Add KnobEventHandler::isInteger(), avoid out of bounds stepping

dgl/EventHandlers.hpp

@@ -120,6 +120,9 @@ public:
     KnobEventHandler& operator=(const KnobEventHandler& other);
     virtual ~KnobEventHandler();
 
+    // if setStep(1) has been called before, this returns true
+    bool isInteger() const noexcept;
+
     // returns raw value, is assumed to be scaled if using log
     float getValue() const noexcept;
 

dgl/src/EventHandlers.cpp

@@ -1,6 +1,6 @@
 /*
  * DISTRHO Plugin Framework (DPF)
- * Copyright (C) 2012-2021 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2012-2022 Filipe Coelho <falktx@falktx.com>
  *
  * Permission to use, copy, modify, and/or distribute this software for any purpose with
  * or without fee is hereby granted, provided that the above copyright notice and this
@@ -455,6 +455,11 @@ struct KnobEventHandler::PrivateData {
             {
                 const float rest = std::fmod(value2, step);
                 value2 -= rest + (rest > step/2.0f ? step : 0.0f);
+
+                if (value2 < minimum)
+                    valueTmp = value2 = minimum;
+                else if (value2 > maximum)
+                    valueTmp = value2 = maximum;
             }
         }
 
@@ -565,6 +570,11 @@ KnobEventHandler::~KnobEventHandler()
     delete pData;
 }
 
+bool KnobEventHandler::isInteger() const noexcept
+{
+    return d_isEqual(pData->step, 1.f);
+}
+
 float KnobEventHandler::getValue() const noexcept
 {
     return pData->value;