From: Matthijs Kooijman <matthijs@stdin.nl>
Date: Mon, 24 Aug 2009 19:55:02 +0000 (+0200)
Subject: Resize the backbuffer when the window is resized.
X-Git-Url: https://git.stderr.nl/gitweb?a=commitdiff_plain;h=34b8f3ca223d5404d5f298e5fe9eb41c4002f0cb;p=matthijs%2Fprojects%2Ffpprac.git

Resize the backbuffer when the window is resized.
---

diff --git a/FPPrac.hs b/FPPrac.hs
index 14e8c4f..7e5a691 100644
--- a/FPPrac.hs
+++ b/FPPrac.hs
@@ -162,8 +162,9 @@ runGUI w h (IS { .. }) = do
 	buffer' <- Cairo.createImageSurface Cairo.FormatARGB32 w h
 	buffer <- newIORef buffer'
 
-	-- Register the expose event
+	-- Register events
 	Gtk.on window Gtk.exposeEvent $ onExpose buffer
+	Gtk.on window Gtk.configureEvent $ onResize buffer
 
 	-- Repack state
 	let state = IS { .. }
@@ -187,6 +188,32 @@ onExpose buffer = do
 		Cairo.paint
 	return True -- No clue what this means
 
+-- | Called when the window is resized. Resize the given buffer if needed.
+onResize :: IORef Cairo.Surface -> EventM.EventM EventM.EConfigure Bool
+onResize buffer = do
+	-- Get the current buffer and see if it's still big enough
+	current_buffer <- liftIO $ readIORef buffer
+	sw <- Cairo.imageSurfaceGetWidth current_buffer
+	sh <- Cairo.imageSurfaceGetHeight current_buffer
+	-- Get the current drawwindow and its size
+	dw <- EventM.eventWindow
+	(w, h) <- liftIO $ Gtk.drawableGetSize dw
+	when (w > sw || h > sh) $ liftIO $ do
+		-- Buffer is too small, expand it.
+		new_buffer <- Cairo.createImageSurface Cairo.FormatARGB32 w h
+		-- Fill it with white and copy the old buffer
+		Cairo.renderWith new_buffer $ do
+			Cairo.setSourceRGB 1 1 1
+			Cairo.paint
+			Cairo.setSourceSurface current_buffer 0 0
+			Cairo.paint
+		-- Clean up the old buffer
+		Cairo.surfaceFinish current_buffer
+		-- Store and return the new buffer
+		writeIORef buffer new_buffer
+	return True -- No clue what this means
+				
+
 {-
 runGUI s IS {..} = do
 	sFrame <- frame