multigrid improvements:

1. correctly parse win_pos and win_float_pos
2. multigrid assumes client to preserve buffer content when resizing
3. implement destroy_grid
4. grid view doesn't kick in until both 1) viewmodel connected 2) visualtree attached
5. initial framebuffer setup without grid resize events

Properties/launchSettings.json

@@ -1,7 +1,8 @@
 {
  "profiles": {
  "fvim": {
- "commandName": "Project"
+ "commandName": "Project",
+ "commandLineArgs": "--debug-multigrid"
  },
  "norc": {
  "commandName": "Project",

ViewModels/EditorViewModel.fs

@@ -36,7 +36,7 @@ type EditorViewModel(_gridid: int, ?parent: EditorViewModel, ?_gridsize: GridSiz
 
  let m_cursor_vm = new CursorViewModel(_cursormode)
  let m_popupmenu_vm = new PopupMenuViewModel()
- let m_child_grids = ObservableCollection<EditorViewModel>()
+ let m_child_grids = ObservableCollection<IGridUI>()
  let m_resize_ev = Event<IGridUI>()
  let m_input_ev = Event<int * InputEvent>()
 
@@ -66,8 +66,20 @@ type EditorViewModel(_gridid: int, ?parent: EditorViewModel, ?_gridsize: GridSiz
  m_griddirty.Clear()
  m_griddirty.Union{ row = 0; col = 0; height = m_gridsize.rows; width = m_gridsize.cols }
 
- let clearBuffer () =
+ let clearBuffer preserveContent =
+ let oldgrid = m_gridbuffer
  m_gridbuffer <- Array2D.create m_gridsize.rows m_gridsize.cols GridBufferCell.empty
+ if preserveContent then
+ let crow = 
+ Array2D.length1 oldgrid
+ |> min m_gridsize.rows
+ let ccol = 
+ Array2D.length2 oldgrid
+ |> min m_gridsize.cols
+ for r = 0 to crow-1 do
+ for c = 0 to ccol-1 do
+ m_gridbuffer.[r,c] <- oldgrid.[r,c]
+ markAllDirty()
  // notify buffer update and size change
  let size: Point = this.GetPoint m_gridsize.rows m_gridsize.cols
  m_fb_w <- size.X
@@ -91,7 +103,7 @@ type EditorViewModel(_gridid: int, ?parent: EditorViewModel, ?_gridsize: GridSiz
  // if the buffer under cursor is updated, also notify the cursor view model
  if row = m_cursor_vm.row && line.col_start <= m_cursor_vm.col && m_cursor_vm.col < col
  then this.cursorConfig()
- //trace "redraw" "putBuffer: writing to %A" dirty
+ // trace _gridid "putBuffer: writing to %A" dirty
  // italic font artifacts I: remainders after scrolling and redrawing the dirty part
  // workaround: extend the dirty region one cell further towards the end
 
@@ -206,7 +218,7 @@ type EditorViewModel(_gridid: int, ?parent: EditorViewModel, ?_gridsize: GridSiz
  (* manually resize and position the child grid as per neovim docs *)
  let origin: Point = parent.GetPoint startrow startcol
  trace _gridid "setWinPos: update parameters: c = %d r = %d X = %f Y = %f" c r origin.X origin.Y
- this.initBuffer r c
+ this.initBuffer r c true
  this.X <- origin.X
  this.Y <- origin.Y
 
@@ -254,8 +266,8 @@ type EditorViewModel(_gridid: int, ?parent: EditorViewModel, ?_gridsize: GridSiz
  let redraw(cmd: RedrawCommand) =
  //trace "%A" cmd
  match cmd with
- | GridResize(_, c, r) -> this.initBuffer r c
- | GridClear _ -> clearBuffer()
+ | GridResize(_, c, r) -> this.initBuffer r c true
+ | GridClear _ -> clearBuffer false
  | GridLine lines -> Array.iter putBuffer lines
  | GridCursorGoto(id, row, col) -> cursorGoto id row col
  | GridScroll(_, top,bot,left,right,rows,cols) -> scrollBuffer top bot left right rows cols
@@ -318,6 +330,7 @@ type EditorViewModel(_gridid: int, ?parent: EditorViewModel, ?_gridsize: GridSiz
  trace _gridid "%s" "ctor"
  fontConfig()
  this.setCursorEnabled theme.cursor_enabled
+ clearBuffer false
 
  this.Watch [
 
@@ -355,12 +368,12 @@ type EditorViewModel(_gridid: int, ?parent: EditorViewModel, ?_gridsize: GridSiz
  member __.GetFontAttrs() =
  theme.guifont, theme.guifontwide, m_fontsize
 
