Implement support for the new PositionOnly constructor

The API putCursor will request positioning but keep cursor invisible.

brick.cabal

@@ -115,7 +115,7 @@ library
     Brick.Widgets.Internal
 
   build-depends:       base < 4.16.0.0,
-                       vty >= 5.31,
+                       vty >= 5.33,
                        transformers,
                        data-clist >= 0.1,
                        directory >= 1.2.5.0,

src/Brick/Main.hs

@@ -441,8 +441,11 @@ renderApp vty app appState rs = do
                                         rs
         picWithCursor = case theCursor of
             Nothing -> pic { picCursor = NoCursor }
-            Just cloc -> pic { picCursor = AbsoluteCursor (cloc^.locationColumnL)
+            Just cloc -> pic { picCursor = (if cursorLocationVisible cloc
-                                                          (cloc^.locationRowL)
+                                            then AbsoluteCursor
+                                            else PositionOnly True)
+                                           (cloc^.locationColumnL)
+                                           (cloc^.locationRowL)
                              }
 
     update vty picWithCursor

src/Brick/Types/Internal.hs

@@ -19,6 +19,7 @@ module Brick.Types.Internal
   , CursorLocation(..)
   , cursorLocationL
   , cursorLocationNameL
+  , cursorLocationVisibleL
   , Context(..)
   , EventState(..)
   , EventRO(..)
@@ -164,6 +165,8 @@ data CursorLocation n =
                    -- ^ The location
                    , cursorLocationName :: !(Maybe n)
                    -- ^ The name of the widget associated with the location
+                   , cursorLocationVisible :: !Bool
+                   -- ^ Weather the cursor should actually be visible
                    }
                    deriving (Read, Show, Generic, NFData)
 

src/Brick/Widgets/Core.hs

@@ -59,6 +59,7 @@ module Brick.Widgets.Core
 
   -- * Cursor placement
   , showCursor
+  , putCursor
 
   -- * Naming
   , Named(..)
@@ -994,7 +995,16 @@ showCursor :: n -> Location -> Widget n -> Widget n
 showCursor n cloc p =
     Widget (hSize p) (vSize p) $ do
       result <- render p
-      return $ result & cursorsL %~ (CursorLocation cloc (Just n):)
+      return $ result & cursorsL %~ (CursorLocation cloc (Just n) True:)
+
+-- | When rendering the specified widget, also register a cursor
+-- positioning request using the specified name and location.
+-- The cursor will only be positioned but not made visible.
+putCursor :: n -> Location -> Widget n -> Widget n
+putCursor n cloc p =
+    Widget (hSize p) (vSize p) $ do
+      result <- render p
+      return $ result & cursorsL %~ (CursorLocation cloc (Just n) False:)
 
 hRelease :: Widget n -> Maybe (Widget n)
 hRelease p =

src/Brick/Widgets/FileBrowser.hs

@@ -798,7 +798,7 @@ renderFileInfo foc maxLen selFiles n listSel info =
         addAttr = maybe id (withDefAttr . attrForFileType) (fileInfoFileType info)
         body = addAttr (hLimit (maxLen + 1) $
                padRight Max $
-               (if foc && listSel then showCursor n (Location (0,0)) else id) $
+               (if foc && listSel then putCursor n (Location (0,0)) else id) $
                str $ fileInfoSanitizedFilename info <> suffix)
         suffix = (if fileInfoFileType info == Just Directory then "/" else "") <>
                  (if sel then "*" else "")