I've implemented a JPanel using a GridBagLayout as follows:
fileSelectionDetails = new JPanel();
fileSelectionGridBagLayout = new GridBagLayout();
fileSelectionDetails.setLayout(fileSelectionGridBagLayout);
JLabel lblFile1 = new JLabel("File 1:");
JTextField txtFile1Path = new JTextField();
JButton btnBrowseFile1 = new JButton("Browse...");
addComponentToFileSelectionGrid(lblFile1, 0, 0, 1, 1, 20, 100, GridBagConstraints.NONE, GridBagConstraints.WEST);
addComponentToFileSelectionGrid(txtFile1Path, 1, 0, 3, 1, 60, 100, GridBagConstraints.HORIZONTAL, GridBagConstraints.WEST);
addComponentToFileSelectionGrid(btnBrowseFile1, 2, 0, 1, 1, 20, 100, GridBagConstraints.HORIZONTAL, GridBagConstraints.WEST);
private void addComponentToFileSelectionGrid(Component component, int gridX, int gridY,
int gridWidth, int gridHeight, int weightX,
int weightY, int fill, int anchor) {
GridBagConstraints constraint = new GridBagConstraints();
constraint.gridx = gridX;
constraint.gridy = gridY;
constraint.gridwidth = gridWidth;
constraint.gridheight = gridHeight;
constraint.weightx = weightX;
constraint.weighty = weightY;
constraint.fill = fill;
constraint.anchor = anchor;
fileSelectionGridBagLayout.setConstraints(component, constraint);
fileSelectionDetails.add(component);
}
I want to see my components laid out as follows:
However, what I'm actually seeing is:
i.e. the 'Browse...' button is missing! Why is this?
From your drawing, I’m guessing you don’t want relative widths at all. It appears you want the label and button to be their preferred sizes, and the JTextField to stretch to take up all of the width not used by the label and button.
As camickr suggested, you should give the JTextField a meaningful preferred size by initializing it with a column count, like new JTextField(20).
You can then take advantage of some useful aspects of GridBagLayout and GridBagConstraints:
The default value of gridx and gridy is RELATIVE, which means each component you add is placed to the right of the last one added. Which just happens to be exactly what you want. Therefore, you should not set gridx or gridy at all.
The default value of gridwidth and gridheight is 1. This is what you want. GridBagLayout cells are flexible, so setting one component’s gridwidth to 3 does not make it three times wider than a component whose gridwidth is 1. The width of a cell, or span of cells, depends entirely on what it contains.
When you add a component to a GridBagLayout, the GridBagConstraints object is cloned inside the GridBagLayout. This means you can safely reuse the same GridBagConstraints object over and over, changing just the fields that need to change.
With this knowledge, your code can be simplified to:
fileSelectionDetails = new JPanel(new GridBagLayout());
JLabel lblFile1 = new JLabel("File 1:");
JTextField txtFile1Path = new JTextField(20);
JButton btnBrowseFile1 = new JButton("Browse\u2026");
txtFile1Path.setMinimumSize(txtFile1Path.getPreferredSize());
GridBagConstraints constraints = new GridBagConstraints();
constraints.fill = GridBagConstraints.HORIZONTAL;
constraints.weight = 0;
fileSelectionDetails.add(lblFile1, constraints);
constraints.weight = 1;
fileSelectionDetails.add(txtFile1Path, constraints);
constraints.weight = 0;
fileSelectionDetails.add(btnBrowseFile1, constraints);
You define gridWidth=3 for txtFile1Path but add btnBrowseFile1 at gridX=2. You must set addComponentToFileSelectionGrid(btnBrowseFile1, 4 ...etc.
Related
The problem
I have a JPanel with the GridBagLayout as a layout manager. I want the columns of the layout to have certain widths. Sometimes the width of a column might be lower than the preferred width of a component inside. In this case, the column should force a component to take only the available space of the column.
But, for now, a component inside a cell doesn't shrink if the column width constraint is less than the component's preferred width.
