GridBagLayout dividing JPanel - java

i am trying to divide my JPanel using GBL on 200 rows and 200 columns(one cell for one pixel. Any idea how to do this properly. Code posted below doesn't work for me.
JPanel pane = new JPanel;
pane.setSize(200,200);
GridBagLayout layout = new GridBagLayout();
layout.columnWidths = new int[200]; layout.rowHeights = new int[200];
I would be grateful for any help.

You could use the GridBagConstraints class to set the size of each pixel using the gridwidth and gridheight properties. Then apply these constraints to your GBL using layout.setConstraints(GridBagConstraints instance)

Something like this would do, you would just need to add the part to change the pixels by either reading a list or array:
int y=0;
int x=0;
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.BOTH;
for(int stop=0;stop<=200;stop++){
c.gridx = ++x;
c.gridy = ++y;
pane.add(each_pixel, c);
}

Related

GridBagLayout creating very small panels

I am trying to set the layout of a JFrame to be a grid bag layout. I want to to essentially look like 4 grids of equal size, but with the bottom 2 merged into one panel. I am adding JPanels to each. However, I get 3 small grids at the middle of the JFrame, not properly sized. It looks like this instead.
My code is as follows:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Hangman extends JPanel{
private String word;
private JPanel hA, gL, letters;
public void setupLayout(JFrame window){
window.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
hA = new JPanel();
hA.setBackground(Color.blue);
c.fill = GridBagConstraints.BOTH;
c.gridx = 0;
c.gridy = 0;
window.add(hA, c);
gL = new JPanel();
gL.setBackground(Color.green);
c.fill = GridBagConstraints.BOTH;
c.gridx = 1;
c.gridy = 0;
window.add(gL, c);
letters = new JPanel();
letters.setBackground(Color.black);
c.fill = GridBagConstraints.BOTH;
c.weightx = 1.0;
c.gridx = 0;
c.gridy = 1;
c.gridwidth = 2;
window.add(letters, c);
}
public void startWindow(){
JFrame window = new JFrame();
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
int screenHeight = (int) screenSize.getHeight();
int windowHeight = (int) ((screenHeight / 4) * 3);
window.setSize(windowHeight, windowHeight);
window.setLocationRelativeTo(null);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setupLayout(window);
window.setVisible(true);
}
public void startGame(){
Prep prepare = new Prep();
word = prepare.findWord(true);
startWindow();
}
public static void main(String[] args){
Hangman start = new Hangman();
start.startGame();
}
}
It's not very important what Prep does. It just takes a random word from a text file. I couldn't see how it would affect the layout. To recap, I need to make it so each of the 4 grid spaces span one fourth of the window, and then make the bottom 2 cells merged with a JPanel added to each of them. Any help is appreciated. Thank you in advance.
EDIT:
I needed to set the weight of all of them to be 1. It is solved.
GridBagLayout displays each component at its preferred size. Since you didn't add any components to the panels you just see a small panel.
If you want the panels to fill the space available then you need to play with the constraints.
Read the section from the Swing tutorial on How to Use GridBagLayout for more information and working examples. You will want to look at the "fill" and "weightx/weighty" constraints.
and then make the bottom 2 cells merged
you will also need to look at the "gridwidth/gridheight" constraints.

Does GridBagLayout require placeholder panels for empty cells?

I made a simple GridBagLayout which adds buttons in the cells (0,0), (1,0), and (0,1).
JPanel panelMain = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
panelMain.add(new JButton("0,0"),c);
c.gridx = 1;
c.gridy = 0;
panelMain.add(new JButton("1,0"),c);
c.gridx = 0;
c.gridy = 1;
panelMain.add(new JButton("0,1"),c);
I was happy to see the resultant UI:
I want to add a JButton in a cell that is not connected to the existing cells. I want it to be separated by an empty space. When I try this, the new JButton is lumped in next to the others. Here is the addition:
JPanel panelMain = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
panelMain.add(new JButton("0,0"),c);
c.gridx = 1;
c.gridy = 0;
panelMain.add(new JButton("1,0"),c);
c.gridx = 0;
c.gridy = 1;
panelMain.add(new JButton("0,1"),c);
c.gridx = 3;
c.gridy = 0;
panelMain.add(new JButton("3,0"),c);
The output:
The JButton("3,0") is displaying at the cell (2,0). Do I need to use an empty JPanel as a place holder in the cell (2,0)? More importantly, why is this happening?
The layout does not know what should be the width to be left at 2,0 unless there is a component placed in the gridx = 2. By the time you complete the UI, if any component gets placed, it should look fine. For e.g.:
In other case you may add empty JPanel with background color matching to the background color of the container.
Do I need to use an empty JPanel as a place holder in the cell (2,0)?
You can use an "insets" grid bag constraint to give space between components. Read the Swing tutorial on How to Use GridBagLayout for more information on the inset constraint.
Or, if you want to have a place holder then you can use a Box.createHorizontalStrut(...) to easily specify the width.
More importantly, why is this happening?
Cells don't have a size unless there is a component in the cell. Each cell is independent of one another so what size would you expect cell (2,0) to be?

