When I insert any button or any component in my frame and set the component gridx and gridy to values 0, it does not put that component at the starting of the frame instead it put the component somewhere in the center.
How to remove the spaces and put my component at the very starting of the frame?
Following is the code:
JFrame frame = new JFrame("Grigbag layout");
JPanel pane = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
JButton button = new JButton("First button");
c.gridx = 0;
c.gridy = 0;
pane.add(button, c);
I suggest you to use Flow Layout and also add this code
frame.pack();
as mentioned by Andrew Thompson above
for more :
https://docs.oracle.com/javase/tutorial/uiswing/layout/flow.html
Use the frame.pack()method and remove the frame.setSize(); method.
frame is using the default layout. Set frame's layout with something like
frame.setLayout(new FlowLayout(FlowLayout.LEFT));
Related
EDIT2: I also get a white/grey area, if I try to add a JLabel to the area, where the checkboxes are, that you see in the second image.
EDIT: Also note this: When I just create a JLabel and add it before totalResultArea is added to panelResults, it also only shows a white/grey area.
I created two JPanels panelResults and totalResultArea, but only see a white/grey area for the second panel (totalResultArea).
At first I set the layout of panelResults to GridBagLayout
JPanel panelResults = new JPanel();
JPanel totalResultArea = new JPanel();
panelResults.setLayout(new GridBagLayout());
Then I add the totalResultArea to panelResults:
GridBagContraints c = new GridBagConstraints();
totalResultArea.setLayout(new BoxLayout(totalResultArea, BoxLayout.Y_AXIS));
c.gridx = 0;
c.gridy = 0;
c.gridwidth = 2;
c.weightx = 2;
panelResults.add(totalResultArea, c);
In a click-event-listener of a button I add a JLabel to the totalResultArea and set the JFrame visible:
JLabel totalResultsText = new JLabel("<html><body>...</body></html>");
totalResultArea.add(totalResultsText);
// revalidate and repaint totalResultArea and panelResults
totalResultArea.revalidate();
totalResultArea.repaint();
panelResults.revalidate();
panelResults.repaint();
// add panelResults to frame
frame.getContentPane().add(panelResults, BorderLayout.NORTH);
// invalidate, repaint the frame and make it visible
frame.invalidate();
frame.repaint();
frame.setVisible(true);
This all looks like this:
I hope you can reproduce this. If not see the picture.
What could be the reson, that I don't see the text from the JLabel, but an only white/grey area?
The background- and the font-color of the label are both white so you can't see the text.
When you take paint and fill the label with another color you will see that there is a text.
So check your style and/or add totalResultsText.setForeground(Color.BLACK);
I am trying to align all the buttons on the left all on top of each other, but whatever i do it always seems to stay in the center, i have tryed "c.anchor = GridBagConstraints.EAST;" but that didn't help and now im stuck please help.
JButton Button1 = new JButton("<html> Li <center> <small> 7 <br> 3<small/> <center/> <html/> ");
JButton Button2 = new JButton("<html> Na <center> <small> 32<br> 11<small/> <center/> <html/> ");
JButton Button3 = new JButton("<html>K<center><small> 39 <br> 19<small/> <center/> <html/> ");
GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
int width = gd.getDisplayMode().getWidth();
int height = gd.getDisplayMode().getHeight();
Button1.setPreferredSize(new Dimension(50, 50));
Button2.setPreferredSize(new Dimension(50, 50));
Button3.setPreferredSize(new Dimension(50, 50));
GridBagLayout layout = new GridBagLayout() ;
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.anchor = GridBagConstraints.EAST;
setLayout(layout);
add(Button1, c);
add(Button2, c);
add(Button3, c);
add(exit);
setSize(width, height);
setExtendedState(JFrame.MAXIMIZED_BOTH);
//TODO Align to left
setUndecorated(true);
setLocationRelativeTo(null);
c.gridx = 0;
c.anchor = GridBagConstraints.EAST;
setLayout(layout);
add(Button1, c);
add(Button2, c);
add(Button3, c);
add(exit);
Well for one thing you are adding all the components to the same cell since you use the same constraints. If you want them on different rows then you need to specify the a different "gridy" value for each component.
it always seems to stay in the center,
This is the default behaviour unless you specify a weightx/weighty value.
