IE4 mouseUp workaround

February 12, 1998
by Andrew White

As I sure most of you are aware IE4 on the Mac fails to pass mouse up messages back to a Shockwave movie. Some of you may have come up with this work around already but this a skeltal button behavior to deal with this problem.

The basic idea is to have a stepframe handler which acts as a backup method in case the mouseUp event isn't caught by checking the mouseDown property to see whether the mouse button is still pressed. It works as normal in situations where the mouseUp event is passed and doesn't need to be updated once a fixed version of IE4 becomes available.

The only overhead imposed is a single if statement every time the playback head loops while the button is pressed. If the user clicks the button at a frequency greater than the frame rate then the number of button then it's possbile that an incorrect number of button clicks will be registered but I've not succeeded in doing this. It's also self-cleaning - no matter how vigorously the button is clicked no instances are left in the actorList.


-- Mac IE4 workaround button behavior
property spriteNum
property mouseDownMember
property mouseUpMember
property mouseDownMe
on beginSprite me
  set mouseDownMe = FALSE
end
on mouseDown me
  
  set mouseDownMe = TRUE
  set the member of sprite spriteNum = ¬
    member mouseDownMember
  
  updateStage
  
  add the actorList, me
  
end
on mouseEnter me
  
  if mouseDownMe then
    set the member of sprite spriteNum = ¬
          member mouseDownMember
  end if
  
end
on mouseLeave me
  
  if mouseDownMe then
    set the member of sprite spriteNum = ¬
          member mouseUpMember
  end if
  
end
on mouseUp me
  update me
end
on mouseUpOutside me
  updateOutside me
end
on update me
  
  if mouseDownMe then
    
    set the member of sprite spriteNum = ¬
          member mouseUpMember
    deleteOne the actorList, me
    
    updateStage
    
    set mouseDownMe = FALSE
    
    -- Do your button action here
    
  end if
  
end
on updateOutside me   
  
  if mouseDownMe then
    
    set the member of sprite spriteNum = ¬
          member mouseUpMember
    deleteOne the actorList, me
    
    updateStage
    
    set mouseDownMe = FALSE
    
  end if
  
end
on stepFrame me
  
  if not the mouseDown then
    
    if the rollover = spriteNum then
      update me
    else
      updateOutside me
    end if
    
  end if
  
end
on getPropertyDescriptionList
  
  set propList = [:]
  
  set tempList = [:]
  addProp tempList, #format, #graphic
  addProp tempList, #default, 1
  addProp tempList, #comment, "Up Member:"
  addProp tempList, #range, #all
  addProp propList, #mouseUpMember, tempList
  
  set tempList = [:]
  addProp tempList, #format, #graphic
  addProp tempList, #default, 1
  addProp tempList, #comment, "Down Member:"
  addProp tempList, #range, #all
  addProp propList, #mouseDownMember, tempList
  
  return propList
  
end

Andrew White is a senior partner in Cathode, a multimedia partnership based in the West Midlands, UK. He has been using Director since it was VideoWorks and has produced Director and Shockwave work for a number of clients including HP, NCR, Budwieser, Polaroid, Digital and Sun. Contact Details: Andrew White Cathode, UK Tel: +44 (0) 1203 689395 Email: andyw@cathode.co.uk