This seems like a simple thing to do, but I can't get it to work.
I have a BorderLayout. I want to use the top part for a title bar. I want to add a JPanel with labels, buttons and other components. However, the PAGE_START part of the border layout won't left align the panel. Here's the situation, with comments in where I've tried to set the alignment.
I noticed that when I don't add a panel to the border layout, and just write the JLabel straight in, it has left alignment by default.
This is not what I want, though, because I am planning on putting a BoxLayout.X_AXIS horizontally through the BorderLayout.PAGE_START title area. Seems to be a reasonable thing to do?
The Container pane argument to the static method is just the single panel on the main JFrame.
public static void addComponentsToPane(Container pane)
{
JLabel jlabel = new JLabel("I want to left align this inside a JPanel");
// Doesn't work: jlabel.setAlignmentX(Component.LEFT_ALIGNMENT);
JPanel jpanel = new JPanel();
//Doesn't work: jlabel.setAlignmentX(Component.LEFT_ALIGNMENT);
jpanel.add(jlabel);
pane.add(jpanel, BorderLayout.PAGE_START);
// Other parts of the BoxLayout (works fine)
JButton button = new JButton("Button 2 (CENTER)");
button.setPreferredSize(new Dimension(200, 100));
pane.add(button, BorderLayout.CENTER);
button = new JButton("Button 3 (LINE_START)");
pane.add(button, BorderLayout.LINE_START);
button = new JButton("Long-Named Button 4 (PAGE_END)");
pane.add(button, BorderLayout.PAGE_END);
button = new JButton("5 (LINE_END)");
pane.add(button, BorderLayout.LINE_END);
}
Even when I tell the panel to left align the label, it doesn't appear left aligned.
Does anyone know what I am doing wrong?
By default a JPanel uses a FlowLayout with "center" alignment.
if you want components "left" aligned, then you need to set the layout on the panel to use a FlowLayout with "left" alignment.
Read the FlowLayout API for the proper constructor to use to set the alignment.
Or you can also read the Swing tutorial on How to Use FlowLayut which gives the constructors and valid values to specify the alignment.
I want to add the possibility for my users to add a comment on a form. To display them, I created JPanel inside a simple JScrollPane. I set the layout of this JPanel to BoxLayout because I wish to add them all in only one column and it seemed to be the easiest way by calling BoxLayout.Y_AXIS in the constructor. I also tried GridLayout and GridBagLayout but it was not what I was looking for.
My problem is that when a JPanel has the BoxLayout layout, it's width automatically is the same as it's container, but my container is a JScrollPane and the caret hides the right side of my comment!
You can see the JTextField and a JButton on the bottom left, here's the code on the click event :
private void btnAjoutCommentaireActionPerformed(java.awt.event.ActionEvent evt) {
//I take the text from the JTextField and format it to html
String formattedComment = "<html><br><div style='width:280px;'>" +
txtArCommentaire.getText().replaceAll("\n", "<br>") +
"</div><br></html>";
JLabel label = new JLabel(formattedComment);
//I add a blue border
label.setBorder(new TitledBorder(new EtchedBorder(Color.lightGray, Color.blue), ConfigUser.getCu().toString()));
//this below doesn't work
label.setSize(280, 200);
//I tried adding a JPanel in between but it didn't really worked out
//JPanel panel = new JPanel();
//panel.setLayout(new GridLayout(1, 1));
//panel.setSize(297, 200);
//panel.add(label);
///pnlCommentaire is the JPanel inside the JScrollPane
pnlCommentaire.setLayout(new BoxLayout(pnlCommentaire, BoxLayout.Y_AXIS));
pnlCommentaire.add(label);
pnlCommentaire.revalidate();
pnlCommentaire.repaint();
}
As you can see I tried to adust the size in html using style='width:280px'and on the JLabel using label.setSize(280, 200); but none of them worked.
Do you have any idea on how I could resize this Jlabel?
EDIT :
I added a margin-right property to the div so that I can at least fully see the text in the JLabel but the right border is still hidden.
