Bug 139110 GUI enhancement to support create subquery more conveniently.
Description: GUI enhancement to support create subquery more conveniently. Steps to reproduce: Subquery means insert table/list inside another table/list item, and the inner table/list item doesn't has its own dataset binding. In latest build, if you want to creat a subquery structure, you have to use dataSetRow as binding expression for data items in inner table/list item. For example: 1. Insert a list, generate column data binding for it. 2. Add a group for the list. 3. Insert table to list group header which is used to display data rows in list group. Dont' bind table to dataset. 4. Insert a data to table detail row. 5. New a binding column for data, click to Open Expression Builder. The issue is that only "Availabel column bindings" is listed in Category but no "Available Data Sets". So I have to type dataSetRow[".."] by myself to generate correct subquery. For users, maybe they will mistakenly use "Available column bindings" which will generate expression like row._outer[".."] and get wrong result. So it is recommended to add "Available Data Sets" in Expression Builder for such case.
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
StringBuffer s = new StringBuffer( 100 );
			for ( int i = 0; i < quotient; i++ )
			{
				s.append( defaultDecs );
			}
			s.append( defaultDecs.substring( 0, remainder ) );
			decStr = s.toString( );
		}
		return decStr;
	}
	/**
	 * @param transferSource
	 * @return true if parameter is parameter group.
	 */
	public static boolean isParameterGroup( Object transferSource )
	{
		return ( transferSource instanceof IDesignElement && ( (IDesignElement) transferSource ).getDefn( )
				.getName( )
				.equals( ReportDesignConstants.PARAMETER_GROUP_ELEMENT ) );
	}
	/**
	 * @return Alphabetically sortted styles list.
	 */
	public static Iterator getStyles( )
	{
		return getStyles( new AlphabeticallyComparator( ) );
	}
	/**
	 * @param comparator
	 * @return return styles list sortted with given comparator.