AOO410/main/odk/examples/DevelopersGuide/Forms/ComponentTreeTraversal.java

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 * Licensed to the Apache Software Foundation (ASF) under one
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 * to you under the Apache License, Version 2.0 (the
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import com.sun.star.uno.*;
import com.sun.star.container.*;
import com.sun.star.lang.*;

/**************************************************************************/
/** an abstract interface for components doing an action on a form component
*/
interface IFormComponentAction
{
	public abstract void handle( Object aFormComponent ) throws java.lang.Exception;
};

/**************************************************************************/
/** a helper class for travelling a form component tree
*/
class ComponentTreeTraversal implements IFormComponentAction
{
	/* ------------------------------------------------------------------ */
	/** Indicator method to decide wether to step down the tree.

		<p>The default implementation checks if the container given is a grid
		control model or a <service scope="com.sun.star.form">FormComponents</service>
		instance.</p>
	*/
	protected boolean shouldStepInto( XIndexContainer xContainer ) throws com.sun.star.uno.Exception
	{
		// step down the tree, if possible
		XServiceInfo xSI = UNO.queryServiceInfo( xContainer );
		if	(	null != xSI
			&&	(	xSI.supportsService( "com.sun.star.form.FormComponents" )
				||	xSI.supportsService( "com.sun.star.form.component.GridControl" )
				)
			)
		{
			return true;
		}
		else
		{
			return false;
		}
	}
	/* ------------------------------------------------------------------ */
	public void handle( Object aFormComponent ) throws com.sun.star.uno.Exception
	{
		XIndexContainer xCont = UNO.queryIndexContainer( aFormComponent );
		if	(	( null != xCont )
			&&	shouldStepInto( xCont )
			)
		{
			for ( int i=0; i<xCont.getCount(); ++i )
			{
				handle( xCont.getByIndex( i ) );
			}
		}
	}
}