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.

1
7
6/30/2016 5:05:59 AM

Accepted Answer

It is time to do some coding behind the scenes(builder) :).
The following code chunk is not a neat solution but better than none. :)

// define width limits
textField.setMinWidth(50);
textField.setPrefWidth(50);
textField.setMaxWidth(400);
// add listner
textField.textProperty().addListener(new ChangeListener<String>() {
    @Override
    public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
        textField.setPrefWidth(textField.getText().length() * 7); // why 7? Totally trial number.
    }
});
5
10/5/2012 1:35:33 PM

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;
    }
}

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