Added viewportIgnoreDragFlag to Component to indicate that mouse drag events should not move the Component's parent Viewport with drag-to-scroll functionality enabled.

modules/juce_gui_basics/components/juce_Component.h

@@ -2230,6 +2230,17 @@ public:
     */
     CachedComponentImage* getCachedComponentImage() const noexcept  { return cachedImage; }
 
+    /** Sets a flag to indicate whether mouse drag events on this Component should be ignored when it is inside a
+        Viewport with drag-to-scroll functionality enabled. This is useful for Components such as sliders that
+        should not move their parent Viewport when dragged.
+    */
+    void setViewportIgnoreDragFlag (bool ignoreDrag) { flags.viewportIgnoreDragFlag = ignoreDrag; };
+
+    /** Retrieves the current state of the Viewport drag-to-scroll functionality flag.
+        @see setViewportIgnoreDragFlag
+    */
+    bool getViewportIgnoreDragFlag() { return flags.viewportIgnoreDragFlag; }
+
     //==============================================================================
     // These methods are deprecated - use localPointToGlobal, getLocalPoint, getLocalPoint, etc instead.
     JUCE_DEPRECATED (Point<int> relativePositionToGlobal (Point<int>) const);
@@ -2288,6 +2299,7 @@ private:
         bool mouseDownWasBlocked        : 1;
         bool isMoveCallbackPending      : 1;
         bool isResizeCallbackPending    : 1;
+        bool viewportIgnoreDragFlag     : 1;
        #if JUCE_DEBUG
         bool isInsidePaintCall          : 1;
        #endif

modules/juce_gui_basics/layout/juce_Viewport.cpp

@@ -211,8 +211,12 @@ struct Viewport::DragToScrollListener   : private MouseListener,
                                                                 (int) offsetY.getPosition()));
     }
 
-    void mouseDown (const MouseEvent&) override
+    void mouseDown (const MouseEvent& e) override
     {
+        for (auto c = e.eventComponent; c != nullptr && c != &viewport; c = c->getParentComponent())
+            if (c->getViewportIgnoreDragFlag())
+                return;
+
         ++numTouches;
     }