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Class java.awt.swing.JRootPane

java.lang.Object
    |
    +----java.awt.Component
            |
            +----java.awt.Container
                    |
                    +----java.awt.swing.JComponent
                            |
                            +----java.awt.swing.JRootPane

public class JRootPane

extends JComponent

implements Accessible

      JRootPane
          glassPane
          layeredPane 
              [menuBar]
              contentPane
 

The contentPane() should be the parent of any children of the JRootPane. You would normally do something:

       rootPane.add(child);
 

       rootPane.getContentPane().add(child);
 

If a JMenuBar component is set on the JRootPane, it will be positioned along the upper edge of the frame. The contentPane() will be adjusted in location and size to fill the remaining area.

The JMenuBar and the contentPane() will be added to the layeredPane() component at the JLayeredPane.FRAME_CONTENT_LAYER layer.

The layeredPane() is an instance of the JLayeredPane class. It's purpose is to be the parent of all children of the JRootPane. It provides the ability to add components at several layers. This is very useful when working with menu popups, dialog boxes, or during dragging. Situations where you need to place a component over the top of all other normal components. The layeredPane() will always be non-null. Attempting to set it to null will cause the JRootPane to throw an exception.

The glassPane() will always be added as the first child of the JRootPane. This allows this glass component to get in the way of all mouse events, as well as providing a convient place to draw above all other components. The glassPane() will always be non-null. Attempting to set it to null will cause the JRootPane to throw an exception. Developers should use the setVisible() call on the glassPane to control when the glassPane displays over the other children. By default the glassPane will not be visible.

The JRootPane uses a custom LayoutManager. This LayoutManager insures the following:

1. The glassPane(), if present, fills the entire viewable area of the JRootPane. (bounds - insets)
2. The layeredPane() fills the entire viewable area of the JRootPane. (bounds - insets)
3. The menuBar() is positioned at the upper edge of the layeredPane().
4. The contentPane() fills the entire viewable area, minus the MenuBar, if present.

See Also:

JLayeredPane, JMenuBar, JWindow, JFrame, JDialog

JRootPane.RootLayout

contentPane

glassPane

layeredPane

menuBar

JRootPane()

addImpl(Component, Object, int)

Overridden to enforce the position of the glass component as the zero child.

createContentPane()

Called by the constructor methods to create the default contentPane.

createGlassPane()

Called by the constructor methods to create the default glassPane.

createLayeredPane()

Called by the constructor methods to create the default layeredPane.

createRootLayout()

Called by the constructor methods to create the default layoutManager.

getAccessibleRole()

Get the role of this object.

getContentPane()

getGlassPane()

getLayeredPane()

getMenuBar()

setContentPane(Container)

setGlassPane(Component)

setLayeredPane(JLayeredPane)

setMenuBar(JMenuBar)

protected JMenuBar menuBar

protected Container contentPane

protected JLayeredPane layeredPane

protected Component glassPane

public JRootPane()

protected JLayeredPane createLayeredPane()

Called by the constructor methods to create the default layeredPane. Bt default it creates a new JLayeredPane.

protected Container createContentPane()

Called by the constructor methods to create the default contentPane. By default this method creates a new JComponent add sets a BorderLayout as its LayoutManager.

protected Component createGlassPane()

Called by the constructor methods to create the default glassPane. By default this method creates a new JComponent with visibility set to false.

protected LayoutManager createRootLayout()

Called by the constructor methods to create the default layoutManager.

public void setMenuBar(JMenuBar menu)

public JMenuBar getMenuBar()

public void setContentPane(Container content)

public Container getContentPane()

public void setLayeredPane(JLayeredPane layered)

public JLayeredPane getLayeredPane()

public void setGlassPane(Component glass)

public Component getGlassPane()

protected void addImpl(Component comp,
                       Object constraints,
                       int index)

Overridden to enforce the position of the glass component as the zero child.

Overrides:

addImpl in class Container

public AccessibleRole getAccessibleRole()

Get the role of this object.

Returns:

an instance of AccessibleRole describing the role of the object

Overrides:

getAccessibleRole in class JComponent

See Also:

AccessibleRole

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