path: root/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/ui/viewmodel/register/RegisterBitFieldVMNode.java

/*******************************************************************************
 * Copyright (c) 2006, 2014 Wind River Systems and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Wind River Systems - initial API and implementation
 *     Marc Khouzam (Ericsson) - Enable per-element formatting (Bug 439624)
 *******************************************************************************/
package org.eclipse.cdt.dsf.debug.ui.viewmodel.register;

import java.util.Map;
import java.util.Set;
import java.util.concurrent.RejectedExecutionException;

import org.eclipse.cdt.dsf.concurrent.ConfinedToDsfExecutor;
import org.eclipse.cdt.dsf.concurrent.CountingRequestMonitor;
import org.eclipse.cdt.dsf.concurrent.DataRequestMonitor;
import org.eclipse.cdt.dsf.concurrent.DsfRunnable;
import org.eclipse.cdt.dsf.concurrent.IDsfStatusConstants;
import org.eclipse.cdt.dsf.concurrent.ImmediateExecutor;
import org.eclipse.cdt.dsf.concurrent.RequestMonitor;
import org.eclipse.cdt.dsf.datamodel.DMContexts;
import org.eclipse.cdt.dsf.datamodel.IDMContext;
import org.eclipse.cdt.dsf.debug.service.IMemory.IMemoryChangedEvent;
import org.eclipse.cdt.dsf.debug.service.IRegisters;
import org.eclipse.cdt.dsf.debug.service.IRegisters.IBitFieldChangedDMEvent;
import org.eclipse.cdt.dsf.debug.service.IRegisters.IBitFieldDMContext;
import org.eclipse.cdt.dsf.debug.service.IRegisters.IBitFieldDMData;
import org.eclipse.cdt.dsf.debug.service.IRegisters.IMnemonic;
import org.eclipse.cdt.dsf.debug.service.IRegisters.IRegisterChangedDMEvent;
import org.eclipse.cdt.dsf.debug.service.IRegisters.IRegisterDMContext;
import org.eclipse.cdt.dsf.debug.service.IRegisters.IRegisterDMData;
import org.eclipse.cdt.dsf.debug.service.IRegisters.IRegisterGroupDMData;
import org.eclipse.cdt.dsf.debug.service.IRunControl.ISuspendedDMEvent;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.ErrorLabelForeground;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.ErrorLabelText;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.IDebugVMConstants;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.expression.AbstractExpressionVMNode;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.numberformat.FormattedValueLabelText;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.numberformat.FormattedValueRetriever;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.numberformat.IFormattedValueVMContext;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.register.RegisterBitFieldCellModifier.BitFieldEditorStyle;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.update.ElementFormatEvent;
import org.eclipse.cdt.dsf.debug.ui.viewmodel.variable.VariableLabelFont;
import org.eclipse.cdt.dsf.internal.ui.DsfUIPlugin;
import org.eclipse.cdt.dsf.service.DsfSession;
import org.eclipse.cdt.dsf.ui.concurrent.ViewerDataRequestMonitor;
import org.eclipse.cdt.dsf.ui.viewmodel.VMDelta;
import org.eclipse.cdt.dsf.ui.viewmodel.datamodel.AbstractDMVMProvider;
import org.eclipse.cdt.dsf.ui.viewmodel.datamodel.IDMVMContext;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.IElementPropertiesProvider;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.IPropertiesUpdate;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.LabelAttribute;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.LabelBackground;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.LabelColumnInfo;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.LabelForeground;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.LabelImage;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.LabelText;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.PropertiesBasedLabelProvider;
import org.eclipse.cdt.dsf.ui.viewmodel.properties.VMDelegatingPropertiesUpdate;
import org.eclipse.cdt.dsf.ui.viewmodel.update.ICachingVMProvider;
import org.eclipse.cdt.dsf.ui.viewmodel.update.StaleDataLabelBackground;
import org.eclipse.cdt.dsf.ui.viewmodel.update.StaleDataLabelForeground;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.model.IExpression;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IChildrenUpdate;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IElementCompareRequest;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IElementEditor;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IElementLabelProvider;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IElementMementoProvider;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IElementMementoRequest;
import org.eclipse.debug.internal.ui.viewers.model.provisional.ILabelUpdate;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IModelDelta;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext;
import org.eclipse.debug.ui.DebugUITools;
import org.eclipse.debug.ui.IDebugModelPresentation;
import org.eclipse.debug.ui.IDebugUIConstants;
import org.eclipse.debug.ui.actions.IWatchExpressionFactoryAdapter2;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.jface.viewers.CellEditor;
import org.eclipse.jface.viewers.ComboBoxCellEditor;
import org.eclipse.jface.viewers.ICellModifier;
import org.eclipse.jface.viewers.TextCellEditor;
import org.eclipse.jface.viewers.TreePath;
import org.eclipse.swt.widgets.Composite;

public class RegisterBitFieldVMNode extends AbstractExpressionVMNode 
    implements IElementEditor, IElementLabelProvider, IElementMementoProvider, IElementPropertiesProvider
{
	/**
     * @since 2.0
     */
    private static final String PROP_BITFIELD_SHOW_TYPE_NAMES = "bitfield_show_type_names"; //$NON-NLS-1$
    
    protected class BitFieldVMC extends DMVMContext
        implements IFormattedValueVMContext
    {
        private IExpression fExpression;
        public BitFieldVMC(IDMContext dmc) {
            super(dmc);
        }
        
        public void setExpression(IExpression expression) {
            fExpression = expression;
        }
        
        @Override
        @SuppressWarnings({ "rawtypes", "unchecked" }) 
        public Object getAdapter(Class adapter) {
            if (fExpression != null && adapter.isAssignableFrom(fExpression.getClass())) {
                return fExpression;
            } else if (adapter.isAssignableFrom(IWatchExpressionFactoryAdapter2.class)) {
                return getWatchExpressionFactory();
            } else {
                return super.getAdapter(adapter);
            }
        }
    
