BorderLayout and JScrollPane problems - java

I have a JFrame with three areas:
A scrollpane with a list of objects
A panel with labels and textfields
A scrollpane with a panel potentially having multiple labels
When you click the item on the list, the textfields on the panel are filled and the labels on the second scroll are created. I have two problems with my code:
For some reason the scrollpane at the botom of the screen does not fill the whole borderlayout's south area, only half of it.
the scrollpane does not show anything when the item on the list is selected.
Here I tried to make an example:
private void jMenuItem1ActionPerformed(java.awt.event.ActionEvent evt) {
JPanel geral = new JPanel();
JPanel lista = new JPanel();
JPanel dados = new JPanel();
JPanel paneHist = new JPanel();
JPanel historico = new JPanel();
GridLayout gridLay = new GridLayout(0, 2, 5, 10);
geral.setLayout(gridLay);
dados.setLayout(gridLay);
historico.setLayout(new BorderLayout());
lista.setLayout(new BorderLayout());
paneHist.setLayout(gridLay);
this.setLayout(new BorderLayout());
this.add(geral);
geral.add(lista, BorderLayout.WEST);
geral.add(dados, BorderLayout.EAST);
geral.add(historico, BorderLayout.SOUTH);
DefaultListModel listModel = new DefaultListModel();
listModel.addElement("just testing");
final JList list = new JList(listModel);
list.setLayoutOrientation(JList.VERTICAL);
list.setVisible(true);
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
JScrollPane scroll = new JScrollPane(list);
scroll.setPreferredSize(new Dimension(100, 500));
lista.add(scroll, BorderLayout.CENTER);
JTextField jtf = new JTextField();
dados.add(new JLabel("test:"));
dados.add(jtf);
list.addListSelectionListener(new ListSelectionListener() {
#Override
public void valueChanged(ListSelectionEvent lse) {
jtf.setText("clicked");
paneHist.add(new JLabel("texttexttext"));
paneHist.add(new JLabel("texttexttext"));
}}
);
JScrollPane scrollHist = new JScrollPane(paneHist);
scrollHist.setPreferredSize(new Dimension(500, 100));
historico.add(new JLabel("Historico:"), BorderLayout.NORTH);
historico.add(scrollHist, BorderLayout.EAST);
//list.setCellRenderer(new CellRenderer());
this.validate();
this.repaint();
}

Can't really tell what you are doing from the posted code.
Some general comments:
Don't use setPreferredSize(). Let each component determined its preferred size. In the case of a JList you can use the setVisibleRowCount(...) method so the JList can calculate a reasonable size.
In your ListSelectionListener, when you add/remove components from a visible GUI you need to revalidate() and repaint() the panel.

Related

using a GridBagLayout, JScrollpane doesn't work (or look appropriate) with JList

I'm aware there are several questions with the same title, and I've tried their answers but to no avail.
I'm getting the following result with my code:
It does not scroll as it should, and there's this empty little space to the right.
Here is the main code for the frame, mainpanel, list panel and the buttons panel that are inside the mainpanel.
public Tester2() {
JPanel mainPanel = new JPanel(); /////// MAIN PANEL
mainPanel.setLayout(new BorderLayout());
mainPanel.setPreferredSize(new Dimension(200, 400));
JPanel upperListPnl = new JPanel(); ////// LIST PANEL
upperPnlSetup(upperListPnl);
JPanel lowerBtnsPnl = new JPanel(); ///// BUTTONS PANEL
lowerBtnsPnl.setLayout(new BorderLayout());
JButton testButton = new JButton("Test the list");
testButton.addActionListener(e -> {
exampleModel.addElement("List has been tested");
updateExampleData();
});
lowerBtnsPnl.add(testButton);
mainPanel.add(upperListPnl, BorderLayout.CENTER);
mainPanel.add(lowerBtnsPnl, BorderLayout.SOUTH);
JFrame frame = new JFrame();
frame.add(mainPanel);
frame.setVisible(true);
frame.pack();
frame.setLocationRelativeTo(null);
}
Here is the code for the JList and the JScrollpane (upper panel):
public void upperPnlSetup(JPanel panel) {
panel.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
exampleList = new JList<>(exampleModel);
JScrollPane jsp = new JScrollPane(exampleList, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
c.fill = GridBagConstraints.BOTH;
c.weighty = 1;
c.weightx = 0.75;
panel.add(exampleList, c);
c.weightx = 0.25;
panel.add(jsp, c);
}
And then the JList and model list as well as the data updating method:
private JList<String> exampleList;
private DefaultListModel<String> exampleModel = new DefaultListModel<>();
public void updateExampleData() {
exampleList.setModel(exampleModel);
}
I tried a FloatLayout, a BorderLayout, and a GridLayout (0,2 and 0,1) all of which didn't work. Finally, I settled for the GridBagLayout since it's seemingly always used for JLists and/or JScrollpanes, and I played with the GridBagConstraints as well as the positioning of the code but seem to always land on the same problem. I've tried giving the scroll pane a preferredSize, didn't do anything.
Okay so, apparently the problem was that I was adding the list to the panel. Adding it to the scrollpane, then adding the scrollpane to the panel was enough, so commenting out the
panel.add(exampleList, c);`
fixed the whole thing.

