Next step for having the settings of effects stored in the greenshot.ini, using a TypeConverter this seems to work. An important change to the IniValue.cs: here a default value is created when the ini doesn't have a value yet. This used to be just "null". Next step would be that settings forms get a reset/default button. [skip ci]

Greenshot/Configuration/EditorConfiguration.cs

@@ -25,6 +25,7 @@ using System.Drawing;
 using Greenshot.Drawing.Fields;
 using GreenshotPlugin.UnmanagedHelpers;
 using Greenshot.IniFile;
+using Greenshot.Core;
 
 namespace Greenshot.Configuration {
 	/// <summary>
@@ -57,6 +58,12 @@ namespace Greenshot.Configuration {
 		[IniProperty("SuppressSaveDialogAtClose", Description="Suppressed the 'do you want to save' dialog when closing the editor.", DefaultValue="False")]
 		public bool SuppressSaveDialogAtClose;
 
+		[IniProperty("DropShadowEffectSettings", Description = "Settings for the drop shadow effect.")]
+		public DropShadowEffect DropShadowEffectSettings;
+
+		[IniProperty("TornEdgeEffectSettings", Description = "Settings for the torn edge effect.")]
+		public TornEdgeEffect TornEdgeEffectSettings;
+
 		public override void AfterLoad() {
 			base.AfterLoad();
 			if (RecentColors == null) {

Greenshot/Forms/DropShadowSettingsForm.Designer.cs

@@ -152,7 +152,7 @@ namespace Greenshot.Forms {
 			this.buttonOK.Size = new System.Drawing.Size(75, 23);
 			this.buttonOK.TabIndex = 11;
 			this.buttonOK.UseVisualStyleBackColor = true;
-			this.buttonOK.Click += new System.EventHandler(this.buttonOK_Click);
+			this.buttonOK.Click += new System.EventHandler(this.ButtonOK_Click);
 			// 
 			// buttonCancel
 			// 

Greenshot/Forms/DropShadowSettingsForm.cs

@@ -27,20 +27,33 @@ using GreenshotPlugin.Core;
 namespace Greenshot.Forms {
 	public partial class DropShadowSettingsForm : BaseForm {
 		private DropShadowEffect effect;
+
 		public DropShadowSettingsForm(DropShadowEffect effect) {
 			this.effect = effect;
 			InitializeComponent();
 			this.Icon = GreenshotResources.getGreenshotIcon();
+			ShowSettings();
+		}
+
+		/// <summary>
+		/// Apply the settings from the effect to the view
+		/// </summary>
+		private void ShowSettings() {
 			trackBar1.Value = (int)(effect.Darkness * 40);
 			offsetX.Value = effect.ShadowOffset.X;
 			offsetY.Value = effect.ShadowOffset.Y;
 		}
 
-		private void buttonOK_Click(object sender, EventArgs e) {
+		private void ButtonOK_Click(object sender, EventArgs e) {
 			effect.Darkness = (float)trackBar1.Value / (float)40;
 			effect.ShadowOffset = new Point((int)offsetX.Value, (int)offsetY.Value);
 			effect.ShadowSize = (int)thickness.Value;
 			DialogResult = DialogResult.OK;
 		}
+
+		private void ButtonReset_Click(object sender, EventArgs e) {
+			effect.Reset();
+			ShowSettings();
+		}
 	}
 }

Greenshot/Forms/ImageEditorForm.cs

@@ -1253,7 +1253,7 @@ namespace Greenshot {
 		/// <param name="sender"></param>
 		/// <param name="e"></param>
 		void AddDropshadowToolStripMenuItemClick(object sender, EventArgs e) {
-			DropShadowEffect dropShadowEffect= new DropShadowEffect();
+			DropShadowEffect dropShadowEffect = editorConfiguration.DropShadowEffectSettings;
 			// TODO: Use the dropshadow settings form to make it possible to change the default values
 			DialogResult result = new DropShadowSettingsForm(dropShadowEffect).ShowDialog(this);
 			if (result == DialogResult.OK) {
@@ -1283,7 +1283,7 @@ namespace Greenshot {
 		/// <param name="sender"></param>
 		/// <param name="e"></param>
 		void TornEdgesToolStripMenuItemClick(object sender, EventArgs e) {
-			TornEdgeEffect tornEdgeEffect = new TornEdgeEffect();
+			TornEdgeEffect tornEdgeEffect = editorConfiguration.TornEdgeEffectSettings;
 			// TODO: Use the dropshadow settings form to make it possible to change the default values
 			DialogResult result = new TornEdgeSettingsForm(tornEdgeEffect).ShowDialog(this);
 			if (result == DialogResult.OK) {

