org.eclipse.linuxtools.lttng2.control.ui/src/org/eclipse/linuxtools/internal/lttng2/control/ui/views/dialogs/EnableKernelEventComposite.java

   1 /**********************************************************************
   2  * Copyright (c) 2012, 2014 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Bernd Hufmann - Initial API and implementation
  11  *   Marc-Andre Laperle - Add filtering textbox
  12  **********************************************************************/
  13 package org.eclipse.linuxtools.internal.lttng2.control.ui.views.dialogs;
  14
  15 import java.util.ArrayList;
  16 import java.util.List;
  17
  18 import org.eclipse.jface.dialogs.MessageDialog;
  19 import org.eclipse.jface.viewers.CheckStateChangedEvent;
  20 import org.eclipse.jface.viewers.CheckboxTreeViewer;
  21 import org.eclipse.jface.viewers.ICheckStateListener;
  22 import org.eclipse.jface.viewers.TreeViewer;
  23 import org.eclipse.linuxtools.internal.lttng2.control.ui.views.messages.Messages;
  24 import org.eclipse.linuxtools.internal.lttng2.control.ui.views.model.ITraceControlComponent;
  25 import org.eclipse.linuxtools.internal.lttng2.control.ui.views.model.impl.BaseEventComponent;
  26 import org.eclipse.linuxtools.internal.lttng2.control.ui.views.model.impl.KernelProviderComponent;
  27 import org.eclipse.linuxtools.internal.lttng2.control.ui.views.model.impl.TraceControlContentProvider;
  28 import org.eclipse.linuxtools.internal.lttng2.control.ui.views.model.impl.TraceControlLabelProvider;
  29 import org.eclipse.linuxtools.internal.lttng2.control.ui.views.model.impl.TraceProviderGroup;
  30 import org.eclipse.swt.SWT;
  31 import org.eclipse.swt.events.SelectionAdapter;
  32 import org.eclipse.swt.events.SelectionEvent;
  33 import org.eclipse.swt.graphics.Image;
  34 import org.eclipse.swt.layout.GridData;
  35 import org.eclipse.swt.layout.GridLayout;
  36 import org.eclipse.swt.widgets.Button;
  37 import org.eclipse.swt.widgets.Composite;
  38 import org.eclipse.swt.widgets.Group;
  39 import org.eclipse.swt.widgets.Label;
  40 import org.eclipse.swt.widgets.Text;
  41 import org.eclipse.ui.dialogs.FilteredTree;
  42 import org.eclipse.ui.dialogs.PatternFilter;
  43
  44 /**
  45  * <p>
  46  * A composite for collecting information about kernel events to be enabled.
  47  * </p>
  48  *
  49  * @author Bernd Hufmann
  50  */
  51 public class EnableKernelEventComposite extends Composite implements IEnableKernelEvents {
  52
  53     // ------------------------------------------------------------------------
  54     // Constants
  55     // ------------------------------------------------------------------------
  56     private enum KernelGroupEnum { TRACEPOINTS, SYSCALLS, PROBE, FUNCTION }
  57
  58     // ------------------------------------------------------------------------
  59     // Attributes
  60     // ------------------------------------------------------------------------
  61
  62     /**
  63      * A button to enable/disable the tracepoints group
  64      */
  65     private Button fTracepointsActivateButton;
  66     /**
  67      * A tree viewer for displaying and selection of available tracepoints.
  68      */
  69     private CheckboxTreeViewer fTracepointsViewer;
  70     /**
  71      * A button to enable/disable the syscalls group
  72      */
  73     private Button fSysCallsActivateButton;
  74     /**
  75      * A button to enable or disable the dynamic probe group.
  76      */
  77     private Button fProbeActivateButton;
  78     /**
  79      * The text field for the event name for the dynamic probe.
  80      */
  81     private Text fProbeEventNameText;
  82     /**
  83      * The text field for the dynamic probe.
  84      */
  85     private Text fProbeText;
  86     /**
  87      * A button to enable or disable the dynamic function probe group.
