Why does that surprise you?
Because i can not find proper answer/article/post etc about it.
I write following code:-
Got answer :-
When i search in google, about javax.swing.plaf.metal.MetalTabbedPaneUI$TabbedPaneLayout
i got
Class MetalTabbedPaneUI.TabbedPaneLayout.
By reading this i got
Class MetalTabbedPaneUI.
& by reading it, i got
Class ComponentUI.
In this 2 lines written
The base class for all UI delegate objects in the Swing pluggable look and feel architecture. The UI delegate object for a Swing component is responsible for implementing the aspects of the component that depend on the look and feel. The JComponent class invokes methods from this class in order to delegate operations (painting, layout calculations, etc.) that may vary depending on the look and feel installed.
When i run program with tabbedPane.setLayout(new BorderLayout(0, 0)); not commented.
Then i got result:-
But same with code & import & declaration for panel not commented,( but all for panel_1 is commented) & run program, i got result same as above
But when both panels (panel & panel_1) are not commented any more then i got result:-
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 0
at javax.swing.plaf.basic.BasicTabbedPaneUI.paintTabArea(Unknown Source)
at javax.swing.plaf.basic.BasicTabbedPaneUI.paint(Unknown Source)
at javax.swing.plaf.metal.MetalTabbedPaneUI.paint(Unknown Source)
at javax.swing.plaf.metal.MetalTabbedPaneUI.update(Unknown Source)
at javax.swing.JComponent.paintComponent(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at javax.swing.JLayeredPane.paint(Unknown Source)
at javax.swing.JComponent.paintChildren(Unknown Source)
at javax.swing.JComponent.paintToOffscreen(Unknown Source)
at javax.swing.BufferStrategyPaintManager.paint(Unknown Source)
at javax.swing.RepaintManager.paint(Unknown Source)
at javax.swing.JComponent.paint(Unknown Source)
at java.awt.GraphicsCallback$PaintCallback.run(Unknown Source)
at sun.awt.SunGraphicsCallback.runOneComponent(Unknown Source)
at sun.awt.SunGraphicsCallback.runComponents(Unknown Source)
at java.awt.Container.paint(Unknown Source)
at java.awt.Window.paint(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.prePaintDirtyRegions(Unknown Source)
at javax.swing.RepaintManager.access$700(Unknown Source)
at javax.swing.RepaintManager$ProcessingRunnable.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
tabbedPane.getLayout() =java.awt.BorderLayout[hgap=0,vgap=0]
Same there are 2 more commented lines at different locations regarding frame visibility, when try to different cases i got different answers.
But look & feel do some calculation to set x,y & width & height of containers/components in swing program.
Is there necessary to set size, set preferred size, set minimum size, set maximum size, x,y ,bounds, location etc all for get fix values when we try to see in print statement?