tree 893e9326b183db759d3a9fc7a30560258db22d1d
parent edeebcfcedfbd001e65c989f24512a419a823a38
author Simeon Andreev <simeon.danailov.andreev@gmail.com> 1542978027 +0100
committer Simeon Andreev <simeon.danailov.andreev@gmail.com> 1544633780 +0100

Bug 540243 - Bad selection when opening Debug View on breakpoint

When the Debug View is not open and a breakpoint is hit, a preference
dictates whether the Debug View is opened. If this preference is used,
it is possible to observe a bad selection in the Debug View. E.g. a
thread is selected and not a stack frame, or a stack frame and a thread
are selected.

The problem is seen for Java debug targets, when owned monitors are
displayed in the Debug View. When the Debug View debug target element is
created, DebugTargetProxy.doInstalled() is called. This will retrieve
the first suspended thread and expand it,  if such a thread is
available. The expand delta contains also the top stack frame at which
the thread is suspended. This stack frame is added to the delta with
index 0. Unfortunately, owned monitors are displayed before stack frames
in the list of thread children. So as soon as the children of the thread
are updated for the tree view, a thread owned monitor will replace the
selected stack frame. This results in an invalid selection handling,
which in turn breaks the selection.

This change allows classes which extend DebugTargetProxy to override
computation of indices for the launch, debug target and suspended stack
frame. A follow-up change in JDT debug will ensure the correct index is
computed for the suspended stack frame, one which takes the thread owned
monitors into account.

Change-Id: Ic8ca2f06a7ea9e47c0322e5d3a62775a0c816652
Signed-off-by: Simeon Andreev <simeon.danailov.andreev@gmail.com>