I am trying to maximize JFrame from within JMenuBar, I can not pass a reference to the frame. Is it possible to get a reference to the frame that it is used in?
i can get to the top level component but it does not have a way to maximize and minimize frame.
public Container getApplicationFrame(ActionEvent event){
JMenuItem menuItem = (JMenuItem) event.getSource();
JPopupMenu popupMenu = (JPopupMenu) menuItem.getParent();
Component invoker = popupMenu.getInvoker();
JComponent invokerAsJComponent = (JComponent) invoker;
Container topLevel = invokerAsJComponent.getTopLevelAncestor();
return topLevel;
}
You can get the Window that contains the JPanel via
Window window = SwingUtilities.getWindowAncestor(popupMenu);
You can then either maximise it using window.setSize() -- or, since you seem to know that it's a JFrame, cast it to Frame and use the setExtendedState method that Kevin mentions. Example code from the Java Developers' Almanac for that:
// This method minimizes a frame; the iconified bit is not affected
public void maximize(Frame frame) {
int state = frame.getExtendedState();
// Set the maximized bits
state |= Frame.MAXIMIZED_BOTH;
// Maximize the frame
frame.setExtendedState(state);
}
Surely you can stash the frame in question in a local variable somewhere?
As for actually maximizing the Frame once you've got ahold of it, Frame.setExtendedState(MAXIMIZED_BOTH) is probably what you want. Javadoc
While not as elegant as it could be, quick path to ground on your existing code:
public Frame getApplicationFrame(ActionEvent event){
if(event.getSource() == null) return null;
Window topLevel = SwingUtilities.getWindowAncestor(event.getSource());
if(!(topLevel instanceof Frame)) return null;
return (Frame)topLevel;
}
...
//Somewhere in your code
Frame appFrame = getApplicationFrame(myEvent);
appFrame.setExtendedState(appFrame.getExtendedState() | Frame.MAXIMIZED_BOTH);
...
Minimum Java version 1.4.2. Be forwarned I have not tested the above code, but you should get the idea.
The class that creates the frame and the menubar can also act as the ActionListener for the menu item, since it has access both the frame and the menubar.
Related
I've got a JPanel, which I want to respond to a mouse click and then open a JDialog. The JDialog constructor needs an instance of JFrame and not JPanel - how do I work around this?
You should really try to attach the JDialog to a parent Dialog or Frame, especially if you want it modal (by passing a parent Window, the dialog will be attached to your Window and bringing the parent will bring the child dialog as well). Otherwise, the user experience can really go wrong: lost dialogs, blocking windows without seeing the modal dialog, etc...
To find your JPanel parent Window, all you need is this code:
JPanel panel = new JPanel();
Window parentWindow = SwingUtilities.windowForComponent(panel);
// or pass 'this' if you are inside the panel
Frame parentFrame = null;
if (parentWindow instanceof Frame) {
parentFrame = (Frame)parentWindow;
}
JDialog dialog = new JDialog(parentFrame);
...
If you don't know if you are in a Frame or Dialog, make the "instanceof" test for both classes.
Using the parameter free constructor will make the dialog owner-less. I think that the best thing to do would be to make the Frame that owns your Panel the owner of the dialog.
By that, I mean that you should use the getParent() from your JPanel to find its owner and then send this object found as the owner of your JFrame.
A crude code for that would be
java.awt.Container c = myPanel.getParent();
while (!(c instanceof javax.swing.JFrame) && (c!=null)) {
c = c.getParent();
}
if (c!=null) {
JFrame owner=(javax.swing.JFrame) c;
JDialog myDialog=new JDialog(owner);
}
I have not tested this code, but it is good enought for you to understand the idea.
If you decided to go with a JOptionPane, you could add a MouseListener to the JPanel with a mouseAdapter inner class to handle mouseClicked events. You would have to declare the panel final in order to access the panel from within the inner class.
final JPanel testPanel = new JPanel();
testPanel.addMouseListener(new MouseAdapter(){
public void mouseClicked(MouseEvent e)
{
JOptionPane.showMessageDialog(testPanel,"Title","InformationMessage",JOptionPane.INFORMATION_MESSAGE);
}});//end of mouseClicked method
There's a constructor that don't need argument:
JDialog dialog = new JDialog();
If what you want is to make the dialog modal, maybe you can get a static reference of you main JFrame, something like:
JDialog dialog = new JDialog(MyMainJFrame.getInstance());
By input elements I mean things like JSpinners and JComboxBoxes. My glasspane is passed a JPanel containing JSpinners, JComboBoxes and for the most part, JLabels. The glasspane has a MouseListener attached. The surprising thing is that mouseEntered is called upon the mouse cursor leaving the input elements and hovering over the other parts or empty space of the JPanel! Is this normal behaviour? How can I get the input elements to be considered part of the JPanel for Glasspane purposes?
