"immediately" is at load time, it is the default, but should only be
used for constant expressions.
"once" is at init time, it can refer to other nodes that precede this
one.
"always" is a constraint, it will track changes in the referred to
values.
Here's a slightly more obvious example:
<canvas>
<simplelayout spacing="5" />
<slider id="m" value="25" minvalue="0" maxvalue="100" />
<text text="$immediately{'immediately: ' + m.value}" />
<text text="$once{'once: ' + m.value}" />
<text text="$always{'always: ' + m.value}" />
</canvas>
On 2008-05-22, at 14:53 EDT, Lou Iorio wrote:
I'm looking at LPP-2037.
I'd like to provide a simple example that illustrates the different
values for
constraints in tags, something like this:
<canvas>
<view x="250" width="20" height="20" bgcolor="red" y="$once{m.y}"/>
<view x="280" width="20" height="20" bgcolor="blue"
y="$immediately{m.y}"/>
<view x="310" width="20" height="20" bgcolor="green"
y="$always{m.y}"/>
<window id="m" x="10" title="Drag me" width="160" height="20"/>
</canvas>
I don't understand the difference between "once" and "immediately",
and this
example doesn't illustrate the difference.
What's the difference, and is there a better example I can use?
Thanks,
Lou