String formattedComment = "<html><br><div style='width:280px;margin-right:50px;'>" +
txtArCommentaire.getText().replaceAll("\n", "<br>") +
"</div><br></html>";
I have multiple JTextAreas inside a JPanel. I am using a BoxLayout to make them align vertically and fill the width of the container.
It works, but they seem to expand to fill the entire height as well.
What I really want is simple - a text area that wraps text where I can control the width but allow the height to scale dynamically as more lines are added. The above method was just my best attempt at it. If there is a solution that uses a different layout manager, different text component, etc, that works.
minimal verifiable example below:
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setPreferredSize(new Dimension(300, 300));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel textAreas = new JPanel();
textAreas.setLayout(new BoxLayout(textAreas, BoxLayout.Y_AXIS));
JTextArea area1 = new JTextArea();
area1.append("this is a string");
area1.setLineWrap(true);
area1.setWrapStyleWord(true);
textAreas.add(area1);
JTextArea area2 = new JTextArea("and another that is much longer, so that it wraps to the next line");
area2.setLineWrap(true);
area2.setWrapStyleWord(true);
textAreas.add(area2);
JScrollPane scrollPane = new JScrollPane();
scrollPane.setViewportView(textAreas);
frame.add(scrollPane);
frame.pack();
frame.setVisible(true);
}
I have done research on this topic on my own, including looking at different layout managers (http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html), and checking other questions on the site, but I haven't had much luck.
TLDR: Can I make it so each element of a layout has a height that scales to its content but a fixed width? If so how?
What I really want is simple - a text area that wraps text where I can control the width but allow the height to scale dynamically as more lines are added.
The BoxLayout respects the maximum size so the text area grows to fill all the space available in the panel. You can override the getMaximumSize() method to return the preferred height by using something like:
JTextArea area1 = new JTextArea()
{
public Dimension getMaximumSize()
{
Dimension d = super.getMaximumSize();
d.height = getPreferredSize().height;
return d;
}
};
It works...
Not really. Make the frame wider and the text will unwrap. Then shrink the frame and the scrollbar will appear. That is the text will not wrap again
What you need to do is force the panel added to the scroll pane to be the same width as the viewport. This will allow wrapping to work properly.
You do this by implementing the Scrollable interface on the panel. Specifically you need to override the getScrollableTracksViewportWidth() method to return true.
Or an easier solution is to use the Scrollable Panel class which allows you to set properties of the panel to control this behaviour.
You can replace a JPanel with the ScrollablePanel:
//JPanel textAreas = new JPanel();
ScrollablePanel textAreas = new ScrollablePanel();
textAreas.setScrollableWidth( ScrollablePanel.ScrollableSizeHint.FIT );
Edit:
If there is a solution that uses a different layout manager
Without overriding the getMaximumSize() method of the text areas and when using the Scrollable Panel you should be able to use the following layout managers.
The GridBagLayout allows you to specify the "weightx" constraint. This will allow the component to fill all the available space in the panel.
Or if you don't like specifying all the constrains of the GridBagLayout you could use the Relative Layout which support vertical/horizontal layout of components at their preferred size.
You would just need to use the following to force the component to fill the horizontal space:
//textAreas.setLayout(new BoxLayout(textAreas, BoxLayout.Y_AXIS));
RelativeLayout rl = new RelativeLayout(RelativeLayout.Y_AXIS);
rl.setFill( true );
textAreas.setLayout(rl);
I am currently trying to create a script editor. But the lineNumber JPanel is not top aligned next to the JTextArea. The lineNumber JPanel appears at the center on the right side of the JTextArea.
It looks like this:
This is the class which instantiates both of these components:
private ScriptEditor() {
((FlowLayout) this.getLayout()).setVgap(0);
((FlowLayout) this.getLayout()).setHgap(0);
//This is the lineNumber JPanel which has no LayoutManager set.
lineNumPanel = new LineNumberPanel();
//I tried setAlignmentY but it did not work
lineNumPanel.setAlignmentY(TOP_ALIGNMENT);
//The text area.
scriptArea = new JTextArea(22,15);
scriptArea.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 15));
scriptArea.setMargin(new Insets(3, 10, 3, 10));
//This JPanel contains the two components: lineNumber JPanel and the JTextArea
JPanel temp = new JPanel();
temp.add(lineNumPanel);
temp.add(scriptArea);
//Set the scrollPane
JScrollPane scrollPane = new JScrollPane(temp);
scrollPane.setPreferredSize(new Dimension(width, height));
//Add the scrollPane to this JPanel.
add(scrollPane);
}
JPanel temp = new JPanel();
By default a JPanel uses a FlowLayout. a FlowLayout vertically centers the components added to the panel. If you don't like this behaviour then try a different layout manager like a horizontal BoxLayout, which will allow you to align the component at the top/center/bottom depending on the components vertical alignment.
