Initial commit

Author: pdulvp

.gitignore

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+obj
+bin
+.vs

Class1.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PatchManager
+{
+    public class RichTextBoxRedrawHandler
+    {
+        RichTextBox rtb;
+
+        public RichTextBoxRedrawHandler(RichTextBox _rtb)
+        {
+            rtb = _rtb;
+        }
+        [DllImport("user32.dll")]
+        private static extern IntPtr SendMessage(IntPtr hWnd, int wMsg, int wParam, ref Point lParam);
+
+        [DllImport("user32.dll")]
+        private static extern IntPtr SendMessage(IntPtr hWnd, int wMsg, int wParam, IntPtr lParam);
+
+        const int WM_USER = 1024;
+        const int WM_SETREDRAW = 11;
+        const int EM_GETEVENTMASK = WM_USER + 59;
+        const int EM_SETEVENTMASK = WM_USER + 69;
+        const int EM_GETSCROLLPOS = WM_USER + 221;
+        const int EM_SETSCROLLPOS = WM_USER + 222;
+
+        private Point _ScrollPoint;
+        private bool _Painting = true;
+        private IntPtr _EventMask;
+        private int _SuspendIndex = 0;
+        private int _SuspendLength = 0;
+
+        public void SuspendPainting()
+        {
+            if (_Painting)
+            {
+                _SuspendIndex = rtb.SelectionStart;
+                _SuspendLength = rtb.SelectionLength;
+                SendMessage(rtb.Handle, EM_GETSCROLLPOS, 0, ref _ScrollPoint);
+                SendMessage(rtb.Handle, WM_SETREDRAW, 0, IntPtr.Zero);
+                _EventMask = SendMessage(rtb.Handle, EM_GETEVENTMASK, 0, IntPtr.Zero);
+                _Painting = false;
+            }
+        }
+
+        public void ResumePainting()
+        {
+            if (!_Painting)
+            {
+                rtb.Select(_SuspendIndex, _SuspendLength);
+                SendMessage(rtb.Handle, EM_SETSCROLLPOS, 0, ref _ScrollPoint);
+                SendMessage(rtb.Handle, EM_SETEVENTMASK, 0, _EventMask);
+                SendMessage(rtb.Handle, WM_SETREDRAW, 1, IntPtr.Zero);
+                _Painting = true;
+                rtb.Invalidate();
+            }
+
+        }
+    }
+}