Wrap FlowLayout


J

Jason Cavett

I'm using a FlowLayout in a JFrame. However, when a user resizes the
JFrame, the components (JCheckBoxes) do not wrap. Instead, they just
disappear completely. Is it possible to have FlowLayout wrap? If so,
what am I doing wrong?

Here is the setup of the JPanel (which is inside my JFrame).

FlowLayout flowLayout = new FlowLayout();
flowLayout.setAlignment(java.awt.FlowLayout.LEFT);
southPropertiesPanel = new JPanel();
southPropertiesPanel.setLayout(flowLayout);
southPropertiesPanel.add(getFirstPropertyCheckBox(), null);
southPropertiesPanel.add(getSecondPropertyCheckBox(), null);
southPropertiesPanel.add(getThirdPropertyCheckBox(), null);
southPropertiesPanel.add(getFourthPropertyCheckBox(), null);
 
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K

Knute Johnson

Jason said:
I'm using a FlowLayout in a JFrame. However, when a user resizes the
JFrame, the components (JCheckBoxes) do not wrap. Instead, they just
disappear completely. Is it possible to have FlowLayout wrap? If so,
what am I doing wrong?

Here is the setup of the JPanel (which is inside my JFrame).

FlowLayout flowLayout = new FlowLayout();
flowLayout.setAlignment(java.awt.FlowLayout.LEFT);
southPropertiesPanel = new JPanel();
southPropertiesPanel.setLayout(flowLayout);
southPropertiesPanel.add(getFirstPropertyCheckBox(), null);
southPropertiesPanel.add(getSecondPropertyCheckBox(), null);
southPropertiesPanel.add(getThirdPropertyCheckBox(), null);
southPropertiesPanel.add(getFourthPropertyCheckBox(), null);

You must have the size of the JPanel constrained somehow so that you
can't see the rest of the components. Just out of curiosity what is the
null constraint for in the add?

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class test {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel p = new JPanel(new FlowLayout());

JButton b;
for (int i=0; i<10; i++) {
b = new JButton(Integer.toString(i));
p.add(b);
}
f.add(p,BorderLayout.CENTER);
f.pack();
f.setVisible(true);
}
});
}
}
 
J

Jason Cavett

Jason said:
I'm using a FlowLayout in a JFrame.  However, when a user resizes the
JFrame, the components (JCheckBoxes) do not wrap.  Instead, they just
disappear completely.  Is it possible to have FlowLayout wrap?  If so,
what am I doing wrong?
Here is the setup of the JPanel (which is inside my JFrame).
FlowLayout flowLayout = new FlowLayout();
flowLayout.setAlignment(java.awt.FlowLayout.LEFT);
southPropertiesPanel = new JPanel();
southPropertiesPanel.setLayout(flowLayout);
southPropertiesPanel.add(getFirstPropertyCheckBox(), null);
southPropertiesPanel.add(getSecondPropertyCheckBox(), null);
southPropertiesPanel.add(getThirdPropertyCheckBox(), null);
southPropertiesPanel.add(getFourthPropertyCheckBox(), null);

You must have the size of the JPanel constrained somehow so that you
can't see the rest of the components.  Just out of curiosity what is the
null constraint for in the add?

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class test {
     public static void main(String[] args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 JFrame f = new JFrame();
                 f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                 JPanel p = new JPanel(new FlowLayout());

                 JButton b;
                 for (int i=0; i<10; i++) {
                     b = new JButton(Integer.toString(i));
                     p.add(b);
                 }
                 f.add(p,BorderLayout.CENTER);
                 f.pack();
                 f.setVisible(true);
             }
         });
     }

}

Actually, after a bit of testing, it may be because of the following
reason:

1. I have a JFrame with a BorderLayout.
2. Inside the JFrame, I have three panels. northPanel, centerPanel
and southPanel. The southPanel is the one that contains the
JCheckBoxes (and the FlowLayout).
3. When I resize the JFrame, it appears that the centerPanel receives
the benefit of the resize, but the south and north panels appear to
stay statically sized.