The easier way would be to use a JPanel with a GridLayout. The add all the button to the panel. Finally you add the panel to the frame using:
frame.add(buttonPanel, BorderLayout.LINE_START);
I suggest you start by reading the section from the Swing tutorial on Layout Managers. There are working examples of all the layout managers mentioned above.
Other problems:
Variable names should not start with an upper case character.
Don't use setPreferredSize() on a component. Each component should determined its own preferred size. The layout manager will then use this information.
The GUI code should execute on the Event Dispatch Thread (EDT).
The Swing tutorials all follow the above standards, so download the demo code to learn from that.
OK I have a panel, and I want to place two panels on to it, left and right, such that the right panel should be double the width of the left side panel.
I want to add a menu to the left side panel, and the details of the selected item will appear in the right side panel.
Secondly, the size of the panels and their components should increase proportionately when the window is expanded (If any methods can be used for the purpose, please suggest!)
I did try to use the GridBagLayout but I think I have not yet been able to grasp it well. So please suggest the simplest layout manager which can serve my purpose.
EDIT:- PROBLEMS WITH WHAT I HAD TRIED WITH THE GRIDBAG
//Set Layout
setLayout(new GridBagLayout());
GridBagConstraints c= new GridBagConstraints();
//Set Layout constraints of components and add them to the MainPanel
c.gridx=0;
c.gridy=0;
c.weightx=0.5;
c.insets= new Insets(5,5,5,5);
c.fill=GridBagConstraints.BOTH;
add(iListPanel);
iListPanel.setBorder(BorderFactory.createTitledBorder("Check") );
GridBagConstraints c1= new GridBagConstraints();
c.gridx=1;
c.gridy=0;
c.weightx=1;
c.insets= new Insets(5,5,5,5);
c.fill=GridBagConstraints.BOTH;
add(iDetailsPanel);
iDetailsPanel.setBorder(BorderFactory.createTitledBorder("Check"));
Of the layout managers that come with Java, I think GridBagLayout is the simplest one that will do that. It's worth the time to learn it, because it's about the only layout manager that's halfway-competent. This should do it:
JPanel panel = new JPanel();
panel.setLayout(new GridBagLayout());
GridBagConstraints c;
JPanel left = new JPanel();
left.setBorder(BorderFactory.createTitledBorder("Left"));
c = new GridBagConstraints();
c.weightx = 1;
c.weighty = 1;
c.fill = c.BOTH;
panel.add(left, c);
JPanel right = new JPanel();
right.setBorder(BorderFactory.createTitledBorder("Right"));
c = new GridBagConstraints();
c.weightx = 2;
c.weighty = 1;
c.fill = c.BOTH;
panel.add(right, c);
However, from the description of your problem, it sounds like JSplitPane will serve you better for this. It's a ready-made component to do more-or-less what you're asking, and has a user-resizeable separator as well. An example:
JSplitPane pane = new JSplitPane();
pane.setResizeWeight(1/3f); // right will be twice size of left
JPanel left = new JPanel();
left.setBorder(BorderFactory.createTitledBorder("Left"));
pane.setLeftComponent(left);
JPanel right = new JPanel();
right.setBorder(BorderFactory.createTitledBorder("Right"));
pane.setRightComponent(right);
Edit: The problem with your original code is that it does not use the constraints.
add(iListPanel);
should be:
add(iListPanel, c);
and likewise for iDetailsPanel.
You want to use a BorderLayout.
panel.add(panelLeft,"West");
panel.add(panelRight,"East");
North, South and Center is also available
I'm new to Java Swing and I have been struggling to start the GridBagLayout from top left corner so that c.gridx=0 c.gridy=0 will put my object on the top left corner.
I'd appreciate if you could help me by telling what I need to do after this point:
JPanel panel = new JPanel(new GridBagLayout());
frame.add(panel);
GridBagConstraints c = new GridBagConstraints();
I know that I have to use NORTHWEST or FIRST_LINE_START constants, but I don't know how. I tried to do it this way' but it did not realize the constants.
frame.getContentPane().add(panel, BorderLayout.NORTHWEST);
Thanks for your help.
Read the section from the Swing tutorial on How to Use GridBagLayout. The secton on "weightx,weighty" states:
Unless you specify at least one non-zero value for weightx or weighty, all the components clump together in the center of their container.
