RFR: 8283387: [macos] a11y : Screen magnifier does not show selected Tab

[Alexander Zuev]

It is impossible right now to manipulate state of the accessible children of the JTabbedPane via their AccessibleValue and because of that some of the assistive technologies are unable to interact with the parts of the JTabbedPane - namely, buttons, representing the JTabbedPane panel navigation buttons. Magnified is just one of the examples that can be engaging without connecting the hardware such as eye movement tracker.

By adding AccessibleValue to the JTabbedPane children containers we eliminate is problem. And since this inner class is private the standard review should be sufficient, no CSR is required.

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

Commit messages:
 - Fix the wildcard imports
 - Make value settable via a11y API when it is logically sound
 - 8283387: [macos] a11y : Screen magnifier does not show selected Tab

Changes: https://git.openjdk.java.net/jdk/pull/8049/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8049&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283387
  Stats: 113 lines in 2 files changed: 110 ins; 1 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8049.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8049/head:pull/8049

PR: https://git.openjdk.java.net/jdk/pull/8049