Penner Tweens, created by Robert Penner, use built-in Flash MX 2004 classes to script tweens. This is the touch of class that adds to any flash application / navigation / presentation. To set it up, you define an ease type, then apply the ease type to a Tween object.
File -> New -> Flash Document
Double-Click Layer 2′ and label it A (for Actions). We will place all actionscript on this layer.
Create a new layer (Insert -> Timeline -> Layer). Double-Click Layer 2′ and label it mc (for movieclips).
Draw a box using the Rectangle Tool (hotkey is R) near the top left of the Stage.
Double-Click on your new box. Now Right-Click on your box and select Convert to Symbol ".
In the Name field put m_box". In the Behavior radio button group, select Movie clip". Press OK.
Having your m_box on the stage still selected, in the Properties toolbar, where there is a white field that has
select Frame 1′ in the A Layer. Open up your actions panel (Window
-> Development Panels -> Actions or using hotkey F9′). Copy and
paste this code into the Actions panel.
var easeType = mx.transitions.easing.Regular.easeOut;
myTween = new mx.transitions.Tween(box_mc, _y", easeType, 0, 300, 30);
Now you might be asking what this just did. Well lets take an indepth look at the code defintion of the Tween object.
(do not enter this code into your movie):
Tween(myMovie:MovieClip, myProperty:Property, easeType, startValue:Number, endValue:Number, frames(or seconds), secondsSet:Boolean);
myMovie:MovieClip Targets the Instance of a Movieclip on the stage.
myProperty:Property Selects the property of the Movieclip on the stage to tween. (I.E. _x, _width, _alpha, etc)
easeType as (Parent.Child) Your tween definition set up as a variable. SetParent Types (Back, Bounce, Elastic, None, Regular, Strong). Child Types (easeIn, easeOut). (i.e. Bounce.easeOut).
startValue:Number Starting value of property to tween. For more advanced tweens, try (box_mc._y) to get the current starting Y position of the targeted Movie Clip.
endValue:Number Starting value of property to tween.
frames(or seconds) Number of frames to tween over, or number of seconds to tween over.
secondsSet:Boolean Optional value, defaults to false. When set to true, uses seconds instead of frames to tween over.
Save your document (File -> Save)
Test your movie (Control -> Test Movie or hotkey Ctr-Enter")
Your box should go from _y position 0 to 300. Now try out variations of properties and movieclips and tweens.
For smoother framerate, try changing the framerate to 31 fps. To do so, go to Modfiy -> Document . In the Frame rate input box, type in 31′. Press OK. Try your movie again.
For more easing variations, view the folder on your computer >>
..Program Files/Macromedia/Flash MX 2004/en/First Run/Classes/mx/transitions
Try out Rober Penners examples at:
Robert Penners Easing Demo