Eclipse Debug Views Update Policy

2 Agenda  Background  Requirements  How does it work now?  How to make it more flexible?

3 Background  Debug Views Update is inflexible and is driven by a pre- defined set of events.  Model cannot control when / how updates are to be commenced  Difficult to define a strategy that is suitable for all debug adapters.

4 Requirements  Make debug views update more flexible – give models better control.  Allow a view to have different update policies.  Allow models to specify different update policies for different views.  Example Policies:  Update what’s visible  Update nothing  Update all  Periodic update  Etc.

5 How does it work now?

6 How to make it more flexible?  Replace static event handler with pluggable updaters.  Updater are bound to a view using the view id and the model identifier of the input element.  Create updater when new input is set to the view.  Updater controls when view is to be populated.

7 How to make it more flexible?  Specialized updaters  Selection Event Updater  Debug Event Updater  Delayed Debug Event Updater  Timer Updater  Preference Store Changed Updater  Etc.  Updaters are responsible for controlling when a view gets content from the model.  Extends IDebugView: IDebugViewExtension.  APIs to allow updaters to update views.  Debug Platform is to provide implementations to some generic updaters.  Clients can also implement their own updaters.

8 Contributing Updaters – extension point  Clients can contribute an updater to a specific view.  Updaters are bound by model identifier and view id.  If no updater is specified, a debug view uses its current event handler as its updater.

9 Handling Multi-Targets View Multi-Targets View Static View Input Model A Model B Model C Updater 1 Updater 2 Update (elementA) Updater 3 Updater 4  Views showing content from different targets simultaneously.  Example: Debug View, Expression View  View has static view input.  Retrieve updater as new models are added.  Updaters are responsible to update elements from its model, not the entire view. Update (elementB) Update (elementC)

10 Fitting into the new scheme…  Separate out logic of view updates from view.  Updaters have no knowledge about its view.  View updates are performed via a generic interface.  Views are not tied to any updater.  View event notifications are also performed via a generic interface.  Generic View needs to handle view updater extension point and honor contributed updaters.  Easy to migrate. Generic Debug View IDebugElement View Updaters Generic Interface for Update (Update an element and its children) Generic Interface for View Events Notification