Greenshot/Forms/TornEdgeSettingsForm.Designer.cs

@@ -166,7 +166,7 @@ namespace Greenshot.Forms {
 			this.buttonOK.Size = new System.Drawing.Size(75, 23);
 			this.buttonOK.TabIndex = 20;
 			this.buttonOK.UseVisualStyleBackColor = true;
-			this.buttonOK.Click += new System.EventHandler(this.buttonOK_Click);
+			this.buttonOK.Click += new System.EventHandler(this.ButtonOK_Click);
 			// 
 			// buttonCancel
 			// 
@@ -348,7 +348,7 @@ namespace Greenshot.Forms {
 			this.shadowCheckbox.Size = new System.Drawing.Size(110, 17);
 			this.shadowCheckbox.TabIndex = 1;
 			this.shadowCheckbox.UseVisualStyleBackColor = true;
-			this.shadowCheckbox.CheckedChanged += new System.EventHandler(this.shadowCheckbox_CheckedChanged);
+			this.shadowCheckbox.CheckedChanged += new System.EventHandler(this.ShadowCheckbox_CheckedChanged);
 			// 
 			// TornEdgeSettingsForm
 			// 

Greenshot/Forms/TornEdgeSettingsForm.cs

@@ -31,6 +31,10 @@ namespace Greenshot.Forms {
 			this.effect = effect;
 			InitializeComponent();
 			this.Icon = GreenshotResources.getGreenshotIcon();
+			ShowSettings();
+		}
+
+		private void ShowSettings() {
 			shadowCheckbox.Checked = effect.GenerateShadow;
 			shadowDarkness.Value = (int)(effect.Darkness * 40);
 			offsetX.Value = effect.ShadowOffset.X;
@@ -44,7 +48,7 @@ namespace Greenshot.Forms {
 			left.Checked = effect.Edges[3];
 		}
 
-		private void buttonOK_Click(object sender, EventArgs e) {
+		private void ButtonOK_Click(object sender, EventArgs e) {
 			effect.Darkness = (float)shadowDarkness.Value / (float)40;
 			effect.ShadowOffset = new Point((int)offsetX.Value, (int)offsetY.Value);
 			effect.ShadowSize = (int)thickness.Value;
@@ -56,7 +60,12 @@ namespace Greenshot.Forms {
 			DialogResult = DialogResult.OK;
 		}
 
-		private void shadowCheckbox_CheckedChanged(object sender, EventArgs e) {
+		private void ButtonReset_Click(object sender, EventArgs e) {
+			effect.Reset();
+			ShowSettings();
+		}
+
+		private void ShadowCheckbox_CheckedChanged(object sender, EventArgs e) {
 			thickness.Enabled = shadowCheckbox.Checked;
 			offsetX.Enabled = shadowCheckbox.Checked;
 			offsetY.Enabled = shadowCheckbox.Checked;

GreenshotPlugin/Core/Effects.cs

@@ -22,6 +22,7 @@
 using GreenshotPlugin.Core;
 using log4net;
 using System;
+using System.ComponentModel;
 using System.Drawing;
 using System.Drawing.Drawing2D;
 using System.Drawing.Imaging;
@@ -32,17 +33,28 @@ namespace Greenshot.Core {
 	/// Interface to describe an effect
 	/// </summary>
 	public interface IEffect {
+		/// <summary>
+		/// Apply this IEffect to the supplied sourceImage.
+		/// In the process of applying the supplied matrix will be modified to represent the changes.
+		/// </summary>
+		/// <param name="sourceImage">Image to apply the effect to</param>
+		/// <param name="matrix">Matrix with the modifications like rotate, translate etc. this can be used to calculate the new location of elements on a canvas</param>
+		/// <returns>new image with applied effect</returns>
 		Image Apply(Image sourceImage, Matrix matrix);
+
+		/// <summary>
+		/// Reset all values to their defaults
+		/// </summary>
+		void Reset();
 	}
 