You need to use your GridBagConstraints' anchor property. This should do it for you:
frame.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.NORTHWEST;
frame.add(panel, gbc);
I'm not guaranteeing that you won't have to set other properties of the constraints object to get the layout you desire. In particular, you may need to set weightx and weighty to be 1 so that the panel takes up all of the available space given to it.
For those, who use IDE (e.g. NetBeans), I finally found nice trick: if you want to add components to top and use their preferred sizes: add another empty panel with weighty = 1.0. Copied from auto-generated code (NetBeans):
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 2;
gridBagConstraints.weighty = 1.0;
jPanelOptions.add(jPanelFiller, gridBagConstraints);
a quick and simple way:
add a blank JLabel to end of page:
// your code goes here
gbc.weightx = 1;
gbc.weighty = 1;
bg.add(new JLabel(" "), gbc); // blank JLabel
There's a workaround. You can put the GridBagLayout panel in a BorderLayout panel with BorderLayout.NORTH. Then Component in GridBagLayout panel will start from top position.
static void test4(){
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(480, 360);
JPanel borderLayoutPanel=new JPanel(new BorderLayout());
JPanel gridBagLayoutPanel = new JPanel(new GridBagLayout());
borderLayoutPanel.add(gridBagLayoutPanel, BorderLayout.NORTH);
frame.add(borderLayoutPanel);
JButton testButton=new JButton("test button");
GridBagConstraints c = new GridBagConstraints();
c.gridx=0;
c.gridy=0;
gridBagLayoutPanel.add(testButton, c);
frame.setVisible(true);
}
if you want the grid to go all the way to the top, simply set all your weighty = 0 until the last item, set it to any number greater than 0, it will effectively push the rest of the buttons to the top.
Don't forget to also increment your button's gridy value.
Otherwise it will be centered.
(the same can be done using gridx and weightx value if you arent using the c.fill = GridBagConstraints.HORIZONTAL property.)
I am using a GridBagLayout to (currently) display two rows. I am aware this layout is overkill for this task, but am trying to learn how to use it. The problem is that I have added the two panels to the two separate rows and there is a huge gap around the content (see image and code below):
alt text http://www.imagechicken.com/uploads/1264533379009864500.png
Image background;
public Table(){
super();
ImageIcon ii = new ImageIcon(this.getClass().getResource("pokerTableV2.png"));
background = ii.getImage();
setSize(Constants.FRAME_WIDTH, Constants.TABLE_HEIGHT);
setLayout(new GridBagLayout());
GridBagConstraints constraints = new GridBagConstraints();
constraints.gridx = 0;
constraints.gridy = 0;
constraints.fill = GridBagConstraints.HORIZONTAL;
JButton button = new JButton("hello world");
JPanel panel1 = new JPanel();
panel1.setPreferredSize(new Dimension(800,100));
panel1.add(button, BorderLayout.CENTER);
panel1.setBackground(Color.yellow);
add(panel1, constraints);
constraints.gridx = 0;
constraints.gridy = 1;
JPanel middlePanel = new JPanel();
middlePanel.setPreferredSize(new Dimension(800,350));
middlePanel.add(button, BorderLayout.CENTER);
middlePanel.setBackground(Color.blue);
add(middlePanel, constraints);
}
Use
constraints.fill = GridBagConstraints.BOTH;
constraints.weightx = 1d;
constraints.weighty = 1d;
JavaDoc for weightx/weighty says:
Specifies how to distribute extra horizontal/vertical space.
JavaDoc for fill:
This field is used when the component's display area is larger
than the component's requested size. It determines whether to
resize the component, and if so, how.
Unfortunately, with GridBagLayout, if the contents do not fill the entire container that it is in, it will automatically center all its contents within its container. That is why you are getting a really large gap.
There are essentially two ways to fix this:
The hard way: Fiddle with the GridBagConstraints. I had limited success with this when trying to avoid the centre-ing behaviour.
The easy way: Put the GridBagLayout inside of a FlowLayout, and then set the alignment of the FlowLayout to top-left, or whatever you wish.
I have asked, and answered, this question myself sometime last week.
So in your case you are adding your panel1 and middlePanel directly to the JFrame (?), with a GridBagLayout
JFrame (GridBagLayout)
- panel1
- middlePanel
I would suggest this alternative structure instead, to get rid of all the extra space (and centre alignment as well, if you like).
JFrame (FlowLayout)
- JPanel (GridBagLayout)
- panel1
- middlePanel
HTH