Issues #36 Realtime transparency preview

Author: AlexanderPro

SmartContextMenu/Forms/TransparencyForm.Designer.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Windows.Forms;
+using SmartContextMenu.Utils;
 
 namespace SmartContextMenu.Forms
 {
@@ -19,8 +20,14 @@ private void InitializeControls(LanguageManager manager, Window window)
             Text = manager.GetString("trans_form");
             numericTransparency.Value = window.Transparency;
             DialogResult = DialogResult.Cancel;
+            numericTransparency.TextChanged += NumericTransparencyValueChanged;
+            ChangeTransparency();
         }
 
+        private void NumericTransparencyValueChanged(object sender, EventArgs e) => ChangeTransparency();
+
+        private void NumericTransparencyKeyDown(object sender, KeyEventArgs e) => ChangeTransparency();
+
         private void ButtonApplyClick(object sender, EventArgs e)
         {
             WindowTransparency = (int)numericTransparency.Value;
@@ -40,5 +47,11 @@ private void FormKeyDown(object sender, KeyEventArgs e)
                 Close();
             }
         }
+
+        private void ChangeTransparency()
+        {
+            var opacity = WindowUtils.TransparencyToAlphaOpacity((int)numericTransparency.Value);
+            WindowUtils.SetOpacity(Handle, opacity);
+        }
     }
 }

SmartContextMenu/Forms/TransparencyForm.cs

@@ -566,5 +566,9 @@ public static Rect GetSystemMargins(IntPtr hWnd)
         }
 
         public static Func<int, double> TransparencyToOpacity = t => 1 - (t / 100.0);
+
+        public static Func<int, byte> TransparencyToAlphaOpacity = t => (byte)Math.Round(255 * (100 - t) / 100f, MidpointRounding.AwayFromZero);
+
+        public static Func<byte, int> AlphaOpacityToTransparency = o => 100 - (int)Math.Round(100 * o / 255f, MidpointRounding.AwayFromZero);
     }
 }

SmartContextMenu/Utils/WindowUtils.cs

@@ -101,8 +101,7 @@ public int Transparency
                 var isLayeredWindow = (style & WS_EX_LAYERED) == WS_EX_LAYERED;
                 if (!isLayeredWindow) return 0;
                 GetLayeredWindowAttributes(Handle, out _, out var alpha, out _);
-                var transparency = 100 - (int)Math.Round(100 * alpha / 255f, MidpointRounding.AwayFromZero);
-                return transparency;
+                return WindowUtils.AlphaOpacityToTransparency(alpha);
             }
         }
 
@@ -314,7 +313,7 @@ public void Resume()
 
         public void SetTransparency(int percent)
         {
-            var opacity = (byte)Math.Round(255 * (100 - percent) / 100f, MidpointRounding.AwayFromZero);
+            var opacity = WindowUtils.TransparencyToAlphaOpacity(percent);
             WindowUtils.SetOpacity(Handle, opacity);
         }