWrappingWidth();
        DEFAULT_LINE_SPACING = helper.getLineSpacing();
        DEFAULT_TEXT = helper.getText();
        DEFAULT_BOUNDS_TYPE = helper.getBoundsType();
    }

    public static double computeTextWidth(Font font, String text, double help0) {
        // Toolkit.getToolkit().getFontLoader().computeStringWidth(field.getText(),
        // field.getFont());

        helper.setText(text);
        helper.setFont(font);

        helper.setWrappingWidth(0.0D);
        helper.setLineSpacing(0.0D);
        double d = Math.min(helper.prefWidth(-1.0D), help0);
        helper.setWrappingWidth((int) Math.ceil(d));
        d = Math.ceil(helper.getLayoutBounds().getWidth());

        helper.setWrappingWidth(DEFAULT_WRAPPING_WIDTH);
        helper.setLineSpacing(DEFAULT_LINE_SPACING);
        helper.setText(DEFAULT_TEXT);
        return d;
    }
}