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scrollTop

Syntax

    member(whichCastMember).scrollTop
    the scrollTop of member whichCastMember

Description

Cast member property; determines the distance, in pixels, from the top of a field cast member to the top of the field that is currently visible in the scrolling box. By changing the value for `scrollTop` member property while the movie plays, you can change the section of the field that appears in the scrolling field.

This is a way to make custom scrolling behaviors for text and field members.

For example, the following Lingo moves the field cast member Credits up or down within a field's box, depending on the value in the variable `sliderVal`:

    global sliderVal

    on prepareFrame
    	newVal = sliderVal * 100
    	member("Credits").scrolltop = newVal
    end

The global variable `sliderVal` could measure how far the user drags a slider. The statement `set newVal = sliderVal * 100` multiplies `sliderVal` to give a value that is greater than the distance the user drags the slider. If `sliderVal` is positive, the text moves up; if `sliderVal` is negative, the text moves down.

Example

This repeat loop makes the field Credits scroll by continuously increasing the value of`scrollTop`:

    on wa
    	member("Credits").scrollTop = 1
    	repeat with count = 1 to 150
    		member("Credits").scrollTop = member("Credits").scrollTop + 1
    		updateStage
    	end repeat
    end