Fixed two issues with the adorner resize, sometime the initial value wasn't set and also there were some drawing artifacts. Still needs testing though.

Greenshot/Drawing/Adorners/AbstractAdorner.cs

@@ -1,20 +1,20 @@
 /*
  * Greenshot - a free and open source screenshot tool
  * Copyright (C) 2007-2020 Thomas Braun, Jens Klingen, Robin Krom
- * 
+ *
  * For more information see: http://getgreenshot.org/
  * The Greenshot project is hosted on Sourceforge: http://sourceforge.net/projects/greenshot/
- * 
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 1 of the License, or
  * (at your option) any later version.
- * 
+ *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
@@ -32,11 +32,12 @@ namespace Greenshot.Drawing.Adorners
 	{
 		public virtual EditStatus EditStatus { get; protected set; } = EditStatus.IDLE;
 
-		private static readonly Size defaultSize = new Size(6, 6);
-		protected Size _size = defaultSize;
+		private static readonly Size DefaultSize = new Size(6, 6);
+		protected Size _size;
 
 		public AbstractAdorner(IDrawableContainer owner)
 		{
+			_size = DpiHelper.ScaleWithDpi(DefaultSize, 0);
 			Owner = owner;
 		}
 
@@ -144,10 +145,10 @@ namespace Greenshot.Drawing.Adorners
 		/// <summary>
 		/// Adjust UI elements to the supplied DPI settings
 		/// </summary>
-		/// <param name="dpi"></param>
+		/// <param name="dpi">uint</param>
 		public void AdjustToDpi(uint dpi)
 		{
-			_size = DpiHelper.ScaleWithDpi(defaultSize, dpi);
+			_size = DpiHelper.ScaleWithDpi(DefaultSize, dpi);
 		}
 
 		/// <summary>

Greenshot/Drawing/DrawableContainer.cs

@@ -32,6 +32,7 @@ using System.Collections.Generic;
 using System.ComponentModel;
 using System.Drawing;
 using System.Drawing.Drawing2D;
+using System.Linq;
 using System.Runtime.Serialization;
 using GreenshotPlugin.IniFile;
 using GreenshotPlugin.Interfaces;
@@ -205,10 +206,8 @@ namespace Greenshot.Drawing
 		}
 
 		public Size Size {
-			get {
-				return new Size(width, height);
-			}
-			set {
+			get => new Size(width, height);
+            set {
 				width = value.Width;
 				height = value.Height;
 			}
@@ -219,15 +218,9 @@ namespace Greenshot.Drawing
 		/// </summary>
 		[NonSerialized]
 		private IList<IAdorner> _adorners = new List<IAdorner>();
-		public IList<IAdorner> Adorners
-		{
-			get
-			{
-				return _adorners;
-			}
-		}
+		public IList<IAdorner> Adorners => _adorners;
 
-		[NonSerialized]
+        [NonSerialized]
 		// will store current bounds of this DrawableContainer before starting a resize
 		protected Rectangle _boundsBeforeResize = Rectangle.Empty;
 
@@ -236,8 +229,8 @@ namespace Greenshot.Drawing
 		protected RectangleF _boundsAfterResize = RectangleF.Empty;
 
 		public Rectangle Bounds {
-			get { return GuiRectangle.GetGuiRectangle(Left, Top, Width, Height); }
-			set {
+			get => GuiRectangle.GetGuiRectangle(Left, Top, Width, Height);
+            set {
 				Left = Round(value.Left);
 				Top = Round(value.Top);
 				Width = Round(value.Width);
@@ -279,8 +272,12 @@ namespace Greenshot.Drawing
 						return new Rectangle(Point.Empty, _parent.Image.Size);
 					}
 				}
-				// Take a base safetymargin
+				// Take a base safety margin
 				int lineThickness = 5;
+
+                // add adorner size
+                lineThickness += Adorners.Max(adorner => Math.Max(adorner.Bounds.Width, adorner.Bounds.Height));
+
 				if (HasField(FieldType.LINE_THICKNESS)) {
 					lineThickness += GetFieldValueAsInt(FieldType.LINE_THICKNESS);
 				}
@@ -372,10 +369,10 @@ namespace Greenshot.Drawing
 		/// <summary>
 		/// Adjust UI elements to the supplied DPI settings
 		/// </summary>
-		/// <param name="dpi"></param>
+		/// <param name="dpi">uint with dpi value</param>
 		public void AdjustToDpi(uint dpi)
 		{
-			foreach(var adorner in Adorners) 
+			foreach(var adorner in Adorners)
 			{
 				adorner.AdjustToDpi(dpi);
 			}

GreenshotPlugin/Core/DpiHelper.cs

@@ -35,6 +35,10 @@ namespace GreenshotPlugin.Core
         /// <returns>double</returns>
         public static float DpiScaleFactor(uint dpi)
         {
+            if (dpi == 0)
+            {
+                dpi = Dpi;
+            }
             return (float)dpi / DefaultScreenDpi;
         }
 

GreenshotPlugin/Interfaces/Drawing/Adorners/IAdorner.cs

@@ -1,20 +1,20 @@
 /*
  * Greenshot - a free and open source screenshot tool
  * Copyright (C) 2007-2020 Thomas Braun, Jens Klingen, Robin Krom
- * 
+ *
  * For more information see: http://getgreenshot.org/
  * The Greenshot project is hosted on Sourceforge: http://sourceforge.net/projects/greenshot/
- * 
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 1 of the License, or
  * (at your option) any later version.
- * 
+ *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
@@ -32,6 +32,11 @@ namespace GreenshotPlugin.Interfaces.Drawing.Adorners
 		/// </summary>
 		bool IsActive { get; }
 
+		/// <summary>
+		/// These are the bounds of the adorner
+		/// </summary>
+		Rectangle Bounds { get; }
+
 		/// <summary>
 		/// The current edit status, this is needed to locate the adorner to send events to
 		/// </summary>
@@ -44,7 +49,7 @@ namespace GreenshotPlugin.Interfaces.Drawing.Adorners
 
 		/// <summary>
 		/// Is the current point "over" the Adorner?
-		/// If this is the case, the 
+		/// If this is the case, the
 		/// </summary>
 		/// <param name="point">Point to test</param>
 		/// <returns>true if so</returns>

GreenshotPlugin/Interfaces/Drawing/Container.cs

@@ -1,20 +1,20 @@
 /*
  * Greenshot - a free and open source screenshot tool
  * Copyright (C) 2007-2020 Thomas Braun, Jens Klingen, Robin Krom
- * 
+ *
  * For more information see: http://getgreenshot.org/
  * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
- * 
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 1 of the License, or
  * (at your option) any later version.
- * 
+ *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
@@ -124,7 +124,7 @@ namespace GreenshotPlugin.Interfaces.Drawing
 		/// <summary>
 		/// Adjust UI elements to the supplied DPI settings
 		/// </summary>
-		/// <param name="dpi"></param>
+		/// <param name="dpi">uint</param>
 		void AdjustToDpi(uint dpi);
 	}