Im trying to add buttons and textfields into my jMenuBar and even after I set the JTextField's PreferredSize, the JTextField keeps on filling the space on my JMenuBar.
Note: this JMenuBar was added by using this method -
public static void setJPanelMenuBar(JPanel parent, JPanel child, JMenuBar menuBar) {
parent.removeAll();
parent.setLayout(new BorderLayout());
JRootPane root = new JRootPane();
parent.add(root, BorderLayout.CENTER);
root.setJMenuBar(menuBar);
root.getContentPane().add(child);
parent.putClientProperty("root", root); //if you need later
}
The code allows me to add a JMenuBar in a JPanel.
now on to the JMenuBar code.
JMenuBar x = jMenuBar1;
x.removeAll();
JTextField searchBar = txtsearch;
JTextField searchBar2 = new JTextField();
searchBar2.setPreferredSize(new Dimension(10,20));
x.add(lblsearch);
x.add(searchBar);
x.add(btnSearch);
x.add(Box.createHorizontalGlue());
x.add(searchBar2);
NOTE: the jMenuBar1,lblsearch,txtsearch, and btnSearch was created using NetBeans.
to test this, I added another JTextField called searchBar2 and set the Preferred Size but both keeps on occupying the space left in the JMenuBar even after I added the Box Glue.
Any Ideas why?
From the How to Use BoxLayout tutorial:
When a BoxLayout lays out components from top to bottom, it tries to size each component at the component's preferred height. If the vertical space of the layout does not match the sum of the preferred heights, then BoxLayout tries to resize the components to fill the space. The components either grow or shrink to fill the space, with BoxLayout honoring the minimum and maximum sizes of each of the components. Any extra space appears at the bottom of the container.
(Emphasis mine)
Obviously the same applies to widths in a horizontal box. In my opinion, the above should be in the actual javadoc for BoxLayout, but it's not.
In your case, the easiest solution is to remove that explicit call to setPreferredSize, and instead set each JTextField's maximum size to match its preferred size:
searchBar.setMaximumSize(searchBar.getPreferredSize());
searchBar2.setMaximumSize(searchBar2.getPreferredSize());
BoxLayout tries to respect minimum and maximum sizes.
Related
I am opening a window with the following:
JFrame clientFrame = new JFrame("Frame");
clientFrame.setLayout(new BorderLayout());
final JPanel client_panel = new JPanel();
client_panel.setLayout(new BorderLayout());
client_panel.add(new Applet());
client_panel.setPreferredSize(new Dimension(765, 555));
clientFrame.getContentPane().add(client_panel, "Center");
clientFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
clientFrame.pack();
clientFrame.setVisible(true);
the frame has a random picture on it.
By default when you drag the bottom border upwards, it will naturally remove from the image from the bottom of the image.
The same if you drag the top border downwards it will again remove incrementally from the bottom of the picture.
How do I swap it around so instead it removes form the top of the picture instead of from the bottom?
clientFrame.getContentPane().add(client_panel, "Center");
Don't use magic values. People don't know where "Center" comes form. Use variables provided by the API:
clientFrame.getContentPane().add(client_panel, BorderLayout.CENTER);
What you are asking is not possible with any layout manager that I am aware of. The problem is that the layout manager only knows about size available to the component. It does not know why the size changed (ie, drag up or down). So the layout manager can only define rules based on the space available.
As a simple test use a JPanel with a BorderLayout. Then create a JLabel with containing an ImageIcon. Add the label to this panel and then add the panel to the content pane of the frame.
If you add the label to the BorderLayout.CENTER, then the image is centered in the space available so you lose part of the top and bottom.
If you add the label to the BorderLayout.PAGE_START then space is always taken from (or given to) the bottom of the component.
If you add the label to the BorderLayout.PAGE_END then space is always taken from (or given to) the top of the component.
If you want to consider the drag up or down of the frame then the solution gets much more complicated because you will need to add a ComponentListener to the frame and handle the componentResized and componentMoved methods. You will then need to track the previous state of the frame and then determine which properties have changed and then you will need to do custom painting of the image based on the property changes or you will need to write a custom layout manager that is aware of the property changes.
So I have got round to creating a panel that has two labels and a button inside and these are alligned on the Y_axis via a box layout.
I am now trying to get it so that the text is alligned to the centre of the panel as well as on the Y axis for neatness.