However, using a JPanel is not the best approach. Instead you should be adding the line number component to the row header of the scroll pane. See Text Component Line Number for an example of this approach.
I am using miglayout to create a form in which there are JTextFields (short input answers) as well as JTextAreas (Longer answers). The problem is twofold.
The border placed around a Scrollpane wrapped text area does not match that of a Text Field.
The width and placement of the textarea/textfield differ, causing them not to line up correctly.
alt text http://grab.by/3O0V
After changing from right/left to right/fill:
alt text http://grab.by/3RMk
You can see that the bounds line up, but that there are still gaps. I tried setting novisualpadding but this did not fix it.
Source code:
package test2;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import net.miginfocom.swing.MigLayout;
public class Test extends JPanel {
private static final int NUM_CHARACTERS_WIDTH = 20;
private static final int NUM_ROWS = 5;
public Test() {
setLayout(new MigLayout(
"wrap 2",
// Align text labels on the so their right edge meets left edge of the text fields
"[right][left]"
));
add(new JLabel("Text field:"));
add(new JTextField(NUM_CHARACTERS_WIDTH));
add(new JLabel("No scrollpane text area:"));
add(new JTextArea(NUM_ROWS, NUM_CHARACTERS_WIDTH));
add(new JLabel("Scrollpane text area:"));
add(new JScrollPane(new JTextArea(NUM_ROWS, NUM_CHARACTERS_WIDTH)));
add(new JLabel("Text field:"));
add(new JTextField(NUM_CHARACTERS_WIDTH));
}
public static void main(String[] args) {
JFrame frame = new JFrame("");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new Test();
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
}
What's the preferred way to mix and match jtextfield and jtextareas, while still maintaining visual harmony? I notice now that the text field has a blue highlight around it when focus is in it, as opposed to the text area... another source of visual discontinuity.
I know this question is pretty old, but to get the border for a TextArea to match that of a TextField:
(myTextArea).setBorder(new JTextField().getBorder());
That should give a border to your TextArea like the one around a TextField.
Not sure how you can fix your border problem but to fix your layout situation I would just use springlayout. Springlayout is just a way to better layout your elements within the JPanel. You can find out more about it Java Sun Tutorial
Specifically you use it by setting where you want your North, South, West and East borders of each element. To do this you would have to first take your label calls out of the add so each one can be named. So instead of:
add(new JLabel("Text field:"));
Do:
JLabel myLabelName = new JLabel("Text field:");
add(myLabelName);
For each of your elements (JLabels, JTextAreas and JTextField). Once this is done you can easily set the layout.
Springlayout layout = new SpringLayout();
setLayout(layout);
Then for each of the elements you have to set any of the borders you want. They have to be in the specific order South, the North, West then East. Though you don't have to use all four borders if you don't want to. Here is an example on how to set your first text area, the one on the top.
layout.putConstraint(SpringLayout.NORTH, FirstTextAreaName, 10, SpringLayout.NORTH, this);
layout.putConstraint(SpringLayout.WEST, FirstTextAreaName, this.getWidth()/2, SpringLayout.WEST, this);
layout.putConstraint(SpringLayout.EAST, FirstTextAreaName, -10, SpringLayout.EAST, this);
This example doesn't set the south of the text area but if you did want to it would have to be first. The first line sets the north side of the text area to be 10 pixels away from the top. When setting the other areas you but the previous (above) areas name instead of this and say it is 10 pixels away from the south of the previous one:
layout.putConstraint(SpringLayout.NORTH, SecondTextAreaName, 10, SpringLayout.SOUTH, FirstTextAreaName);
The second line in the above example sets the east side of the text area to start halfway through your main panel. The last, third, line sets the east side of the text area to be 10 pixels from the east side of your main panel.