  88      */
  89     private Button fFunctionActivateButton;
  90     /**
  91      * The text field for the event name for the dynamic probe.
  92      */
  93     private Text fFunctionEventNameText;
  94     /**
  95      * The text field for the dynamic function entry/return probe.
  96      */
  97     private Text fFunctionText;
  98     /**
  99      * The referenced trace provider group containing the kernel provider
 100      * component which contains a list of available tracepoints.
 101      */
 102     private final TraceProviderGroup fProviderGroup;
 103     /**
 104      * The flag indicating that tracepoints are selected.
 105      */
 106     private boolean fIsTracepoints;
 107     /**
 108      * The flag indicating that all tracepoints are selected.
 109      */
 110     private boolean fIsAllTracepoints;
 111     /**
 112      * The flag indicating that syscalls are selected.
 113      */
 114     private boolean fIsSysCalls;
 115     /**
 116      * The list of tracepoints to be enabled.
 117      */
 118     private List<String> fSelectedEvents;
 119     /**
 120      * The flag indicating that dynamic probe is selected.
 121      */
 122     private boolean fIsDynamicProbe;
 123     /**
 124      *  The event name of the dynamic probe.
 125      */
 126     private String fProbeEventName;
 127     /**
 128      * The dynamic probe.
 129      */
 130     private String fProbeString;
 131     /**
 132      * The flag indicating that the dynamic function probe is selected.
 133      */
 134     private boolean fIsDynamicFunctionProbe;
 135     /**
 136      * The event name of the dynamic function entry/return probe.
 137      */
 138     private String fFunctionEventName;
 139     /**
 140      * The dynamic function entry/return probe.
 141      */
 142     private String fFunctionString;
 143
 144     // ------------------------------------------------------------------------
 145     // Constructors
 146     // ------------------------------------------------------------------------
 147
 148     /**
 149      * Constructor
 150      *
 151      * @param parent
 152      *            The parent composite
 153      * @param style
 154      *            The index of the style for this event composite
 155      * @param providerGroup
 156      *            The trace provider group
 157      */
 158     public EnableKernelEventComposite(Composite parent, int style, TraceProviderGroup providerGroup) {
 159         super(parent, style);
 160         fProviderGroup = providerGroup;
 161     }
 162
 163     // ------------------------------------------------------------------------
 164     // Acessors
 165     // ------------------------------------------------------------------------
 166
 167     @Override
 168     public boolean isTracepoints() {
 169         return fIsTracepoints;
 170     }
 171
 172     @Override
 173     public boolean isAllTracePoints() {
 174         return fIsAllTracepoints;
 175     }
 176
 177     @Override
 178     public boolean isSysCalls() {
 179         return fIsSysCalls;
 180     }
 181
 182     @Override
 183     public boolean isAllSysCalls() {
 184         return fIsSysCalls;
 185     }
 186
 187     @Override
 188     public List<String> getEventNames() {
 189         return new ArrayList<>(fSelectedEvents);
 190     }
 191
 192     @Override
 193     public boolean isDynamicProbe() {
 194         return fIsDynamicProbe;
 195     }
 196
 197     @Override
 198     public String getProbeName() {
 199         return fProbeString;
 200     }
 201
 202     @Override
 203     public String getProbeEventName() {
 204         return fProbeEventName;
 205     }
 206
 207     @Override
 208     public boolean isDynamicFunctionProbe() {
 209         return fIsDynamicFunctionProbe;
 210     }
 211
 212     @Override
 213     public String getFunctionEventName() {
 214         return fFunctionEventName;
 215     }
 216
 217     @Override
 218     public String getFunction() {
 219         return fFunctionString;
 220     }
 221
 222     // ------------------------------------------------------------------------
 223     // Operations
 224     // ------------------------------------------------------------------------
 225
 226     /**
 227      * Creates the composite content
 228      */
 229     public void createContent() {
 230
 231         // Tracepoints Group
 232         createTracepointsGroup();
 233
 234         // Syscalls Group
 235         createSysCallsGroup();
 236
 237         // Dynamic Probe Group
 238         createDynamicProbeGroup();
 239
 240         // Dynamic Function Probe Group
 241         createDynamicFunctionPropeGroup();
 242
 243         // Set default enablements
 244         setKernelEnablements(KernelGroupEnum.TRACEPOINTS);
 245     }
 246
 247     /**
 248      * Validates the kernel composite input data.
