java fx | Tech Tips & Tricks

How To Set Dynamic Height Of TextArea Based On Width In Java FX 2

September 21, 2013 by blogmeister·4 Comments

I wish Oracle simply included this feature so developers would not have to code it from scratch. However, I came across a custom made class called ScrollFreeTextArea from the javafx-demos website.

This class simply did the trick for me. So whenever you type a long text and it wraps itself or press the ENTER key for a new line, the height of the TextArea increases without displaying the scrollbar.

Here is the complete source code.

public class ScrollFreeTextArea extends StackPane {
	private Label label;
	private TextArea textArea;
	private Character enterChar = new Character((char) 10);
	private Region content;
	private SimpleDoubleProperty contentHeight = new SimpleDoubleProperty();	
	private final double NEW_LINE_HEIGHT = 18D;
	private final double TOP_PADDING = 3D;
	private final double BOTTOM_PADDING = 6D;
	public ScrollFreeTextArea() {
		super();
		configure();
	}
	private void configure() {
		setAlignment(Pos.TOP_LEFT);
		this.textArea = new TextArea() {
            @Override
			protected void layoutChildren() {
				super.layoutChildren();
				if (content == null) {
					content = (Region) lookup(".content");
					contentHeight.bind(content.heightProperty());
					content.heightProperty().addListener(new ChangeListener<Number>() {
						@Override
						public void changed(ObservableValue<? extends Number> paramObservableValue,	Number paramT1, Number paramT2) {
							//System.out.println("Content View Height :"+paramT2.doubleValue());
						}
					});
				}
			};
		};
		this.textArea.setWrapText(true); 
        this.label = new Label();
		this.label.setWrapText(true);
		this.label.prefWidthProperty().bind(this.textArea.widthProperty());
		label.textProperty().bind(new StringBinding() {
			{
				bind(textArea.textProperty());
			}
			@Override
			protected String computeValue() {
				if (textArea.getText() != null && textArea.getText().length() > 0) {
					if (!((Character)textArea.getText().charAt(textArea.getText().length() - 1)).equals(enterChar)) { 
						return textArea.getText() + enterChar;
					}
				}
				return textArea.getText();
			}
		});
		StackPane lblContainer = StackPaneBuilder.create()
										  .alignment(Pos.TOP_LEFT)
										  .padding(new Insets(4,7,7,7))
										  .children(label)
										  .build();
		// Binding the container width/height to the TextArea width.
		lblContainer.maxWidthProperty().bind(textArea.widthProperty());        
		textArea.textProperty().addListener(new ChangeListener<String>() {
			@Override
			public void changed(ObservableValue<? extends String> paramObservableValue,	String paramT1, String value) {
				layoutForNewLine(textArea.getText());
			}
		});
		label.heightProperty().addListener(new ChangeListener<Number>() {
			@Override
			public void changed(ObservableValue<? extends Number> paramObservableValue,	Number paramT1, Number paramT2) {
				layoutForNewLine(textArea.getText());
			}
		});
		getChildren().addAll(lblContainer, textArea);
	}
	private void layoutForNewLine(String text){
		if (text != null && text.length() > 0 && ((Character)text.charAt(text.length() - 1)).equals(enterChar)) {
			textArea.setPrefHeight(label.getHeight() + NEW_LINE_HEIGHT + TOP_PADDING + BOTTOM_PADDING);
			textArea.setMinHeight(textArea.getPrefHeight());
		} 
        else {
			textArea.setPrefHeight(label.getHeight() + TOP_PADDING + BOTTOM_PADDING);
			textArea.setMinHeight(textArea.getPrefHeight());
		}
	}
    public TextArea getTextArea() {
        return textArea;
    }
}

public class ScrollFreeTextArea extends StackPane {

private Label label;

private TextArea textArea;

private Character enterChar = new Character((char) 10);

private Region content;

private SimpleDoubleProperty contentHeight = new SimpleDoubleProperty();

private final double NEW_LINE_HEIGHT = 18D;

private final double TOP_PADDING = 3D;

private final double BOTTOM_PADDING = 6D;

public ScrollFreeTextArea() {

super();

configure();

}

private void configure() {

setAlignment(Pos.TOP_LEFT);

this.textArea = new TextArea() {

@Override

protected void layoutChildren() {

super.layoutChildren();

if (content == null) {

content = (Region) lookup(".content");

contentHeight.bind(content.heightProperty());

content.heightProperty().addListener(new ChangeListener<Number>() {

@Override

public void changed(ObservableValue<? extends Number> paramObservableValue, Number paramT1, Number paramT2) {

//System.out.println("Content View Height :"+paramT2.doubleValue());

}

});

}

};

this.textArea.setWrapText(true);

this.label = new Label();

this.label.setWrapText(true);

this.label.prefWidthProperty().bind(this.textArea.widthProperty());

label.textProperty().bind(new StringBinding() {

{

bind(textArea.textProperty());

}

@Override

protected String computeValue() {

if (textArea.getText() != null && textArea.getText().length() > 0) {

if (!((Character)textArea.getText().charAt(textArea.getText().length() - 1)).equals(enterChar)) {

return textArea.getText() + enterChar;