 	/// <summary>
 	/// DropShadowEffect
 	/// </summary>
+	[TypeConverter(typeof(EffectConverter))]
 	public class DropShadowEffect : IEffect {
 		public DropShadowEffect() {
-			Darkness = 0.6f;
-			ShadowSize = 7;
-			ShadowOffset = new Point(-1, -1);
+			Reset();
 		}
 		public float Darkness {
 			get;
@@ -56,32 +68,25 @@ namespace Greenshot.Core {
 			get;
 			set;
 		}
+
+		public virtual void Reset() {
+			Darkness = 0.6f;
+			ShadowSize = 7;
+			ShadowOffset = new Point(-1, -1);
+		}
+
 		public virtual Image Apply(Image sourceImage, Matrix matrix) {
 			return ImageHelper.CreateShadow(sourceImage, Darkness, ShadowSize, ShadowOffset, matrix, PixelFormat.Format32bppArgb);
 		}
-
-		public override string ToString() {
-			StringBuilder sb = new StringBuilder();
-			sb.AppendFormat("Darkness:{0:F2}|ShadowSize:{1}|ShadowOffset:{2},{3}", Darkness, ShadowSize, ShadowOffset.X, ShadowOffset.Y);
-			return sb.ToString();
-		}
-
-		public void ApplySettings(string settings) {
-
-		}
 	}
 
 	/// <summary>
 	/// TornEdgeEffect extends on DropShadowEffect
 	/// </summary>
+	[TypeConverter(typeof(EffectConverter))]
 	public class TornEdgeEffect : DropShadowEffect {
 		public TornEdgeEffect() : base() {
-			ShadowSize = 7;
-			ToothHeight = 12;
-			HorizontalToothRange = 20;
-			VerticalToothRange = 20;
-			Edges = new bool[] {true, true, true, true};
-			GenerateShadow = true;
+			Reset();
 		}
 		public int ToothHeight {
 			get;
@@ -104,6 +109,15 @@ namespace Greenshot.Core {
 			set;
 		}
 
+		public override void Reset() {
+			base.Reset();
+			ShadowSize = 7;
+			ToothHeight = 12;
+			HorizontalToothRange = 20;
+			VerticalToothRange = 20;
+			Edges = new bool[] { true, true, true, true };
+			GenerateShadow = true;
+		}
 		public override Image Apply(Image sourceImage, Matrix matrix) {
 			Image tmpTornImage = ImageHelper.CreateTornEdge(sourceImage, ToothHeight, HorizontalToothRange, VerticalToothRange, Edges);
 			if (GenerateShadow) {
@@ -113,16 +127,6 @@ namespace Greenshot.Core {
 			}
 			return tmpTornImage;
 		}
-
-		public override string ToString() {
-			StringBuilder sb = new StringBuilder();
-			sb.AppendFormat("{0}|GenerateShadow:{1}|ToothHeight:{2}|HorizontalToothRange:{3}|VerticalToothRange:{4}|Edges:{5},{6},{7},{8}", base.ToString(), GenerateShadow, ToothHeight, HorizontalToothRange, VerticalToothRange, Edges[0], Edges[1], Edges[2], Edges[3]);
-			return sb.ToString();
-		}
-
-		public void ApplySettings(string settings) {
-			
-		}
 	}
 
 	/// <summary>
@@ -132,6 +136,9 @@ namespace Greenshot.Core {
 		public Image Apply(Image sourceImage, Matrix matrix) {
 			return ImageHelper.CreateGrayscale(sourceImage);
 		}
+		public void Reset() {
+			// No settings to reset
+		}
 	}
 
 	/// <summary>
@@ -143,6 +150,9 @@ namespace Greenshot.Core {
         public MonochromeEffect(byte threshold) {
             this.threshold = threshold;
         }
+		public void Reset() {
+			// TODO: Modify the threshold to have a default, which is reset here
+		}
 		public Image Apply(Image sourceImage, Matrix matrix) {
 			return ImageHelper.CreateMonochrome(sourceImage, threshold);
 		}
@@ -153,9 +163,7 @@ namespace Greenshot.Core {
 	/// </summary>
 	public class AdjustEffect : IEffect {
 		public AdjustEffect() : base() {
-			Contrast = 1f;
-			Brightness = 1f;
-			Gamma = 1f;
+			Reset();
 		}
 		public float Contrast {
 			get;
@@ -169,6 +177,11 @@ namespace Greenshot.Core {
 			get;
 			set;
 		}
+		public void Reset() {
+			Contrast = 1f;
+			Brightness = 1f;
+			Gamma = 1f;
+		}
 		public Image Apply(Image sourceImage, Matrix matrix) {
 			return ImageHelper.Adjust(sourceImage, Brightness, Contrast, Gamma);
 		}
@@ -180,12 +193,15 @@ namespace Greenshot.Core {
 	public class ReduceColorsEffect : IEffect {
 		private static ILog LOG = LogManager.GetLogger(typeof(ReduceColorsEffect));
 		public ReduceColorsEffect() : base() {
-			Colors = 256;
+			Reset();
 		}
 		public int Colors {
 			get;
 			set;
 		}
+		public void Reset() {
+			Colors = 256;
+		}
 		public Image Apply(Image sourceImage, Matrix matrix) {
 			using (WuQuantizer quantizer = new WuQuantizer((Bitmap)sourceImage)) {
 				int colorCount = quantizer.GetColorCount();
@@ -208,6 +224,9 @@ namespace Greenshot.Core {
 		public Image Apply(Image sourceImage, Matrix matrix) {
 			return ImageHelper.CreateNegative(sourceImage);
 		}
+		public void Reset() {
+			// No settings to reset
+		}
 	}
 
