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POIntelliJ gui creator: JPanel gives runtime null pointer exception upon adding any component
 

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  1. POIntelliJ gui creator: JPanel gives runtime null pointer exception upon adding any component
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    <p>I am having a problem with IntelliJ's java gui creation. Most of the code behind the panel is unfortunately hidden within the gui creator and not editable by me.</p> <p>I created a blank JPanel "questionPanel" with the ItelliJ GridLayoutManager. When I try to add anything to that panel, I get a null pointer exception even though the panel is definitely not null. I also tried adding a JTextField to the layout (out of curiosity) and that did not help either. The JTextField shows up, but I still cannot add anything from within the code.</p> <p>When I change the layout manager to anything else (GridBagLayout, FormLayout, BorderLayout, etc.), I no longer get errors, but nothing shows up.</p> <p>DisplayView.java</p> <pre><code>private JPanel questionPane; public void initialize() { questionPane.addMouseListener(new MouseListener() { @Override public void mouseReleased(MouseEvent e) { questionPane.add(new JLabel("Test")); System.out.println("Click event received."); } //other overrides hidden } </code></pre> <p>Does anybody have an idea of what is going on behind the scenes or a way for me to get components onto the panel? Thanks.</p> <p>Sample Stack Trace (this trace is not made by the same code as above, but it is the same error):</p> <pre><code>Exception occurred during event dispatching: java.lang.NullPointerException at com.intellij.uiDesigner.core.GridLayoutManager.addLayoutComponent( GridLayoutManager.java:134) at java.awt.Container.addImpl(Container.java:1074) at java.awt.Container.add(Container.java:365) at [MyProject].UI.View.DisplayView$1.actionPerformed(DisplayView.java:91) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995) ..... </code></pre>
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    1. USkevin948
    1. USkevin948
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    1. COFor better help sooner, post an [SSCCE](http://sscce.org/).
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      1. USAndrew Thompson
 

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