i just programmed a program which has a JFrame containing an array of JLabel components. The array gets the position of the single labels assigned by a for-loop:
for(int i=0; i<label_entries.length; i++){
label_entries[i].setLocation(10, i*30);
label_entries[i].setSize(120,30);
dialog.add(label_entries[i]);
}
Do not get confused, my frame's name is "dialog".
There is one simple problem: The for-loop doesn't work like a for-loop should, and I don't know why, here is the result in my frame:
Imgur.
Don't care about the single label entries, the interesting thing is the position of Telefon.
If I set the beginning of the loop to the following, it is the same problem, just with another label.
for(int i=0; i<label_entries.length-1; i++){...}
Here is the full code
JFrame dialog = new JFrame();
dialog.setBounds(25, 50, 500, 500);
dialog.setTitle("Eintrag hinzufügen");
dialog.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
dialog.setVisible(true);
JLabel[] label_entries = new JLabel[11];
JTextField[] textfields = new JTextField[11];
label_entries[0] = new JLabel("Vorname :");
label_entries[1] = new JLabel("Nachname :");
label_entries[2] = new JLabel("Nummer :");
label_entries[3] = new JLabel("Geburtstag :");
label_entries[4] = new JLabel("Land :");
label_entries[5] = new JLabel("PLZ :");
label_entries[6] = new JLabel("Stadt :");
label_entries[7] = new JLabel("Strasse :");
label_entries[8] = new JLabel("Hausnummer :");
label_entries[9] = new JLabel("E-Mail :");
label_entries[10] = new JLabel("Telefon :");
for(int i=0; i<label_entries.length; i++){
label_entries[i].setLocation(10, i*30);
label_entries[i].setSize(120,30);
dialog.add(label_entries[i]);
}
This should be easier to understand.
One obvious problem is that you are setting absolute positions of your components. Typically a LayoutManager is used for this purpose.
To clear whatever the default layout manager of a JFrame's content pane is, set it to null just after creating the frame.
JFrame dialog = new JFrame();
dialog.setLayout(null);
As the javadoc of JFrame says:
The default content pane will have a BorderLayout manager set on it.
Javadoc of BorderLayout says:
A border layout lays out a container, arranging and resizing its components to fit in five regions: north, south, east, west, and center. Each region may contain no more than one component, and is identified by a corresponding constant: NORTH, SOUTH, EAST, WEST, and CENTER. When adding a component to a container with a border layout, use one of these five constants, for example:
Panel p = new Panel();
p.setLayout(new BorderLayout());
p.add(new Button("Okay"), BorderLayout.SOUTH);
As a convenience, BorderLayout interprets the absence of a string specification the same as the constant CENTER:
Panel p2 = new Panel();
p2.setLayout(new BorderLayout());
p2.add(new TextArea()); // Same as p.add(new TextArea(), BorderLayout.CENTER);
Since you call the 1-arg version of add(), all your JLabels are added with BorderLayout.CENTER, and so the last one wins, and the BorderLayout manager then auto-positions it at left-center.
To prevent that from happening, just remove the layout manager:
dialog.setLayout(null);
Related
I'm trying practice my GUI and I am having troubles putting gap between component and the frame.
The picture above is what I have so far. But I really want to put a gap between the left side of the frame and "label1".
private void initialize() {
frame = new JFrame();
frame.setTitle("WINDOW");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 300);
panel = new JPanel();
panel.setLayout(new BorderLayout());
bottomPanel = new JPanel();
bottomPanel.setLayout(new GridLayout(1, 5));
l1 = new JLabel("Label1");
l2 = new JLabel("Label2");
l3 = new JLabel("Label3");
l4 = new JLabel("Label4");
l5 = new JLabel("Label5");
bottomPanel.add(l1);
bottomPanel.add(l2);
bottomPanel.add(l3);
bottomPanel.add(l4);
bottomPanel.add(l5);
panel.add(bottomPanel, BorderLayout.SOUTH);
frame.add(panel);
}
Above is part my code. I tried doing:
bottomPanel.setLayout(new GridLayout(1, 5, -20, 0));
to put some horizontal gap but that only added gap between the components. That didn't move "label1" away from the frame at all. Is there any other way of doing this? I am very new to Java so I don't really know much of the other tricks. I would appreciate any help! Thank you!
The other answers are fudges that won't achieve the desired effect when the GUI is resized. Instead use:
JLabel.setHorizontalAlignment(SwingConstants.CENTER);
By centering the text within the JLabel, combined with GridLayout stretching the components to the full width of the cell, each label will have as much space either side as the GUI can allow. E.G. here is the effect when the GUI is at minimum size.
And when stretched wider:
(The red border is added to show the bounds of each label.)
Add a Border to the panel:
bottomPanel = new JPanel();
bottomPanel.setBorder( new EmptyBorder(0, 10, 0, 0) );
Read the section from the Swing tutorial on How to Use Borders for more information about the different borders you can create.
