[svn] 2700: With the Marshal Plan, when create an instance of a manager, we need to talk to the system manager.

Question

Revision: 2700
Author: [email protected]
Date: 2008-07-31 21:12:03 -0700 (Thu, 31 Jul 2008)
Log Message:
With the Marshal Plan, when create an instance of a manager, we need to talk to the system manager. Unfortunately sometimes these manager instances can be created before the Application class is created and/or before the systemManager property is set on the application. So to get the reference to the system manager from the manager instances, we can't use ApplicationGlobals.application.systemManager. We need to use SystemManagerGlobals.topLevelSystemManagers[0] instead. This property is set in the SystemManager constructor, and fortunately for us, Flash runs your root display object's constructor before anything else, even before static initializers (atleast ones not defined in SystemManager or a dependency of it).
QE: Yes
Doc: No
Bugs: SDK-16207, SDK-16208, SDK-16209
Reviewer: Alex
Ticket Links:
http://bugs.adobe.com/jira/browse/SDK-16207
http://bugs.adobe.com/jira/browse/SDK-16208
http://bugs.adobe.com/jira/browse/SDK-16209
Modified Paths:
flex/sdk/branches/3.0.x/frameworks/projects/framework/src/mx/managers/CursorManagerImpl.a s
flex/sdk/branches/3.0.x/frameworks/projects/framework/src/mx/managers/ToolTipManagerImpl. as

Answer 1

an instance p for Point class is created like this?
Instead we can create and instance of Point class
as:
Point p = new Point();
Can any one of you explain this?Your Point() constructor doesn't throw exceptions, so there's no need to catch them. The Class.forName() and Class.getInstance() methods can throw exceptions, so it's necessary to handle them if they arise. Check out the docs for those methods, it lists what exceptions they can throw.
http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Class.html#forName(java.lang.String)
http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Class.html#newInstance()
2) In the above Class Point what is the use of
creating an instance of Point with in that Point
class?
static Point origin = new Point(0,0);
What the reason to create an instance like this
within the same class. We can create this instance of
point
class when ever we need. There doesn't seem to be any in your code, since that variable is never accessed. It could be useful if you wanted to have a Point that was shared across all instances. This is not a good example of that though.