        @Override
        public boolean equals(Object other) {
            if (other instanceof BitFieldVMC && super.equals(other)) {
                BitFieldVMC otherBitField = (BitFieldVMC)other;
                return (otherBitField.fExpression == null && fExpression == null) ||
                       (otherBitField.fExpression != null && otherBitField.fExpression.equals(fExpression));
            }
            return false;
        }
        
        @Override
        public int hashCode() {
            return super.hashCode() + (fExpression != null ? fExpression.hashCode() : 0);
        }
    }

    protected class BitFieldExpressionFactory implements IWatchExpressionFactoryAdapter2 {
        
        @Override
        public boolean canCreateWatchExpression(Object element) {
            return element instanceof BitFieldVMC;
        }
        
        /**
         * Expected format: GRP( GroupName ).REG( RegisterName ).BFLD( BitFieldname )
         */
        @Override
        public String createWatchExpression(Object element) throws CoreException {
            IRegisterGroupDMData groupData = getSyncRegisterDataAccess().getRegisterGroupDMData(element);
            IRegisterDMData registerData   = getSyncRegisterDataAccess().getRegisterDMData(element);
            IBitFieldDMData bitFieldData   = getSyncRegisterDataAccess().getBitFieldDMData(element);

            if (groupData != null && registerData != null && bitFieldData != null) { 
                StringBuffer exprBuf = new StringBuffer();
                
                exprBuf.append("GRP( ");   exprBuf.append(groupData.getName());    exprBuf.append(" )"); //$NON-NLS-1$ //$NON-NLS-2$
                exprBuf.append(".REG( ");  exprBuf.append(registerData.getName()); exprBuf.append(" )"); //$NON-NLS-1$ //$NON-NLS-2$
                exprBuf.append(".BFLD( "); exprBuf.append(bitFieldData.getName()); exprBuf.append(" )"); //$NON-NLS-1$ //$NON-NLS-2$
                
                return exprBuf.toString();
            }

            return null;
        }
    }
    
    private SyncRegisterDataAccess fSyncRegisterDataAccess = null;
    protected IWatchExpressionFactoryAdapter2 fBitFieldExpressionFactory = null; 
    
    /**
     * The label provider delegate.  This VM node will delegate label updates to this provider
     * which can be created by sub-classes. 
     *  
     * @since 2.0
     */    
    private IElementLabelProvider fLabelProvider;

    /**
     * Retriever for formatted values configured for this VM node.
     * @since 2.2
     */
    private final FormattedValueRetriever fFormattedValueRetriever;
    
    public RegisterBitFieldVMNode(AbstractDMVMProvider provider, DsfSession session, SyncRegisterDataAccess access) {
        super(provider, session, IBitFieldDMContext.class);
        fSyncRegisterDataAccess = access;
        fLabelProvider = createLabelProvider();
        fFormattedValueRetriever = 
            new FormattedValueRetriever(this, session, IRegisters.class, IBitFieldDMContext.class);
    }

    @Override
    public void dispose() {
        super.dispose();
        fFormattedValueRetriever.dispose();
    }
    
    @Override
    public String toString() {
        return "RegisterBitFieldVMNode(" + getSession().getId() + ")";  //$NON-NLS-1$ //$NON-NLS-2$
    }

    private Object[] constructTypeObjects( Map<String, Object> properties ) {
    	int readAttr = 0;
        if ( Boolean.TRUE.equals(properties.get(IRegisterVMConstants.PROP_IS_READABLE)) ) { 
            readAttr = 1;
        } else if ( Boolean.TRUE.equals(properties.get(IRegisterVMConstants.PROP_IS_READONCE)) ) {
            readAttr = 2;
        }

        int writeAttr = 0;
        if ( Boolean.TRUE.equals(properties.get(IRegisterVMConstants.PROP_IS_WRITEABLE)) ) { 
            writeAttr = 1;
        } else if ( Boolean.TRUE.equals(properties.get(IRegisterVMConstants.PROP_IS_WRITEONCE)) ) {
            writeAttr = 2;
        }
        
        Object[] messageAttrs = new Object[] { readAttr, writeAttr };
        
    	return messageAttrs;
    }
    
    /**
     * Creates the label provider delegate.  This VM node will delegate label 
     * updates to this provider which can be created by sub-classes.   
     *  
     * @return Returns the label provider for this node. 
     *  
     * @since 2.0
     */    
    protected IElementLabelProvider createLabelProvider() {
        PropertiesBasedLabelProvider provider = new PropertiesBasedLabelProvider();

        // The name column consists of the bit field name.   
        provider.setColumnInfo(
            IDebugVMConstants.COLUMN_ID__NAME,
            new LabelColumnInfo(new LabelAttribute[] { 
                new LabelText(
                    MessagesForRegisterVM.RegisterBitFieldVMNode_Name_column__text_format, 
                    new String[] { PROP_NAME }),
                new LabelImage(DebugUITools.getImageDescriptor(IDebugUIConstants.IMG_OBJS_REGISTER)),
                new StaleDataLabelForeground(),
                new VariableLabelFont(),
            }));

        // The description column contains a brief description of the bit field. 
        provider.setColumnInfo(
            IDebugVMConstants.COLUMN_ID__DESCRIPTION,
            new LabelColumnInfo(new LabelAttribute[] { 
                new LabelText(
                    MessagesForRegisterVM.RegisterBitFieldVMNode_Description_column__text_format, 
                    new String[] { IRegisterVMConstants.PROP_DESCRIPTION }),
                new StaleDataLabelForeground(),
                new VariableLabelFont(),
            }));

