Add basic support for tables with fixed-size cell contents

brick.cabal

@@ -105,6 +105,7 @@ library
     Brick.Widgets.FileBrowser
     Brick.Widgets.List
     Brick.Widgets.ProgressBar
+    Brick.Widgets.Table
     Data.IMap
     Data.Text.Markup
   other-modules:
@@ -139,6 +140,19 @@ library
   if impl(ghc < 8.0)
     build-depends:     semigroups
 
+executable brick-table-demo
+  if !flag(demos)
+    Buildable: False
+  hs-source-dirs:      programs
+  ghc-options:         -threaded -Wall -Wcompat -O2
+  default-language:    Haskell2010
+  default-extensions:  CPP
+  main-is:             TableDemo.hs
+  build-depends:       base,
+                       brick,
+                       text,
+                       vty
+
 executable brick-tail-demo
   if !flag(demos)
     Buildable: False

programs/TableDemo.hs

@@ -0,0 +1,15 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE CPP #-}
+module Main where
+
+#if !(MIN_VERSION_base(4,11,0))
+import Data.Monoid ((<>))
+#endif
+import Brick
+import Brick.Widgets.Table
+
+ui :: Widget ()
+ui = table [[txt "foo", txt "bar"], [txt "stuff", txt "more things"]]
+
+main :: IO ()
+main = simpleMain ui

src/Brick/Widgets/Table.hs

@@ -0,0 +1,35 @@
+module Brick.Widgets.Table
+  ( table
+  )
+where
+
+import Control.Monad (forM)
+import Data.List (transpose, intersperse)
+import Graphics.Vty (imageHeight, imageWidth)
+
+import Brick.Types
+import Brick.Widgets.Core
+import Brick.Widgets.Border
+
+table :: [[Widget n]] -> Widget n
+table [] = emptyWidget
+table rows =
+    joinBorders $ border $ Widget Fixed Fixed $ do
+        cellResults <- forM rows $ mapM render
+        let rowHeights = rowHeight <$> cellResults
+            colWidths = colWidth <$> byColumn
+            rowHeight = maximum . fmap (imageHeight . image)
+            colWidth = maximum . fmap (imageWidth . image)
+            byColumn = transpose cellResults
+            toW = Widget Fixed Fixed . return
+            totalHeight = sum rowHeights
+            mkColumn (width, colCells) = do
+                paddedCells <- forM (zip rowHeights colCells) $ \(height, cell) ->
+                    render $ padBottom (Pad (height - (imageHeight $ image cell)))
+                        (toW cell)
+                render $ vBox $ intersperse (hLimit width hBorder) $
+                    toW <$> paddedCells
+        columns <- mapM mkColumn $ zip colWidths byColumn
+        render $ hBox $
+            intersperse (vLimit (totalHeight + (length rows - 1)) vBorder) $
+            toW <$> columns