Unhandled Eventloop Exception (MacOS 14.3.1)

開啟 Choordinates 視窗的 WindowBuilder Design 索引標籤以重現失敗，然後檢查第 273 行的 FretPanel.java，並比較連結提交前後的行為。追蹤 drawString 堆疊追蹤所回報的 null 值，並判定新的 ToneChord 建構函式為何會觸發它。設計索引標籤能在沒有未處理例外的情況下呈現，即表示完成。

Windowbuilder was working with this window until the last batch of changes I made to it. I get no warnings or compile errors in my project, the Windowbuilder Design tap just show up empty.

My project is opensource and after doing some digging, the error appears in this (small) commit:
https://github.com/obscurestar/choordinates/commit/10c3ec90987c35c822aa5a1f17a3f8c548a0cc9e#diff-24bc5d99104ec827f095ecd47ae668ae04b178c150fd5750a9c31aa8502f89e9L136

and appears to be related to the creation of a new public constructor in the unrelated 'ToneChord' class. (Even with the removal of 'foo' object)

Below is the stack trace from the General Error log stack trace when I click the design tab for the 'Choordinates' window in my project.

java.lang.NullPointerException: String is null
at java.desktop/sun.java2d.SunGraphics2D.drawString(SunGraphics2D.java:2925)
at choordinates.FretPanel.paintComponent(FretPanel.java:273)
at java.desktop/javax.swing.JComponent.printComponent(JComponent.java:1292)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1132)
at java.desktop/javax.swing.JComponent.print(JComponent.java:1274)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:965)
at java.desktop/javax.swing.JComponent.printChildren(JComponent.java:1305)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1140)
at java.desktop/javax.swing.JComponent.print(JComponent.java:1274)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:965)
at java.desktop/javax.swing.JComponent.printChildren(JComponent.java:1305)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1140)
at java.desktop/javax.swing.JLayeredPane.paint(JLayeredPane.java:586)
at java.desktop/javax.swing.JComponent.print(JComponent.java:1274)
at java.desktop/javax.swing.JComponent.paintChildren(JComponent.java:965)
at java.desktop/javax.swing.JComponent.printChildren(JComponent.java:1305)
at java.desktop/javax.swing.JComponent.paint(JComponent.java:1140)
at java.desktop/javax.swing.JComponent.print(JComponent.java:1274)
at java.desktop/java.awt.GraphicsCallback$PrintCallback.run(GraphicsCallback.java:50)
at java.desktop/sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:75)
at java.desktop/sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:112)
at java.desktop/java.awt.Container.print(Container.java:2060)
at java.desktop/sun.lwawt.LWComponentPeer.print(LWComponentPeer.java:807)
at java.desktop/sun.lwawt.LWContainerPeer.print(LWContainerPeer.java:276)
at java.desktop/java.awt.GraphicsCallback$PeerPrintCallback.run(GraphicsCallback.java:103)
at java.desktop/sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:75)
at java.desktop/java.awt.Component.printAll(Component.java:3534)
at org.eclipse.wb.internal.swing.utils.SwingScreenshotMaker.makeShots(SwingScreenshotMaker.java:146)
at org.eclipse.wb.internal.swing.model.component.ComponentInfo.refresh_fetch(ComponentInfo.java:156)
at org.eclipse.wb.internal.swing.model.component.ComponentInfo.refresh_fetch(ComponentInfo.java:140)
at org.eclipse.wb.internal.swing.model.component.ContainerInfo.refresh_fetch(ContainerInfo.java:258)
at org.eclipse.wb.core.model.ObjectInfo.lambda$6(ObjectInfo.java:481)
at org.eclipse.wb.internal.core.utils.execution.ExecutionUtils.runDesignTime(ExecutionUtils.java:147)
at org.eclipse.wb.core.model.ObjectInfo.lambda$5(ObjectInfo.java:480)
at org.eclipse.wb.internal.swing.utils.SwingUtils$2.run(SwingUtils.java:78)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)