        // In the type column add information about bit field read/write/fload flags.
        provider.setColumnInfo(
            IDebugVMConstants.COLUMN_ID__TYPE,
            new LabelColumnInfo(new LabelAttribute[] { 
                new LabelText(
                    MessagesForRegisterVM.RegisterBitFieldVMNode_Type_column__text_format, 
                    new String[] { 
                        IRegisterVMConstants.PROP_IS_READABLE, 
                        IRegisterVMConstants.PROP_IS_READONCE, 
                        IRegisterVMConstants.PROP_IS_WRITEABLE,
                        IRegisterVMConstants.PROP_IS_WRITEONCE}) 
                {
                    @Override
                    public void updateAttribute(ILabelUpdate update, int columnIndex, IStatus status, Map<String, Object> properties) {
                        Object[] messageAttrs = constructTypeObjects( properties );
                        try {
                            update.setLabel(getMessageFormat().format(
                                messageAttrs, new StringBuffer(), null).toString(), columnIndex);
                        } catch (IllegalArgumentException e) {
                            update.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, 0, "Failed formatting a message for column " + columnIndex + ", for update " + update, e)); //$NON-NLS-1$ //$NON-NLS-2$
                        }
                    }                    
                },
                new StaleDataLabelForeground(),
                new VariableLabelFont(),
            }));

        // Value column shows the value in the active value format, followed by the active mnemonic if one is 
        // available.
        // 
        // In case of error, show the error message in the value column (instead of the usual "...".  This is needed 
        // for the expressions view, where an invalid expression entered by the user is a normal use case.
        // 
        // For changed value high-lighting check the value in the active format.  But if the format itself has changed, 
        // ignore the value change.
        provider.setColumnInfo(
            IDebugVMConstants.COLUMN_ID__VALUE,
            new LabelColumnInfo(new LabelAttribute[] { 
                new FormattedValueLabelText(
                    MessagesForRegisterVM.RegisterBitFieldVMNode_Value_column__With_mnemonic__text_format, 
                    new String[] { 
                        IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE,
                        IRegisterVMConstants.PROP_CURRENT_MNEMONIC_LONG_NAME}), 
                new FormattedValueLabelText(),
                new ErrorLabelText(),
                new ErrorLabelForeground(),
                new LabelBackground(
                    DebugUITools.getPreferenceColor(IDebugUIConstants.PREF_CHANGED_VALUE_BACKGROUND).getRGB()) 
                {
                    { 
                        setPropertyNames(new String[] { 
                            IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE, 
                            ICachingVMProvider.PROP_IS_CHANGED_PREFIX + IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE,
                            IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT, 
                            ICachingVMProvider.PROP_IS_CHANGED_PREFIX + IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT}); 
                    }
    
                    @Override
                    public boolean isEnabled(IStatus status, java.util.Map<String,Object> properties) {
                        Boolean activeFormatChanged = (Boolean)properties.get(
                            ICachingVMProvider.PROP_IS_CHANGED_PREFIX + IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT);
                        Boolean activeChanged = (Boolean)properties.get(
                            ICachingVMProvider.PROP_IS_CHANGED_PREFIX + IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE);
                        return  Boolean.TRUE.equals(activeChanged) && !Boolean.TRUE.equals(activeFormatChanged);
                    }
                },
                new StaleDataLabelForeground(),
                new VariableLabelFont(),
            }));

        // Expression column is visible only in the expressions view.  It shows the expression string that the user 
        // entered.  Expression column images are the same as for the name column.
        provider.setColumnInfo(
            IDebugVMConstants.COLUMN_ID__EXPRESSION,
            new LabelColumnInfo(new LabelAttribute[] { 
                new LabelText(
                    MessagesForRegisterVM.RegisterBitFieldVMNode_Expression_column__text_format, 
                    new String[] { PROP_ELEMENT_EXPRESSION }),
                new LabelImage(DebugUITools.getImageDescriptor(IDebugUIConstants.IMG_OBJS_REGISTER)),
                new StaleDataLabelForeground(),
                new VariableLabelFont(),
            }));

        provider.setColumnInfo(
            PropertiesBasedLabelProvider.ID_COLUMN_NO_COLUMNS, 
            new LabelColumnInfo(new LabelAttribute[] { 
                new FormattedValueLabelText(
                    MessagesForRegisterVM.RegisterBitFieldVMNode_No_columns__With_mnemonic__text_format, 
                    new String[] {
                        PROP_NAME, 
                        IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE,  
                        IRegisterVMConstants.PROP_CURRENT_MNEMONIC_LONG_NAME})
                {
                	@Override
                    public boolean isEnabled(IStatus status, Map<String, Object> properties) {
                        Boolean showTypeNames = (Boolean) properties.get(PROP_BITFIELD_SHOW_TYPE_NAMES);
                        return 
                            showTypeNames != null && 
                           !showTypeNames.booleanValue() &&
                            super.isEnabled(status, properties);
                    }                  
                },
                new FormattedValueLabelText(
                    MessagesForRegisterVM.RegisterBitFieldVMNode_No_columns__With_mnemonic__text_format_with_type, 
                    new String[] {
                        PROP_NAME, 
                        IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE,  
                        IRegisterVMConstants.PROP_CURRENT_MNEMONIC_LONG_NAME,
                        IRegisterVMConstants.PROP_IS_READABLE, 
                        IRegisterVMConstants.PROP_IS_READONCE, 
                        IRegisterVMConstants.PROP_IS_WRITEABLE,
                        IRegisterVMConstants.PROP_IS_WRITEONCE,
                        PROP_BITFIELD_SHOW_TYPE_NAMES})
                {
                    @Override
                    public void updateAttribute(ILabelUpdate update, int columnIndex, IStatus status, Map<String, Object> properties) {
                        Object[] messageAttrs = constructTypeObjects( properties );
                        Object[] combinedAttrs = new Object[ messageAttrs.length + 3 ];
                        combinedAttrs[0] = super.getPropertyValue(PROP_NAME, status, properties);
                        combinedAttrs[1] = super.getPropertyValue(IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE, status, properties);
                        combinedAttrs[2] = super.getPropertyValue(IRegisterVMConstants.PROP_CURRENT_MNEMONIC_LONG_NAME, status, properties);
                        for ( int idx = 0 ; idx < messageAttrs.length; idx ++ ) {
                        	combinedAttrs[ idx + 3 ] = messageAttrs[ idx ];
                        }
                        	
