polymorphic tray icon loading

[overheadhunter]

This is an attempt to solve the problem mentioned in #17 (comment):

Using sealed classes and IoC, we can now let the implementation decide, which kind of icon it needs, e.g.

class PngConsumingTrayMenuController implements TrayMenuController {
    // ...
    public void updateTrayIcon(Consumer<TrayIconLoader> iconLoader) {
        TrayIconLoader.PngData callback = this::updateTrayIconWithPngData;
        iconLoader.accept(callback);
    }
    
    private void updateTrayIconWithPngData(byte[] data) {
        // ...
    }
    // ...
}

On the consumer side, invocation would look like this:

// with JEP 433:
updateTrayIcon(loader -> {
	switch (loader) {
		case TrayIconLoader.PngData l -> l.loadPng(new byte[0]);
		case TrayIconLoader.FreedesktopIconName l -> l.lookupByName("foo");
	}
});

// without JEP 433:
updateTrayIcon(loader -> {
	if (loader instanceof TrayIconLoader.PngData l) {
		l.loadPng(new byte[0]);
	} else if (loader instanceof TrayIconLoader.FreedesktopIconName l) {
		l.lookupByName("");
	}
});

Note that the consumer is only required to implement loaders permitted by the sealed interface, so there can only be as many required implementation as the API allows:

integrations-api/src/main/java/org/cryptomator/integrations/tray/TrayIconLoader.java

Line 6 in cdf313e

sealed public interface TrayIconLoader permits TrayIconLoader.PngData, TrayIconLoader.FreedesktopIconName {

When the API is updated, new implementations can be added without breaking previous ones. With JEP 433, one will even get a compiler error due to exhaustiveness checks, if an implementation is missing.

[purejava]

Sophisticated approach! Something seems to be missing though ...
I could not fully implement it in integrations-linux. Error is:

I commited all changes so far to integrations-linux, including this half-way implemented PR.

Edit: typo.

[overheadhunter]

Should have been accept(...).

[purejava]

Polymorphic tray icon loading implemented.
This does work on Linux. Will test it on Mac later this day.

[purejava]

Mac (AwtTrayMenuController) is ok. Had two minor issues there that are fixed and commited now too.