Here is a screenshot of my UI with its input elements and jLabels.
Here is an example piece of Code:
import javax.swing.*;
public class DialogTest {
public DialogTest() {
JPanel dialogPanel = new JPanel();
SpinnerModel edgeModel = new SpinnerNumberModel(1, 1, 9, 1);
JSpinner edgeSpn = new JSpinner(edgeModel);
dialogPanel.add(edgeSpn);
JDialog initialDialog = new JDialog(new JFrame(), "Test", true);
initialDialog.setContentPane(dialogPanel);
initialDialog.pack();
glass = new GlassComponent(dialogPanel);
initialDialog.setGlassPane(glass);
glass.setOpaque(false);
glass.setVisible(true);
initialDialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
initialDialog.setVisible(true);
}
}
public class GlassComponent implements MouseListener {
JPanel c;
public GlassComponent(JPanel c) {
this.c = c;
this.c.addMouseListener(this);
}
...
public mouseEntered(MouseEvent e) {
System.out.println("Entered JPanel");
}
}
By way of explanation, my goal is to eventually use the GlassPane to block input for those elements marked with the prohibition sign. However, given that the mouseListener assigned to the dialogPanel is seemingly generating new events upon leaving the input elements, I may have some difficulties achieving this.
You can forward mouse events to the underlying components, as shown in The Glass Pane demo's method, redispatchMouseEvent().
You appear to be using glasspane in a way that I feel it shouldn't be used.
As far as I know, a glasspane typically shouldn't be holding components at all but rather cover over the top-level window and then can act as a gate-keeper for the components that are below it, all held by the top level window's contentPane.
you can use GlassPane for overlay required Container or JComponent by #camickr, or my questions based on his code here or here,
another suggestion could be use JLayer (required Java7 for Java6 is there JXLayer)
I am designing an application in NetBeans, as illustrated in the screenshot below.
When the user clicks on a JButton on a JFrame, a JDialog pops-up asking the user to enter a numeric value using a numeric keypad. I would like the JDialog to dynamically add 2 JPanels. JPanel 1 will contain a textbox for input. JPanel 2 will contain a numeric keypad. I designed them this way so that I could reuse the numeric keypad whenever I need it. The problem I am facing is displaying dynamically these 2 JPanels on the JDialog that pops-up. JDialog pops-up empty. Please take a look at my code below. Thank you all, I appreciate your help
This is the sample code of JDialog:
public class MyDialog extends javax.swing.JDialog {
public MyDialog(java.awt.Frame parent, boolean modal) {
super(parent, modal);
initComponents();
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {//Add JPanel 2 (Numeric Keypad) to JDialog
Container contentPane = getContentPane();
NumericKeypadPanel nkp = new NumericKeypadPanel();
nkp.setLayout(new java.awt.BorderLayout());
contentPane.removeAll();
contentPane.add(nkp);
contentPane.validate();
contentPane.repaint();
}
});
}
This is the sample code for JPanel 2 (Numeric Keypad):
public class NumericKeypadPanel extends javax.swing.JPanel {
/** Creates new form NumericKeypadPanel */
public NumericKeypadPanel() {
initComponents();//Draws 10 number buttons
}
}
basicall there are two ways
1) add a new JComponent by holding JDialog size (in pixels) on the screen, all JCompoenets
or part of them could be shrinked
2) resize JDialog by calling pack(), then JDialog will be resized
both my a.m. rulles works by using Standard LayoutManagers (excepting AbsoluteLayout)
What is in the initComponents() function of the NumericKeypadPanel? If it's not actually creating components, you're not going to see anything in the dialog. I added a single line to the NumericKeypadPanel's constructor to change the background color of this panel, and indeed, it shows up in the dialog as a green panel.
public NumericKeypadPanel() {
//initComponents();//Draws 10 number buttons
setBackground(Color.green);
}
I'm trying to close a frame yet open a new frame.
My application has page A, a JPanel with some controls and a specific button, and when the user clicks the button, I want page A to disappear and page B to appear (page B has controls that depend on the choices that are made by the user on page A).
This has been asked before, but there was no satisfactory answer. Inside the ActionListener implementation, namely public void ActionPerformed(ActionEvent e) from my jpanelForPageA class, I can comfortably write this.setVisible(false), but how can I set page B to a visible state?
You can do the removal of panel a and then the addition of panel b trick. Another is to use a CardLayout.