                        try {
                        	update.setLabel(getMessageFormat().format(combinedAttrs, new StringBuffer(), null).toString(), columnIndex);
                        } catch (IllegalArgumentException e) {
                        	update.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, 0, "Failed formatting a message for column " + columnIndex + ", for update " + update, e)); //$NON-NLS-1$ //$NON-NLS-2$
                        }
                    }   
                        
                    @Override
                    public boolean isEnabled(IStatus status, Map<String, Object> properties) {
                        Boolean showTypeNames = (Boolean) properties.get(PROP_BITFIELD_SHOW_TYPE_NAMES);
                        return 
                            showTypeNames != null && 
                            showTypeNames.booleanValue() &&
                            super.isEnabled(status, properties);
                    }  
                },
                new FormattedValueLabelText(
                    MessagesForRegisterVM.RegisterBitFieldVMNode_No_columns__text_format, 
                    new String[] {
                        PROP_NAME, 
                        IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE})
                {
                    @Override
                    public boolean isEnabled(IStatus status, Map<String, Object> properties) {
                        Boolean showTypeNames = (Boolean) properties.get(PROP_BITFIELD_SHOW_TYPE_NAMES);
                        return 
                             showTypeNames != null && 
                            !showTypeNames.booleanValue() &&
                             super.isEnabled(status, properties);
                    }  
                },
                new FormattedValueLabelText(
                       MessagesForRegisterVM.RegisterBitFieldVMNode_No_columns__text_format_with_type, 
                       new String[] {
                           PROP_NAME, 
                           IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE,
                           IRegisterVMConstants.PROP_IS_READABLE, 
                           IRegisterVMConstants.PROP_IS_READONCE, 
                           IRegisterVMConstants.PROP_IS_WRITEABLE,
                           IRegisterVMConstants.PROP_IS_WRITEONCE,
                           PROP_BITFIELD_SHOW_TYPE_NAMES})     
                {
                    @Override
                    public void updateAttribute(ILabelUpdate update, int columnIndex, IStatus status, Map<String, Object> properties) {
                        Object[] messageAttrs = constructTypeObjects( properties );
                        Object[] combinedAttrs = new Object[ messageAttrs.length + 2 ];
                        combinedAttrs[0] = super.getPropertyValue(PROP_NAME, status, properties);
                        combinedAttrs[1] = super.getPropertyValue(IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE, status, properties);
                        for ( int idx = 0 ; idx < messageAttrs.length; idx ++ ) {
                        	combinedAttrs[ idx + 2 ] = messageAttrs[ idx ];
                        }
                        	
                        try {
                        	update.setLabel(getMessageFormat().format(combinedAttrs, new StringBuffer(), null).toString(), columnIndex);
                        } catch (IllegalArgumentException e) {
                        	update.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, 0, "Failed formatting a message for column " + columnIndex + ", for update " + update, e)); //$NON-NLS-1$ //$NON-NLS-2$
                        }
                    }   
                        
                    @Override
                    public boolean isEnabled(IStatus status, Map<String, Object> properties) {
                        Boolean showTypeNames = (Boolean) properties.get(PROP_BITFIELD_SHOW_TYPE_NAMES);
                        return 
                            showTypeNames != null && 
                            showTypeNames.booleanValue() &&
                            super.isEnabled(status, properties);
                    }  
                },
                new ErrorLabelText(
                    MessagesForRegisterVM.RegisterBitFieldVMNode_No_columns__Error__text_format, 
                    new String[] { PROP_NAME }),                    
                new LabelImage(DebugUITools.getImageDescriptor(IDebugUIConstants.IMG_OBJS_REGISTER)),
                new LabelForeground(
                    DebugUITools.getPreferenceColor(IDebugUIConstants.PREF_CHANGED_DEBUG_ELEMENT_COLOR).getRGB())
                {
                    { 
                        setPropertyNames(new String[] { 
                            IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE, 
                            ICachingVMProvider.PROP_IS_CHANGED_PREFIX + IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE,
                            IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT, 
                            ICachingVMProvider.PROP_IS_CHANGED_PREFIX + IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT}); 
                    }
    
                    @Override
                    public boolean isEnabled(IStatus status, java.util.Map<String,Object> properties) {
                        Boolean activeFormatChanged = (Boolean)properties.get(
                            ICachingVMProvider.PROP_IS_CHANGED_PREFIX + IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT);
                        Boolean activeChanged = (Boolean)properties.get(
                            ICachingVMProvider.PROP_IS_CHANGED_PREFIX + IDebugVMConstants.PROP_FORMATTED_VALUE_ACTIVE_FORMAT_VALUE);
                        return  Boolean.TRUE.equals(activeChanged) && !Boolean.TRUE.equals(activeFormatChanged);
                    }
                },
                new StaleDataLabelBackground(),
                new VariableLabelFont(),
            }));

        return provider;
    }

    /**
     * @since 1.1
     */
    public SyncRegisterDataAccess getSyncRegisterDataAccess() {
        return fSyncRegisterDataAccess;
    }

    /**
     * @since 1.1
     */
    public IWatchExpressionFactoryAdapter2 getWatchExpressionFactory() {
    	if ( fBitFieldExpressionFactory == null ) {
    		fBitFieldExpressionFactory = new BitFieldExpressionFactory();
    	}
    	return fBitFieldExpressionFactory;
    }
    
    @Override
    public void update(final ILabelUpdate[] updates) {
        fLabelProvider.update(updates);
    }