Choosing a layout manager

I'm trying to set up a couple of labels and textfields in a table-like style.
Currently I'm using the GridLayout, which kind of works as I want it to. However, the TextFields and Button is expanding to the full size of the cell.
How can I make the TextFields and Button "normal" sized, and what Layout Manager would accomplish this the easiest way?
Here's the current code and a screenshot:
JPanel forms = new JPanel();
forms.setLayout(new GridLayout(3, 2));
JLabel lbl_navn = new JLabel("Virksomhedsnavn:");
JTextField txt_navn = new JTextField();
JLabel lbl_adresse = new JLabel("Adresse:");
JTextField txt_adresse = new JTextField();
forms.add(lbl_navn);
forms.add(txt_navn);
forms.add(lbl_adresse);
forms.add(txt_adresse);
forms.add(Box.createRigidArea(new Dimension(10, 10)));
forms.add(new JButton("Opret virksomhed"));
I suggest you use gridBagLayout:
http://docs.oracle.com/javase/tutorial/uiswing/layout/gridbag.html
As an example:
JPanel forms = new JPanel();
forms.setLayout(new GridBagLayout());
JLabel lbl_navn = new JLabel("Virksomhedsnavn:");
JTextField txt_navn = new JTextField();
JLabel lbl_adresse = new JLabel("Adresse:");
JTextField txt_adresse = new JTextField();
//Setting grid bag constraints
GridBagConstraints c = new GridBagConstraints();
// Grid position coordinates
c.gridx = 0; c.gridy = 0;
//Align panel in top-left corner
c.anchor=GridBagConstraints.LINE_START;
forms.add(lbl_navn, c);
c.gridx = 1; c.ipadx = 195;
forms.add(txt_navn, c);
c.gridy = 1; c.gridx = 0; c.ipadx = 0;
forms.add(lbl_adresse, c);
c.gridx = 1; c.ipadx = 195;
forms.add(txt_adresse,c);
c.gridy = 2; c.gridx = 0; c.ipadx = 0;
forms.add(Box.createRigidArea(new Dimension(10, 10)),c);
c.anchor=GridBagConstraints.CENTER;
c.gridy = 2; c.gridx = 1;
forms.add(new JButton("Opret virksomhed"),c);
Hope this helps.
I think you can refer to this question where useful answers have been given:
JTextField Fixed Height
I read good things about Mig layout a while ago, I never used, but seems very powerful.
Check this Mig layout, may be a good solution for your problems.
UPDATE:
Mig layout is not a "standard" layout from sun/oracle.
GridBagLayout as mentioned, can accomplished your objectives(from experience). I personally when I want fixed sizes components I use to work with "null layouts".

JTextField size

I have a JPanel like this:
GridBagConstraints constPanelInfo = new GridBagConstraints();
panelInfo = new JPanel(new GridBagLayout());
JLabel sensor1 = new JLabel("Sensor: ");
constPanelInfo.gridx = 0;
constPanelInfo.gridy = 0;
constPanelInfo.weightx = 0.0;
constPanelInfo.fill = GridBagConstraints.NONE;
panelInfo.add(sensor1, constPanelInfo);
constPanelInfo.gridx = 1;
constPanelInfo.gridy = 0;
constPanelInfo.weightx = 1.0;
constPanelInfo.fill = GridBagConstraints.HORIZONTAL;
campoSensor.setPreferredSize(new Dimension(100, campoSensor.getPreferredSize().height));
panelInfo.add(campoSensor, constPanelInfo);
where campoSensor is defined as:
private JTextField campoSensor = new JTextField();
...but the JTextField is not scaled to 100 px weight as I want: it stays the same size it had before writting the setPreferredSize method. Any idea here?
Hopefully this is what you're looking for... setting
constPanelInfo.weightx = 0;
for the sensor should keep it at the specified 100px. i.e If all the weights are zero, all the extra space appears between the grids of the cell and the left and right edges.
Remember that if the weigths are set and because of
constPanelInfo.fill = GridBagConstraints.HORIZONTAL;
The campoSensor is going to fill the full width of the cell regardless of the preferred size.
This width will probably be determined by the size of the JFrame that your panel is sitting in.
Try to set constPanelInfo.iPadX=100; instead of setting preferred size.

