Rewrite tweet screenshot functionality to use native methods

Core/Notification/Screenshot/FormNotificationScreenshotable.cs

@@ -4,6 +4,9 @@
 using TweetDck.Core.Bridge;
 using TweetDck.Core.Controls;
 using TweetDck.Resources;
+using System.Drawing;
+using System.Drawing.Imaging;
+using TweetDck.Core.Utils;
 
 namespace TweetDck.Core.Notification.Screenshot{
     sealed class FormNotificationScreenshotable : FormNotificationBase{
@@ -21,15 +24,30 @@ public void LoadNotificationForScreenshot(TweetNotification tweet, int width, in
             browser.LoadHtml(tweet.GenerateHtml(enableCustomCSS: false), "http://tweetdeck.twitter.com/?"+DateTime.Now.Ticks);
             
             Location = ControlExtensions.InvisibleLocation;
-            FormBorderStyle = Program.UserConfig.ShowScreenshotBorder ? FormBorderStyle.FixedToolWindow : FormBorderStyle.None;
-
             SetNotificationSize(width, height);
         }
 
         public void TakeScreenshotAndHide(){
             MoveToVisibleLocation();
-            Activate();
-            SendKeys.SendWait("%{PRTSC}");
+            
+            bool border = Program.UserConfig.ShowScreenshotBorder;
+            IntPtr context = NativeMethods.GetDeviceContext(this, border);
+
+            if (context == IntPtr.Zero){
+                MessageBox.Show("Could not retrieve a graphics context handle for the notification window to take the screenshot.", "Screenshot Failed", MessageBoxButtons.OK, MessageBoxIcon.Error);
+            }
+            else{
+                using(Bitmap bmp = new Bitmap(border ? Width : ClientSize.Width, border ? Height : ClientSize.Height, PixelFormat.Format32bppRgb)){
+                    try{
+                        NativeMethods.RenderSourceIntoBitmap(context, bmp);
+                    }finally{
+                        NativeMethods.ReleaseDeviceContext(this, context);
+                    }
+
+                    Clipboard.SetImage(bmp);
+                }
+            }
+
             Reset();
         }
 

Core/Notification/Screenshot/TweetScreenshotManager.cs

@@ -4,14 +4,11 @@
 
 namespace TweetDck.Core.Notification.Screenshot{
     sealed class TweetScreenshotManager : IDisposable{
-        private readonly FormBrowser browser;
         private readonly FormNotificationScreenshotable screenshot;
         private readonly Timer timeout;
 
-        public TweetScreenshotManager(FormBrowser browser){
-            this.browser = browser;
-
-            this.screenshot = new FormNotificationScreenshotable(Callback, browser, NotificationFlags.DisableContextMenu | NotificationFlags.TopMost){
+        public TweetScreenshotManager(Form owner){
+            this.screenshot = new FormNotificationScreenshotable(Callback, owner, NotificationFlags.DisableContextMenu | NotificationFlags.TopMost){
                 CanMoveWindow = () => false
             };
 
@@ -31,10 +28,7 @@ private void Callback(){
             }
 
             timeout.Stop();
-
-            browser.PauseNotification();
             screenshot.TakeScreenshotAndHide();
-            browser.ResumeNotification();
         }
 
         public void Dispose(){

Core/Utils/NativeMethods.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Drawing;
 using System.Runtime.InteropServices;
 using System.Windows.Forms;
 
@@ -45,6 +46,19 @@ private struct LASTINPUTINFO{
         [DllImport("user32.dll")]
         private static extern bool GetLastInputInfo(ref LASTINPUTINFO info);
 
+        [DllImport("user32.dll")]
+        private static extern IntPtr GetWindowDC(IntPtr hWnd);
+
+        [DllImport("user32.dll")]
+        private static extern IntPtr GetDC(IntPtr hWnd);
+
+        [DllImport("user32.dll")]
+        private static extern bool ReleaseDC(IntPtr hWnd, IntPtr hDC);
+
+        [DllImport("gdi32.dll")]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static extern bool BitBlt(IntPtr hdc, int nXDest, int nYDest, int nWidth, int nHeight, IntPtr hdcSrc, int nXSrc, int nYSrc, uint dwRop);
+
         [DllImport("user32.dll")]
         public static extern IntPtr SendMessage(IntPtr hWnd, uint msg, int wParam, IntPtr lParam);
 
@@ -106,5 +120,25 @@ public static int GetIdleSeconds(){
             int seconds = (int)Math.Floor(TimeSpan.FromMilliseconds(ticks-info.dwTime).TotalSeconds);
             return Math.Max(0, seconds); // ignore rollover after several weeks of uptime
         }
+
+        public static IntPtr GetDeviceContext(Form form, bool includeBorder){
+            return includeBorder ? GetWindowDC(form.Handle) : GetDC(form.Handle);
+        }
+
+        public static void RenderSourceIntoBitmap(IntPtr source, Bitmap target){
+            using(Graphics graphics = Graphics.FromImage(target)){
+                IntPtr graphicsHandle = graphics.GetHdc();
+
+                try{
+                    BitBlt(graphicsHandle, 0, 0, target.Width, target.Height, source, 0, 0, 0x00CC0020);
+                }finally{
+                    graphics.ReleaseHdc(graphicsHandle);
+                }
+            }
+        }
+
+        public static void ReleaseDeviceContext(Form form, IntPtr ctx){
+            ReleaseDC(form.Handle, ctx);
+        }
     }
 }