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https://issues.apache.org/jira/browse/PIVOT-743?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13034794#comment-13034794
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Andrei Pozolotin commented on PIVOT-743:
----------------------------------------
APPLETS:
1) re: "The issues you describe could very easily be due to the plugin
implementation on Linux"
2) I verified this page:
http://www.carrotgarden.com:8080/webstart-carrot-bug-pivot-applet-static-staging/index-applet.jsp?plugin=V1
on:
* windows 7 (6.1 b 7600)
java version "1.6.0_23"
Java(TM) SE Runtime Environment (build 1.6.0_23-b05)
Java HotSpot(TM) 64-Bit Server VM (build 19.0-b09, mixed mode)
- firefox 4.0.1
- internet explorer 8.0.7600
- google chrome 11.0.696.68
* ubuntu 10.04 2.6.32-29-generic #58-Ubuntu SMP Fri Feb 11 20:52:10 UTC 2011
x86_64 GNU/Linux
java version "1.6.0_24"
Java(TM) SE Runtime Environment (build 1.6.0_24-b07)
Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02, mixed mode)
- firefox 3.6.17
- google chrome 11.0.696.68
* macosx 10.6.7
java version "1.6.0_24"
Java(TM) SE Runtime Environment (build 1.6.0_24-b07-334-10M3326)
Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02-334, mixed mode)
- firefox 3.6.6
- google chrome 11.0.696.68
- safari 5.0.5
3) and confirmed that "counter still goes up";
which means that the perferred way you use to start all your pivot apps:
http://pivot.apache.org/demos/kitchen-sink.html
var attributes = {
code:"org.apache.pivot.wtk.BrowserApplicationContext$HostApplet",
width:"100%",
height:"100%"
};
var libraries = [];
libraries.push("/lib/pivot-core-2.0.jar");
libraries.push("/lib/pivot-wtk-2.0.jar");
libraries.push("/lib/pivot-wtk-terra-2.0.jar");
libraries.push("/lib/pivot-tutorials-2.0.jar");
libraries.push("/lib/svgSalamander-tiny.jar");
attributes.archive = libraries.join(",");
var parameters = {
codebase_lookup:false,
application_class_name:'org.apache.pivot.tutorials.KitchenSink'
};
var javaArguments =
["-Dsun.awt.noerasebackground=true","-Dsun.awt.erasebackgroundonresize=true"];
parameters.java_arguments = javaArguments.join(" ");
deployJava.runApplet(attributes, parameters, "1.6");
4) which is so called "legacy plugin mode",
will share all static fields between applet invocations,
even if you navigate away form applet and then come back
(the timeout is about 2 minutes for jvm to expire, when there are no active
applets,
but static fields are still active before jvm expires)
5) re "The static fields are there by design"; indeed, I understand;
I am merely asking to improve the design; what I would ideally want is:
a) instaniate all of pivot as a single instance via spi;
b) no static fields - based singletons inside pivot framework;
c) pivot caches watever it wants in singletons (which are not static fields);
> pivot & static
> --------------
>
> Key: PIVOT-743
> URL: https://issues.apache.org/jira/browse/PIVOT-743
> Project: Pivot
> Issue Type: Improvement
> Affects Versions: 2.0
> Reporter: Andrei Pozolotin
> Fix For: 2.1
>
>
> Greg, hello:
> 1) in this example you say:
> http://pivot.apache.org/tutorials/list-buttons.html
> "Note that this example makes use of the global resource cache to store the
> loaded images."
> 2) which reminds of the "java evil singleton pattern"
> http://java.sun.com/developer/technicalArticles/Programming/singletons/
> http://www.ibm.com/developerworks/webservices/library/co-single/index.html
> http://beust.com/weblog/2011/03/10/rehabilitating-the-singleton-pattern/
> http://tech.puredanger.com/2007/07/03/pattern-hate-singleton/
> and the consensus seems to be:
> "Singletons are fine as long as you don't implement them with static"
> 3) and pivot uses them freely; few examples
> public abstract class ApplicationContext {
> protected static ArrayList<Display> displays = new ArrayList<Display>();
> protected static ArrayList<Application> applications = new
> ArrayList<Application>();
> private static HashMap<URI, Object> resourceCache = new HashMap<URI,
> Object>();
> private static ResourceCacheDictionary resourceCacheDictionary = new
> ResourceCacheDictionary();
> public abstract class Theme {
> private static Theme theme = null;
> 4) do you think is it feasible to convert all of pivot into SPI:
> ServiceLoader<PivotFrameworkFactory> loader =
> ServiceLoader.load(PivotFrameworkFactory.class);
> PivotFrameworkFactory factory = loader.iterator().next();
> Map<String, Object> config = new HashMap<String, Object>();
> PivotFramework framework = factory.newFramework(config);
> 5) the two use cases that affect me now:
> a) applet reload shares static
> b) pivot + osgi (not sure yet if I can find a workaround; possibly depends on
> what you do about PIVOT-742 PIVOT-22)
> thank you;
> Andrei
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