Stop expansion of JScrollPane within a BoxLayout

The JScrollPane in the JPanel below expands to fill the Frame. How can I stop this expansion so that the size of the JScrollPane is the size of the JButton within it?
public class GUITest extends JFrame {
public GUITest() {
setPreferredSize(new Dimension(700, 500));
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));
add(mainPanel);
JButton button1 = new JButton();
JButton button2 = new JButton();
JButton button3 = new JButton();
JScrollPane pane1 = new JScrollPane();
mainPanel.add(button1);
mainPanel.add(pane1);
pane1.setViewportView(button2);
mainPanel.add(button3);
//Display the window.
super.pack();
super.setLocationRelativeTo(null);
super.setVisible(true);
}
}
I tried
pane1.setMaximumSize(button2.getPreferredSize());
but the scrollbars appear and I can't see the button. Also, in my real program, the components within the JScrollPane will be dynamically added during runtime so I will need the JScrollPane to expand for this.
Use
pane1.setPreferredSize(button2.getPreferredSize());
If you still have autoresizing problems fix the panel size with:
pane1.setMaximumSize(button2.getPreferredSize());
pane1.setMinimumSize(button2.getPreferredSize());

How can I make a layout like the attached image

I am trying to design a layout which contains a form and couple of items. but I found it too hard to put items in right places.
In the following image, the right frame is what I am aiming to design and the left on is what I could made.
And this is the code for the right frame:
public class GUI extends JFrame{
public GUI(){
JFrame frame = new JFrame("frame");
frame.setSize(600, 600);
JPanel panel = new JPanel(new BorderLayout());
panel.add(new JLabel("Title"), BorderLayout.NORTH);
JPanel formPanel = new JPanel(new GridLayout(1,2));
panel.add(formPanel);
TitledBorder formPanelTitle = BorderFactory.createTitledBorder("GridLayout(1,2)");
formPanel.setBorder(formPanelTitle);
//LEFT PANEL
JPanel labelsPanel = new JPanel(new GridLayout(4,1));
TitledBorder labelsPanelTitle = BorderFactory.createTitledBorder("GridLayout(4,1)");
labelsPanel.setBorder(labelsPanelTitle);
labelsPanel.add(new JLabel("Label 1"));
labelsPanel.add(new JLabel("Label 2"));
labelsPanel.add(new JLabel("Label 3"));
labelsPanel.add(new JLabel("Label 4"));
formPanel.add(labelsPanel);
//RIGHT PANEL
JPanel fieldsPanel = new JPanel(new GridLayout(4,1));
TitledBorder fieldsPanelTitle = BorderFactory.createTitledBorder("GridLayout(4,1)");
fieldsPanel.setBorder(fieldsPanelTitle);
fieldsPanel.add(new JTextField("Label 1"));
fieldsPanel.add(new JTextField("Label 2"));
fieldsPanel.add(new JTextField("Label 3"));
fieldsPanel.add(new JTextField("Label 4"));
formPanel.add(fieldsPanel);
//BOTTOM PANEL
JPanel bottomPanel = new JPanel(new GridLayout(2,1));
TitledBorder BottomPanelTitle = BorderFactory.createTitledBorder("GridLayout(2,1)");
bottomPanel.setBorder(BottomPanelTitle);
panel.add(bottomPanel, BorderLayout.SOUTH);
JPanel buttonPanel = new JPanel(new FlowLayout());
buttonPanel.add(new JButton("Browse"));
buttonPanel.add(new JLabel("Label"));
TitledBorder buttonPanelTitle = BorderFactory.createTitledBorder("FlowLayout()");
buttonPanel.setBorder(buttonPanelTitle);
bottomPanel.add(buttonPanel);
JPanel secondButtonPanel = new JPanel(new GridLayout(1,2));
secondButtonPanel.add(new JButton("Back"));
secondButtonPanel.add(new JButton("Next"));
TitledBorder secondButtonPanelTitle = BorderFactory.createTitledBorder("GridLayout(1,2)");
secondButtonPanel.setBorder(secondButtonPanelTitle);
bottomPanel.add(secondButtonPanel);
frame.add(panel);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static void main(String[] args) {
// TODO code application logic here
new GUI();
}
}
I am not sure if the code is really optimal, since there are a lot of inner panels and made it too complicated. Also I could not put items in the places I wanted to. Is there any suggestion or idea to make this layout look better?
Create a JPanel, using GridBagLayout and add your labels/fields to it, this forms the "center" portion of your layout.
Create a JPanel and add the Browse button a JLabel to it. Using GridBagConstraints#gridwidth set to REMAINDER, add this to your first panel
Create a JPanel, using BorderLayout, add the first panel to the CENTER position. Add the title Label to the NORTH position, you may need to adjust it's horizontalAlignment property
Create a JPanel using FlowLayout, aligned to the RIGHT and add your "Back" and "Next" buttons to it. Add this to the SOUTH position of the previous panel.
Check out Laying Out Components Within a Container for more details

