| [ve-dev] More SWT issues |
While we're on the topic of SWT support, I thought I'd document a few other SWT quirks that will need addressing at the codegen and other levels: * ControlEditor (used by Table, TableTree, and Tree for hooking up edit controls as editors) inherits from Object * The approved way to "subclass" an SWT control is to embed it in a Composite and then make the Composite a decorator of the embedded control. This works fine until one needs to add children to the embedded control. For example, suppose someone wanted to subclass Table in order to create a version that had some default cell editing behavior. It would still be necessary for clients to be able to add TableColumns, Widgets, and possibly ControlEditor objects as children of the *TABLE* in the containership hierarchy, not as children of the *enclosing* Composite. Similarly, JFace Viewers don't inherit from anywhere in the SWT hierarchy, and have the same problem to solve WRT adding child controls. JFace's solution to this problem is to have a: public Control getControl(); method that returns the underlying control for clients that need to access it directly (for whatever reason). At ASC, in our custom SWT controls, we have followed JFace's lead and always provide a getControl() method on our SWT controls if the SWT control is really a Composite that encapsulates some other control. Therefore, when adding child controls to some arbitrary control, it is necessary to java.lang.Reflect for a getControl() method and if found, use the result of calling it as the parent object rather than using the "parent" control itself. Establishing this convention will take us a good way toward JFace support in VE and will automatically support all new SWT and JFace controls that follow this coding convention. * There are variations in what class the "parent" argument should be and if there are style bits across the SWT class hierarchy. This will need to be addressed in the target vm. I've attached a utility class from XSWT that can construct arbitrary SWT controls. That's all I can think of right now off the top of my head. Eric, Kosta, can you think of anything else right now? Dave
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ClassBuilder.java
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