Tree views
Use a tree view to display objects, such as folders, in a hierarchical manner.
Objects in the tree view are nodes. The highest node is the root node. A node in the tree can have child nodes under it. A node that has a child is a parent node.
Users can perform the following action in a tree view:
Action |
BlackBerry devices without a touch screen |
BlackBerry devices with a touch screen |
|---|---|---|
Expand or collapse an object with a plus sign (+) or minus sign (-) in a hierarchy . |
Press the Space key or click the trackwheel, trackball, or trackpad. |
Click the screen. |
Best practice: Implementing tree views
- Use the TreeField class to create tree views.
- On BlackBerry devices with a trackball or trackpad, provide a context menu if users can perform multiple actions when they click a parent node. For example, when users click a folder that contains subfolders and files, a context menu should appear that allows users to either expand the folder or view the files.
- Include a root node only if users need the ability to perform actions on the entire tree. Otherwise, exclude the root node.
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