Fix regressions when changing the pitch widget with the mousewheel

qtgui/pattern_grid.py

@@ -637,7 +637,8 @@ class Scale(QtWidgets.QGraphicsRectItem):
             widget.rememberLastValue = scaleMidiPitch
 
     def setNoteNames(self, pNoteNames):
-        """A list of 128 strings. Gets only called by the callback."""
+        """A list of 128 strings. Gets only called by the callback.
+        E.g. it happens when you switch the active gui track"""
         #if pNoteNames in pitch.notenames.keys():
         #    self.simpleNoteNames = pitch.notenames[pNoteNames]
         #else:
@@ -787,6 +788,8 @@ class PitchWidget(QtWidgets.QGraphicsProxyWidget):
 
         self.setWidget(widget)
 
+
+        self.spinBox.wheelEvent = self.spinBoxMouseWheelEvent        
         self.spinBox.valueChanged.connect(self.spinBoxValueChanged)
         self.spinBox.editingFinished.connect(self.spinBoxEditingFinished)
         #self.spinBoxValueChanged()  #Delay that. The engine Data is not ready yet. It will be sent by the callback
@@ -818,7 +821,7 @@ class PitchWidget(QtWidgets.QGraphicsProxyWidget):
 
     def spinBoxValueChanged(self):
         self.label.setText(self.midiToNotename(self.spinBox.value()))        
-        self.parentItem.sendToEngine(callback=False)
+        #self.parentItem.sendToEngine(callback=False) # results in a loop with callback, and in wrong data without. This is not the right place to implement immediate note feedback while editing is still going on.
 
     def spinBoxEditingFinished(self):
         if not self.rememberLastValue == self.spinBox.value():
@@ -834,6 +837,19 @@ class PitchWidget(QtWidgets.QGraphicsProxyWidget):
         else:
             QtWidgets.QAbstractSpinBox.stepBy(self.spinBox, n)
 
+    def spinBoxMouseWheelEvent(self, event):
+        """We cannot use spinBoxValueChanged to send mousewheel scrolling pitch changing directly
+        to the engine while editing is still active. this results in signal loops and various
+        data corruptions. Fixing this would be far too much work. 
+        You can either use the arrow keys and press enter, which triggers editingFinished. 
+        But here we intercept the mousewheel directly."""
+        event.ignore()        
+        QtWidgets.QSpinBox.wheelEvent(self.spinBox, event) #this changes to the new text and therefore the new value. Call BEFORE sendToEngine
+        self.parentItem.sendToEngine(callback=False)
+        #if event.angleDelta().y() > 0: #up        
+        #else: #down
+
+
 class Playhead(QtWidgets.QGraphicsLineItem):
     def __init__(self, parentScene):
         super().__init__(0, 0,  0, api.NUMBER_OF_STEPS*SIZE_UNIT) # (x1, y1, x2, y2)