drag and drop of jcomponents in java in rum time

I can do this:
I have a JFrame with 2 JPanel objects. In the panel on the left, I want to put the components of Java Swing useful for the construction of an user interface. The panel on the right is empty.
On run-time, my user should to be able to copy with drag and drop drag from one panel to another the selected component. But the copied component on the right panel, can be moved or deleted.
I have created the panel, but I don't know if is better inserire the component as image, label or true component.. and how to make this possible..
This is my panel for the customization.. I have to insert the component in the JTabbedPane in the PanelSx..
public class Customize extends JFrame {
private JPanel panelSx, panelCx, panelMobile;
private JButton buttonSave;
private TabbedPaneComponents tpc;
public Customize(){
Container c = getContentPane();
c.setLayout(new BorderLayout());
setResizable(true);
setTitle("Design Preview");
setSize(800, 650);
setLocation(250,50);
panelSx = new JPanel();
panelSx.setPreferredSize(new Dimension(300, 200));
panelSx.setOpaque(true);
panelSx.setBackground(Color.RED.darker());
panelCx = new JPanel();
panelCx.setPreferredSize(new Dimension(200, 200));
panelCx.setOpaque(true);
panelCx.setBackground(Color.BLUE);
// display panel
panelMobile = new JPanel();
panelMobile.setPreferredSize(new Dimension(300,500));
panelMobile.setOpaque(true);
panelMobile.setBackground(Color.PINK.darker());
panelMobile.setFocusable(false);
buttonSave = new JButton("Save");
panelCx.add(panelMobile);
c.add(panelSx, BorderLayout.WEST);
c.add(panelCx, BorderLayout.CENTER);
tpc = new TabbedPaneComponents();
panelSx.add(tpc);
}
}
public class TabbedPaneComponents extends JTabbedPane{
private JPanel panel1,panel2,panel3;
public TabbedPaneComponents(){
panel1 = new JPanel();
panel1.setPreferredSize(new Dimension(200,300));
addTab("Form Widgets", panel1);
panel1 = new JPanel();
panel1.setPreferredSize(new Dimension(200,300));
addTab("Text Field", panel2);
panel1 = new JPanel();
panel1.setPreferredSize(new Dimension(200,300));
addTab("Other", panel3);
}
}
I would have to suggest using a JToolBar because of it's built in drag'n'drop features. I would put the component inside of the toolbar.

JScrollPane for a panel containing a set of labels with BoxLayout

I'd like to use a JScrollPane for a panel which has an arbitrary list of labels in it using box layout. I'm trying to get it so that the scrollbar would appear if there were too many items (labels) to display.
I tried adding a JScrollPane to the panel and then add the labels but then I don't see any scroll bar.
Any ideas?
TIA
For this kind of thing, you'd normally use a JList or JTable (if you need custom rendering).
Make sure that you call validate() or revalidate() on the JScrollPane after adding an item, to force the preferred size of the panel to be recalculated.
Here's how I did it.
JPanel midPanel = new JPanel();
midPanel.setLayout(new BoxLayout(midPanel, BoxLayout.Y_AXIS));
midPanel.add(new JLabel("<html><u>Label</u>"));
Box box = Box.createVerticalBox();
for (Item item : data.getInventory()) {
inventory.add(box.add(new JLabel(item.getName())));
}
JScrollPane jscrlpBox = new JScrollPane(box);
midPanel.add(jscrlpBox);
add(midPanel, BorderLayout.CENTER);
From:
http://www.java2s.com/Code/Java/Swing-JFC/JScrollPanetoholdscrollablecomponent.htm
Did you remember to set the preferred size of the content panel?
final JFrame frame = new JFrame("Scroll Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
final Box textArea = Box.createVerticalBox();
final JScrollPane textAreaScroll = new JScrollPane(textArea);
textAreaScroll.setPreferredSize(new Dimension(80,150)); /* essential! */
JButton addButton = new JButton("ADD");
addButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
textArea.add(new JLabel("abc"));
textArea.revalidate();
}
});
frame.getContentPane().add(textAreaScroll, BorderLayout.SOUTH);
frame.getContentPane().add(Box.createRigidArea(new Dimension(10,10)), BorderLayout.CENTER);
frame.getContentPane().add(addButton, BorderLayout.NORTH);
frame.pack();
frame.setVisible(true);
In this example, the scroll bar works correctly, but if you remove the line marked as "essential", it will not work anymore.

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