 	/// <summary>
@@ -215,8 +234,7 @@ namespace Greenshot.Core {
 	/// </summary>
 	public class BorderEffect : IEffect {
 		public BorderEffect() {
-			Width = 2;
-			Color = Color.Black;
+			Reset();
 		}
 		public Color Color {
 			get;
@@ -226,6 +244,10 @@ namespace Greenshot.Core {
 			get;
 			set;
 		}
+		public void Reset() {
+			Width = 2;
+			Color = Color.Black;
+		}
 		public Image Apply(Image sourceImage, Matrix matrix) {
 			return ImageHelper.CreateBorder(sourceImage, Width, Color, sourceImage.PixelFormat, matrix);
 		}
@@ -242,6 +264,9 @@ namespace Greenshot.Core {
 			get;
 			set;
 		}
+		public void Reset() {
+			// Angle doesn't have a default value
+		}
 		public Image Apply(Image sourceImage, Matrix matrix) {
 			RotateFlipType flipType;
 			if (Angle == 90) {
@@ -280,6 +305,9 @@ namespace Greenshot.Core {
 			get;
 			set;
 		}
+		public void Reset() {
+			// values don't have a default value
+		}
 		public Image Apply(Image sourceImage, Matrix matrix) {
 			return ImageHelper.ResizeImage(sourceImage, MaintainAspectRatio, Width, Height, matrix);
 		}
@@ -316,8 +344,170 @@ namespace Greenshot.Core {
 			get;
 			set;
 		}
+		public void Reset() {
+			// values don't have a default value
+		}
 		public Image Apply(Image sourceImage, Matrix matrix) {
 			return ImageHelper.ResizeCanvas(sourceImage, BackgroundColor, Left, Right, Top, Bottom, matrix);
 		}
 	}
+
+	public class EffectConverter : TypeConverter {
+		public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
+			if (sourceType == typeof(string)) {
+				return true;
+			}
+			return base.CanConvertFrom(context, sourceType);
+		}
+
+		public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
+			if (destinationType == typeof(string)) {
+				return true;
+			}
+			if (destinationType == typeof(DropShadowEffect)) {
+				return true;
+			}
+			if (destinationType == typeof(TornEdgeEffect)) {
+				return true;
+			}
+			return base.CanConvertTo(context, destinationType);
+		}
+
+		public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType) {
+			// to string
+			if (destinationType == typeof(string)) {
+				StringBuilder sb = new StringBuilder();
+				if (value.GetType() == typeof(DropShadowEffect)) {
+					DropShadowEffect effect = value as DropShadowEffect;
+					RetrieveDropShadowEffectValues(effect, sb);
+					return sb.ToString();
+				}
+				if (value.GetType() == typeof(TornEdgeEffect)) {
+					TornEdgeEffect effect = value as TornEdgeEffect;
+					RetrieveDropShadowEffectValues(effect, sb);
+					sb.Append("|");
+					RetrieveTornEdgeEffectValues(effect, sb);
+					return sb.ToString();
+				}
+			}
+			// from string
+			if (value.GetType() == typeof(string)) {
+				string settings = value as string;
+				if (destinationType == typeof(DropShadowEffect)) {
+					DropShadowEffect effect = new DropShadowEffect();
+					ApplyDropShadowEffectValues(settings, effect);
+					return effect;
+				}
+				if (destinationType == typeof(TornEdgeEffect)) {
+					TornEdgeEffect effect = new TornEdgeEffect();
+					ApplyDropShadowEffectValues(settings, effect);
+					ApplyTornEdgeEffectValues(settings, effect);
+					return effect;
+				}
+			}
+			return base.ConvertTo(context, culture, value, destinationType);
+		}
+
+		public override object ConvertFrom(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value) {
+			if (value != null && value.GetType() == typeof(string)) {
+				string settings = value as string;
+				if (settings.Contains("ToothHeight")) {
+					return ConvertTo(context, culture, value, typeof(TornEdgeEffect));
+				} else {
+					return ConvertTo(context, culture, value, typeof(DropShadowEffect));
+				}
+			}