- member private __.initBuffer nrow ncol =
+ member private __.initBuffer nrow ncol preserveContent =
  let new_gridsize = { rows = nrow; cols = ncol }
  if m_gridsize <> new_gridsize then
  m_gridsize <- new_gridsize
  trace _gridid "buffer resize = %A" m_gridsize
- clearBuffer()
+ clearBuffer preserveContent
 
  interface IGridUI with
  member __.Id = _gridid
@@ -375,6 +388,12 @@ type EditorViewModel(_gridid: int, ?parent: EditorViewModel, ?_gridsize: GridSiz
  let child = new EditorViewModel(id, this, {rows=r; cols=c}, Size(child_size.X, child_size.Y), m_gridscale, m_cursor_vm.modeidx)
  m_child_grids.Add child
  child :> IGridUI
+ member __.RemoveChild c =
+ ignore <| m_child_grids.Remove c
+ member __.Detach() =
+ match parent with
+ | None -> ()
+ | Some p -> (p:>IGridUI).RemoveChild this
 
  member __.markClean = m_griddirty.Clear
 

Views/Cursor.xaml.fs

@@ -137,6 +137,10 @@ type Cursor() as this =
  let cellw p = min (double(p) / 100.0 * this.Width) 1.0
  let cellh p = min (double(p) / 100.0 * this.Height) 5.0
  let scale = this.GetVisualRoot().RenderScaling
+
+ if this.ViewModel = Unchecked.defaultof<CursorViewModel> then ()
+ else
+
  match this.ViewModel.shape, this.ViewModel.cellPercentage with
  | CursorShape.Block, _ ->
  let _, typeface = GetTypeface(this.ViewModel.text, this.ViewModel.italic, this.ViewModel.bold, this.ViewModel.typeface, this.ViewModel.wtypeface)

Views/Editor.xaml.fs

@@ -44,8 +44,10 @@ type Editor() as this =
 
  let mutable m_debug = States.ui_multigrid
 
+ // !Only call this if VisualRoot is attached
  let resizeFrameBuffer() =
  trace grid_vm "resizeFrameBuffer bufw=%A bufh=%A" grid_vm.BufferWidth grid_vm.BufferHeight
+ let vroot = this.GetVisualRoot()
  grid_scale <- this.GetVisualRoot().RenderScaling
  if grid_fb <> null then 
  grid_fb.Dispose()
@@ -176,6 +178,7 @@ type Editor() as this =
  let onViewModelConnected(vm: EditorViewModel) =
  grid_vm <- vm
  trace grid_vm "%s" "viewmodel connected"
+ resizeFrameBuffer()
  vm.Watch
  [ Observable.merge (vm.ObservableForProperty(fun x -> x.BufferWidth))
  (vm.ObservableForProperty(fun x -> x.BufferHeight))
@@ -240,9 +243,13 @@ type Editor() as this =
 
  do
 
+
+
  this.Watch
  [ this.GetObservable(Editor.DataContextProperty)
  |> Observable.ofType
+ |> Observable.zip this.AttachedToVisualTree
+ |> Observable.map snd
  |> Observable.subscribe onViewModelConnected
 
  this.Bind(Canvas.LeftProperty, Binding("X"))

common.fs

@@ -75,6 +75,13 @@ let (|Integer32|_|) (x:obj) =
  | :? uint8 as x -> Some(int32 x)
  | _ -> None
 
+let (|Float|_|) (x:obj) =
+ match x with
+ | Integer32 x -> Some(float x)
+ | :? single as x -> Some(float x)
+ | :? float as x -> Some(float x)
+ | _ -> None
+
 // converts to bool in a desperate (read: JavaScript) attempt
 let (|ForceBool|_|) (x:obj) =
  match x with

def.fs

@@ -262,7 +262,7 @@ type RedrawCommand =
 /// displayed above another grid `anchor_grid` at the specified position
 /// `anchor_row` and `anchor_col`. For the meaning of `anchor` and more
 /// details of positioning, see |nvim_open_win()|.
-| WinFloatPos of grid: int * win: int * anchor: Anchor * anchor_grid: int * anchor_row: int * anchor_col: int * focusable: bool
+| WinFloatPos of grid: int * win: int * anchor: Anchor * anchor_grid: int * anchor_row: float * anchor_col: float * focusable: bool
 /// Display or reconfigure external window `win`. The window should be
 /// displayed as a separate top-level window in the desktop environment,
 /// or something similar.
@@ -315,6 +315,7 @@ type RedrawCommand =
 //| UpdateBg of Color
 //| UpdateSp of Color
 | UnknownCommand of data: obj
+| MultiRedrawCommand of xs: RedrawCommand []
 
 type EventParseException(data: obj) =
  inherit exn()
@@ -344,6 +345,15 @@ let (|P|_|) (parser: obj -> 'a option) (xs:obj) =
  Some result
  | _ -> None
 