I know that MiGLAyout (which I love, BTW) has the ability to do special handling for visual alignment vs strict pixel alignment. You may be running into this... The 'al' unit identifier is used for this, but I haven't had to use it so can't provide examples. It would probably be worth downloading the MiG sample project and see if they have the same alignment issue (I'm sure they have panels similar to yours).
For what it's worth, we mix text fields and areas in the same panel quite frequently and don't run into this... We do have to set the border of the scroll pane to be the same as the border of the text field as suggested by Noel Ang.
Also, instead of specifying constraints in the layout constructor, we generally specify them as we add each component - not sure if that makes a difference or not...
For the layout problem, try a columnConstraints value of [right][fill] instead of [right][left].
For the other issue, this appears to be a look-and-feel inconsistency. I ran your code in Windows, and the differences are there too, but less flagrant. My suggestion would be to set identifical borders explicitly for text fields and text areas.
setLayout(new MigLayout(
"wrap 2",
"[right][fill]"
));
JTextField textField;
JScrollPane scrollPane;
add(new JLabel("Text field:"));
textField = new JTextField(NUM_CHARACTERS_WIDTH);
textField.setBorder( new EtchedBorder( EtchedBorder.LOWERED ) );
add(textField);
add(new JLabel("No scrollpane text area:"));
add(new JTextArea(NUM_ROWS, NUM_CHARACTERS_WIDTH));
add(new JLabel("Scrollpane text area:"));
scrollPane = new JScrollPane(new JTextArea(NUM_ROWS, NUM_CHARACTERS_WIDTH));
scrollPane.setBorder( new EtchedBorder( EtchedBorder.LOWERED ) );
add(scrollPane);
add(new JLabel("Text field:"));
textField = new JTextField(NUM_CHARACTERS_WIDTH);
textField.setBorder( new EtchedBorder( EtchedBorder.LOWERED ) );
add(textField);
If you can't get MigLayout to align your components, considering using java.awt.GridBagLayout:
import static java.awt.GridBagConstraints.*;
setLayout( new GridBagLayout() );
GridBagConstraints leftCons = new GridBagConstraints();
leftCons.anchor = NORTHEAST;
leftCons.fill = NONE;
leftCons.weightx = 1.0;
leftCons.gridy = RELATIVE;
leftCons.gridx = 0;
leftCons.insets = new Insets( 4, 8, 4, 8 );
GridBagConstraints rightCons = new GridBagConstraints();
rightCons.anchor = NORTHWEST;
rightCons.fill = HORIZONTAL;
rightCons.weightx = 1.0;
rightCons.gridy = RELATIVE;
rightCons.gridx = 1;
rightCons.insets = leftCons.insets;
add(new JLabel("Text field:"), leftCons);
add(new JTextField(NUM_CHARACTERS_WIDTH), rightCons);
add(new JLabel("No scrollpane text area:"), leftCons);
add(new JTextArea(NUM_ROWS, NUM_CHARACTERS_WIDTH), rightCons);
add(new JLabel("Scrollpane text area:"), leftCons);
add(new JScrollPane(new JTextArea(NUM_ROWS, NUM_CHARACTERS_WIDTH)), rightCons);
add(new JLabel("Text field:"), leftCons);
add(new JTextField(NUM_CHARACTERS_WIDTH), rightCons);
First off +1 for screen shots.
Since you are using Mac, did you try Quaqua Look And Feel? It renders the textboxes/areas properly.
The answer is that MiG Layout folks are working on a fix for their next version.
Hello,
Apple has a nasty habbit of compensating by default and not let the developer decide. This is such a case where they have added a border to make it more visually like OS X. This should be the choice of the layout manager...
MigLayout can compensate for visual bounds like this but it is only done for JTabbedPane in Windows XP. I'm not sure it can be done 100% good in OS X though. I'll have to check. We don't want the text field to just grow into the bounds.
I have added this to the todo list for the next version.