I am creating a Swing dialog window like below:
The header and footer areas have fixed size. The area 1 and 2's size are not fixed. They can have several lines of content and the line number can increase at runtime.
And in future, I may need to add area 3.
How should I use Swing layout managers to achieve this UI?
ADD 1
The area 1 and 2 are independent of each other.
In each of them, I want to place several panels vertically. Each panel hold a line of string. The panel number can vary at runtime.
Use a BorderLayout for the main layout.
add the "header" to the NORTH.
add the "footer" to the SOUTH.
Create another panel and add it to the CENTER. Then set the layout manager of this panel to an appropriate layout manager. We can't advise you what layout manager to use for this panel since we don't know how the two components area related. Then add "area1" and "area2" to this panel.
The key to this answer is that you don't need to use a single layout manager, you can nest panels with different layout managers.
I'd use a BorderLayout for this one:
header in PAGE_START
footer in PAGE_END
area1 & area2 (each in a JScrollPane) in a JSplitPane in the CENTER
Related
I have two JPanel instances in a JLayeredPane, on different z-orders. I want both of my child JPanels to always fill the space of the LayeredPane.
The idea is for me to toggle the display of a 2nd panel over top of the first to display a modal-like dialog. Yes, I could just use a JDialog, but I thought it would be fun to try and create some transparancy overtop of the covered JPanel for a nice effect.
I find that using a layout manager on the JLayeredPane, like BorderLayout, and trying to set both children to CENTER conflicts since both panels can't be in the Center.
Is there a trick that I'm not seeing?
The idea is for me to toggle the display of a 2nd panel over top of the first
The easiest way to do this is to use a Glass Pane.
Check out the Disabled Glass Pane for an example of this approach.
There are two ways to create some "Glass Panel like" overlay for JPanels with JLayeredPane:
Add a ComponentListener to the JLayeredPane and update the sizes of all child components whenever the size of the JLayeredPane changes
Create a simple FillLayout, which expands the size of its child Components to the size of the Layout Container (In our case the JLayeredPane). You need to keep a list of children Components. During layoutContainer you copy the dimensions of the Container to these child Components. I wrote this and its really simple, but unfortunately I can't post it, since it's corporate. But if anyone is interested just ask in the comments. The implementation basically consists of one-liners.
For both solutions you need to make sure, that the panels on top are transparent, by setting setOpaque to false. This ensures that underlying panels render their content.
I'm having trouble organizing the contents of a JPanel. I've tried different layout managers but haven't gotten anything to work.
The JPanel contains 3 other JPanels and should look like this:
Does anyone know how I can achieve this layout?
Thanks in advance.
What you want is similar to a BorderLayout, but using one natively will cause the second pane to fill the bottom space (rather than the 3rd pane.)
However, you could use two in tandem to get this effect - The first BorderLayout pane would contain the second BorderLayout pane (in its centre) and panel 3 (on its east.)
In the second BorderLayout pane, you could then just set pane 1 to be the centre, and pane 2 to be the south.
Simplest, but not best solution, is to use null Layout Manager with manually set components bounds. It is called Absolute Positioning
Other approach is to use horizontal SplitPane with nested Vertical SplitPane: left one will contain vertical splitPane with Panel1 and Panel2, and right will be just Panel3.
I've got an arbitrary number of JPanels being created based on user input (like 1-8 panels). Right now, I'm putting all the panels in a larger panel using FlowLayout, and then adding that panel to my main window which is using BoxLayout. I want the panels to fit the width of the main window but right now they are very small. Should I use a different layout or is there a way to do this?
You have to choose GridLayout or GridBagLayout.
Yes, you should use a different layout manager. Use BorderLayout (tutorial here), which streches all the contents to fit the container.
Also, BorderLayout doesn't allow more than one component in each area, thus you will need another sub-panel to hold your panels. Don't use FlowLayout for that sub-panel, as it will not have the streching behaviour your are looking for.
How would I go about making the length of the tabs automatically resize based on how much room is left in that row of tabs.
Picture:
As you can see the tab's width is based off the text in the tab.
If you need me to explain what I want better then just ask me because I don't know if I made it clear enough.
You can use a custom component and set it's preferred size. For example, in ButtonTabComponent of TabComponentsDemo:
label.setPreferredSize(new Dimension(...));
You have to choose an appropriate dimension based on other aspects of your layout, so it won't be automatic.
I want to define a size for the actual tabbed pan.
The size of the JTabbedPane is a function of the dimensions and LayoutManager of the Container to which it has been added. In the example cited, the default layout of the frame's content pane is BorderLayout, and add(pane) adds it to the center by default.
To accomplish your goal, I see two approaches:
Divide the current width of the enclosing Container among the existing tabs and repaint the tabbed pane, as shown in this example.
Develop your own implementation of TabbedPaneUI and interpret SCROLL_TAB_LAYOUT accordingly.
In which Swing layout manager it is possible to change layout areas programmatically? And how to do this with lowest cost?
I have to create component with functionality similar to JSplitPane but with three panels from scratch. One of the moments is to Expand/Collapse one of the panels after clicking oneTouchExpandable button on the divider. But the problem is that I don't know how to implement this collapse action. I tried just setting panels width to 0, but the layout area which contains this panel doesn't shrink after the component. I tried to do this in all Layout Managers, but effect is the same.
Thanks.
When making a change that affects the layout of a panel after the GUI is visible you need to revalidate() the panel which essentially invoke the layout on the panel. In your case it might be easier to simply make the component invisible:
component.setVisible(false);
panel.revalidate();
panel.repaint(); // this is only required sometimes
All layout managers resize dynamically. However, the width and height properties are the result of the layouting, and will be overwritten.
The properties you should look at are preferredSize, minimumSize, and maximumSize - the layout managers base their calculations on those properties, though the exact effect depends on the layout manager (e.g. BorderLayout will give the NORTH, SOUTH, WEST and EAST components their preferred size if possibe and assign the remainder to the CENTER component).
Once you've changed the size properties, you have to call revalidate() on the container, then you should see the changes.
I'm with the revalidate()/preferredSize answers but just wanted to suggest this: don't re-invent the wheel! Use the JideSplitPane (part of JIDE's free "Common Layer") - it supports more than two splits.
Thanks to all for the answers. Finally I ended up with combining solutions from several answers.
My final solution is following:
I use BorderLayout, set West, Center and East panels and then manipulate their sizes by setting PreferredSize to West and East panels. The scheme of rendering is following: while laying out the components BorderLayout gives East and West panels their PreferredSize and rest of the space to Center panel. So with a bit of easy calculations I can manipulate size of each of three panels painlessly.
I also added dividers(originally just JPanel components with fixed size) to West and East panels(their size is also considered while calculating). For dynamic resize I handle dragging events on this dividers and recalculate panel sizes.
Refreshing is done with following snippet:
container.setVisible(false);
container.revalidate();
container.repaint();
container.setVisible(true);
I'd like to put this code somewhere to be available for others, but don't know where exactly to do this. So if you know such place, please point me to it in the comments.