Flex 4 scrollers mouse wheel speed ?

The better way is to catch FlexMouseEvent.MOUSE_WHEEL_CHANGING on VScrollBar or HScrollBar, ( addEventListener(FlexMouseEvent.MOUSE_WHEEL_CHANGING,mouseWheelChangingHandler)) or override VScrollBar.dispatchEvent to change the delta, for more control override LayoutBase.getVerticalScrollPositionDelta(navigationUnit:uint) method

Note! Remember to keep sign of delta.

I had a slightly different problem with mouse wheel scrolling; the scroller would jump WAY too far with each click of the wheel.  I figured out a solution that I think is much simpler than trying to subclass the scrollbar or intercept mouse wheel events.  The viewport for a scroller dictates how far to scroll through the getVerticalScrollPositionDelta method in IViewport, so I extended s:Group and overrode that method to return a smaller value.  Now I just use the new group subclass as the viewport for a Scroller and set the step size to something reasonable and it works great!  This allows you to mimic the old Canvas.verticalLineScrollSize property which was very useful for solving this problem.  Here's the code, I hope this helps someone overcome the stupid scrolling in Flex4.

ControlledScrollGroup.as

package scroll
{    
    import spark.components.Group;

    public class ControlledScrollGroup extends Group
    {
        private var _step_size:int = 0;
        
        public function get stepSize():int
        {
            return _step_size;
        }
        
        public function set stepSize(value:int):void
        {
            _step_size = value;
        }
        
        override public function getVerticalScrollPositionDelta(navigationUnit:uint):Number
        {
            var megaValue:Number = super.getVerticalScrollPositionDelta(navigationUnit);
            
            if(megaValue == 0)
            {
                return 0;
            }
            
            var smallerValue:int =  _step_size;
            
            if(smallerValue ==0)
            {
                return megaValue;
            }
            
            if(megaValue < 0)
            {
                smallerValue = -1*smallerValue;
            }
            
            return smallerValue;
        }
        
        public function ControlledScrollGroup()
        {
            super();
        }
    }
}

usage:

<s:Scroller  height="400" width="400">
     <scroll:ControlledScrollGroup stepSize="40">
          <... content what needs scrolln' ...>
     </scroll:ControlledScrollGroup> 
</s:Scroller>

Ok,

I just took my Notebook in the garden with me and created a Slider Example.

On my MacBookPro it is working ! but not on my PC.

Here you can try the code:

http://wensauer.info/flex/ConstantDeltaSlider/ConstantDeltaSlider.html

For some reason it is neither working at all for a HScrollBar.

Have a Nice Day

Marc

Hi,

that's what I have:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
                  xmlns:s="library://ns.adobe.com/flex/spark"
                  xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"
                  creationComplete="application1_creationCompleteHandler(event)"
                  >
     <fx:Declarations>
          <!-- Place non-visual elements (e.g., services, value objects) here -->
     </fx:Declarations>
     <fx:Script>
          <![CDATA[
               import mx.events.FlexEvent;
               

               protected function application1_creationCompleteHandler(event:FlexEvent):void
               {
                    systemManager.addEventListener(MouseEvent.MOUSE_WHEEL,mouseWheelSpeed,true);
                    
               }
               
               public function mouseWheelSpeed(evt:MouseEvent):void {
                    evt.delta *= 0.50;
               }
          ]]>
     </fx:Script>
     
     <s:HSlider id='hSlider'  stepSize="1" maximum="10" minimum="0" />
          

</s:Application>

But this still did not solve the issue.

When I turn the MouseWheel the Slider jumps from 0 to 2 but I want to be able to scroll trough each(1,2,...,n) value with the mouse.

This behaviour has to be the same on any computer.

How do I get that ?

 evt.delta *= 0.50;

This line is interesting, so you also can use events in the other direction  and override the dispatcher of the event ?

Anyone please like to explain that to me for deeper insight?

bump

This post might help: http://forums.adobe.com/message/2787169

I believe mouse wheel works on Mac in Flash Player 10.1.