https://resources.mpi-inf.mpg.de/d5/teaching/ss05/is05/javadoc/javax/swing/plaf/basic/BasicToolBarUI.ToolBarContListener.html
BasicToolBarUI.ToolBarContListener
https://docs.oracle.com/javase/jp/18/docs/api/java.desktop/javax/swing/plaf/basic/BasicToolBarUI.ToolBarContListener.html
BasicToolBarUI.ToolBarContListener (Java SE 18 & JDK 18)
declaration: module: java.desktop, package: javax.swing.plaf.basic, class: BasicToolBarUI, class: ToolBarContListener
java sejdk