    /**
     * Update the variable view properties.  The formatted values need to be 
     * updated in the VM executor thread while the rest of the properties is
     * updated in the service session's executor thread.  The implementation
     * splits the handling of the updates to accomplish that.  
     * 
     * @see IElementPropertiesProvider#update(IPropertiesUpdate[])
     * 
     * @since 2.0
     */    
    @Override
    public void update(final IPropertiesUpdate[] updates) {
        final CountingRequestMonitor countingRm = new CountingRequestMonitor(ImmediateExecutor.getInstance(), null) {
            @Override
            protected void handleCompleted() {
                for (int i = 0; i < updates.length; i++) {
                    updates[i].done();
                }
            };
        };
        int count = 0;

        fFormattedValueRetriever.update(updates, countingRm);
        count++;

        final IPropertiesUpdate[] subUpdates = new IPropertiesUpdate[updates.length];
        for (int i = 0; i < updates.length; i++) {
            final IPropertiesUpdate update = updates[i];
            subUpdates[i] = new VMDelegatingPropertiesUpdate(update, countingRm);
            count++;
        }
        countingRm.setDoneCount(count);

        try {
            getSession().getExecutor().execute(new DsfRunnable() {
                @Override
                public void run() {
                    updatePropertiesInSessionThread(subUpdates);
                }});
        } catch (RejectedExecutionException e) {
            for (IPropertiesUpdate subUpdate : subUpdates) {
                subUpdate.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.REQUEST_FAILED, "Session executor shut down " + getSession().getExecutor(), e)); //$NON-NLS-1$
                subUpdate.done();
            }
        }
    }
    

    //
    //  @param return-value Boolean.TRUE  --> Show Types ICON is     selected/depressed
    //  @param return-value Boolean.FALSE --> Show Types ICON is not selected/depressed
    //
	private Boolean getShowTypeNamesState( IPresentationContext context ) {
      Boolean attribute = (Boolean) context.getProperty(IDebugModelPresentation.DISPLAY_VARIABLE_TYPE_NAMES);
      
      if (attribute != null) {
    	  return attribute;
      }
      
      return Boolean.FALSE;
    }
    
    /**
     * @since 2.0
     */
    @ConfinedToDsfExecutor("getSession().getExecutor()")
    protected void updatePropertiesInSessionThread(final IPropertiesUpdate[] updates) {
        IRegisters service = getServicesTracker().getService(IRegisters.class, null);

        final CountingRequestMonitor countingRm = new CountingRequestMonitor(ImmediateExecutor.getInstance(), null) {
            @Override
            protected void handleCompleted() {
                for (final IPropertiesUpdate update : updates) {
                    update.done();
                }
            };
        };
        int count = 0;
        
        for (final IPropertiesUpdate update : updates) {
            IExpression expression = (IExpression)DebugPlugin.getAdapter(update.getElement(), IExpression.class);
            if (expression != null) {
                update.setProperty(AbstractExpressionVMNode.PROP_ELEMENT_EXPRESSION, expression.getExpressionText());
            }

         // Capture the current "Show Type Names" ICON state in case there are no columns.
            if (update.getProperties().contains(PROP_BITFIELD_SHOW_TYPE_NAMES)) {
            	update.setProperty(PROP_BITFIELD_SHOW_TYPE_NAMES, getShowTypeNamesState(update.getPresentationContext()));
            }
            
            IBitFieldDMContext dmc = findDmcInPath(update.getViewerInput(), update.getElementPath(), IBitFieldDMContext.class);
            if (dmc == null || service == null) {
                handleFailedUpdate(update);
                continue;
            }
            
            service.getBitFieldData(
                dmc,             
                // Use the ViewerDataRequestMonitor in order to propagate the update's cancel request. Use an immediate 
                // executor to avoid the possibility of a rejected execution exception.
                new ViewerDataRequestMonitor<IBitFieldDMData>(getSession().getExecutor(), update) { 
                    @Override
                    protected void handleCompleted() {
                        if (isSuccess()) {
                            fillBitFieldDataProperties(update, getData());
                        } else {
                            update.setStatus(getStatus());
                        }
                        countingRm.done();
                    }
                });        
            count++;
        }
        countingRm.setDoneCount(count);
    }
    
    /**
     * @since 2.0
     */
    @ConfinedToDsfExecutor("getSession().getExecutor()")
    protected void fillBitFieldDataProperties(IPropertiesUpdate update, IBitFieldDMData data) {
        update.setProperty(PROP_NAME, data.getName());
        update.setProperty(IRegisterVMConstants.PROP_DESCRIPTION, data.getDescription());
        update.setProperty(IRegisterVMConstants.PROP_IS_READABLE, data.isReadable());
        update.setProperty(IRegisterVMConstants.PROP_IS_READONCE, data.isReadOnce());
        update.setProperty(IRegisterVMConstants.PROP_IS_WRITEABLE, data.isWriteable());
        update.setProperty(IRegisterVMConstants.PROP_IS_WRITEONCE, data.isWriteOnce());
        update.setProperty(IRegisterVMConstants.PROP_HAS_SIDE_EFFECTS, data.hasSideEffects());
        update.setProperty(IRegisterVMConstants.PROP_IS_ZERO_BIT_LEFT_MOST, data.isZeroBitLeftMost());
        update.setProperty(IRegisterVMConstants.PROP_IS_ZERO_BASED_NUMBERING, data.isZeroBasedNumbering());
        IMnemonic mnemonic = data.getCurrentMnemonicValue();
        if (mnemonic != null) {
            update.setProperty(IRegisterVMConstants.PROP_CURRENT_MNEMONIC_LONG_NAME, mnemonic.getLongName());
            update.setProperty(IRegisterVMConstants.PROP_CURRENT_MNEMONIC_SHORT_NAME, mnemonic.getShortName());
        }
        
        /*
         * If this node has an expression then it has already been filled in by the higher
         * level logic. If not then we need to supply something.  In the  previous version
         * ( pre-property based ) we supplied the name. So we will do that here also.
         */
        IExpression expression = (IExpression)DebugPlugin.getAdapter(update.getElement(), IExpression.class);
        if (expression == null) {
            update.setProperty(AbstractExpressionVMNode.PROP_ELEMENT_EXPRESSION, data.getName());
        }
    }
    