+/// Chooses from ObjArray with a parser
+let (|PX|_|) (parser: obj -> 'a option) (xs:obj) =
+ match xs with
+ | :? (obj seq) as xs ->
+ let result = Seq.choose parser xs |> Array.ofSeq
+ if Seq.length xs = Seq.length result then Some result
+ else None
+ | _ -> None
+
 /// Matches ObjArray against the form [|key; value|]
 let (|KV|_|) (k: string) (x: obj) =
  match x with
@@ -492,6 +502,12 @@ let parse_grid_line (x: obj) =
  -> Some {grid = grid; row=row; col_start=col_start; cells=cells}
  | _ -> None
 
+let parse_win_pos (x: obj) =
+ match x with
+ | ObjArray [| (Integer32 grid); (Integer32 win); (Integer32 start_row); (Integer32 start_col); (Integer32 width); (Integer32 height) |] 
+ -> Some <| WinPos(grid, win, start_row, start_col, width, height)
+ | _ -> None
+
 let (|Anchor|_|) =
  function
  | String "NE" -> Some NorthEast
@@ -500,6 +516,12 @@ let (|Anchor|_|) =
  | String "SW" -> Some SouthWest
  | _ -> None
 
+let parse_win_float_pos (x: obj) =
+ match x with
+ | ObjArray [| (Integer32 grid); (Integer32 win); (Anchor anchor); (Integer32 anchor_grid); (Float anchor_row); (Float anchor_col); (Bool focusable) |] 
+ -> Some <| WinFloatPos(grid, win, anchor, anchor_grid, anchor_row, anchor_col, focusable)
+ | _ -> None
+
 let parse_complete_item =
  function
  | ObjArray [| (String word); (String abbr); (String menu); (String info) |] -> 
@@ -522,6 +544,11 @@ let parse_semantic_hlgroup =
  | _ -> None
  | _ -> None
 
+let unwrap_multi xs =
+ match xs with
+ | [| one |] -> one
+ | _ -> MultiRedrawCommand xs
+
 let parse_redrawcmd (x: obj) =
  match x with
  | C("option_set", P(parse_uioption)options) -> SetOption options
@@ -548,15 +575,8 @@ let parse_redrawcmd (x: obj) =
  (Integer32 left); (Integer32 right) 
  (Integer32 rows); (Integer32 cols) |]) -> GridScroll(grid, top, bot, left, right, rows, cols)
  | C("grid_line", P(parse_grid_line)lines) -> GridLine lines
- | C1("win_pos", [| 
- (Integer32 grid); (Integer32 win) 
- (Integer32 start_row); (Integer32 start_col)
- (Integer32 width); (Integer32 height) |]) -> WinPos(grid,win,start_row,start_col,width,height)
- | C1("win_float_pos", [| 
- (Integer32 grid); (Integer32 win)
- (Anchor anchor); (Integer32 anchor_grid)
- (Integer32 anchor_row); (Integer32 anchor_col)
- (Bool focusable) |]) -> WinFloatPos(grid, win, anchor, anchor_grid, anchor_row, anchor_col, focusable)
+ | C("win_pos", PX(parse_win_pos)ps) -> unwrap_multi ps
+ | C("win_float_pos", PX(parse_win_float_pos)ps) -> unwrap_multi ps
  | C1("win_external_pos", [| 
  (Integer32 grid); (Integer32 win) |]) -> WinExternalPos(grid, win)
  | C1("win_hide", [| (Integer32 grid) |]) -> WinHide(grid)

