oh i suppose you also need to reset the value in onBeforeRender(). it's a
small pain, but how often does this really become a quantifiable problem and
not just a worry?
Jonathan Locke wrote:
>
>
> sure, that's the clean way to do it, but it comes at the expense of
> possibly breaking user code by surprise.
>
> i'm not sure how big of a deal this is. i've heard people talk about it,
> but i'd be interested in some examples of how performance of this method
> has been a problem for people. i've never run into it myself and if i did
> see it in a profiler, i'd probably just cache the value in a Boolean. it's
> literally just this little bit in your anonymous class:
>
> Boolean visible = null;
> public isVisible() {
> if (visible == null) {
> visible = // whatever boolean computation
> }
> return visible;
> }
>
> and then it disappears from the profiler and who cares about the rest.
>
>
> Scott Swank wrote:
>>
>> My idea what an inversion of that one:
>>
>> Add a method to Component, such as isVisibleInternal() [no I don't
>> love the name] that would cache the results of isVisible(). Then all
>> code that currently calls isVisible() would be changed to call
>> isVisibleInternal() instead. Someone who really wanted non-cached
>> visibility (seemingly the 1% case) could override isVisibleInternal(),
>> but everyone else would get caching for free with their current code.
>>
>> On Thu, Jan 15, 2009 at 2:35 PM, Jonathan Locke
>> <[email protected]> wrote:
>>>
>>>
>>> well, one simple design that would avoid the reuse problem is:
>>>
>>> Boolean Component#isCachedVisible() { return null; }
>>>
>>> then override to use visibility caching and return true or false.
>>> if you don't override you get the current functionality.
>>> of course you need two more bits in Component to support this...
>>> one for whether isCachedVisible returned non-null and another
>>> for the value it returned.
>>>
>>
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