image_buttons

Ignore-this: 418dbf488435c7c803695407557eecfb

* Added a XMonad.Util.Image module to manipulate simple images
  and show them into an X drawable
* Added the possibility of using image buttons instead of plain
  text buttons into the title bar
* Added a XMonad.Layout.ImageButtonDecoration as an example of
  how to use the image buttons

darcs-hash:20100331093808-a84fe-e6d3ce505f7656eef13f0c0609a8d236d9cd8d25.gz

1 files changed, 93 insertions, 0 deletions

diff --git a/XMonad/Util/Image.hs b/XMonad/Util/Image.hs
new file mode 100644
index 0000000..fe42a17
--- /dev/null
+++ b/XMonad/Util/Image.hs
@@ -0,0 +1,93 @@
+----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Util.Image
+-- Copyright   :  (c) 2010 Alejandro Serrano
+-- License     :  BSD-style (see xmonad/LICENSE)
+--
+-- Maintainer  :  trupill@gmail.com
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- Utilities for manipulating [[Bool]] as images
+--
+-----------------------------------------------------------------------------
+
+module XMonad.Util.Image
+    ( -- * Usage:
+      -- $usage
+      Placement(..),
+      iconPosition,
+      drawIcon
+    ) where
+
+import XMonad
+import Graphics.X11.Xlib.Misc
+import Graphics.X11.Xlib.Types
+import XMonad.Util.Font (stringToPixel)
+
+-- | Placement of the icon in the title bar
+data Placement = OffsetLeft Int Int   -- ^ An exact amount of pixels from the upper left corner
+                 | OffsetRight Int Int  -- ^ An exact amount of pixels from the right left corner
+                 | CenterLeft Int        -- ^ Centered in the y-axis, an amount of pixels from the left
+                 | CenterRight Int       -- ^ Centered in the y-axis, an amount of pixels from the right
+                   deriving (Show, Read)
+                   
+-- $usage
+-- This module uses matrices of boolean values as images. When drawing them,
+-- a True value tells that we want the fore color, and a False value that we
+-- want the background color to be painted.
+-- In the module we suppose that those matrices are represented as [[Bool]],
+-- so the lengths of the inner lists must be the same.
+--
+-- See "Xmonad.Layout.Decoration" for usage examples
+
+-- | Gets the ('width', 'height') of an image
+imageDims :: [[Bool]] -> (Int, Int)
+imageDims img = (length (head img), length img)
+
+-- | Return the 'x' and 'y' positions inside a 'Rectangle' to start drawing
+--   the image given its 'Placement'
+iconPosition :: Rectangle -> Placement -> [[Bool]] -> (Position,Position)
+iconPosition (Rectangle _ _ _ _) (OffsetLeft x y) _ = (fi x, fi y)
+iconPosition (Rectangle _ _ w _) (OffsetRight x y) icon =
+  let (icon_w, _) = imageDims icon
+  in (fi w - fi x - fi icon_w, fi y)
+iconPosition (Rectangle _ _ _ h) (CenterLeft x) icon =
+  let (_, icon_h) = imageDims icon
+  in  (fi x, fi (h `div` 2) - fi (icon_h `div` 2))
+iconPosition (Rectangle _ _ w h) (CenterRight x) icon =
+  let (icon_w, icon_h) = imageDims icon
+  in  (fi w - fi x - fi icon_w, fi (h `div` 2) - fi (icon_h `div` 2))
+
+-- | Converts an image represented as [[Bool]] to a series of points
+--   to be painted (the ones with True values)
+iconToPoints :: [[Bool]] -> [Point]
+iconToPoints icon =
+  let labels_inside = map (zip (iterate (1+) 0)) icon
+      filtered_inside = map (\l -> [x | (x, t) <- l, t]) labels_inside
+      labels_outside = zip (iterate (1+) 0) filtered_inside
+  in [Point x y | (y, l) <- labels_outside, x <- l]
+
+-- | Displaces a point ('a', 'b') along a vector ('x', 'y')
+movePoint :: Position -> Position -> Point -> Point
+movePoint x y (Point a b) = Point (a + x) (b + y)
+
+-- | Displaces a list of points along a vector 'x', 'y'
+movePoints :: Position -> Position -> [Point] -> [Point]
+movePoints x y points = map (movePoint x y) points
+
+-- | Draw an image into a X surface
+drawIcon :: (Functor m, MonadIO m) => Display -> Drawable -> GC -> String
+            ->String -> Position -> Position -> [[Bool]] -> m ()
+drawIcon dpy drw gc fc bc x y icon = do
+  let (i_w, i_h) = imageDims icon
+  fcolor <- stringToPixel dpy fc
+  bcolor <- stringToPixel dpy bc
+  io $ setForeground dpy gc bcolor
+  io $ fillRectangle dpy drw gc x y (fi i_w) (fi i_h)
+  io $ setForeground dpy gc fcolor
+  io $ drawPoints dpy drw gc (movePoints x y (iconToPoints icon)) coordModeOrigin
+
+-- | Short-hand for 'fromIntegral'
+fi :: (Integral a, Num b) => a -> b
+fi = fromIntegral