Here is the code I have right now:
JPanel statPanel = new JPanel();
statPanel.setBorder(BorderFactory.createTitledBorder("Text Statistics"));
statPanel.add((averageLength = new JLabel("The average length of the words: ")));
statPanel.add((totalWords = new JLabel("The total number of words: ")));
//Create button inside statPanel
statPanel.add((stats = new JButton("Update Text Statistics")));
stats.addActionListener(new ButtonListener());
statPanel.setOpaque(false);
statPanel.setLayout(new BoxLayout(statPanel, BoxLayout.Y_AXIS));
As you can see I have already used BoxLayout in order to get the vertical alignment and I have tried the following code which didnt seem to affect my situation at all (and did seem very long winded):
averageLength.setHorizontalAlignment(SwingConstants.CENTER);
averageLength.setVerticalAlignment(SwingConstants.CENTER);
totalWords.setHorizontalAlignment(SwingConstants.CENTER);
totalWords.setVerticalAlignment(SwingConstants.CENTER);
stats.setHorizontalAlignment(SwingConstants.CENTER);
stats.setVerticalAlignment(SwingConstants.CENTER);
If you could advise me that would be much appreciated!
Thanks
You don't need to set the horizontal or vertical alignment. Those properties are used with a layout manager (ie BorderLayout) that changes the size of the component to be something greater than the preferred size of the component. Then the component aligns the text based on its painting rules.
Instead, you need to set the x alignment. In this case the component size is still the preferred size. However, the layout manager aligns the component to the space available in the container. So to center the component in the width of the container you would use:
averageLength.setAlignmentX(0.5f);
totalWords.setAlignmentX(0.5f);
stats.setAlignmentX(0.5f);
The BoxLayout doesn't change the size of the component so it respects this property.
Colleagues.
I'm trying to construct simple GUI in Java, where JFrame has Border Layout. I want to put JScrollPane with JTable to CENTER, and JPanel without layout to NORTH.
The problem is that JPanel doesn't visible. There is simple examle of the problem:
JFrame frame = new JFrame("Test frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("Test button");
button.setBounds(10, 10, 40, 20);
JPanel panelN = new JPanel(null); // layout = null, panelN without layout
panelN.add(button);
frame.add(panelN, BorderLayout.NORTH);
JTable table = new JTable(new DefaultTableModel(4, 4));
JScrollPane scrollPane = new JScrollPane(table);
frame.add(scrollPane, BorderLayout.CENTER);
frame.setSize(400, 400);
frame.setVisible(true);
You have to use a LayoutManager. It's totally discouraged not using layoutManager, but if you want this you have to set panel.setBounds(..) to the panel too.
By default JPanel has FlowLayout so if you put
JPanel panelN = new JPanel(); // FlowLayout used
panelN.add(button);
frame.add(panelN, BorderLayout.NORTH);
So your frame will look like this.
Layout Managers determines the size and position of the components within a container. Although components can provide size and alignment hints, a container's layout manager has the final say on the size and position of the components within the container.
It's strongly recommended cause for example if you have to resizes components or show in differentes resolutions you delegate this work to layout managers
I don't know the expected behavior of a null layout, but without further requirements you might as well just instantiate with the zero-arg constructor:
new JPanel();
If you didn't set any layout to the panel, when adding components the panel don't know where to put the component, so baisicly the component don't show until you set a specific location for components one by one by component.setBounds(x,y,width,hieght) method.
Note that it's not a good practice to remove the layout manager because of the different platformes, suppose that your program working on Window and MacOS and Linux, you'v better to use the layout managers instead.
Take a look at this post also and see #Andrew Thompson's comment on my answer:
Java GUIs might have to work on a number of platforms, on different
screen resolutions & using different PLAFs. As such they are not
conducive to exact placement of components. For a robust GUI, instead
use layout managers, or combinations of them, along with layout
padding & borders for white space, to organize the components.
After all:
If you have a requirement or an assignment telling you you must use absolute layout, then use it, otherwise avoid it.
It is OK to use containers with no layout manager because you actually CAN set container's layout to NULL. And it's a nice idea to position your components with setBounds(). But in this case, you just have to consider your container. What size it need to be? A layout manager would calculate this for you, and if you don't have one, you have to set the size of your panel by yourself, according to components you have added to it.
As pointed by others here, the case it that the border-layout manager of your frame needs the preferred size of your NORTH panel (actually, the preferred height). And you have to set it, or values will be zeros and the container will become invisible. Note that for the CENTER panel this is not needed as it gets all space possible.
I had a problem like yours before and have written a fast function to resize a container according to bounds of a given component. It will be as large as needed to show this component, so dimension (w,h) and position (x,y) are considered. There's an "auto-resize" version that can be used once, after all components are added.
public static void updatePreferredSize(Container cont, Component comp) {
int w = cont.getPreferredSize().width;
int h = cont.getPreferredSize().height;
int W = comp.getBounds().x + comp.getBounds().width;
int H = comp.getBounds().y + comp.getBounds().height;
if (W>w||H>h) cont.setPreferredSize(new Dimension(W>w?W:w, H>h?H:h));
}
public static void autoPreferredSize(Container cont) {
for (Component comp : cont.getComponents())
updatePreferredSize(cont, comp);
}
You can use updatePreferredSize() after adding every component to a panel, or use autoPreferredSize() once, after all addings.
