JTextArea on JPanel inside JScrollPane doesn't resize

Question

I would like to do the following:

+------------------Other container(s)-----------------+ | +------JScrollPane (vertical)-------+ | | | JTextField | | | | Box.createRigidArea (vertical) | | | | JTextArea | | | | { etc.. any other J-component } | | | | | | | | | | | | | | | | | | | +-----------------------------------+ | +-----------------------------------------------------+ 

The closest I can get with the following (pseudo) code:

 JPanel container = new JPanel(new BorderLayout()); JPanel innerContainer = new JPanel(); innerContainer.setLayout(new BoxLayout(_innerContainer, BoxLayout.Y_AXIS)); JScrollPane scrollPane = new JScrollPane(innerContainer); container.add(scrollPane, BorderLayout.NORTH); 

When I would like to add components, they are added to the inner container:

 innerContainer.add(new JTextField()); innerContainer.add(Box.createRigidArea(new Dimension(0, 10))); innerContainer.add(new JTextArea()); innerContainer.add(Box.createRigidArea(new Dimension(0, 10))); innerContainer.add(new JLabel()); 

.... etc.

I encountered the following problems:

I let layout managers take care of all sizes of the user interface element. Therefore, I prefer to use some kind of .setxxSize () method. JTextArea, busy with large text, will use all the necessary space (vertical and horizontal). This is completely normal. Whenever the frame size changes, JTextArea will grow, and this is still great. But whenever I compress the frame, JTextArea is not configured accordingly. Therefore, a horizontal scrollbar appears, but I would like to avoid this. I want users to only scroll vertically.

Does anyone have any good tips? Thanks!

EDIT:

SSCCE:

 import java.awt.*; import javax.swing.*; public class VerticalStackPanel extends JFrame { public static void main(String[] args) { JFrame frame = new VerticalStackPanel(); frame.setSize(800, 600); frame.setVisible(true); } public VerticalStackPanel() { super(); JScrollPane scrollPane = new JScrollPane(createVerticalStackPanel()); scrollPane.getVerticalScrollBar().setUnitIncrement(16); scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED); scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); getContentPane().add(scrollPane); } private Component createVerticalStackPanel() { JPanel container = new JPanel(new BorderLayout()); container.add(createInnerContainer(), BorderLayout.NORTH); return container; } private Component createInnerContainer() { JPanel innerContainer = new JPanel(); innerContainer.setLayout(new BoxLayout(innerContainer, BoxLayout.Y_AXIS)); innerContainer.add(createTextArea()); innerContainer.add(Box.createRigidArea(new Dimension(0, 10))); innerContainer.add(createTextArea()); innerContainer.add(Box.createRigidArea(new Dimension(0, 10))); innerContainer.add(createTextArea()); innerContainer.add(Box.createRigidArea(new Dimension(0, 10))); innerContainer.add(createTextArea()); innerContainer.add(Box.createRigidArea(new Dimension(0, 10))); innerContainer.add(createTextArea()); innerContainer.add(Box.createRigidArea(new Dimension(0, 10))); innerContainer.add(createTextArea()); innerContainer.add(Box.createRigidArea(new Dimension(0, 10))); return innerContainer; } private Component createTextArea() { JTextArea textArea = new JTextArea(); textArea.setText("Lorem ipsum dolor sit amet, consectetur adipiscing elit. In vitae diam nunc. Proin vulputate, odio consectetur tincidunt aliquet, metus ipsum rhoncus tellus, in dignissim ligula tortor at risus. Aenean rhoncus lorem a magna luctus molestie. Fusce consequat enim vel quam pharetra varius. Vivamus porta condimentum orci non ultrices. Duis magna arcu, fringilla ut eleifend a, volutpat ac elit. Sed ligula enim, dictum id fringilla vitae, ornare vel nulla. Proin lobortis suscipit lectus eget placerat. Morbi aliquam dolor quis lectus tincidunt eu volutpat risus fermentum. Nunc et sapien a nisl aliquet auctor. Phasellus nec sem tellus, et scelerisque sapien. In a nibh vestibulum velit convallis sodales. Vestibulum tempor fringilla vulputate. Duis hendrerit dolor id urna aliquam cursus auctor enim pulvinar. Nulla rutrum fringilla eros, id congue nisi mattis in. Pellentesque consectetur eleifend mauris, ut aliquam purus convallis ac. Vestibulum pretium, sem at congue faucibus, leo leo volutpat odio, ut feugiat nulla felis a diam. Praesent dignissim eros ac eros semper auctor. Phasellus eu sapien nibh. Quisque pulvinar tristique lectus, quis porttitor purus suscipit sed. Curabitur gravida, ipsum ut vehicula aliquet, erat ipsum tincidunt nulla, eget bibendum felis dolor vel risus. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Phasellus vitae nisl odio, blandit laoreet nibh."); textArea.setLineWrap(true); textArea.setWrapStyleWord(true); return textArea; } } 

Whenever you resize the frame horizontally, the text will disappear whenever the frame gets smaller. A horizontal scrollbar will appear, but since:

 scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); 

The text just disappears. JTextArea needs to adjust accordingly

Answer 1

So, the problem is that JPanel does not like to integrate into JScrollPane.

In order for the "Play Nice" component using JScrollPane, it needs to implement scrollable. If you just added JTextArea to JScrollPane, it will work exactly as you needed.

Instead of using JPanel to store all of your JTextAreas, you need to create a small custom class that extends JPanel and implements scrollable.

I rewrote your example and entered it here: http://pastebin.com/q9x4fv3H so you can see all the code. A scrollable JPanel should look like this:

 private static class ScrollablePanel extends JPanel implements Scrollable{ public Dimension getPreferredScrollableViewportSize() { return super.getPreferredSize(); //tell the JScrollPane that we want to be our 'preferredSize' - but later, we'll say that vertically, it should scroll. } public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) { return 16;//set to 16 because that what you had in your code. } public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) { return 16;//set to 16 because that what you had set in your code. } public boolean getScrollableTracksViewportWidth() { return true;//track the width, and re-size as needed. } public boolean getScrollableTracksViewportHeight() { return false; //we don't want to track the height, because we want to scroll vertically. } } 

Hooray!

Answer 2

You must add a Viewport for your scrollPane :

 scrollPane.setViewportView(textArea) 

Answer 3

Use

 txtArea.setWrapStyleWord(true); txtArea.setLineWrap(true); 

It wraps text and avoids horizontal scrolling.

And try GridBagLayout. Use weightx and weighty. He will take care of resizing problems.

Answer 4

JTextArea never shrinks when line wrapping is enabled

I have a JTextArea in a JPanel with a Gridlayout that has this problem. The mine was solved by simply setting the minimum size of the TextArea.

 textArea.setMinimumSize(new Dimension(20,40));