fvim.fsproj

@@ -78,11 +78,11 @@
  </ItemGroup>
 
  <ItemGroup>
- <PackageReference Include="Avalonia" Version="0.9.9" />
+ <PackageReference Include="Avalonia" Version="0.9.11" />
  <PackageReference Include="Avalonia.Angle.Windows.Natives" Version="2.1.0.2019013001" />
- <PackageReference Include="Avalonia.Desktop" Version="0.9.9" />
- <PackageReference Include="Avalonia.ReactiveUI" Version="0.9.9" />
- <PackageReference Include="FSharp.Control.Reactive" Version="4.2.0" />
+ <PackageReference Include="Avalonia.Desktop" Version="0.9.11" />
+ <PackageReference Include="Avalonia.ReactiveUI" Version="0.9.11" />
+ <PackageReference Include="FSharp.Control.Reactive" Version="4.4.2" />
  <PackageReference Include="FSharp.Data" Version="3.3.3" />
  <PackageReference Include="GitInfo" Version="2.0.26">
  <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
@@ -98,7 +98,7 @@
  </PackageReference>
  <PackageReference Include="SkiaSharp.HarfBuzz" Version="1.68.0" />
  <PackageReference Include="TaskBuilder.fs" Version="2.1.0" />
- <PackageReference Update="FSharp.Core" Version="4.7.1" />
+ <PackageReference Update="FSharp.Core" Version="4.7.2" />
  <PackageReference Include="UACHelper" Version="1.3.0.5" />
  </ItemGroup>
 

model.fs

@@ -42,7 +42,13 @@ module ModelImpl =
  // by default add to grid #1
  (*if id <> 1 then*)
  (*ignore <| grids.[1].AddChild id r c*)
-
+
+ let destroy_grid(id) =
+ match grids.TryGetValue id with
+ | false, _ -> ()
+ | true, grid ->
+ ignore <| grids.Remove id
+ grid.Detach()
 
  let add_window(win: IWindow) = 
  let id = win.RootId
@@ -67,11 +73,10 @@ module ModelImpl =
  if RuntimeInformation.IsOSPlatform(OSPlatform.OSX) then id
  else Observable.throttle(TimeSpan.FromMilliseconds 10.0)
 
- let redraw cmd = 
+ let rec redraw cmd = 
  match cmd with
  // Global
  | UnknownCommand x -> trace "unknown command %A" x
- | GridDestroy id -> trace "GridDestroy %d" id //TODO
  | SetTitle title -> setTitle 1 title
  | SetIcon icon -> trace "icon: %s" icon // TODO
  | Bell -> bell true
@@ -87,25 +92,30 @@ module ModelImpl =
  | Busy _ | Mouse _
  | ModeChange _ | Flush 
  | GridCursorGoto(_,_,_) 
- -> broadcast cmd
+  -> broadcast cmd
  // Unicast
- | GridClear id | GridScroll(id,_,_,_,_,_,_)
- -> unicast id cmd
- | MsgSetPos(id, _, _, _) ->
- if not(grids.ContainsKey id) then
- add_grid <| grids.[1].AddChild id 1 grids.[1].GridWidth
- unicast id cmd
+ | GridClear id | GridScroll(id,_,_,_,_,_,_) ->
+ unicast id cmd
+ | WinFloatPos(id, _, _, _, _, _, _) -> 
+ trace "win_float_pos %A" cmd
+ unicast id cmd
+ | MsgSetPos(id, _, _, _) ->
+ if not(grids.ContainsKey id) then
+ add_grid <| grids.[1].AddChild id 1 grids.[1].GridWidth
+ unicast id cmd
  | WinPos(id, _, _, _, w, h)
- | GridResize(id, w, h) 
- -> 
+ | GridResize(id, w, h) -> 
  if not(grids.ContainsKey id) then
  add_grid <| grids.[1].AddChild id h w
  unicast id cmd
- | GridLine lines -> 
+ | GridLine lines  -> 
  lines 
  |> Array.groupBy (fun (line: GridLine) -> line.grid)
  |> Array.iter (fun (id, lines) -> unicast id (GridLine lines))
- | x -> trace "unimplemented command: %A" x
+ | GridDestroy id -> trace "GridDestroy %d" id; destroy_grid id
+ | WinClose id -> trace "WinClose %d (unimplemented)" id // TODO
+ | MultiRedrawCommand xs -> Array.iter redraw xs
+ | x -> trace "unimplemented command: %A" x
 
  let onGridResize(gridui: IGridUI) =
  trace "Grid #%d resized to %d %d" gridui.Id gridui.GridWidth gridui.GridHeight

ui.fs

@@ -126,6 +126,8 @@ type IGridUI =
  abstract HasChildren: bool
  abstract Redraw: RedrawCommand -> unit
  abstract AddChild: int -> int -> int -> IGridUI
+ abstract RemoveChild: IGridUI -> unit
+ abstract Detach: unit -> unit
 
 type IWindow =
  abstract Title: string with get, set