Enable and disable operations

From AIBenchWiki

In order to make the AIBench applications more user-friendly, we have added the possibility to enable and disable operations via these 2 changes:

• Added two methods to the Core: enableOperation(String uid) and disableOperation(String uid), that can be used to change the operation state at run-time.
• Added the boolean "enabled" attribute to the @Operation annotation. This attribute controls if the operation is enabled/disabled at startup.

Example

A typical usage of this new functionality is to enable an operation only when some object of a specific datatype is available in the Clipboard. You have to follow these steps:

1. Disable the operation by default with:

@Operation(name="operation", enabled=false)

2. Add a PluginLifecycle class configuring it in the plugin.xml

<plugin start="true">
	<uid>myplugin</uid>
	<name>MyPlugin</name>
	   <version>0.1</version>
	<lifecycleclass>myplugin.Lifecycle</lifecycleclass>
...

3. In the lifecycle class, add your custom ClipboardListener where you can enable and disable operations.

public class Lifecycle extends PluginLifecycle {
	...
	public void start(){		
	  Core.getInstance().getClipboard().addClipboardListener(new ClipboardListener(){ //the clipboard listener
	    public void elementAdded(ClipboardItem arg0) {
	      //Enable the operation if an object of class String is in the clipboard
	      if (Core.getInstance().getClipboard().getItemsByClass(String.class).size()>0){
	        Core.getInstance().enableOperation("operationuid");
	      }
           }
		
           public void elementRemoved(ClipboardItem arg0) {
	      //Disable the operation if no object of class String is in the clipboard
             if (Core.getInstance().getClipboard().getItemsByClass(String.class).size()==0){
	        Core.getInstance().disableOperation("operationuid");
	      } 			
           }
			
         });
      }
}

Clipboard-based enabling/disabling operations

Here is a utility class to enable/disabling operations, based on the existence of objects of a given class in the clipboard. This class has to be connected as a ClipboardListener (the programmer is responsible of doing this!)

class ClipboardBasedOperationActivator implements ClipboardListener{
	

  HashMap<String, HashSet<Class>> operationRequirements = new HashMap<String, HashSet<Class>>();
	
  public void addRequirement(String uid, Class c){
    HashSet<Class> reqs = operationRequirements.get(uid);
    if (reqs == null){
      reqs = new HashSet<Class>();
      operationRequirements.put(uid, reqs);
    }
    reqs.add(c);		
  }
	
  private void processClipboard(){
    for (String uid: operationRequirements.keySet()){
      boolean requirementsSatisfied = true;
      for (Class c: operationRequirements.get(uid)){
        if (Core.getInstance().getClipboard().getItemsByClass(c).size()==0){
          requirementsSatisfied = false;
          break;
        }
      }
      if (requirementsSatisfied){
        Core.getInstance().enableOperation(uid);
      }else{
        Core.getInstance().disableOperation(uid);
      }
    }
		
  }
  public void elementAdded(ClipboardItem arg0) {
    processClipboard();
  }
  
  public void elementRemoved(ClipboardItem arg0) {
    processClipboard();
  }
}