add scaffolding in imperative shell to help update canvas width and height

fcore/normal-mode.sml

@@ -252,8 +252,9 @@ struct
   fun updateBlue model = (AppWith.b model, [])
   fun updateAlpha model = (AppWith.a model, [])
 
-  fun updateCanvasWidth (model, newCanvasWidth) =
+  fun updateCanvasWidth model =
     let
+      val newCanvasWidth = #modalNum model
       val model = AppWith.canvasWidth (model, newCanvasWidth)
 
       val
@@ -322,7 +323,7 @@ struct
     | KEY_G => updateGreen model
     | KEY_B => updateBlue model
     | KEY_A => updateAlpha model
-    | KEY_W newCanvasWidth => updateCanvasWidth (model, newCanvasWidth)
+    | KEY_W => updateCanvasWidth model
     | RESIZE_WINDOW {width, height} => resizeWindow (model, width, height)
     | UNDO_ACTION => undoAction model
     | REDO_ACTION => redoAction model

ffi/glfw-input.c

@@ -20,6 +20,7 @@ int KEY_I = GLFW_KEY_I;
 int KEY_L = GLFW_KEY_L;
 int KEY_O = GLFW_KEY_O;
 int KEY_A = GLFW_KEY_A;
+int KEY_W = GLFW_KEY_W;
 
 int KEY_ENTER = GLFW_KEY_ENTER;
 int KEY_SPACE = GLFW_KEY_SPACE;

ffi/glfw-input.sml

@@ -57,6 +57,8 @@ struct
     _symbol "KEY_O" public : ( unit -> int ) * ( int -> unit );
   val (KEY_A, _) =
     _symbol "KEY_A" public : ( unit -> int ) * ( int -> unit );
+  val (KEY_W, _) =
+    _symbol "KEY_W" public : ( unit -> int ) * ( int -> unit );
 
   val (KEY_ENTER, _) =
     _symbol "KEY_ENTER" public : ( unit -> int ) * ( int -> unit );

imperative-shell/input-callbacks.sml

@@ -72,6 +72,10 @@ struct
       key = Input.KEY_A () andalso action = Input.PRESS () andalso mods = 0
     then
       Mailbox.send (mailbox, KEY_A)
+    else if
+      key = Input.KEY_W () andalso action = Input.PRESS () andalso mods = 0
+    then
+      Mailbox.send (mailbox, KEY_W)
     else if
       key = Input.KEY_UP () andalso action <> Input.RELEASE ()
       andalso mods = 0x0

message-types/input-msg.sml

@@ -12,7 +12,7 @@ struct
   | KEY_B
   | KEY_T
   | KEY_A
-  | KEY_W of int
+  | KEY_W
   | KEY_CTRL_S
   | KEY_CTRL_L
   | KEY_CTRL_E