    @Override
    protected void updateElementsInSessionThread(final IChildrenUpdate update) {
        final IRegisterDMContext regDmc = findDmcInPath(update.getViewerInput(), update.getElementPath(), IRegisterDMContext.class);

        if (regDmc == null) {
            handleFailedUpdate(update);
            return;
        }          
        
        IRegisters regService = getServicesTracker().getService(IRegisters.class);
        
        if ( regService == null ) {
        	handleFailedUpdate(update);
            return;
        }
        
        
        regService.getBitFields(
            regDmc,
            new ViewerDataRequestMonitor<IBitFieldDMContext[]>(getSession().getExecutor(), update) {
                @Override
                protected void handleFailure() {
                    handleFailedUpdate(update);
                }

                @Override
                protected void handleSuccess() {
                    fillUpdateWithVMCs(update, getData());
                    update.done();
                }
            });            
    }
    
    /*
     * (non-Javadoc)
     * @see org.eclipse.cdt.dsf.ui.viewmodel.datamodel.AbstractDMVMNode#createVMContext(org.eclipse.cdt.dsf.datamodel.IDMContext)
     */
    @Override
    protected IDMVMContext createVMContext(IDMContext dmc) {
        return new BitFieldVMC(dmc);
    }
    
    /*
     * (non-Javadoc)
     * @see org.eclipse.cdt.dsf.ui.viewmodel.IVMNode#getDeltaFlags(java.lang.Object)
     */
    @Override
    public int getDeltaFlags(Object e) {
        if ( e instanceof ISuspendedDMEvent || 
             e instanceof IMemoryChangedEvent ||
             e instanceof IRegisterChangedDMEvent || 
             (e instanceof PropertyChangeEvent &&
              ((PropertyChangeEvent)e).getProperty() == IDebugVMConstants.PROP_FORMATTED_VALUE_FORMAT_PREFERENCE) ) 
        {
            return IModelDelta.CONTENT;
        } 

        if (e instanceof IBitFieldChangedDMEvent) {
            return IModelDelta.STATE;
        }

        return IModelDelta.NO_CHANGE;
    }

    /*
     * (non-Javadoc)
     * @see org.eclipse.cdt.dsf.ui.viewmodel.IVMNode#buildDelta(java.lang.Object, org.eclipse.cdt.dsf.ui.viewmodel.VMDelta, int, org.eclipse.cdt.dsf.concurrent.RequestMonitor)
     */
    @Override
    public void buildDelta(Object e, VMDelta parentDelta, int nodeOffset, RequestMonitor rm) {
        // The following events can affect any bit field's values, 
        // refresh the contents of the parent element (i.e. all the registers). 
        if ( e instanceof ISuspendedDMEvent || 
             e instanceof IMemoryChangedEvent ||
             e instanceof IRegisterChangedDMEvent || 
             (e instanceof PropertyChangeEvent &&
              ((PropertyChangeEvent)e).getProperty() == IDebugVMConstants.PROP_FORMATTED_VALUE_FORMAT_PREFERENCE) ) 
        {
            parentDelta.setFlags(parentDelta.getFlags() | IModelDelta.CONTENT);
        } 

        if (e instanceof IBitFieldChangedDMEvent) {
            // Create a delta indicating that the value of bit field has changed.
            parentDelta.addNode( createVMContext(((IBitFieldChangedDMEvent)e).getDMContext()), IModelDelta.STATE );
        } 

        rm.done();
    }

    /*
     * (non-Javadoc)
     * @see org.eclipse.debug.internal.ui.viewers.model.provisional.IElementEditor#getCellEditor(org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext, java.lang.String, java.lang.Object, org.eclipse.swt.widgets.Composite)
     */
    @Override
    public CellEditor getCellEditor(IPresentationContext context, String columnId, Object element, Composite parent) {
        
        if (IDebugVMConstants.COLUMN_ID__VALUE.equals(columnId)) {
            /*
             *   In order to decide what kind of editor to present we need to know if there are 
             *   mnemonics which can be used to represent the values. If there are then we will
             *   create a Combo editor for them. Otherwise we will just make a normal text cell
             *   editor.  If there are bit groups then the modifier will check the size of  the
             *   value being entered.
             */
            IBitFieldDMData bitFieldData = getSyncRegisterDataAccess().readBitField(element);

            if ( bitFieldData != null && bitFieldData.isWriteable() ) {

                IMnemonic[] mnemonics = bitFieldData.getMnemonics();

                if ( mnemonics != null  && mnemonics.length != 0 ) {

                    /*
                     *   Create the list of readable dropdown selections.
                     */
                    String[] StringValues = new String[ mnemonics.length ];

                    int idx = 0 ;
                    for ( IMnemonic mnemonic : mnemonics ) {
                        StringValues[ idx ++ ] = mnemonic.getLongName();
                    }

                    /*
                     *  Not we are complex COMBO and return the right editor.
                     */
                    return new ComboBoxCellEditor(parent, StringValues); 
                }
                else {
                    /*
                     *  Text editor even if we need to clamp the value entered.
                     */
                    return new TextCellEditor(parent); 
                }
            }
        } else if (IDebugVMConstants.COLUMN_ID__EXPRESSION.equals(columnId)) {
            return new TextCellEditor(parent);            
        }
        return null;
    }

    /*
     * (non-Javadoc)
     * @see org.eclipse.debug.internal.ui.viewers.model.provisional.IElementEditor#getCellModifier(org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext, java.lang.Object)
     */
    @Override
    public ICellModifier getCellModifier(IPresentationContext context, Object element) {
        
