On Thu, 15 Sep 2022 12:20:51 GMT, Jayathirth D V <j...@openjdk.org> wrote:
>> Basically, when a tab index is selected via `tbp.setSelectedIndex()` in >> testcase, it fires a state change event (via >> `DefaultSingleSelectionModel#setSelectedIndex`) which is caught by the >> application and in this case, state change listener in the testcase calls >> `JTabbedPane.updateUI() `which calls `JComponent.setUI() `which first >> uninstalls UI (which made `tabPane null` in `BasicTabbedPaneUI#uninstallUI`) >> and then install new UI instance but when it goes to JDK's stateChange >> listener `BasicTabbedPaneUI.stateChanged()` it passes the new instance but >> scrollableTabLayoutEnabled() still uses old UI instance in which tabPane is >> already made null so NPE happens, so it is better to use the tabPane >> instance passed to UI's stateChange listener.. > > When we install new UI instance will we not call > BasicTabbedPaneUI.installUI() to update current tabPane object? or is it > happening at later stage(like after BasicTabbedPaneUI.stateChanged() is > called)? installUI is called for new UI instance with current tabpane object but scrollableTabLayoutEnabled was using the old UI instance whose tabpane object is already reset to null. ------------- PR: https://git.openjdk.org/jdk/pull/10216