When you create your panels, you add them to a containing JPanel that you initialize with a CardLayout:
JPanel container = new JPanel(new CardLayout());
containter.add(getPanelA(), "PANEL_A");
containter.add(getPanelB(), "PANEL_B");
Then, in your actionPerformed, when you want to show panelB, you do this:
CardLayout cl = (CardLayout) container.getLayout();
cl.show("PANEL_B");
Take a look at this tutorial for some more ideas.
For some reason, I can never to get setVisible() to work for me to do what you're describing. Instead, I do this:
frame.remove(panelA);
frame.add(panelB);
"frame" is just the JFrame you want to put the panels in. Try this if the setVisible() method doesn't work :)
To your original question, all you have to do is (like aioobe said):
panelB.setVisible(true);
((btw, posting some of your code would help me figure out what you're trying to ask))
And this is just a guess as to what you're trying to do -- I'm guessing your JPanels are in different classes. Then, you'll need to do this:
class pages extends JFrame implements ActionListener
{
public pages()
{
panelA a = new panelA(this)
}
changeToA(panelB b)
{
remove(panelB);
add(new panelA(this));
}
changeToB(panelA a)
{
remove(panelA);
add(new panelB(this));
}
}
class panelA extends JPanel implements ActionListener
{
pages p;
public panelA(pages p)
{
this.p = p
}
// all that actionlistener code stuff
p.changeToB(this);
}
class panelB extends JPanel implements ActionListener
{
pages p;
public panelB(pages p)
{
this.p = p
}
// all that actionlistener code stuff
p.changeToA(this);
}
You pass the pages class to the panels so the panels can tell the pages class to remove themselves.
((I don't know if there is an easier way, but this is what I do all the time))
I hope I helped :)
You have to remove Panel A from the frame, add Panel B to the frame, and call invalidate on the frame (or containing panel). At least in Swing, I'm not sure about AWT, there you might need repaint or revalidate instead of invalidate.
You could also just create a whole new JFrame and dispose the one containing panel A.
I am implementing a Comment box facility in my application which user can resize using mouse. This comment box contains a scrollpane which instead contains a JEditorPane in which user can insert comment. I have added the editor pane inside a scroll pane for the following reason:
auto scolling of jeditorpane
When the user resizes the comment box, I am setting the desired size for JScrollPane and the JEditorPane. When the user is increasing the size of the comment box, the size of these components are increasing as desired but when the size of the comment box is decreased, the size of the JEditorPane does not decrease even after setting the size. This leads to the scrollbars inside the scrollpane.
I tried using setPreferrredSize, setSize, setMaximumSize for JEditorPane. Still the size of the editor pane is not reducing. I tried calling revalidate() or updateUI() after the setting of size but no use.
I am using Java 1.4.2.
Please provide me some insight....
I realise this is long since answered, but for future reference all you need to do is override the getScrollableTracksViewportWidth() to always return true, eg.
JEditorPane pane = new JEditorPane() {
public boolean getScrollableTracksViewportWidth() {
return true;
}
};
panel.add(new JScrollPane(pane));
Actually it is possible, luiscubal. Here is how,
To the JScrollPane add a ComponentListener for resize events
public static void main(String...args) {
//our test frame
JFrame frame = new JFrame("JEditorPane inside JScrollPane resizing");
frame.setLayout(new BorderLayout());
//our editing pane
final JEditorPane editor = new JEditorPane();
//our simple scroll pane
final JScrollPane scroller = new JScrollPane(editor);
//NOTE: this is the magic that is kind of a workaround
// you can also implement your own type of JScrollPane
// using the JScrollBar and a JViewport which is the
// preferred method of doing something like this the
// other option is to create a JEditorPane subclass that
// implements the Scrollable interface.
scroller.addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e) {
editor.setSize(new Dimension(
scroller.getWidth()-20,
scroller.getHeight()-20));
}
});
//just use up the entire frame area.
frame.add(scroller, BorderLayout.CENTER);
//quick and dirty close event handler
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(320, 240); //something not too big
frame.setLocationRelativeTo(null); //centers window on screen
frame.setVisible(true); // normally done in a SwingUtilities.invokeLater
}
Look luiscubal it is possible. Don't be so quick to announce things in Java as not possible. The swing api is quiet flexible and can do a lot of the work for you. However, if you use JComponents in ways they weren't made to be used you will end up with problems and have two options.
subclass subclass subclass basically create your own component.
find a work around, like the above solution.
Decreasing the size of a JEditorPane in a JScrollPane and then reducing it, is not possible.
You may want to use a JTextArea instead.