Added mousewheel scrolling on all knobs

Signed-off-by: Damien Zammit <damien@zamaudio.com>

2 files changed, 32 insertions, 0 deletions

diff --git a/libs/dgl/ImageKnob.hpp b/libs/dgl/ImageKnob.hpp
index e774a4a..85f626e 100644
--- a/libs/dgl/ImageKnob.hpp
+++ b/libs/dgl/ImageKnob.hpp
@@ -61,6 +61,7 @@ public:
 protected:
      void onDisplay() override;
      bool onMouse(int button, bool press, int x, int y) override;
+     bool onScroll(int x, int y, float dx, float dy) override;
      bool onMotion(int x, int y) override;
      void onReshape(int width, int height) override;
      void onClose() override;
diff --git a/libs/dgl/src/ImageKnob.cpp b/libs/dgl/src/ImageKnob.cpp
index 78eb79e..ee99d09 100644
--- a/libs/dgl/src/ImageKnob.cpp
+++ b/libs/dgl/src/ImageKnob.cpp
@@ -311,6 +311,37 @@ void ImageKnob::onDisplay()
     }
 }
 
+bool ImageKnob::onScroll(int x, int y, float, float dy)
+{
+    float d, value;
+
+    if (! getArea().contains(x,y))
+        return false;
+
+    d     = (getModifiers() & MODIFIER_CTRL) ? 2000.0f : 200.0f;
+    value = (fValueTmp) + (float(fMaximum - fMinimum) / d * 10.f * dy );
+
+    if (value < fMinimum)
+    {
+        value = fMinimum;
+        fValueTmp = value;
+    }
+    else if (value > fMaximum)
+    {
+        value = fMaximum;
+        fValueTmp = value;
+    }
+    else if (fStep != 0.0f)
+    {
+        fValueTmp = value;
+        const float rest = std::fmod(value, fStep);
+        value = value - rest + (rest > fStep/2.0f ? fStep : 0.0f);
+    }
+
+    setValue(value, true);
+    return true; 
+}
+
 bool ImageKnob::onMouse(int button, bool press, int x, int y)
 {
     if (button != 1)