Java-Swing: A problem using layout managers!

I'm working on a JDialog (by hand, no GUI builders) and I'm having a problem doing the layout.
I have this:
My problem is that I don't know what how to tell that JList (within a JScrollPane) to have a Maximum width, I used the setSize, setMaximumSize and nothing works! I need that JList's width to be the half of the picture's size.
Explain the layouts:
The "Gene Information" is a GridLayout 2x4, it's contained by a JPanel with BoxLayout, the +/- JButtons is a BoxLayout also, all what I said before is within a BoxLayout.
Now, the "Genes" JPanel is a GridBagLayout.
What can I do?
Thanks in advance!
PD: The other borders are just for seeign the boundaries of the components.
Source Code:
scpGenesList.setViewportView(lstGenesList);
pnlGeneInfo.setLayout(new GridLayout(4, 2, 10, 10));
pnlGeneInfo.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Gene Information"),
BorderFactory.createEmptyBorder(10, 10, 10, 10)));
lblGeneSymbol.setText("Symbol:");
lblGeneSymbol.setHorizontalAlignment(SwingConstants.RIGHT);
lblGeneChromosome.setText("Chromosome:");
lblGeneChromosome.setHorizontalAlignment(SwingConstants.RIGHT);
lblGeneStartPosition.setText("Start Position:");
lblGeneStartPosition.setHorizontalAlignment(SwingConstants.RIGHT);
lblGeneStopPosition.setText("Stop Position:");
lblGeneStopPosition.setHorizontalAlignment(SwingConstants.RIGHT);
pnlGeneInfo.add(lblGeneSymbol);
pnlGeneInfo.add(lblGeneSymbolValue);
pnlGeneInfo.add(lblGeneChromosome);
pnlGeneInfo.add(lblGeneChromosomeValue);
pnlGeneInfo.add(lblGeneStartPosition);
pnlGeneInfo.add(lblGeneStartPositionValue);
pnlGeneInfo.add(lblGeneStopPosition);
pnlGeneInfo.add(lblGeneStopPositionValue);
pnlGWASAddRemoveButtons.setLayout(new BoxLayout(pnlGWASAddRemoveButtons, BoxLayout.X_AXIS));
pnlGWASAddRemoveButtons.add(Box.createHorizontalGlue());
pnlGWASAddRemoveButtons.add(cmdGenesAdd);
pnlGWASAddRemoveButtons.add(Box.createHorizontalStrut(10));
pnlGWASAddRemoveButtons.add(cmdGenesRemove);
pnlGWASAddRemoveButtons.add(Box.createHorizontalGlue());
pnlGeneInfoButtons.setLayout(new BoxLayout(pnlGeneInfoButtons, BoxLayout.Y_AXIS));
pnlGeneInfoButtons.add(pnlGeneInfo);
pnlGeneInfoButtons.add(Box.createVerticalStrut(10));
pnlGeneInfoButtons.add(pnlGWASAddRemoveButtons);
pnlGenesPanel.setLayout(new GridBagLayout());
pnlGenesPanel.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Genes"),
BorderFactory.createEmptyBorder(10, 10, 10, 10)));
GridBagConstraints ctrGenes = new GridBagConstraints();
ctrGenes.fill = GridBagConstraints.BOTH;
ctrGenes.gridx = 0;
ctrGenes.gridy = 0;
ctrGenes.gridwidth = 1;
ctrGenes.gridheight = 1;
ctrGenes.weighty = 1.0;
ctrGenes.weightx = 1.0;
ctrGenes.insets = new Insets(0, 0, 0, 10);
pnlGenesPanel.add(scpGenesList, ctrGenes);
GridBagConstraints ctrGenesInfoButton = new GridBagConstraints();
ctrGenesInfoButton.fill = GridBagConstraints.BOTH;
ctrGenesInfoButton.gridx = 1;
ctrGenesInfoButton.gridy = 0;
ctrGenesInfoButton.gridwidth = 1;
ctrGenesInfoButton.gridheight = 1;
ctrGenesInfoButton.weighty = 1.0;
ctrGenesInfoButton.weightx = 1.0;
pnlGenesPanel.add(pnlGeneInfoButtons, ctrGenesInfoButton);
contentPane.add(pnlGenesPanel);
pack();
Why not give the "Genes" panel a 2x1 GridLayout? That should ensure that both sides have the same size.
But actually, it would make more sense to me to give the list all space not taken by the controls, since those require a fixed amount of space while the list may benefit from all additional space it can get, if there are wide entries.
