Debugging custom components

[me-nkr]

I am trying to create a custom component and debug it, and there are two issues I am facing

• when debugging the component is greyed out
  

  • I tried using java -cp "digitaln2t-1.0-SNAPSHOT.jar:/path/to/Digital/Digital.jar" com.github.itoshkov.digitaln2t.Nand2TetrisComponentSource, java -cp "target/pluginExample-1.0-SNAPSHOT.jar:Digital.jar" de.neemann.digital.plugin.DemoCompone ntSource and tried using vscode java debugger, the same is the result
  • it worked when I provided the jar path as Java Library option in Digital Settings

• this is a minor inconvenience, but just wanted to know about it, when using vscode java debugger and making changes to the file the changes are not reflected in the Digital instance that was opened with debugger.

[hneemann]

This happens if there are two components with the same name. The simulator identifies the components by name. If there are two with the same name, this name is no longer unique. For example, has a jar file been included which contains a component with a certain name and another component with the same name registered in debug mode?

[me-nkr]

• I freshly cloned the demo repo
• replaced Digital.jar with what I use
• inside the repo, I did mvn install
• then java -cp "target/pluginExample-1.0-SNAPSHOT.jar:Digital.jar" de.neemann.digital.plugin.DemoComponentSource
• Digital was opened but the custom components were greyed out

And to answer your question, I don't think there is.

[me-nkr]

Some tinkering later, here are my observations

• I did get it working in an accident, I opened a dig file which has some custom dig components in the same directory
  • now the Nand2Tetris component can be selected and custom components also can be selected but custom components has no icon preview until it's selected once
• I do feel like this has something to do with these lines of code, but I am not sure since the custom components made it work

will update if I get more info into the situation

[me-nkr]

Hey @hneemann, I found out why it's not working and why it worked when there was a file in file history.

It has to do with the order of executions and the following lines of code

Digital/src/main/java/de/neemann/digital/gui/Main.java

Lines 194 to 202 in 426a1e1

	if (builder.fileToOpen != null) {
	LOGGER.debug("create with given file " + builder.fileToOpen);
	SwingUtilities.invokeLater(() -> loadFile(builder.fileToOpen, builder.library == null, builder.library == null));
	} else {
	File name = fileHistory.getMostRecent();
	LOGGER.debug("create with history file " + name);
	if (name != null) {
	SwingUtilities.invokeLater(() -> loadFile(name, true, false));
	}

Here is a detailed explanation

The order of executions is as follows when debugging

1. create a new element library
   a. calls the LibraryNode.traverse() method from populateNodeMap()
   b. calls the LibraryNode.traverse() method directly
   

   Digital/src/main/java/de/neemann/digital/draw/library/ElementLibrary.java

   Lines 255 to 263 in 426a1e1

   	populateNodeMap();
   	isProgrammable.clear();
   	root.traverse(libraryNode -> {
   	ElementTypeDescription d = libraryNode.getDescriptionOrNull();
   	if (d != null && d.hasAttribute(Keys.BLOWN))
   	isProgrammable.add(d.getName());
   	});

2. register components from custom Java components to the above-created library using the ElementLibrary.registerComponentSource() method
3. set the above created and modified library as the library of MainBuilder using the MainBuilder.setLibrary() method
4. then the MainBuilder.openLater() method calls the MainBuilder.build() method which in turn instantiates the Main class
5. while instantiating the Main class, as per the first block of code linked, the LibraryNode.traverse() method is called once more as a result of calling the Main.loadFile() method which only happens if there is a file in File History

The gotcha

First two calls to the LibraryNode.traverse() method happens before the ElementLibrary.registerComponentSource() and the MainBuilder.setLibrary() method calls. Because of this, the custom Java components are not in the element library when the LibraryNode.traverse() method is called which is responsible for marking library nodes as unique. Since the custom Java components are not marked as unique, they become unusable. And since the LibraryNode.traverse() method is called once more after all this when there is a file in File History, the custom Java components become usable.