Example
Below is the demo with 4x4 grid. I want the JLabel in the top-left corner to shrink in accordance with the min widths I have set when initialized GridBagLayout (10 px)
As I run the example below, the following result is obtained:
The cell in the top-left takes more space than it was allowed initially by the GridBagLayout
public class ResizeDemo extends JFrame {
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
ResizeDemo resizeDemo = new ResizeDemo();
resizeDemo.pack();
resizeDemo.setDefaultCloseOperation(EXIT_ON_CLOSE);
resizeDemo.setVisible(true);
});
}
public ResizeDemo() {
GridBagLayout gridBagLayout = new GridBagLayout();
gridBagLayout.columnWidths = new int[]{0, 0};
gridBagLayout.rowHeights = new int[]{0, 0};
gridBagLayout.columnWeights = new double[]{1.0, Double.MIN_VALUE};
gridBagLayout.rowWeights = new double[]{1.0, Double.MIN_VALUE};
getContentPane().setLayout(gridBagLayout);
JPanel panel = new JPanel();
GridBagConstraints gbc_panel = new GridBagConstraints();
gbc_panel.fill = GridBagConstraints.BOTH;
gbc_panel.gridx = 0;
gbc_panel.gridy = 0;
getContentPane().add(panel, gbc_panel);
GridBagLayout gbl_panel = new GridBagLayout();
// ============ Set the column widths here ============
// Note that the width of the first column is 10 px
gbl_panel.columnWidths = new int[] {10, 150, 0};
// =====================================================
gbl_panel.rowHeights = new int[]{0, 0, 0};
gbl_panel.columnWeights = new double[]{0.0, 0.0, 0.0};
gbl_panel.rowWeights = new double[]{0.0, 0.0, Double.MIN_VALUE};
panel.setLayout(gbl_panel);
JLabel label1 = new JLabel("A very long string here");
label1.setHorizontalAlignment(SwingConstants.CENTER);
GridBagConstraints gbc_label1 = new GridBagConstraints();
gbc_label1.fill = GridBagConstraints.HORIZONTAL;
gbc_label1.gridx = 0;
gbc_label1.gridy = 0;
panel.add(label1, gbc_label1);
JLabel label2 = new JLabel("Label");
GridBagConstraints gbc_label2 = new GridBagConstraints();
gbc_label2.gridx = 1;
gbc_label2.gridy = 0;
panel.add(label2, gbc_label2);
JLabel label3 = new JLabel("Label");
GridBagConstraints gbc_label3 = new GridBagConstraints();
gbc_label3.fill = GridBagConstraints.HORIZONTAL;
gbc_label3.gridx = 0;
gbc_label3.gridy = 1;
panel.add(label3, gbc_label3);
JLabel label4 = new JLabel("Label");
GridBagConstraints gbc_label4 = new GridBagConstraints();
gbc_label4.gridx = 1;
gbc_label4.gridy = 1;
panel.add(label4, gbc_label4);
}
}
Question:
How can I force the JLabel inside a GridBagLayout cell to shrink itself?
The GridBagLayout sizes each column based on the largest "preferred size" of any component added to the column.
The "columnWidths" is used to set the minimum value for any column. This is used when you resize the frame. If there is not enough space to display the component at it preferred size and you have set a resize weight for the component, then the component will shrink in size from its preferred size to its minimum size.
How can I force the JLabel inside a GridBagLayout cell to shrink itself?
One possibility is to wrap the label in a panel using a BoxLayout. The BoxLayout will respect the maximum size of size of the component. The basic logic would be:
//panel.add(label1, gbc_label1);
Dimension max = label1.getPreferredSize();
max.width = 10;
label1.setMaximumSize(max);
Box wrapper = Box.createHorizontalBox();
wrapper.add(label1);
panel.add(wrapper, gbc_label1);
Don't know what your real application is, but if you are only using labels, then maybe you can use a JTable. With a JTable you can control the actual column width.
This is the piece in your code that is setting the widths. Lack of setting the column width defaults shrinking to fit the enclosed component.
gbl_panel.columnWidths = new int[] {10, 150, 0};
I'm building a GUI layout for my application using the grid bag and I'm trying to come up with a function to layout each element so that I don't have to keep re typing the same grid bag code over and over. I want to rewrite this code:
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints bc = new GridBagConstraints();
this.setLayout(gridbag);
bc.fill = GridBagConstraints.HORIZONTAL;
bc.anchor = GridBagConstraints.WEST;
bc.insets = new Insets(0, 10, 10, 0);
bc.gridx = 0;
bc.gridy = 0;
bc.gridwidth = 1;
this.add(programNameLabel, bc);
so that it can be written calling a function like this:
labelPosition(GridBagConstraints.HORIZONTAL, GridBagConstraints.WEST, 0, 10, 10, 0, 0, 0, 1, programNameLabel);
Here is the function that I have written for the task.
protected void labelPosition(int axis, int direction, int insetOne, int insetTwo, int insetThree, int insetFour, int gridX, int gridY, int gridWidth, JLabel name)
{
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints bc = new GridBagConstraints();
this.setLayout(gridbag);
bc.fill = axis;
bc.anchor = direction;
bc.insets = new Insets(insetOne, insetTwo, insetThree, insetFour);
bc.gridx = gridX;
bc.gridy = gridY;
bc.gridwidth = gridWidth;
this.add(name, bc);
}
Now it compiles, but when I run it, it doesn't work. All the labels are displayed in a single line rather than the layout that I'm looking for.
Is what I'm trying to do simply possible or am I missing something in my code?? Any suggestions?
You are creating a new GridBagLayout() each time you call your method. You should do that only once, and in your method only create the GridBagConstraints and add the new label to your container (and, btw, by using a more generic type like JComponent you can reuse the same method even for other components than JLabel):
protected void addComponent(int axis, int direction, int insetOne, int insetTwo, int insetThree, int insetFour,
int gridX, int gridY, int gridWidth, JComponent component) {
GridBagConstraints bc = new GridBagConstraints();
bc.fill = axis;
bc.anchor = direction;
bc.insets = new Insets(insetOne, insetTwo, insetThree, insetFour);
bc.gridx = gridX;
bc.gridy = gridY;
bc.gridwidth = gridWidth;
this.add(component, bc);
}
...
