Don't change the value of equalalways

We were trying to avoid equalalways from changing the UI layout by
unsetting it and resetting it after changes. However, re-setting
equalalways actually resizes all the windows, so this never worked.

Instead we judiciously use rightbelow, leftabove, etc. and specify the
exact window sizes we want.

As a side-effect we make the terminal sizing a little more pleasant by
default, ensuring that it is no wider than 80 chars, and tries to use
any remianing vertical space after reserving 80 chars for the code
window.

autoload/vimspector/internal/neoterm.vim

@@ -48,7 +48,7 @@ endfunction
 function! vimspector#internal#neoterm#Start( cmd, opts ) abort
   " Prepare current buffer to be turned into a term if curwin is not set
   if ! get( a:opts, 'curwin', 0 )
-    let mods = ''
+    let mods = 'rightbelow '
     if get( a:opts, 'vertical', 0 )
       let mods .= 'vertical '
       let mods .= get( a:opts, 'term_cols', '' )

autoload/vimspector/internal/term.vim

@@ -20,7 +20,7 @@ set cpoptions&vim
 " }}}
 
 function! vimspector#internal#term#Start( cmd, opts ) abort
-  return term_start( a:cmd, a:opts )
+  rightbelow return term_start( a:cmd, a:opts )
 endfunction
 
 function! vimspector#internal#term#IsFinished( bufno ) abort

python3/vimspector/code.py

@@ -233,24 +233,33 @@ class CodeView( object ):
 
     if self._terminal_window is not None and self._terminal_window.valid:
       assert self._terminal_buffer_number
+      window_for_start = self._terminal_window
       if ( self._terminal_window.buffer.number == self._terminal_buffer_number
            and int( utils.Call( 'vimspector#internal#{}term#IsFinished'.format(
                                   self._api_prefix ),
                                 self._terminal_buffer_number ) ) ):
-        window_for_start = self._terminal_window
         options[ 'curwin' ] = 1
+      else:
+        options[ 'vertical' ] = 0
 
     buffer_number = None
     terminal_window = None
-    with utils.TemporaryVimOptions( { 'splitright': True,
-                                      'equalalways': False } ):
-      with utils.LetCurrentWindow( window_for_start ):
-        buffer_number = int(
-          utils.Call(
-            'vimspector#internal#{}term#Start'.format( self._api_prefix ),
-            args,
-            options ) )
-        terminal_window = vim.current.window
+    with utils.LetCurrentWindow( window_for_start ):
+      # If we're making a vertical split from the code window, make it no more
+      # than 80 columns and no fewer than 10. Also try and keep the code window
+      # at least 82 columns
+      if options[ 'vertical' ] and not options.get( 'curwin', 0 ):
+        options[ 'term_cols' ] = max(
+          min ( int( vim.eval( 'winwidth( 0 ) - 82' ) ), 80 ),
+          10
+        )
+
+      buffer_number = int(
+        utils.Call(
+          'vimspector#internal#{}term#Start'.format( self._api_prefix ),
+          args,
+          options ) )
+      terminal_window = vim.current.window
 
     if buffer_number is None or buffer_number <= 0:
       # TODO: Do something better like reject the request?

python3/vimspector/debug_session.py

@@ -487,39 +487,39 @@ class DebugSession( object ):
     self._codeView = code.CodeView( code_window, self._api_prefix )
 
     # Call stack
-    with utils.TemporaryVimOptions( { 'splitright':  False,
-                                      'equalalways': False, } ):
-      vim.command( 'topleft vertical 50new' )
-      stack_trace_window = vim.current.window
-      self._stackTraceView = stack_trace.StackTraceView( self,
-                                                         self._connection,
-                                                         stack_trace_window )
+    vim.command( 'topleft vertical 50new' )
+    stack_trace_window = vim.current.window
+    one_third = int( vim.eval( 'winheight( 0 )' ) ) / 3
+    self._stackTraceView = stack_trace.StackTraceView( self,
+                                                       self._connection,
+                                                       stack_trace_window )
 
-    with utils.TemporaryVimOptions( { 'splitbelow':  False,
-                                      'eadirection': 'ver',
-                                      'equalalways': True } ):
-      # Watches
-      vim.command( 'new' )
-      watch_window = vim.current.window
+    # Watches
+    vim.command( 'leftabove new' )
+    watch_window = vim.current.window
 
-      # Variables
-      vim.command( 'new' )
-      vars_window = vim.current.window
+    # Variables
+    vim.command( 'leftabove new' )
+    vars_window = vim.current.window
 
-      self._variablesView = variables.VariablesView( self._connection,
-                                                     vars_window,
-                                                     watch_window )
+    with utils.LetCurrentWindow( vars_window ):
+      vim.command( f'{ one_third }wincmd _' )
+    with utils.LetCurrentWindow( watch_window ):
+      vim.command( f'{ one_third }wincmd _' )
+    with utils.LetCurrentWindow( stack_trace_window ):
+      vim.command( f'{ one_third }wincmd _' )
 
+    self._variablesView = variables.VariablesView( self._connection,
+                                                   vars_window,
+                                                   watch_window )
 
-    with utils.TemporaryVimOption( 'splitbelow', True ):
-      vim.current.window = code_window
-
-      # Output/logging
-      vim.command( '10new' )
-      output_window = vim.current.window
-      self._outputView = output.OutputView( self._connection,
-                                            output_window,
-                                            self._api_prefix )
+    # Output/logging
+    vim.current.window = code_window
+    vim.command( 'rightbelow 10new' )
+    output_window = vim.current.window
+    self._outputView = output.OutputView( self._connection,
+                                          output_window,
+                                          self._api_prefix )
 
     # TODO: If/when we support multiple sessions, we'll need some way to
     # indicate which tab was created and store all the tabs