Try the following:
bottomPanel.add(javax.swing.Box.createHorizontalStrut(10));
im trying to make a program to add an admin to a ms access database
I researched many times, figured out all the components need to be in a panel, and only the same type of J stuff can be in a panel, so i made many panels and combined them in a big panel
//frame details
final int FRAME_WIDTH = 1000;
final int FRAME_HEIGHT = 1000;
JFrame aFrame = new JFrame("Add admin");
aFrame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
aFrame.setVisible(true);
aFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//panel declaration
JPanel BigPanel = new JPanel();
JPanel adminnameenter = new JPanel();
JPanel typeadminname = new JPanel();
JPanel adminlastnameenter = new JPanel();
JPanel typeadminlastname = new JPanel();
JPanel buttonaddadmin = new JPanel();
//labels, textfields, and buttons
JLabel newAdminName = new JLabel("Enter admin name");
JTextField adminName = new JTextField(7);
JLabel newadminlastname = new JLabel("Enter admin last name");
JTextField adminlastname = new JTextField(7);
JButton addadmin = new JButton("Add Admin");
//add things to panel
adminnameenter.add(newAdminName);
typeadminname.add(adminName);
adminlastnameenter.add(newadminlastname);
typeadminlastname.add(adminlastname);
buttonaddadmin.add(addadmin);
//add things to big jPanel
BigPanel.add(adminnameenter);
BigPanel.add(typeadminname);
BigPanel.add(adminlastnameenter);
BigPanel.add(typeadminlastname);
BigPanel.add(buttonaddadmin);
//add things to frame
aFrame.add(BigPanel);
the only thing that popped up was a frame that said add admin
Add this code to the end of your function:
aFrame.setVisible(false);
aFrame.setVisible(true);
Or alternatively put
aFrame.setVisible(true);
at the end of your function instead of the beginning.
And all the components will appear. This is because whenever you change anything to your JFrame, it will only change on the user side once it is told to resize or refresh the frame. Also you don't need to put every single component in it's own JPanel, you can simply insert them directly in your BigPanel (small nitpick, but the b in bigPanel, shouldn't be capitalized, seeing as variables start with non-capitalized letters).
Also look into LayoutManagers, they will probably be useful for your application.
https://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html
I'm looking at the How To Use BoxLayout documentation, which clearly says that
What if none of the components has a maximum width? In this case, if
all the components have identical X alignment, then all components are
made as wide as their container.
Let's assume we're adding a lot of JButton instances to a JPanel. If the maximum width of these buttons are none AND we invoke setAlignmentX(Component.LEFT_ALIGNMENT) on all of these buttons - then each of these buttons should stretch across its entire row. The documentation even illustrates this using the below picture.
I can't get this to work!
I've tried doing setMaximumSize(null) and setMaximumSize(new Dimension(-1,-1)) and setMaximumSize(new Dimension(0,0)) on the buttons but nothing gives me the described behaviour.
What excactly does the documentation mean when it says :
What if none of the components has a maximum width?
What is a maximum width of none?
The best I've been able to produce is the below. Reading the documentation I would expect that the buttons should be able to stretch across their entire rows. I know I can use other layout managers as well for this, but I would like to achieve this with BoxLayout (granted the documentation is right / I've understood the documentation right).
public class CustomList extends JPanel {
private final Box box = Box.createVerticalBox();
public CustomList() {
for (int i = 0; i < 10; i++) {
JButton b = new JButton("Button item" + i);
//b.setMaximumSize(new Dimension(0,0));
b.setAlignmentX(Component.LEFT_ALIGNMENT);
box.add(b);
}
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(box, BorderLayout.CENTER);
}
public static void main(String[] args) {
CustomList l = new CustomList();
l.setSize(200, 200);
l.setBackground(Color.red);
JFrame frame = new JFrame("Vertical Box");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(l, BorderLayout.CENTER);
frame.setSize(300, 200);
frame.setVisible(true);
}
}
Your buttons actually have a maximum width.
What you can do is create JPanel objects with BorderLayout in your loop, add each button to each panel (to BorderLayout.CENTER, which is the default anyway).
BorderLayout.CENTER doesn't care about the maximum size of its child Component, so you end up with a JPanel whose whole content is filled by a JButton.
Since the JPanel itself has a huge default maximum size of new Dimension(Short.MAX_VALUE, Short.MAX_VALUE) (this is width=32767,height=32767 !!) which is the default maximum size of Component, you will get the expected result :
public CustomList() {
for (int i = 0; i < 10; i++) {
JPanel panel = new JPanel(new BorderLayout());
JButton b = new JButton("Button item" + i);
//b.setMaximumSize(new Dimension(0,0));
b.setAlignmentX(Component.LEFT_ALIGNMENT);
panel.add(b);
box.add(panel);
}
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(box, BorderLayout.CENTER);
}
Trying to add 3 panels i created to a frame in Java with the JSplitPane. Have tried this with 2 panels, and that worked great, but with 3 it still does not do what i want.