        /*
         *   In order to decide what kind of modifier to present we need to know if there
         *   are mnemonics which can be used to represent the values. 
         */
        IBitFieldDMData bitFieldData = getSyncRegisterDataAccess().readBitField(element);

        if ( bitFieldData != null && bitFieldData.isWriteable() ) {

            IMnemonic[] mnemonics = bitFieldData.getMnemonics();

            if ( mnemonics != null  && mnemonics.length != 0 ) {
                /*
                 *  Note we are complex COMBO and return the right editor.
                 */
                return new RegisterBitFieldCellModifier(
                    getDMVMProvider(), BitFieldEditorStyle.BITFIELDCOMBO, getSyncRegisterDataAccess() );
            }
            else {
                /*
                 *  Text editor even if we need to clamp the value entered.
                 */
                return new RegisterBitFieldCellModifier( 
                    getDMVMProvider(), BitFieldEditorStyle.BITFIELDTEXT, getSyncRegisterDataAccess() );
            }
        }
        else {
            return null;
        }
    }

    /**
     * Expected format: GRP( GroupName ).REG( RegisterName ).BFLD( BitFieldname )
     */
    
    @Override
    public boolean canParseExpression(IExpression expression) {
        return parseExpressionForBitFieldName(expression.getExpressionText()) != null;
    }
    
    private String parseExpressionForBitFieldName(String expression) {
    	
    	if (expression.startsWith("GRP(")) { //$NON-NLS-1$
    		
    		/*
    		 *  Get the group portion.
    		 */
    		int startIdx = "GRP(".length(); //$NON-NLS-1$
            int endIdx = expression.indexOf(')', startIdx);
            if ( startIdx == -1 || endIdx == -1 ) {
            	return null;
            }
            String remaining = expression.substring(endIdx+1);
            if ( ! remaining.startsWith(".REG(") ) { //$NON-NLS-1$
                return null;
            }
            
            /*
             * Get the register portion.
             */
            startIdx = ".REG(".length(); //$NON-NLS-1$
            endIdx = remaining.indexOf(')', startIdx);
            if ( startIdx == -1 || endIdx == -1 ) {
            	return null;
            }
            remaining = remaining.substring(endIdx+1);
            
            /*
             * Get the bit-field portion.
             */
            if ( ! remaining.startsWith(".BFLD(") ) { //$NON-NLS-1$
                return null;
            }
            startIdx = ".BFLD(".length(); //$NON-NLS-1$
            endIdx = remaining.indexOf(')', startIdx);
            if ( startIdx == -1 || endIdx == -1 ) {
            	return null;
            }
            String bitFieldName = remaining.substring(startIdx, endIdx);
            
            /*
             * Make sure there is nothing following. If there is then this
             * is not a properly formed expression and we do not claim it.
             */
            remaining = remaining.substring( endIdx + 1);
            
            if ( remaining.length() != 0 ) {
            	return null;
            }
            
            return bitFieldName.trim();
        }
    	
        return null;
    }
    
    /*
     * (non-Javadoc)
     * @see org.eclipse.cdt.dsf.debug.ui.viewmodel.expression.AbstractExpressionVMNode#testElementForExpression(java.lang.Object, org.eclipse.debug.core.model.IExpression, org.eclipse.cdt.dsf.concurrent.DataRequestMonitor)
     */
    @Override
    protected void testElementForExpression(Object element, IExpression expression, final DataRequestMonitor<Boolean> rm) {
        if (!(element instanceof IDMVMContext)) {
            rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_HANDLE, "Invalid context", null)); //$NON-NLS-1$
            rm.done();
            return;
        }
        
        final IBitFieldDMContext dmc = DMContexts.getAncestorOfType(((IDMVMContext)element).getDMContext(), IBitFieldDMContext.class);
        if (dmc == null) {
            rm.setStatus(new Status(IStatus.ERROR, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_HANDLE, "Invalid context", null)); //$NON-NLS-1$
            rm.done();
            return;
        }
        
        final String bitFieldName = parseExpressionForBitFieldName(expression.getExpressionText());
        try {
            getSession().getExecutor().execute(new DsfRunnable() {
                @Override
				public void run() {
                    IRegisters registersService = getServicesTracker().getService(IRegisters.class);
                    if (registersService != null) {
                        registersService.getBitFieldData(
                            dmc, 
                            new DataRequestMonitor<IBitFieldDMData>(ImmediateExecutor.getInstance(), rm) {
                                @Override
                                protected void handleSuccess() {
                                    rm.setData( getData().getName().equals(bitFieldName) );
                                    rm.done();
                                }
                            });
                    } else {
                        rm.setStatus(new Status(IStatus.WARNING, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "Register service not available", null)); //$NON-NLS-1$                        
                        rm.done();
                    }
                }
            });
        } catch (RejectedExecutionException e) {
            rm.setStatus(new Status(IStatus.WARNING, DsfUIPlugin.PLUGIN_ID, IDsfStatusConstants.INVALID_STATE, "DSF session shut down", null)); //$NON-NLS-1$
            rm.done();
        }
    }

    /*
     * (non-Javadoc)
     * @see org.eclipse.cdt.dsf.debug.ui.viewmodel.expression.AbstractExpressionVMNode#associateExpression(java.lang.Object, org.eclipse.debug.core.model.IExpression)
     */
    @Override
    protected void associateExpression(Object element, IExpression expression) {
        if (element instanceof BitFieldVMC) {
            ((BitFieldVMC)element).setExpression(expression);
        }
    }
    
