I have been using the printComponent that was shown in another question. It works great for printing a JPanel if I first add that JPanel to a JFrame and draw that JFrame to screen. But if I don't do that before I print, I get a blank page printed. Why is this?
I've used code like the following to create a BufferedImage on a panel that is not visible on the frame:
JPanel panel = new JPanel();
... // add components
panel.setSize(300, 300);
panel.doLayout();
that is because the panel you wish to draw has an initial size of 0,0. Once added to a container with a layout manager and is displayed, then it gets its "normal" size.
Related
I have been researching for 30 minutes on how to automatically resize a JFrame when the elements are too large. I am trying to fit line segments inside the JFrame but it always exceeds the space but does not automatically generate more space.
What should I do?
DrivePanel panel = new DrivePanel(aCar, coordinates);
JFrame application = new JFrame();
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
application.add(panel);
application.setSize(600,600);
application.setVisible(true);
Example of output:
Some things to consider :
if you are doing custom painting on your panel, remember that the panel's size it's not changed by what you are drawing.
For example, if the "last" point (i mean the point with the biggest values of x and y) is drawn at (1000,1000) coordinates, you should set the preferred size of your panel in order to contain it.
To let your application using the preferred size of your components, you should call application.pack() (where application is your JFrame object) instead of setting size manually.
If your panel is too big to be displayed enterily on your screen, you might add it to a JScrollPane, and then add the scrollpane to your jframe (not the panel itself).
The scrollpane will automatically use scroll bars if your panel can't be fully displayed on your screen.
So consider this small example, based on your code :
DrivePanel panel = new DrivePanel(aCar, coordinates);
JFrame application = new JFrame();
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel.setPreferredSize(new Dimension(1000,1000)); // change 1000,1000 with the coordinates you need ...
JScrollPane scrollPane = new JScrollPane(panel);
application.add(scrollPane);
application.pack();
application.setVisible(true);
Hope this helps :)
I want to add a background image to a JFrame which doesn't have any panels. It is a project I'm working on and I have almost completed it. So, I can't add a background using a JLabel because I will have to change a lot of code to do that and also I'm using netbeans. Is there any solution for this?
I want to add a background image to a JFrame which doesn't have any panels.
The content pane of the frame is a JPanel, so yes it does have panels.
I have almost completed it. So, I can't add a background using a JLabel because I will have to change a lot of code
If you want a background image then you will need to change your code to make sure the content pane can display the image. So yes you will need to change your code whether you use a JLabel of a JPanel that paints an image.
Check out Background Panel for code that will allow you to use either approach.
The key is that you need to set the content pane of your frame BEFORE you start adding components to the frame. So the code might look something like:
BackgroundPanel panel = new BackgroundPanel( yourImage );
frame.setContentPane( panel );
frame.add(northPanel, BorderLayout.PAGE_START);
frame.add(centerPanel, BorderLayout.CENTER);
I don't know what the Netbeans generated code looks like so I'll leave it up to you to figure out where to put the code.
I have a 2 JPanels, 1 a button Panel and one a Graphic Panel. I would like the button panel to situated right below the graphic panel but the button panel cuts off the Graphics Panel in the middle. I've been trying the box layout which seems from discussions seems like the best format for what I am trying to do. Can anyone please give me some advice on my formatting problem.
JFrame canvas = new JFrame("Baseball Strike K");
JFrame canvas = new JFrame ("GraphicBoard");
canvas.setVisible(true);
canvas.setSize(1000,1000);
canvas.setDefaultCloseOperation(EXIT_ON_CLOSE);
//create two panels
//add them to contentPane
//set Layout
JPanel buttonPanel = createButtons();
JPanel mainPanel = new Graphic(); //extends JPanel and writes the paint method
mainPanel.setSize(1000, 1000);
Container content = canvas.getContentPane();
content.setLayout(new BoxLayout(content, BoxLayout.Y_AXIS));
content.add(mainPanel);
content.add(buttonPanel);
mainPanel.setSize(1000, 1000);
The job of the layout manager is to determine the size of the component, so you would never invoke the setSize() method of a components.
Instead you give hints to the layout manager on what the size should be. You would do this by overriding the getPreferredSize() method to return an appropriate value. Also, I would pick a more reasonable size (1000, 1000) is a little big to display on most screens. If you really want your painting area this large then I would add the paint panel to a JScrollPane and then add the scrollpane to the frame.
Try getting your code to work using a BoxLayout. Then I would suggest a better layout manager would be to use a BorderLayout. Then you add the paint panel to the CENTER and the buttons to the SOUTH. Now as you resize the frame the paint panel will be adjusted in size.
canvas.setVisible(true);
Also, the placement of that line of code is wrong. You should add all your components to the frame first, before making the frame visible.
I am writing a simple game withing which I am using a JFrame which contains a grid and a JPanel.
Here is my pseudo code:
void MyJframeConstructor()
{
// some basic bootstrap logic
// calling repaint to draw grid
repaint();
// Grid is drawn fine.
// Showing user a confirm dialog box on which I add below JPanel.
if(confirmed)
{
// GameInfoPanel extends JPanel.
infoPanel = new GameInfoPanel(new FlowLayout(FlowLayout.LEFT));
infoPanel.setPreferredSize(new Dimension(400, 100));
infoPanel.setLocation(500, 50);
this.add(infoPanel);
infoPanel.validate();
}
}
My problem here is my JFrame or window is 480 x 680.
Within this I am drawing a grid in 480 x 480 area.
Below which I want the JPanel to be located at 500,50 with dimension 400, 100.
However, when I run this code, once the user confirms with OK, the JPanel fills up the entire JFrame.
How can I keep the panel in its location and consistent in size through out the life of the app ?
Any help is highly appreciated and thanks in advance.
Within this I am drawing a grid in 480 x 480 area.
override PreferredSize for JPanel
then call JFrame.pack() and JFrame.setVisible(true) as last code lines
have to read InitialThread
if is there only one JPanel (JPanel filling entire JFrame) then to use built_in BorderLayout in JFrame f.e. myFrame.add(infoPanel, BorderLayout.CENTER) not FlowLayout
don't to extend JFrame create this Object as local variable
I've seen many answers for this question when it's a JFrame, but none for JPanel, and all that I've tried didn't work.
So basically I've written this simple class/app that extends JPanel, and all is working fine. Now I'd like to change the Default Icon.
Any ideas?
Just as guys are saying here in comments please reconsider what you are trying to do.
The only option to change an icon is to set it for the frame in which the panel is child, since the icon is a part/belongs to the frame.
If you want setting of the icon to be a functionality of a panel then in addNotify() method, which is called when a component receives a parent, look through the panel's parent and it parent and so on until you will reach the frame and set the icon for it.
Sample showing a number of parent you must go through to get to frame if a panel is its content pane.
JPanel p = new JPanel();
JFrame f = new JFrame();
f.setContentPane(p);
System.out.println(SwingUtilities.windowForComponent(p));