From 52f25dfe9637ef235eb6e6f62e24814315176cd6 Mon Sep 17 00:00:00 2001
From: pubpub-zz <4083478+pubpub-zz@users.noreply.github.com>
Date: Mon, 8 Mar 2021 23:42:37 +0100
Subject: [PATCH] Enh : shift/CapsLock + MouseWheel to rotate between pens

rotate between pens with shift pressed of with caps lock toggled on
issue #59
---
 src/FormCollection.cs | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/FormCollection.cs b/src/FormCollection.cs
index d6e00d2..c651709 100644
--- a/src/FormCollection.cs
+++ b/src/FormCollection.cs
@@ -960,6 +960,24 @@ private void IC_MouseWheel(object sender, CancelMouseEventArgs e)
                 ZoomForm.Width += t*10;
                 return;
             }
+            if (((GetKeyState(VK_LSHIFT ) | GetKeyState(VK_RSHIFT)) & 0x8000)!= 0 || System.Windows.Input.Keyboard.IsKeyToggled(System.Windows.Input.Key.CapsLock))
+            {
+                int p = LastPenSelected + (e.Delta>0?1:-1);
+                if (p >= Root.MaxPenCount)
+                    p = 0;
+                if (p < 0)
+                    p = Root.MaxPenCount - 1;
+                while (!Root.PenEnabled[p])
+                {
+                    p += (e.Delta > 0 ? 1 : -1);
+                    if (p >= Root.MaxPenCount)
+                        p = 0;
+                    if (p < 0)
+                        p = Root.MaxPenCount - 1;
+                }
+                SelectPen(p);
+                return;
+            }
             Root.GlobalPenWidth += Root.PixelToHiMetric(e.Delta > 0 ? 2 : -2);
             if (Root.GlobalPenWidth < 1)
                 Root.GlobalPenWidth = 1;