> How would I make the alpha transition smooth, taking
> about 1/2 to 1 second to go from 35% to 100% and back?

> stillwaiting,
>
>
>>How would I make the alpha transition smooth, taking
>>about 1/2 to 1 second to go from 35% to 100% and back?
>
>
> This kind of transition, as *any* kind of animated transition, occurs
> when you make small increments over time. Your sample code is, as you
> mentioned, instant. To make the alpha change over half a second, you would
> look at your fps (frames per second) -- default is 12 -- and decide how many
> frames it would take to transpire over half a second. Well, at 12 fps, half
> a second would be 6.
>
> So, the difference between 100% and 35% is 65. 65 divided by 6 is
> (approximately) 11. So you'll need to adjust the _alpha property by 11 once
> every frame for 6 frames. Fudge the numbers a bit, as you like, but that's
> the general idea.
>
> As it turns out, every movie clip features an event called onEnterFrame.
> (In fact, every movie clip features *all kinds* of events and other useful
> features. To see them all, look up the "MovieClip class" entry of the
> ActionScript Language Reference.) The onEnterFrame event occurs every time
> a movie clip enters a frame -- even if the movie clip has been stopped with
> a stop() action. (Just imagine the onEnterFrame event as a car engine
> that's idling: even when the car isn't moving, the engine is turning over.)
>
> Give your movie clip an instance name. Step away from that old
> fashioned on() handler business. :-p It's much more convenient to give
> your clips instance names ... this lets you write all your code in the same
> place (in a keyframe of a scripts layer), rather than having to touch each
> movie clip and lob code all over the place.
>
> Create a new layer, then, and name it scripts (or actions, or whatever
> strikes your fancy). In a keyframe that occurs in the same frame as your
> movie clip, type the following -- substituting my sample instance name with
> the one you give your clip ...
>
> yourMovieClipInstanceName.onRollOver = function() {
> }
>
> ... which means you're about to assign a function to its onRollOver event.
> The function you're going to assign will, as it turns out, assign a second
> function to this clip's onEnterFrame event.
>
> yourMovieClipInstanceName.onRollOver = function() {
> this.onEnterFrame = function() {
> }
> }
>
> ... with me so far? Now the second function will adjust this clip's _alpha
> property and decrease it by 11 every time, as discussed above.
>
> yourMovieClipInstanceName.onRollOver = function() {
> this.onEnterFrame = function() {
> this._alpha = this._alpha - 11;
> }
> }
>
> A short way to say this._alpha = this._alpha - 11; is to simply put
> this._alpha -= 11, so I'll use that moving ahead.
>
> We'll add an if() statement to stop the onEnterFrame loop when _alpha
> reaches 35 (this is something you can't do, by the way, with the on()
> handler .... loops just continue forever).
>
> yourMovieClipInstanceName.onRollOver = function() {
> this.onEnterFrame = function() {
> if (this._alpha > 35) {
> this._alpha = this._alpha - 11;
> } else {
> delete this.onEnterFrame;
> }
> }
> }
>
> To be really sure about it, let's make sure to set _alpha to exactly 35,
> for good measure, at the right time.
>
> yourMovieClipInstanceName.onRollOver = function() {
> this.onEnterFrame = function() {
> if (this._alpha > 35) {
> this._alpha = this._alpha - 11;
> } else {
> this._alpha = 35;
> delete this.onEnterFrame;
> }
> }
> }
>
> Badda bing. This is very similar to how it would be done with an on()
> handler, so if you really prefer to go that route, toy with the essential
> mechanism of what I've shown here. Using the above sample, you should try
> to reverse the situation for the onRollOut even of the same clip. Just
> write *that* event handler underneath the first (or over it; makes no
> difference).
>
>
> David
> stiller (at) quip (dot) net
> "Luck is the residue of good design."
>