Have read something about making 2 JSplitPanes and put the one in the other, but that does not actually work what i would like it to do.
My code shows that there are 3 panels, but the size are all wrong.. it should be filled out.
My code:
frame = new JFrame(); // Create a new frame
frame.setVisible(true); // Makes it visible
frame.setSize(900, 500); // Sets size
frame.setTitle(""); // Sets title
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null); // Sets the window on the center of the screen
temp_panel = new JPanel(); // Creates new JPanel
water_panel = new JPanel(); // Creates new JPanel
power_panel = new JPanel(); // Creates new JPanel
temp_panel.setBackground(Color.decode("#2ecc71")); // Sets color
water_panel.setBackground(Color.decode("#3498db")); // Sets color
power_panel.setBackground(Color.decode("#f1c40f")); // Sets color
temp_label = new JLabel("This is Temperature");
water_label = new JLabel("This is Water consumption");
power_label = new JLabel("This is Power consumption");
// Add labels on panel
temp_panel.add(temp_label);
water_panel.add(water_label);
power_panel.add(power_label);
JSplitPane splitPaneLeft = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT);
JSplitPane splitPaneRight = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT);
splitPaneLeft.setLeftComponent( temp_panel );
splitPaneLeft.setRightComponent( water_panel );
splitPaneRight.setLeftComponent( splitPaneLeft );
splitPaneRight.setRightComponent( power_panel );
splitPaneLeft.setEnabled(false);
splitPaneLeft.setDividerSize(0);
splitPaneRight.setEnabled(false);
splitPaneRight.setDividerSize(0);
// put splitPaneRight onto a single panel
JPanel panelSplit = new JPanel();
panelSplit.add( splitPaneRight );
frame.add(panelSplit, BorderLayout.CENTER);
It should look like this, but just with 3 panels with 3 different colors instead of 2!
Hope someone can help
If you don't need to change the relative sizes of the components during runtime, don't use a JSplitPane. Instead create a container JPanel that uses GridLayout, say new GridLayout(1, 0) for 1 row and variable number of columns, add your three colored JPanels to the GridLayout-using JPanel, and add this then to the JFrame.
you could make one of the panels another JSplitPane, unfortunately there is no other solution for this.
I have a code:
Box box_general = Box.createHorizontalBox();
Box box_panel1 = Box.createVerticalBox();
Box box_panel2 = Box.createVerticalBox();
JPanel jpanel_1 = new JPanel();
jpanel_1.setPreferredSize(new Dimension(50, 152));
jpanel_1.setOpaque(true);
jpanel_1.setBorder(BorderFactory.createLineBorder(Color.BLUE));
JPanel jpanel_2 = new JPanel();
jpanel_2.setPreferredSize(new Dimension(340, 152));
jpanel_2.setOpaque(true);
jpanel_2.setBorder(BorderFactory.createLineBorder(Color.RED));
JTextField jtxtf_populationSize = new JTextField();
jtxtf_populationSize.setSize(10, 20);
JTextField jtxtf_processorsAmount = new JTextField();
JButton jbtn_loadProcesses = new JButton("File path");
box_panel1.add(Box.createRigidArea(new Dimension(0,4)));
box_panel1.add(jtxtf_processorsAmount);
box_panel1.add(Box.createRigidArea(new Dimension(0,20)));
box_panel1.add(jbtn_loadProcesses);
jpanel_1.add(box_panel1);
JLabel jlbl_populationSize = new JLabel("Enter the population size");
JLabel jlbl_processorsAmount = new JLabel("Enter the amount of processors");
JLabel jlbl_loadProcesses = new JLabel("Load processes from file");
jlbl_populationSize.setFont(font);
jlbl_processorsAmount.setFont(font);
jlbl_loadProcesses.setFont(font);
box_panel2.add(jlbl_populationSize);
box_panel2.add(Box.createRigidArea(new Dimension(0,4)));
box_panel2.add(jlbl_processorsAmount);
box_panel2.add(Box.createRigidArea(new Dimension(0,15)));
box_panel2.add(jlbl_loadProcesses);
jpanel_2.add(box_panel2);
box_general.add(jpanel_2);
box_general.add(Box.createRigidArea(new Dimension(10,0)));
box_general.add(jpanel_1);
It creates 3 boxes, where the general box contains two other boxes. The problem is: in the box all the compopents are stretched of width. For example, there is a line jtxtf_populationSize.setSize(10, 20); but this text field is stretched in the box_panel1 on width. I tried to use a BoxLayout with it's Alignment_X but this didn't work.
Could you, please, advise me, what to do - how to avoid stretching?
Most of the swing layouts will use the preferred size and the minimum/maximum size over a call to setSize. The key here is to get the right preferred and minimums so that they don't shrink too much, and then insert a strut (Box#createHorizontalStrut) to fill up space where you don't want a component.
With complex layouts like this, consider the SpringLayout, which admittedly has a higher learning curve, but once you get used to it, will allow you to more naturally state the constraints you want.