| [riena-dev] 3.4 Tree Databinding |
Hi Christian & Carsten, I spend some time today to look at the Tree Databinding in 3.4. The attached .zip contains an example project that should work in Eclipse 3.4. Make sure to disable the Riena target first. Requirements: In general I like the 3.4 approach for Trees because it is very simple. The bean in the tree has to satisfy these requirements: - a pair of get/setXXXXX methods that provide access to a Set/List of children - a pair of get/setXXXXX methods that provide access to a Value Drawbacks: - all Beans have to be of the same class (in the example: StringBean) - beans have to provide access to the Set/List of their children - label provider does not support images (but we can easily add support for fixed style "folder" images) See my modified StringBean class and Snippet020StringBean for details. Recommendation: Assuming we can break API: (a) if we are ok with imposing the above requirements on the bean we could have a method like: AnyBean rootElement; treeRidget.bind(rootElement, AnyBean.class, "children", "value"); // "children" -> beanInstance#get/setChildren() // "value" -> beanInstance#get/setValue() and get rid of the ITreeNode / ITreeModel and subclasses. (b) Additionally, a more flexible approach that requires wrapping is using a very light-weight ITreeNode that satisfies the requirements above. Based on the original ITreeNode I've created a minimal version that has only get/setChildren; get/setValue; getParent methods. All other functionality has moved away from the interface into a utility class TreeNodeUtils. This makes the implementation of ITreeNode very easy, while providing the same amount of functionality (comparable to the original ITreeNode / ITreeModel). The only thing missing is support for the ITreeNodeModelListener, which is not needed anymore. See ITreeNode / TreeNode / Snippet020TreeNode for details. The benefit of this approach is that we can still use the Eclipse Databinding; but can wrap more than one bean type at a time. I.e. from Eclipse POV we bind to the type TreeNode; however the TreeNode can wrap any bean. This style also imposes less requirements on the Bean. The drawback is the wrapping. The usage would be the same, so it can be combined with approach (a): TreeNode rootElement; treeRidget.bind(rootElement, TreeNode.class, "children", "value"); Let me know what you think of this. @Carsten: if you would like to discuss, feel free to join our call on Wednesday or contact me via skype. Kind regards, Elias. --- Elias Volanakis Technical Lead Innoopract, Inc. 351 NW 12th Avenue Portland, Oregon 97209 Tel: +1-503-552-1457 Fax: +1-503-715-4915 Mobile: +1-503-929-5537 evolanakis@xxxxxxxxxxxxxx http://rapblog.innoopract.com
Attachment:
tree_binding_example_34.zip
Description: tree_binding_example_34.zip