That's at least what I am seeing. Not sure if there is any way to
change/fix this.
 
K

Knute Johnson

Jason said:
Jason said:
I'm using a FlowLayout in a JFrame. However, when a user resizes the
JFrame, the components (JCheckBoxes) do not wrap. Instead, they just
disappear completely. Is it possible to have FlowLayout wrap? If so,
what am I doing wrong?
Here is the setup of the JPanel (which is inside my JFrame).
FlowLayout flowLayout = new FlowLayout();
flowLayout.setAlignment(java.awt.FlowLayout.LEFT);
southPropertiesPanel = new JPanel();
southPropertiesPanel.setLayout(flowLayout);
southPropertiesPanel.add(getFirstPropertyCheckBox(), null);
southPropertiesPanel.add(getSecondPropertyCheckBox(), null);
southPropertiesPanel.add(getThirdPropertyCheckBox(), null);
southPropertiesPanel.add(getFourthPropertyCheckBox(), null);
You must have the size of the JPanel constrained somehow so that you
can't see the rest of the components. Just out of curiosity what is the
null constraint for in the add?

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class test {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel p = new JPanel(new FlowLayout());

JButton b;
for (int i=0; i<10; i++) {
b = new JButton(Integer.toString(i));
p.add(b);
}
f.add(p,BorderLayout.CENTER);
f.pack();
f.setVisible(true);
}
});
}

}

Actually, after a bit of testing, it may be because of the following
reason:

1. I have a JFrame with a BorderLayout.
2. Inside the JFrame, I have three panels. northPanel, centerPanel
and southPanel. The southPanel is the one that contains the
JCheckBoxes (and the FlowLayout).
3. When I resize the JFrame, it appears that the centerPanel receives
the benefit of the resize, but the south and north panels appear to
stay statically sized.

That's at least what I am seeing. Not sure if there is any way to
change/fix this.

BorderLayout for the JFrame will be problematic, the edge areas in BL do
not follow the same rules as the center. I would try GridBagLayout,
it's always more complicated but you can usually get it to do almost
anything.
 
K

Knute Johnson

Jason said:
Jason said:
I'm using a FlowLayout in a JFrame. However, when a user resizes the
JFrame, the components (JCheckBoxes) do not wrap. Instead, they just
disappear completely. Is it possible to have FlowLayout wrap? If so,
what am I doing wrong?
Here is the setup of the JPanel (which is inside my JFrame).
FlowLayout flowLayout = new FlowLayout();
flowLayout.setAlignment(java.awt.FlowLayout.LEFT);
southPropertiesPanel = new JPanel();
southPropertiesPanel.setLayout(flowLayout);
southPropertiesPanel.add(getFirstPropertyCheckBox(), null);
southPropertiesPanel.add(getSecondPropertyCheckBox(), null);
southPropertiesPanel.add(getThirdPropertyCheckBox(), null);
southPropertiesPanel.add(getFourthPropertyCheckBox(), null);
You must have the size of the JPanel constrained somehow so that you
can't see the rest of the components. Just out of curiosity what is the
null constraint for in the add?

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class test {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel p = new JPanel(new FlowLayout());

JButton b;
for (int i=0; i<10; i++) {
b = new JButton(Integer.toString(i));
p.add(b);
}
f.add(p,BorderLayout.CENTER);
f.pack();
f.setVisible(true);
}
});
}

}

Actually, after a bit of testing, it may be because of the following
reason:

1. I have a JFrame with a BorderLayout.
2. Inside the JFrame, I have three panels. northPanel, centerPanel
and southPanel. The southPanel is the one that contains the
JCheckBoxes (and the FlowLayout).
3. When I resize the JFrame, it appears that the centerPanel receives
the benefit of the resize, but the south and north panels appear to
stay statically sized.

That's at least what I am seeing. Not sure if there is any way to
change/fix this.

