Using percentages in the past, circa 2014/15, could noticeably affect layout
speed, but devices are so fast anymore that I don't recommend spending the time
to do this.
But if you want to, the most efficient place to do your sizing (I like Bill's
approach) is to override UIComponent.measure() and add the scaling logic there.
The reason is because creationComplete() isn't fired until the displayList has
been measured and rendered so you are sizing everything twice.
But keep in mind that every size change you make to a component's bindable
properties (like width/height) in your creationComplete handler causes every
component in the display list for that component to re measure and be rendered
all over again as you apply the changes, causing a ripple effect.
Any change you make to a component's bindable property like width/height fires
a property change event that has to be handled, and that change will likely
fire change events on every component up the display list. Flash/AIR is
optimized to prevent property change events from firing up the chain when it
calculates sizes from properties set in MXML, or applied in actionscript before
measure() is called in the layout sequence.
Just do all your measuring and sizing in the measure() function to be most
efficient, but I still believe Flash/AIR is really good at working with
percentages and the development speed/efficiency gains of using percentages is
totally worth the cost of not having to write a lot of scaling logic, IMHO. :-)
override protected function measure():void {
// size all your components here and then call super.measure() - this is easy
to test
// just drop this code into any UIComponent derived component add sizing logic
super.measure();
}
Erik
On May 23, 2018, at 6:51 PM, bilbosax <waspenc...@comcast.net> wrote:
leokan23, I don't know if this will help you, but I will tell you my process
for laying things out. I do not place and widths, heights, positions, or
paddings in my MXML. When you use percentages for these settings, AIR has
to do a lot of self-measuring, calculating, and then laying out components
and this can be expensive on mobile devices, especially all of the
self-measuring.
It is a little more laborious, but I lay everything out manually, but for my
rather large app, it has helped performance a lot. So in the main app in
the Application tag, I listen for the applicationComplete event. When it
fires, I get the width and height of the device I am on using the following.
AppVars.appWidth = stage.stageWidth;
AppVars.appHeight = stage.stageHeight;
AppVars is just a dummy class that I made to hold a bunch of values that can
be shared across all of my components so I just have to measure the
dimensions one time when the app boots up. After that, in each component
that I create, I listen for the creationComplete event and set all my
widths, heights, positions and paddings manually like this:
<s:BorderContainer xmlns:fx="http://ns.adobe.com/mxml/2009";
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
creationPolicy="all"
creationComplete="init(event)" visible="false">
<fx:Script>
<