Allow more mouse modifiers and include them on mousewheel events

keybinding.go

@@ -286,8 +286,9 @@ const (
 
 // Modifiers.
 const (
-	ModNone Modifier = Modifier(0)
-	ModAlt           = Modifier(tcell.ModAlt)
-	// ModCtrl doesn't work with keyboard keys. Use CtrlKey in Key and ModNone. This is was for mouse clicks only (tcell.v1)
-	// ModCtrl = Modifier(tcell.ModCtrl)
+	ModNone       Modifier = Modifier(0)
+	ModAlt                 = Modifier(tcell.ModAlt)
+	ModMouseAlt            = Modifier(tcell.ModAlt)
+	ModMouseShift          = Modifier(tcell.ModShift)
+	ModMouseCtrl           = Modifier(tcell.ModCtrl)
 )

tcell_driver.go

@@ -179,15 +179,19 @@ func pollEvent() gocuiEvent {
 		// process mouse wheel
 		if button&tcell.WheelUp != 0 {
 			mouseKey = MouseWheelUp
+			mouseMod = Modifier(tev.Modifiers())
 		}
 		if button&tcell.WheelDown != 0 {
 			mouseKey = MouseWheelDown
+			mouseMod = Modifier(tev.Modifiers())
 		}
 		if button&tcell.WheelLeft != 0 {
 			mouseKey = MouseWheelLeft
+			mouseMod = Modifier(tev.Modifiers())
 		}
 		if button&tcell.WheelRight != 0 {
 			mouseKey = MouseWheelRight
+			mouseMod = Modifier(tev.Modifiers())
 		}
 
 		// process button events (not wheel events)