}

return textArea.getText();

}

});

StackPane lblContainer = StackPaneBuilder.create()

.alignment(Pos.TOP_LEFT)

.padding(new Insets(4,7,7,7))

.children(label)

.build();

// Binding the container width/height to the TextArea width.

lblContainer.maxWidthProperty().bind(textArea.widthProperty());

textArea.textProperty().addListener(new ChangeListener<String>() {

@Override

public void changed(ObservableValue<? extends String> paramObservableValue, String paramT1, String value) {

layoutForNewLine(textArea.getText());

}

});

label.heightProperty().addListener(new ChangeListener<Number>() {

@Override

public void changed(ObservableValue<? extends Number> paramObservableValue, Number paramT1, Number paramT2) {

layoutForNewLine(textArea.getText());

}

});

getChildren().addAll(lblContainer, textArea);

}

private void layoutForNewLine(String text){

if (text != null && text.length() > 0 && ((Character)text.charAt(text.length() - 1)).equals(enterChar)) {

textArea.setPrefHeight(label.getHeight() + NEW_LINE_HEIGHT + TOP_PADDING + BOTTOM_PADDING);

textArea.setMinHeight(textArea.getPrefHeight());

}

else {

textArea.setPrefHeight(label.getHeight() + TOP_PADDING + BOTTOM_PADDING);

textArea.setMinHeight(textArea.getPrefHeight());

}

public TextArea getTextArea() {

return textArea;

}

Width Of ComboBox Popup List Is Too Small In Java FX 2

September 20, 2013 by blogmeister·0 Comments

The first time I encountered this I really did not pay much attention but after experiencing it the second time in my other ComboBox, I decided to look into it.

The issue happens when I click on the ComboBox the first time and the popup menu list that is shown has its width very short. The second time I click on the ComboBox and the list is shown again, the width is now correct as the width of the list now aligns itself with the ListView.

Seems this is a bug in Java FX 2. User shakir.gusaroff in the Oracle forumprovided an insightful answer regarding this issue.

There is a bug: https://javafx-jira.kenai.com/browse/RT-28876 where the ComboBox popup list is set with the wrong width the first time it is shown if it is wider than prefWidth.

This is fixed in Java FX 8.0 already, but not in Java FX 2.

How To Add A Titled Border On A TextArea In Java FX

September 16, 2013 by blogmeister·0 Comments

You may want yo create something like this.

Now, even using CSS this is not possible if you directly add a label on the TextArea itself and change its z-location. I came across a post somewhere in the Stack Overflow forum and user jewelsea created a custom made BorderedTitledPane class that simulates a Titled Border in Java’s Swing.

Using this class I added a TextArea to the BorderedTitledPane and with a little CSS tweaking, removed the border and changed its z-location so that the Label title will be positioned right between the border of the TextArea.

Here is the BorderedTitlePane.

public class BorderedTitledPane extends StackPane {
    public BorderedTitledPane(String titleString, Node content) {
        Label title = new Label(" " + titleString + " ");
        title.getStyleClass().add("bordered-titled-title");
        StackPane.setMargin(title, new Insets(0, 25, 0, 0));
        StackPane.setAlignment(title, Pos.TOP_RIGHT);
        StackPane contentPane = new StackPane();
        contentPane.getChildren().add(content);
        getStyleClass().add("bordered-titled-border");
        getChildren().addAll(contentPane, title);
    }
}

public class BorderedTitledPane extends StackPane {

public BorderedTitledPane(String titleString, Node content) {

Label title = new Label(" " + titleString + " ");

title.getStyleClass().add("bordered-titled-title");

StackPane.setMargin(title, new Insets(0, 25, 0, 0));

StackPane.setAlignment(title, Pos.TOP_RIGHT);

StackPane contentPane = new StackPane();

contentPane.getChildren().add(content);

getStyleClass().add("bordered-titled-border");

getChildren().addAll(contentPane, title);

}

And here is the CSS code to make that possible.

.bordered-titled-title {
    -fx-background-color: darkgray;
    -fx-translate-y: -13;
    -fx-padding: 0 0 5 0;
}
.bordered-titled-border {
    -fx-content-display: top;
    -fx-border-insets: 15 0 0 0;
    -fx-border-color: transparent;
}
.bordered-titled-content {
    -fx-border-insets: 20 0 0 0;
}

.bordered-titled-title {

-fx-background-color: darkgray;

-fx-translate-y: -13;

-fx-padding: 0 0 5 0;

}

.bordered-titled-border {

-fx-content-display: top;

-fx-border-insets: 15 0 0 0;

-fx-border-color: transparent;

}

.bordered-titled-content {

-fx-border-insets: 20 0 0 0;

}

Doing this in Swing is possibly tedious but Java FX and CSS gives developers so much flexibility creating new layouts.

To use the class, call it like this.

BorderedTitledPane btp = new BorderedTitledPane("My Title, myTextArea);

1	BorderedTitledPane btp = new BorderedTitledPane("My Title, myTextArea);

And add it to the scene’s container.

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Category: java fx

How To Set Dynamic Height Of TextArea Based On Width In Java FX 2

How To Add A Titled Border On A TextArea In Java FX