 249      * @return true if configured data is valid and can be retrieved.
 250      */
 251     public boolean isValid() {
 252         fIsTracepoints = fTracepointsActivateButton.getSelection();
 253         fIsSysCalls = fSysCallsActivateButton.getSelection();
 254         fIsDynamicProbe = fProbeActivateButton.getSelection();
 255         fIsDynamicFunctionProbe = fFunctionActivateButton.getSelection();
 256
 257         // initialize tracepoint fields
 258         fIsAllTracepoints = false;
 259         fSelectedEvents = new ArrayList<>();
 260
 261         if (fIsTracepoints) {
 262             List<ITraceControlComponent> comps = fProviderGroup.getChildren(KernelProviderComponent.class);
 263             fIsAllTracepoints = fTracepointsViewer.getChecked(comps.get(0));
 264
 265             Object[] checkedElements = fTracepointsViewer.getCheckedElements();
 266             for (int i = 0; i < checkedElements.length; i++) {
 267                 ITraceControlComponent component = (ITraceControlComponent)checkedElements[i];
 268                 if (component instanceof BaseEventComponent) {
 269                     fSelectedEvents.add(component.getName());
 270                 }
 271             }
 272         }
 273
 274         if (fIsDynamicProbe) {
 275             String temp = fProbeEventNameText.getText();
 276             if (temp.isEmpty() ||
 277                 fProbeText.getText().matches("\\s*") || //$NON-NLS-1$
 278                 (!temp.matches("^[\\s]{0,}$") && !temp.matches("^[a-zA-Z0-9\\-\\_]{1,}$"))) { //$NON-NLS-1$ //$NON-NLS-2$
 279                 MessageDialog.openError(getShell(),
 280                         Messages.TraceControl_EnableEventsDialogTitle,
 281                         Messages.TraceControl_InvalidProbeNameError + " (" + temp + ") \n");  //$NON-NLS-1$ //$NON-NLS-2$
 282
 283                 return false;
 284             }
 285
 286             fProbeEventName = temp;
 287             // fProbeString will be validated by lttng-tools
 288             fProbeString = fProbeText.getText();
 289         }
 290
 291         // initialize function string
 292         fFunctionEventName = null;
 293         fFunctionString = null;
 294         if (fIsDynamicFunctionProbe) {
 295             String functionTemp = fFunctionEventNameText.getText();
 296             if (functionTemp.isEmpty() ||
 297                 functionTemp.matches("\\s*") || //$NON-NLS-1$
 298                 (!functionTemp.matches("^[\\s]{0,}$") && !functionTemp.matches("^[a-zA-Z0-9\\-\\_]{1,}$"))) { //$NON-NLS-1$ //$NON-NLS-2$
 299                 MessageDialog.openError(getShell(),
 300                         Messages.TraceControl_EnableEventsDialogTitle,
 301                         Messages.TraceControl_InvalidProbeNameError + " (" + functionTemp + ") \n");  //$NON-NLS-1$ //$NON-NLS-2$
 302
 303                 return false;
 304             }
 305
 306             fFunctionEventName = functionTemp;
 307             // fFunctionString will be validated by lttng-tools
 308             fFunctionString = fFunctionText.getText();
 309         }
 310
 311         return true;
 312     }
 313
 314     /**
 315      * Creates tracepoints group.
