Add mapping for Focus, and make focusing a stack frame focus the thread

README.md

@@ -751,6 +751,9 @@ Scopes and variables are represented by the buffer `vimspector.Variables`.
 
 ## Watches
 
+The watch window is used to inspect variables and expressions. Expressions are
+evaluated in the selected stack frame which is "focussed"
+
 The watches window is a prompt buffer, where that's available. Enter insert mode
 to add a new watch expression.
 
@@ -767,7 +770,7 @@ The watches are represented by the buffer `vimspector.StackTrace`.
 
 ### Watch autocompletion
 
-The watch prompt buffer  has its `omnifunc` set to a function that will
+The watch prompt buffer has its `omnifunc` set to a function that will
 calcualte completion for the current expression. This is trivailly used with
 `<Ctrl-x><Ctrl-o>` (see `:help ins-completion`), or integrated with your
 favourite completion system. The filetype in the buffer is set to
@@ -783,8 +786,28 @@ let g:ycm_semantic_triggers =  {
 
 ## Stack Traces
 
-* In the threads window, use `<CR>`, or double-click with left mouse to expand/collapse.
+The stack trace window shows the state of each progream thread. Threads which
+are stopped can be expanded to show the strack trace of that thread.
+
+Often, but not always, all threads are stopped when a breakpoint is hit. The
+status of a thread is show in parentheses after the thread's name. Where
+supported by the underlying debugger, threads can be paused and continued
+individually from within the Stack Trace window.
+
+A particular thread, highlighted with the `CursorLine` highlight group is the
+"focussed" thread. This is the thread that receives commands like "Stop In",
+"Stop Out", "Continue" and "Pause" in the code window. The focussed thread can
+be changed manually to "switch to" that thread.
+
+* Use `<CR>`, or double-click with left mouse to expand/collapse a thread stack
+  trace, or use the WinBar button.
 * Use `<CR>`, or double-click with left mouse on a stack frame to jump to it.
+* Use the WinBar or `vimspector#PauseContinueThread()` to individually pause or
+  continue the selected thread.
+* Use the "Focus" WinBar button, `<leader><CR>` or `vimspector#SetCurrentThread()`
+  to set the "focussed" thread to the currently selected one. If the selected
+  line is a stack frame, set the focussed thread to the thread of that frame and
+  jump to that frame in the code window.
 
 ![stack trace](https://puremourning.github.io/vimspector-web/img/vimspector-callstack-window.png)
 

python3/vimspector/stack_trace.py

@@ -110,6 +110,8 @@ class StackTraceView( object ):
     with utils.LetCurrentWindow( win ):
       vim.command( 'nnoremap <silent> <buffer> <CR> '
                    ':<C-U>call vimspector#GoToFrame()<CR>' )
+      vim.command( 'nnoremap <silent> <buffer> <leader><CR> '
+                   ':<C-U>call vimspector#SetCurrentThread()<CR>' )
       vim.command( 'nnoremap <silent> <buffer> <2-LeftMouse> '
                    ':<C-U>call vimspector#GoToFrame()<CR>' )
 
@@ -320,16 +322,22 @@ class StackTraceView( object ):
     thread = self._GetSelectedThread()
     return thread.id if thread else thread
 
+  def _SetCurrentThread( self, thread: Thread ):
+    self._current_thread = thread.id
+    self._DrawThreads()
 
   def SetCurrentThread( self ):
     thread = self._GetSelectedThread()
-    if not thread:
-      utils.UserMessage( "No thread selected" )
+    if thread:
+      self._SetCurrentThread( thread )
+    elif vim.current.buffer != self._buf:
+      return
+    elif vim.current.window.cursor[ 0 ] in self._line_to_frame:
+      thread, frame = self._line_to_frame[ vim.current.window.cursor[ 0 ] ]
+      self._SetCurrentThread( thread )
+      self._JumpToFrame( frame )
     else:
-      self._current_thread = thread.id
-
-    self._DrawThreads()
-
+      utils.UserMessage( "No thread selected" )
 
   def ExpandFrameOrThread( self ):
     thread = self._GetSelectedThread()
@@ -345,12 +353,15 @@ class StackTraceView( object ):
     elif vim.current.buffer != self._buf:
       return
     elif vim.current.window.cursor[ 0 ] in self._line_to_frame:
-      self._JumpToFrame( self._line_to_frame[ vim.current.window.cursor[ 0 ] ] )
+      thread, frame = self._line_to_frame[ vim.current.window.cursor[ 0 ] ]
+      self._JumpToFrame( frame )
 
 
   def _JumpToFrame( self, frame, reason = '' ):
     def do_jump():
       if 'line' in frame and frame[ 'line' ] > 0:
+        # Should this set the current _Thread_ too ? If i jump to a frame in
+        # Thread 2, should that become the focussed thread ?
         self._current_frame = frame
         return self._session.SetCurrentFrame( self._current_frame, reason )
       return False
@@ -469,7 +480,7 @@ class StackTraceView( object ):
                                        source[ 'name' ],
                                        frame[ 'line' ] ) )
 
-      self._line_to_frame[ line ] = frame
+      self._line_to_frame[ line ] = ( thread, frame )
 
   def _ResolveSource( self, source, and_then ):
     source_reference = int( source[ 'sourceReference' ] )

support/test/node/simple/simple.js

@@ -3,7 +3,7 @@ var msg = 'Hello, world!'
 var obj = {
   test: 'testing',
   toast: function() {
-    return 'toasty' . this.test;
+    return 'toasty' + this.test;
   }
 }