To that end, I would give the "Genes" panel a BorderLayout, put the list in the CENTER slot and the controls in the EAST slot.
Following #Michael Borgwardt's suggestion to let the list grow, you can use setVisibleRowCount() to produce a convenient initial panel size. If necessary, you can also examine the Dimension returned by getPreferredScrollableViewportSize(), which "computes the size of viewport needed to display visibleRowCount rows."
Without seeing all the code here it may be impossible to tell you what is wrong. One thing I would suggest if you have time is to take a look at MigLayout. You can use it with Swing & SWT and once you learn it is a pretty powerful layout manager IMHO.
Hope this helps, good luck.
It doesn't answer your question - but I've found that the JGoodies FormLayout to be more intuitive than the GridBagLayout. The library, as well as some examples, can be found here:
http://jgoodies.com/freeware/forms/index.html
I think the earlier solutions are all valid, and it is more of a coding preference in terms of which layout managers to use. Based on your requirement, here is a working one with standard layout managers only (Grid, GridBag and Border). Have fun, - MS.
import java.awt.;
import javax.swing.;
import javax.swing.border.*;
public class GeneDialog extends JDialog {
private String[] plusMinus = {"+","-"}, tfNames = {
"Symbol", "Chromosome", "Start position", "Stop position"},
listData = {"Gene01", "Gene02", "Gene03", "Gene04", "Gene05", "Gene06",
"Gene07", "Gene08", "Gene09", "Gene10", "Gene11", "Gene12"};
private JTextField[] gtField= new JTextField[tfNames.length];
private JList list = new JList (new DefaultListModel());
public GeneDialog (Frame f, String title) {
super (f, title, true);
Container cp = getContentPane();
cp.setLayout (new GridLayout(1,2));
JScrollPane listScrollPane = new JScrollPane (list);
listScrollPane.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createTitledBorder("Genes"),
BorderFactory.createEmptyBorder(10, 10, 10, 10)));
DefaultListModel lm = (DefaultListModel) list.getModel();
for (int k = 0 ; k < listData.length ; k++)
lm.addElement (listData[k]);
cp.add (listScrollPane);
cp.add (controlPanel());
pack();
}
private GridBagConstraints makeGBC (int inset) {
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets (inset, inset, inset, inset);
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.gridx = 0;
gbc.gridy = GridBagConstraints.RELATIVE;
return gbc;
}
private JPanel controlPanel() {
JPanel cp = new JPanel (new BorderLayout()),
bp = new JPanel (new GridBagLayout()),
tp = new JPanel (new GridBagLayout());
GridBagConstraints gbc = makeGBC (10);
for (int i = 0 ; i < tfNames.length ; i++) {
JLabel label = new JLabel (tfNames[i], JLabel.TRAILING);
tp.add (label, gbc);
}
gbc.gridx++; gbc.weightx = 1.0f;
for (int i = 0 ; i < tfNames.length ; i++) {
gtField[i] = new JTextField(12);
tp.add (gtField[i], gbc);
}
gbc = makeGBC (10);
for (int i = 0 ; i < plusMinus.length ; i++) {
JButton b = new JButton (plusMinus[i]);
bp.add (b, gbc);
gbc.gridx++;
}
cp.add (tp, "Center");
cp.add (bp, "South");
return cp;
}
public static void main (String[] args) {
new GeneDialog (null, "Genes").setVisible (true);
}}
Try setting the maximum width for both the JScrollPane and the JList that is within it.
I just want to tell that I share the same opinion as javamonkey79. Take a look at MigLayout, you'll love it, and from Java 7 on it will be standart java-onboard layout.

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