 316      */
 317     private void createTracepointsGroup() {
 318
 319         GridLayout layout;
 320         GridData data;
 321         Group tpMainGroup = new Group(this, SWT.SHADOW_NONE);
 322         tpMainGroup.setText(Messages.TraceControl_EnableEventsTracepointGroupName);
 323         layout = new GridLayout(2, false);
 324         tpMainGroup.setLayout(layout);
 325         data = new GridData(GridData.FILL_BOTH);
 326         tpMainGroup.setLayoutData(data);
 327
 328         Composite buttonComposite = new Composite(tpMainGroup, SWT.NONE);
 329         layout = new GridLayout(1, true);
 330         buttonComposite.setLayout(layout);
 331         data = new GridData(SWT.BEGINNING, SWT.CENTER, false, true);
 332         buttonComposite.setLayoutData(data);
 333
 334         fTracepointsActivateButton = new Button(buttonComposite, SWT.RADIO);
 335         fTracepointsActivateButton.setText(Messages.TraceControl_EnableGroupSelectionName);
 336         data = new GridData(GridData.FILL_HORIZONTAL);
 337         fTracepointsActivateButton.setLayoutData(data);
 338         fTracepointsActivateButton.addSelectionListener(new SelectionAdapter() {
 339             @Override
 340             public void widgetSelected(SelectionEvent e) {
 341                 setKernelEnablements(KernelGroupEnum.TRACEPOINTS);
 342             }
 343         });
 344
 345         Group tracepointsGroup = new Group(tpMainGroup, SWT.SHADOW_NONE);
 346         layout = new GridLayout(1, true);
 347         tracepointsGroup.setLayout(layout);
 348         data = new GridData(GridData.FILL_BOTH);
 349         tracepointsGroup.setLayoutData(data);
 350
 351         new FilteredTree(tracepointsGroup, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER, new PatternFilter(), true) {
 352             @Override
 353             protected TreeViewer doCreateTreeViewer(Composite aparent, int style) {
 354                 fTracepointsViewer = new CheckboxTreeViewer(aparent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
 355                 fTracepointsViewer.getTree().setToolTipText(Messages.TraceControl_EnableEventsTracepointTreeTooltip);
 356
 357                 fTracepointsViewer.setContentProvider(new KernelContentProvider());
 358                 fTracepointsViewer.setLabelProvider(new KernelLabelProvider());
 359                 fTracepointsViewer.addCheckStateListener(new KernelCheckListener());
 360                 fTracepointsViewer.setInput(fProviderGroup);
 361
 362                 fTracepointsViewer.getTree().setLayoutData(new GridData(GridData.FILL_BOTH));
 363                 return fTracepointsViewer;
 364             }
 365         };
 366     }
 367
 368     /**
 369      * Creates syscalls group.
 370      */
 371     private void createSysCallsGroup() {
 372         GridLayout layout;
 373         GridData data;
 374         Group sysCallsMainGroup = new Group(this, SWT.SHADOW_NONE);
 375         sysCallsMainGroup.setText(Messages.TraceControl_EnableEventsSyscallName);
 376         sysCallsMainGroup.setToolTipText(Messages.TraceControl_EnableEventsSyscallTooltip);
 377         layout = new GridLayout(2, false);
 378         sysCallsMainGroup.setLayout(layout);
 379         data = new GridData(GridData.FILL_HORIZONTAL);
 380         sysCallsMainGroup.setLayoutData(data);
 381
 382         Composite buttonComposite = new Composite(sysCallsMainGroup, SWT.NONE);
 383         layout = new GridLayout(1, false);
 384         buttonComposite.setLayout(layout);
 385         data = new GridData(SWT.BEGINNING, SWT.CENTER, false, true);
 386         buttonComposite.setLayoutData(data);
 387
 388         fSysCallsActivateButton = new Button(buttonComposite, SWT.RADIO);
 389         fSysCallsActivateButton.setText(Messages.TraceControl_EnableGroupSelectionName);
 390         fSysCallsActivateButton.setToolTipText(Messages.TraceControl_EnableEventsSyscallTooltip);
 391         fSysCallsActivateButton.setSelection(false);
 392         data = new GridData(GridData.FILL_HORIZONTAL);
 393         fSysCallsActivateButton.setLayoutData(data);
 394         fSysCallsActivateButton.addSelectionListener(new SelectionAdapter() {
 395             @Override
 396             public void widgetSelected(SelectionEvent e) {
 397                 setKernelEnablements(KernelGroupEnum.SYSCALLS);
 398             }
 399         });
 400     }
 401
 402     /**
 403      * Creates dynamic probe group.
