iOS scrolling fix

Author: timothyschoen

Source/Components/BouncingViewport.h

@@ -20,10 +20,16 @@ class BouncingViewportAttachment final : public MouseListener
     ~BouncingViewportAttachment() override = default;
 
 #if JUCE_IOS
-    void mouseDrag(MouseEvent const& e) override
+    void mouseDown(MouseEvent const& e) override
     {
-        if(e.getDistanceFromDragStart() > 8) {
-            OSUtils::ScrollTracker::setAllowOneFingerScroll(true);
+        OSUtils::ScrollTracker::setAllowOneFingerScroll(true);
+    }
+        
+    void mouseUp(MouseEvent const& e) override
+    {
+        if(!OSUtils::ScrollTracker::isScrolling())
+        {
+            OSUtils::ScrollTracker::setAllowOneFingerScroll(false);
         }
     }
 #endif

Source/Utility/OSUtils.mm

@@ -407,7 +407,7 @@ - (void)scrollEventOccurred:(UIPanGestureRecognizer*)gesture {
         [gesture setCancelsTouchesInView: false];
         return;
     }
-
+    
     juce::MouseWheelDetails details;
     details.deltaX = scale * (float) (offset.x - lastPosition.x);
     details.deltaY = scale * (float) (offset.y - lastPosition.y);
@@ -453,9 +453,8 @@ - (void)updateInertia
 
     const auto time = (juce::Time::currentTimeMillis() - juce::Time::getMillisecondCounter())
     + (juce::int64) ([[NSProcessInfo processInfo] systemUptime] * 1000.0);
-    
+
     peer->handleMouseWheel(juce::MouseInputSource::InputSourceType::touch, lastMousePosition, time, details);
-    *allowOneFingerScroll = false;
 }
 @end
 
@@ -805,7 +804,7 @@ BOOL openURLImplementation(id self, SEL _cmd, UIApplication* app, NSURL* url, NS
         juce::String juceFilePath = juce::String::fromUTF8([filePath UTF8String]);
         [url startAccessingSecurityScopedResource];
 
-        if (auto* juceApp = juce::JUCEApplicationBase::getInstance())
+        if (juce::JUCEApplicationBase::getInstance())
         {
             juce::MessageManager::callAsync([juceFilePath]()
             {