// [...]
panelN.add(button);
updatePreferredSize(panelN, button);
// [...]
// or...
// [...]
autoPreferredSize(panelN);
// [...]
frame.setVisible(true);
This way, if you do not set you north panel height with a fixed value, with help of these functions you can expect your button will be visible according the position you set it with setBounds().
I need to create a panel where I can put some rectangles and it automatically reorder just inserting a scrollbar and growing up vertically. Also this panel can be resizable and again the rectangles must to be reordered to correctly be displayed inside the panel.
If I understand the question you want components to wrap to the next line so that the panel grows vertically while the width remains fixed.
If so then check out the WrapLayout
Note: the FlowLayout already supports the wrapping of components to a new row on the panel. This issue is that the preferred size calculation assumes all components are placed on a single row. The WrapLayout overrides the preferred size calculation to support the wrapping of components on a new row.
Use a JScrollPane. If you never want a horizontal scroll bar you can add the following:
scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
(By default the scroll pane will add horizontal and vertical scroll bars when required.)
The scroll pane itself will only be resizeable if you add it to a Container with the appropriate layout manager; e.g.
JFrame frm = new JFrame();
frm.setLayout(new BorderLayout());
JScrollPane sp = new JScrollPane();
frm.add(sp, BorderLayout.CENTER); // Adding a component to the CENTER will cause the component to grow as the frame is resized.
My current problem is that I have a JFrame with a 2x2 GridLayout. And inside one of the squares, I have a JPanel that is to display a grid. I am having a field day with the java swing library... take a look
Image
Java is automatically expanding each JLabel to fit the screen. I want it to just be those blue squares (water) and the black border and not that gray space. Is there a way I can just set the size of that JPanel permanently so that I don't have to go through changing the size of the JFrame a million times before I get the exact dimension so that the gray space disappears?
I also would like to set the size of those buttons so they are not so huge (BorderLayout is being used for the buttons and TextField)
GridBagLayout is what you really want to use. The GridLayout will force the same size for each component in the layout no matter what size constraints you put on them. GridBagLayout is a lot more powerful and a lot more complicated. Study up on the API page for it. Using GridBagLayout, the components won't fill the whole grid space if you don't want them to and can even stay the size that you ask it to be. To keep a component's size from changing, I would set all three available size constraints:
water.setPreferredSize(new Dimension(20, 20));
water.setMinimumSize(new Dimension(20, 20));
water.setMaximumSize(new Dimension(20, 20));
For your buttons, I would definitely use an inner panel as Bryan mentions. You could use either a GridLayout like he suggests or a FlowLayout if you don't want all the buttons to be the same size. Add all your buttons to that inner panel instead of the main one.
If you want the two checkerboards to stay the same size, then you'll need to have them each contained in their own JPanel. Set each of those parent JPanel's to have a layout type of GridBagLayout. Set the preferedSize for each checkerboard component and then add them to their respective containers. GridBagLayout should by default lay each board out in the center of the parent JPanel. So as the window is resized, the JPanel parent area will get larger or smaller, but the checkerboard components inside will remain the same size.
Alternatively, you could have your blue squares scale to the right size as the window is resized by having each checkboard square be a JPanel with a BorderLayout layout manager and adding the JLabel (with a blue background color) to its BorderLayout.CENTER location.
As for your buttons, try something like this:
JPanel theButtonPanel = new JPanel(new BorderLayout());
JButton button1 = new JButton("Fire");
JButton button2 = new JButton("Pass");
JButton button3 = new JButton("Forfiet");
JPanel innerButtonContainer = new JPanel(new Grid(1, 3, 8, 8));
innerButtonContainer.add(button1);
innerButtonContainer.add(button2);
innerButtonContainer.add(button3);
theButtonPanel.add(innterButtonContainer);
Lastly, consider using a design tool for your Swing user interface. Netbeans has an excellent UI designer built into it. Download Netbeans here.
If you can setResizeable( false ) on the top level frame you can then set your layout manager to null and hard code each location and size via setBounds. This is how I would do it (contingent on resizing of course).
I have had success solving problems like these using TableLayout which is a third party layout manager. You will need to download it and read the tutorial but the key would be to set the justification to CENTER when adding the JButtons to their positions in the layout.