From 980d9d7ea78ec3d93cced0713ef88428bf27fe80 Mon Sep 17 00:00:00 2001
From: Craig Oates <craig@craigoates.net>
Date: Tue, 11 Sep 2018 02:33:19 +0100
Subject: [PATCH] make public function in library asynchronous. Adds initial
 workings of a function to save image to stream in library.

---
 DeathSocket/Domain.fs        |  9 +++++++++
 DeathSocket/GridPainter.fs   | 12 +++++++-----
 DeathSocket/ImageServices.fs | 16 +++++++++++++++-
 DeathSocket/ScratchPad.fsx   |  2 +-
 4 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/DeathSocket/Domain.fs b/DeathSocket/Domain.fs
index e181d0c..04be768 100644
--- a/DeathSocket/Domain.fs
+++ b/DeathSocket/Domain.fs
@@ -4,6 +4,7 @@
     module Domain =
 
         open System.Drawing
+        open System.Drawing.Imaging
 
         type ImageSpec =
             { originalPath: string;
@@ -11,4 +12,12 @@
               colour: Brush; 
               penWidth: float32 
               rows: int;
+              columns: int }
+
+        type StreamSpec =
+            { imagePath: string;
+              format: ImageFormat;
+              colour: Brush; 
+              penWidth: float32 
+              rows: int;
               columns: int }
\ No newline at end of file
diff --git a/DeathSocket/GridPainter.fs b/DeathSocket/GridPainter.fs
index 643ba5b..f24c2ef 100644
--- a/DeathSocket/GridPainter.fs
+++ b/DeathSocket/GridPainter.fs
@@ -8,9 +8,11 @@ namespace DeathSocket
         open ImageServices
 
         let applyGrid spec =
-            try
-                validateFilePath |> ignore
-                drawGrid spec |> ignore
-            with
-            | :? FileNotFoundException as ex -> printfn"%s" ex.Message
+            async {
+                try
+                    validateFilePath |> ignore
+                    drawGrid spec |> ignore
+                with
+                | :? FileNotFoundException as ex -> printfn"%s" ex.Message
+            }
             
\ No newline at end of file
diff --git a/DeathSocket/ImageServices.fs b/DeathSocket/ImageServices.fs
index 05815bf..9b621fc 100644
--- a/DeathSocket/ImageServices.fs
+++ b/DeathSocket/ImageServices.fs
@@ -3,6 +3,7 @@
     open System.Drawing
     open System.Drawing.Imaging
     open DeathSocket
+    open System.IO
 
     let createHorizontalLines width height rows =
         let interval = width / rows
@@ -29,4 +30,17 @@
         img.Dispose ()
         graphics.Dispose ()
         pen.Dispose ()
-        ()
\ No newline at end of file
+
+    let drawGridToStream (imgStream: Stream) spec =
+        let img = Bitmap.FromFile (spec.imagePath)
+        let graphics = Graphics.FromImage img
+        let pen = new Pen (spec.colour, width = spec.penWidth)
+        let horizontalLines =
+            createHorizontalLines (img.Size.Width) (img.Size.Height) (spec.columns)
+        let verticalLines = createVerticalLines (img.Size.Height) (spec.columns)
+        for line in horizontalLines do graphics.DrawLines (pen, line)
+        for line in verticalLines do graphics.DrawLines (pen, line)
+        graphics.Dispose ()
+        pen.Dispose ()
+        img.Save (imgStream, spec.format)
+        img.Dispose ()
\ No newline at end of file
diff --git a/DeathSocket/ScratchPad.fsx b/DeathSocket/ScratchPad.fsx
index ed5ad1a..fa5b9cd 100644
--- a/DeathSocket/ScratchPad.fsx
+++ b/DeathSocket/ScratchPad.fsx
@@ -59,4 +59,4 @@ let spec =
       penWidth = float32 (10)
       rows = 10
       columns = 10 }
-GridPainter.applyGrid spec
\ No newline at end of file
+GridPainter.applyGrid spec |> Async.RunSynchronously