[rfc][icedtea-web][policyeditor] Invoking runnables on EDT

[Andrew Azores]

Hi,

PolicyEditor has a few odd cases with window resizing and with "changes 
made" being marked as true when the editor is opened without any 
arguments. Both of these cases arise because although the EDT is the 
current thread when these actions are taken, they are (for safety, in 
case they are invoked by a non-EDT thread) wrapped in a 
SwingUtilities.invokeLater call. In the case of "changes made", this 
leads to addNewCodebase("") (adding the default all-applets codebase) 
marking "changes made" as true when the PolicyEditor is instantiated, 
even though the constructor has setChangesMade(false) immediately after 
the addNewCodebase call. This happens because the addNewCodebase() call 
updates the UI and so its main functionality is within an invokeLater - 
including the setChangesMade(true) call. Although a simple fix would be 
to pull the setChangesMade out of the invokeLater block, this would mean 
that the editor could potentially report changes made before the UI 
updates, which I'd like to avoid. Another solution would be to also wrap 
the setChangesMade(false) in the constructor in yet another invokeLater, 
but this is messy, and as this doesn't touch any UI elements it's also 
unnecessary. And another solution, which this patch implements, is to 
use a helper method, here called invokeRunnableOrEnqueueLater, which 
replaces SwingUtilities.invokeLater in the PolicyEditor. If the current 
thread is already the EDT then it calls Runnable#run() directly on its 
sole parameter. If the current thread is not the EDT then the runnable 
argument is passed along to SwingUtilities.invokeLater to be enqueued 
and processed as usual.

A similar technique was used for 
updateCheckboxes/updateCheckboxesInvokeAndWait/updateCheckboxesImpl, 
although in that case it was SwingUtilities.invokeAndWait rather than 
invokeLater. These have been slightly refactored to go along with the 
new method.

Thanks,

-- 
Andrew A

-------------- next part --------------
A non-text attachment was scrubbed...
Name: policyeditor-invoke-runnable-edt.patch
Type: text/x-patch
Size: 6162 bytes
Desc: not available
URL: <http://mail.openjdk.java.net/pipermail/distro-pkg-dev/attachments/20140624/5c887955/policyeditor-invoke-runnable-edt-0001.patch>