+			return base.ConvertFrom(context, culture, value);
+		}
+
+		private void ApplyDropShadowEffectValues(string valuesString, DropShadowEffect effect) {
+			string[] values = valuesString.Split('|');
+			foreach(string nameValuePair in values) {
+				string[] pair = nameValuePair.Split(':');
+				switch (pair[0]) {
+					case "Darkness" :
+						float darkness;
+						if (float.TryParse(pair[1], out darkness)) {
+							effect.Darkness = darkness;
+						}
+						break;
+					case "ShadowSize":
+						int shadowSize;
+						if (int.TryParse(pair[1], out shadowSize)) {
+							effect.ShadowSize = shadowSize;
+						}
+						break;
+					case "ShadowOffset":
+						Point shadowOffset = new Point();
+						int shadowOffsetX;
+						int shadowOffsetY;
+						string[] coordinates = pair[1].Split(',');
+						if (int.TryParse(coordinates[0], out shadowOffsetX)) {
+							shadowOffset.X = shadowOffsetX;
+						}
+						if (int.TryParse(coordinates[1], out shadowOffsetY)) {
+							shadowOffset.Y = shadowOffsetY;
+						}
+						effect.ShadowOffset = shadowOffset;
+						break;
+				}
+			}
+		}
+
+		private void ApplyTornEdgeEffectValues(string valuesString, TornEdgeEffect effect) {
+			string[] values = valuesString.Split('|');
+			foreach (string nameValuePair in values) {
+				string[] pair = nameValuePair.Split(':');
+				switch (pair[0]) {
+					case "GenerateShadow":
+						bool generateShadow;
+						if (bool.TryParse(pair[1], out generateShadow)) {
+							effect.GenerateShadow = generateShadow;
+						}
+						break;
+					case "ToothHeight":
+						int toothHeight;
+						if (int.TryParse(pair[1], out toothHeight)) {
+							effect.ToothHeight = toothHeight;
+						}
+						break;
+					case "HorizontalToothRange":
+						int horizontalToothRange;
+						if (int.TryParse(pair[1], out horizontalToothRange)) {
+							effect.HorizontalToothRange = horizontalToothRange;
+						}
+						break;
+					case "VerticalToothRange":
+						int verticalToothRange;
+						if (int.TryParse(pair[1], out verticalToothRange)) {
+							effect.VerticalToothRange = verticalToothRange;
+						}
+						break;
+					case "Edges":
+						string[] edges = pair[1].Split(',');
+						bool edge;
+						if (bool.TryParse(edges[0], out edge)) {
+							effect.Edges[0] = edge;
+						}
+						if (bool.TryParse(edges[1], out edge)) {
+							effect.Edges[1] = edge;
+						}
+						if (bool.TryParse(edges[2], out edge)) {
+							effect.Edges[2] = edge;
+						}
+						if (bool.TryParse(edges[3], out edge)) {
+							effect.Edges[3] = edge;
+						}
+						break;
+				}
+			}
+		}
+
+		private void RetrieveDropShadowEffectValues(DropShadowEffect effect, StringBuilder sb) {
+			sb.AppendFormat("Darkness:{0:F2}|ShadowSize:{1}|ShadowOffset:{2},{3}", effect.Darkness, effect.ShadowSize, effect.ShadowOffset.X, effect.ShadowOffset.Y);
+		}
+		private void RetrieveTornEdgeEffectValues(TornEdgeEffect effect, StringBuilder sb) {
+			sb.AppendFormat("GenerateShadow:{0}|ToothHeight:{1}|HorizontalToothRange:{2}|VerticalToothRange:{3}|Edges:{4},{5},{6},{7}", effect.GenerateShadow, effect.ToothHeight, effect.HorizontalToothRange, effect.VerticalToothRange, effect.Edges[0], effect.Edges[1], effect.Edges[2], effect.Edges[3]);
+		}
+	}
 }

GreenshotPlugin/IniFile/IniValue.cs

@@ -305,7 +305,7 @@ namespace Greenshot.IniFile {
 					Value = defaultValueFromConfig;
 					return;
 				}
-			} else if (propertyValue != null) {
+			} else if (!string.IsNullOrEmpty(propertyValue)) {
 				if (valueType.IsGenericType && valueType.GetGenericTypeDefinition().Equals(typeof(Nullable<>))) {
 					// We are dealing with a generic type that is nullable
 					valueType = Nullable.GetUnderlyingType(valueType);