    /*
     * (non-Javadoc)
     * @see org.eclipse.cdt.dsf.debug.ui.viewmodel.expression.IExpressionVMNode#getDeltaFlagsForExpression(org.eclipse.debug.core.model.IExpression, java.lang.Object)
     */
    @Override
    public int getDeltaFlagsForExpression(IExpression expression, Object event) {
        if (event instanceof ISuspendedDMEvent) {
            return IModelDelta.CONTENT;
        }

        if (event instanceof PropertyChangeEvent && 
            ((PropertyChangeEvent)event).getProperty() == IDebugVMConstants.PROP_FORMATTED_VALUE_FORMAT_PREFERENCE) {
            return IModelDelta.CONTENT;            
        }

        if (event instanceof IMemoryChangedEvent) {
            return IModelDelta.CONTENT;
        }
        
        if (event instanceof ElementFormatEvent) {
        	int depth = ((ElementFormatEvent)event).getApplyDepth();
        	if (depth == 0) return IModelDelta.NO_CHANGE;
        	if (depth == 1) return IModelDelta.STATE;
            return IModelDelta.CONTENT;
        }
        
        return IModelDelta.NO_CHANGE;
    }
    
    /*
     * (non-Javadoc)
     * @see org.eclipse.cdt.dsf.debug.ui.viewmodel.expression.IExpressionVMNode#buildDeltaForExpression(org.eclipse.debug.core.model.IExpression, int, java.lang.Object, org.eclipse.cdt.dsf.ui.viewmodel.VMDelta, org.eclipse.jface.viewers.TreePath, org.eclipse.cdt.dsf.concurrent.RequestMonitor)
     */
    @Override
    public void buildDeltaForExpression(final IExpression expression, final int elementIdx, final Object event, final VMDelta parentDelta, final TreePath path, final RequestMonitor rm) 
    {
        // Always refresh the contents of the view upon suspended event.
        if (event instanceof ISuspendedDMEvent) {
            parentDelta.setFlags(parentDelta.getFlags() | IModelDelta.CONTENT);
        }         

        rm.done();
    }

    /*
     * (non-Javadoc)
     * @see org.eclipse.cdt.dsf.debug.ui.viewmodel.expression.IExpressionVMNode#buildDeltaForExpressionElement(java.lang.Object, int, java.lang.Object, org.eclipse.cdt.dsf.ui.viewmodel.VMDelta, org.eclipse.cdt.dsf.concurrent.RequestMonitor)
     */
    @Override
    public void buildDeltaForExpressionElement(Object element, int elementIdx, Object event, VMDelta parentDelta, final RequestMonitor rm) 
    {
        // The following events can affect register values, refresh the state 
        // of the expression. 
        if ( event instanceof IRegisterChangedDMEvent ||
             event instanceof IMemoryChangedEvent ||
             (event instanceof PropertyChangeEvent && 
                ((PropertyChangeEvent)event).getProperty() == IDebugVMConstants.PROP_FORMATTED_VALUE_FORMAT_PREFERENCE) )
        {
            parentDelta.addNode(element, IModelDelta.STATE);
        } 
        else if (event instanceof ElementFormatEvent) 
        {
        	int depth = ((ElementFormatEvent)event).getApplyDepth();
        	if (depth != 0) {
        		int deltaType = IModelDelta.CONTENT;
        		if (depth == 1) deltaType = IModelDelta.STATE;

        		Set<Object> elements = ((ElementFormatEvent)event).getElements();
        		for (Object elem : elements) {
        			parentDelta.addNode(elem, deltaType);
        		}
        	}
        }
        
        rm.done();
    }
    
    /*
     * (non-Javadoc)
     * @see org.eclipse.debug.internal.ui.viewers.model.provisional.IElementMementoProvider#compareElements(org.eclipse.debug.internal.ui.viewers.model.provisional.IElementCompareRequest[])
     */
    private final String MEMENTO_NAME = "BITFIELD_MEMENTO_NAME"; //$NON-NLS-1$
    
    @Override
    public void compareElements(IElementCompareRequest[] requests) {
        for ( final IElementCompareRequest request : requests ) {
            final String mementoName = request.getMemento().getString(MEMENTO_NAME);
            
            final IBitFieldDMContext regDmc = findDmcInPath(request.getViewerInput(), request.getElementPath(), IBitFieldDMContext.class);
            if (regDmc == null || mementoName == null) {
                request.done();
                continue;
            }
            
            //  Now go get the model data for the single register group found.
            try {
                getSession().getExecutor().execute(new DsfRunnable() {
                    @Override
                    public void run() {
                        final IRegisters regService = getServicesTracker().getService(IRegisters.class);
                        if ( regService != null ) {
                            regService.getBitFieldData(
                                regDmc, 
                                new DataRequestMonitor<IBitFieldDMData>(regService.getExecutor(), null) {
                                    @Override
                                    protected void handleCompleted() {
                                        if ( getStatus().isOK() ) {
                                            // Now make sure the register group is the one we want.
                                            request.setEqual( mementoName.equals( "BitField." + getData().getName() ) ); //$NON-NLS-1$
                                        }
                                        request.done();
                                    }
                                });
                        } else {
                            request.done();
                        }
                    }
                });
            } catch (RejectedExecutionException e) {
                request.done();
            }
        }
    }
    
    /*
     * (non-Javadoc)
     * @see org.eclipse.debug.internal.ui.viewers.model.provisional.IElementMementoProvider#encodeElements(org.eclipse.debug.internal.ui.viewers.model.provisional.IElementMementoRequest[])
     */
    @Override
    public void encodeElements(IElementMementoRequest[] requests) {
        for ( final IElementMementoRequest request : requests ) {
            final IBitFieldDMContext regDmc = findDmcInPath(request.getViewerInput(), request.getElementPath(), IBitFieldDMContext.class);
            if (regDmc == null) {
                request.done();
                continue;
            }
            
            //  Now go get the model data for the single register group found.
            try {
                getSession().getExecutor().execute(new DsfRunnable() {
                    @Override
                    public void run() {
                        final IRegisters regService = getServicesTracker().getService(IRegisters.class);
                        if ( regService != null ) {
                            regService.getBitFieldData(
                                regDmc, 
                                new DataRequestMonitor<IBitFieldDMData>(regService.getExecutor(), null) {
                                    @Override
                                    protected void handleCompleted() {
                                        if ( getStatus().isOK() ) {
                                            // Now make sure the register group is the one we want.
                                            request.getMemento().putString(MEMENTO_NAME, "BitField." + getData().getName()); //$NON-NLS-1$
                                        }
                                        request.done();
                                    }
                                });
                        } else {
                            request.done();
                        }
                    }
                });
            } catch (RejectedExecutionException e) {
                request.done();
            }
        }
    }
}