[jdk17] RFR: JDK-8259499: Handling type arguments from outer classes for inner class in javadoc

[Hannes Wallnöfer]

This change adds support for generating HTML links to the type arguments of enclosing classes when creating a link to an inner class. Previously, only a link to the inner class was created and the type arguments were even omitted from the link label.

The new feature to create separate links to the enclosing class and its type arguments is only activated if the enclosing class has type arguments. If the enclosing class is non-generic, the old behavior is preserved to create a single link to the inner class. The reason for this is that a dedicated link to the enclosing class itself provides little benefit, since it can be easily reached via the "Enclosing class" link of the inner class. Also, linking the enclosing type in absence of type arguments makes it hard to see that there are two links and easy to click on the wrong link by mistake.

On the other hand, for type arguments a separate link should be useful since it is often not a "nearby" type. It is also easier to detect the different links than for non-generic nested classes. I came to like this "mixed" solution best after trying several other approaches.

-------------

Commit messages:
 - JDK-8259499: Handling type arguments from outer classes for inner class in javadoc

Changes: https://git.openjdk.java.net/jdk17/pull/195/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17&pr=195&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8259499
  Stats: 142 lines in 10 files changed: 128 ins; 2 del; 12 mod
  Patch: https://git.openjdk.java.net/jdk17/pull/195.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17 pull/195/head:pull/195

PR: https://git.openjdk.java.net/jdk17/pull/195