GridBagLayout gridbag = new GridBagLayout();
this.setLayout(gridbag);
addComponent(GridBagConstraints.HORIZONTAL, GridBagConstraints.WEST, 0, 10, 10, 0, 0, 0, 1, new JLabel("Hello"));
addComponent(GridBagConstraints.HORIZONTAL, GridBagConstraints.WEST, 0, 10, 10, 0, 0, 1, 1, new JButton("World"));
...
On a side note, if this is a new project, you might consider looking at JavaFX instead of Swing.
I'm learning how to use GridBagLayout. I created two buttons in a JFrame. I tried making it that one of them occupies one collumn (the default), and the other two collumns, thus being twice the size of the first one (I know I can acheive this using setPrefferredSize, but my intention is to learn how to use gridwidth and gridheight).
What's the problem? Thanks
import java.awt.*;
import javax.swing.*;
public class Main extends JFrame {
Main(){
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(500,500);
JPanel panel1 = new JPanel(new GridBagLayout());
JButton b1,b2;
b1 = new JButton("button 1");
b2 = new JButton("button 2");
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 1;
gbc.gridwidth = 1;
panel1.add(b1);
gbc.gridx = 2;
gbc.gridwidth = 2;
panel1.add(b2);
add(panel1);
setVisible(true);
}
public static void main(String[]args){
Main m = new Main();
}
}
It doesn't matter how many columns the second button's width.
Actually both buttons will be asked for their preferred width and the width will be set to them if it's enough space for them.
If it's less space then min width is used.
If there is extra space it's distributed between controls according to weights proportions.
You can try to set iPadX=100 for the first and iPadx=200 and set proportion iPadX=1 for the first and iPadx=2 for the second.
The problem is that all the columns of a GridBagLayout don't have the same width. The widths are computed based on the preferred size of the components they contain. So, you could use 3, 4 or 100 as the gridwidth for the second button, it wouldn't change anything.
You need to use fillx and weightx to change the way the buttons resize.
Try using GridBagConstraint in this way, hope this will help you.
import java.awt.*;
import javax.swing.*;
public class Main extends JFrame {
Main(){
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(500,500);
JPanel panel1 = new JPanel(new GridBagLayout());
JButton b1,b2;
b1 = new JButton("button 1");
b2 = new JButton("button 2");
panel1.add(b1, new GridBagConstraints(0, 0, 1, 1, 0.0, 0.0, GridBagConstraints.WEST, GridBagConstraints.HORIZONTAL, new Insets(0, 0, 0, 0), 0, 0));
panel1.add(b2, new GridBagConstraints(1, 0, 1, 1, 2.0, 0.0, GridBagConstraints.WEST, GridBagConstraints.HORIZONTAL, new Insets(0, 0, 0, 0), 0, 0));
add(panel1);
setVisible(true);
}
public static void main(String[]args){
Main m = new Main();
}
}
EDIT
Or change in your code Like this below:
gbc.gridx = 1;
gbc.gridwidth = 1;
panel1.add(b1, gbc);
gbc.gridx = 2;
gbc.gridwidth = 2;
gbc.fill = gbc.HORIZONTAL; //set fill property to HORIZONTAL
gbc.weightx= 2.0;
panel1.add(b2, gbc); //While adding button also add it with gbc
Hello so I wanted to add text area, text field and a button to my panel. I wanted area to use 3/4 of height and full width, field to use 1/4 of height and 3/4 of width and a button to use 1/4 height and 1/4 width. I post a pic to show what I want to get. Code for this looks like:
// My JPanel class
public MainPanel() {
setLayout(new GridBagLayout());
add(area, new GBC(0, 0, 4, 3).setWeight(4,4).setFill(GBC.BOTH));
add(field, new GBC(0, 3, 3, 1).setWeight(1,1).setFill(GBC.HORIZONTAL));
}
GBC is my class which inherits from GridBagConstraints class:
public class GBC extends GridBagConstraints {
public GBC(int gridx, int gridy) {
this.gridx = gridx;
this.gridy = gridy;
weightx = 100;
weighty = 100;
}
public GBC(int gridx, int gridy, int gridwidth, int gridheight) {
this(gridx, gridy);
this.gridwidth = gridwidth;
this.gridheight = gridheight;
}
public GBC setFill(int fill) {
this.fill = fill;
return this;
}
}
So the problem is that both area and field take half of height and a button is in the center, hidden under field... Look terrible anyway, how to solve if?
weightx and weighty is what specifies how extra space is distributed. In your case, they both have the same value horizontally and vertically which is 100.
Try to set weightx and weighty to 4 for JTextArea and set weightx and weighty to 1 for JTextField
You can check the doc for what does every field do in GridBagConstraints:
http://docs.oracle.com/javase/7/docs/api/java/awt/GridBagConstraints.html
That's how it should look like:
add(area, new GBC(0, 0, 4, 3).setWeight(4,4).setFill(GBC.BOTH));
add(field, new GBC(0, 3, 3, 1).setWeight(1,1).setFill(GBC.HORIZONTAL));
Also read about weightx and weighty, cause you're using them in wrong way
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.