On 5/18/18, 2:50 AM, "Harbs" <harbs.li...@gmail.com> wrote:
And basic.css has:
RadioButton
{
font-size: 12px;
font-family: sans-serif;
}
RadioButton is a Royale Type Selector as it should be. No discussion on
that front (with the exception that the styling should be removed from the
defaults.css).
Te whole question is what happens in MyApp.css which is compiled standard
HTML CSS.
Currently we get:
.RadioButton {
font-family: sans-serif;
font-size: 12px;
}
This CSS comes from the Type Selector in basic.css. This seems to be
included in the app.css even if RadioButton is not included. But putting that
point aside at the moment, the question is what the class selector (in app.css)
should be *produced* from the type selector.
It is not obvious why RadioButton is in the app.css. This might be a new bug
from the theme handling I did recently. I will investigate more.
I think we agree that “.RadioButton" is not right because there can be
RadioButton from more than one component set.
One option is to fully qualify the *compiled* class selector so it’s named
“.org_apache_royale_html_RadioButton”. I’m pretty sure this is what you are
proposing. The primary objection to that is that it’s a rather long string and
kind of “ugly”.
You can choose other string transformations, but the key point is that they
should be derived from the unique QName. Any other scheme just means that the
developer has to solve the unique name problem twice which increases the chance
of collision.
Another option is “.basic.Button”. The advantage of this approach is mostly
aesthetics. It also has the advantage of being theoretically more flexible
because CSS can be applied to “basic" and “Button” separately. Of course that
goes both ways and if there’s css applied to “.Button” by mistake, it can
effect the “basic” Button where it’s not supposed to.
I'm not clear how the compiler or the ValuesManager (at runtime) can
efficiently associate .basic.Button with org.apache.royale.basic.Button.
Metadata lookups can be expensive.
> If one problem is with Type Selectors in Royale inheriting styles from
Base Classes, we should discuss ways to manage that. Metadata is possible, but
metadata is expensive at runtime.
Good point about extra code from meta tags. Maybe the compiler could strip
these out?
My point is that ValuesManager will need this information at runtime.
My suggestion with meta-data was a way to enable the second option. It does
not need to be specifically meta-tags. It could be something like this as well:
/**
* royaleclassselector RadioButton
* royaleclassprefix basic
* royaleinheritsbaseselector
*/
These ASDoc directives are definitely not available at runtime.
> There are two parts to how Type Selectors work. The main concern appears
to be the ClassReferences kind of CSS, which is not handled by the Browser.
The IValuesImpl has to decide whether to look up the base class and it would
have to fetch and parse metadata at runtime to do that. And, as I mentioned
earlier, I'm not sure the compiler can know whether the base class is in the
output because it was directly instantiated or not.
I’m not sure how the IValuesImpl actually works, so I have no thoughts on
this front. I’m not clear on whether there is currently an issue with that.
I’ve been discussing plain CSS which *is* handled by the browser.
> Historically, the only reason Type Selectors inherit from Base Classes in
Flex is because of app developer subclassing. For sure, we the framework
developers can always take the time to fill out the Type Selectors such that
the lookup never goes to the Base Class. But the app devs just want to use a
component as the top tag in an MXMLComponent or do a cheap "MyButton extends
Button" in AS. And without inheritance, you don't get any defaults and things
blow up.
>
> We could say to the app devs:: "too bad, in Royale you gotta copy the
base class type selector". I would imagine non-Royale folks have to copy HTML
Type Selectors in some cases already.
>
> We could try to find all subclasses of classes that have Type Selectors
that don't have their own Type Selector and have the compiler auto-copy that
base class Type Selector (or add the subclass to the list of classes for that
selector.
I think we *should* have inheritance (like we have today) unless a subclass
specifically disables it using metadata or what-have-you.
Let's try some example code:
<Application>
<initialView>
<View>
<ComboBox>
<RadioButton />
</View>
</iniialView>
</Application>
Button will be linked in because ComboBox composites a Button. It will also be
linked in because RadioButton subclasses Button. There is code in IValuesImpls
that loop through the base classes to resolve Type Selector inheritance.
Roughly:
Var baseClass:Class = thisObject.getBaseClass();
While (baseClass) {
Var qname = getQualifiedClassName(baseClass);
Var stylesObject:Object = styles[qname];
If (stylesObject != null && stylesObject[styleProp] !== undefined)
Return stylesObject[styleProp]
baseClass = baseClass.getBaseClass();
}
When looking up styles for RadioButton, if you don't want this code to then go
check for Button (which will rightly be in the app.css because of ComboBox) you
will need some metadata or other information at runtime. You can't rely on the
Button styles not being there because the compiler saw the metadata on
RadioButton and decided not to put the Button styles in the app.css.
And also, I don't think there is a way to easily know what caused a reference
to Button in the first place. Take out ComboBox and replace it with:
<fx:Script>
Var foo:Button;
</fx:Script>
Button never gets instantiated, but it was used and therefore linked in. I
don't see how the compiler could know that Button was never directly
instantiated and thus can be pruned from the app.css.
That's why instead of coming up with fancy pruning schemes, I recommend that we
try different ways of solving the problems caused if Type Selectors don't
inherit styles from base classes ever. Then the code in the IValuesImpl
wouldn't have a loop. Then maybe the compiler should detect that a simple
subclass has no styles and add that subclass to the styles in the app.css
MyRadioButton, RadioButton {
...
}
Thoughts?
-Alex