Jason:

Here's a simple example with three components, the bottom one containing
8 JButtons in a FlowLayout. Each of the three components have the same
weights so they should take approximately the same space. The buttons
will reorganize as the JFrame is resized. You can do a lot here with
setting some preferred/minimum sizes.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class test {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setLayout(new GridBagLayout());

GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.BOTH;
c.weightx = c.weighty = 1.0;

c.gridy = 0;
JPanel north = new JPanel();
north.setBackground(Color.RED);
f.add(north,c);

c.gridy = 1;
JPanel center = new JPanel();
center.setBackground(Color.BLUE);
f.add(center,c);

c.gridy = 2;
JPanel p = new JPanel(new FlowLayout());
JButton b;
for (int i=0; i<10; i++) {
b = new JButton(Integer.toString(i));
p.add(b);
}
f.add(p,c);
f.pack();
f.setVisible(true);
}
});
}
}
 
C

Chase Preuninger

Not quite sure, but if the flow layout doesn't have enough room then
it can't wrap. Also try using the add method that only takes a
component.
 
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C

Chase Preuninger

I always design the component that sits in the center to be able to
work at any size and I also assume that NORTH,SOUTH,EAST,WEST will
always be the same size and only the needed amount in (NORTH/SOUTH
height; EAST/WEST width)
 
J

Jason Cavett

Not quite sure, but if the flow layout doesn't have enough room then
it can't wrap.  Also try using the add method that only takes a
component.

Yeah. The reason the "null" was in place was because, originally, a
visual editor had been used to create the GUI (man...those things make
horrible code, even if they are easy to use). I've since rectified
that.
 
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J

Jason Cavett

Jason said:
Jason Cavett wrote:
I'm using a FlowLayout in a JFrame.  However, when a user resizes the
JFrame, the components (JCheckBoxes) do not wrap.  Instead, they just
disappear completely.  Is it possible to have FlowLayout wrap?  If so,
what am I doing wrong?
Here is the setup of the JPanel (which is inside my JFrame).
FlowLayout flowLayout = new FlowLayout();
flowLayout.setAlignment(java.awt.FlowLayout.LEFT);
southPropertiesPanel = new JPanel();
southPropertiesPanel.setLayout(flowLayout);
southPropertiesPanel.add(getFirstPropertyCheckBox(), null);
southPropertiesPanel.add(getSecondPropertyCheckBox(), null);
southPropertiesPanel.add(getThirdPropertyCheckBox(), null);
southPropertiesPanel.add(getFourthPropertyCheckBox(), null);
You must have the size of the JPanel constrained somehow so that you
can't see the rest of the components.  Just out of curiosity what is the
null constraint for in the add?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class test {
     public static void main(String[] args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 JFrame f = new JFrame();
                 f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                 JPanel p = new JPanel(new FlowLayout());
                 JButton b;
                 for (int i=0; i<10; i++) {
                     b = new JButton(Integer.toString(i));
                     p.add(b);
                 }
                 f.add(p,BorderLayout.CENTER);
                 f.pack();
                 f.setVisible(true);
             }
         });
     }
}
Actually, after a bit of testing, it may be because of the following
reason:
1. I have a JFrame with a BorderLayout.
2. Inside the JFrame, I have three panels.  northPanel, centerPanel
and southPanel.  The southPanel is the one that contains the
JCheckBoxes (and the FlowLayout).
3. When I resize the JFrame, it appears that the centerPanel receives
the benefit of the resize, but the south and north panels appear to
stay statically sized.
That's at least what I am seeing.  Not sure if there is any way to
change/fix this.

BorderLayout for the JFrame will be problematic, the edge areas in BL do
not follow the same rules as the center.  I would try GridBagLayout,
it's always more complicated but you can usually get it to do almost
anything.

--

Knute Johnson
email s/nospam/linux/

--
Posted via NewsDemon.com - Premium Uncensored Newsgroup Service
      ------->>>>>>http://www.NewsDem- Hide quoted text -

- Show quoted text -

Alright. At least I don't feel like I'm going crazy anymore. Thanks
for the response and thank for the code example below.
 

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