 404      */
 405     private void createDynamicProbeGroup() {
 406         GridLayout layout;
 407         GridData data;
 408         Group probeMainGroup = new Group(this, SWT.SHADOW_NONE);
 409         probeMainGroup.setText(Messages.TraceControl_EnableEventsProbeGroupName);
 410         layout = new GridLayout(2, false);
 411         probeMainGroup.setLayout(layout);
 412         data = new GridData(GridData.FILL_HORIZONTAL);
 413         probeMainGroup.setLayoutData(data);
 414
 415         Composite buttonComposite = new Composite(probeMainGroup, SWT.NONE);
 416         layout = new GridLayout(1, false);
 417         buttonComposite.setLayout(layout);
 418         data = new GridData(SWT.BEGINNING, SWT.CENTER, false, true);
 419         buttonComposite.setLayoutData(data);
 420
 421         fProbeActivateButton = new Button(buttonComposite, SWT.RADIO);
 422         fProbeActivateButton.setText(Messages.TraceControl_EnableGroupSelectionName);
 423         fProbeActivateButton.setSelection(false);
 424         data = new GridData(GridData.FILL_HORIZONTAL);
 425         fProbeActivateButton.setLayoutData(data);
 426         fProbeActivateButton.addSelectionListener(new SelectionAdapter() {
 427             @Override
 428             public void widgetSelected(SelectionEvent e) {
 429                 setKernelEnablements(KernelGroupEnum.PROBE);
 430             }
 431         });
 432
 433         Group probeGroup = new Group(probeMainGroup, SWT.SHADOW_NONE);
 434         layout = new GridLayout(4, true);
 435         probeGroup.setLayout(layout);
 436         probeGroup.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
 437
 438         Label probeNameLabel = new Label(probeGroup, SWT.LEFT);
 439         probeNameLabel.setText(Messages.TraceControl_EnableEventsEventNameLabel);
 440         data = new GridData(GridData.FILL_BOTH);
 441         data.horizontalSpan = 1;
 442         probeNameLabel.setLayoutData(data);
 443
 444         fProbeEventNameText = new Text(probeGroup, SWT.LEFT);
 445         fProbeEventNameText.setToolTipText(Messages.TraceControl_EnableEventsProbeEventNameTooltip);
 446
 447         data = new GridData(GridData.FILL_BOTH);
 448         data.horizontalSpan = 3;
 449         fProbeEventNameText.setLayoutData(data);
 450
 451         Label probeLabel = new Label(probeGroup, SWT.LEFT);
 452         probeLabel.setText(Messages.TraceControl_EnableEventsProbeNameLabel);
 453         data = new GridData(GridData.FILL_BOTH);
 454         data.horizontalSpan = 1;
 455         probeLabel.setLayoutData(data);
 456
 457         fProbeText = new Text(probeGroup, SWT.LEFT);
 458         fProbeText.setToolTipText(Messages.TraceControl_EnableEventsProbeNameTooltip);
 459         data = new GridData(GridData.FILL_BOTH);
 460         data.horizontalSpan = 3;
 461         fProbeText.setLayoutData(data);
 462     }
 463
 464     /**
 465      * Creates dynamic function entry/return probe group.
 466      */
 467     private void createDynamicFunctionPropeGroup() {
 468         GridLayout layout;
 469         GridData data;
 470         Group functionMainGroup = new Group(this, SWT.SHADOW_NONE);
 471         functionMainGroup.setText(Messages.TraceControl_EnableEventsFucntionGroupName);
 472         layout = new GridLayout(2, false);
 473         functionMainGroup.setLayout(layout);
 474         data = new GridData(GridData.FILL_HORIZONTAL);
 475         functionMainGroup.setLayoutData(data);
 476
 477         Composite buttonComposite = new Composite(functionMainGroup, SWT.NONE);
 478         layout = new GridLayout(1, false);
 479         buttonComposite.setLayout(layout);
 480         data = new GridData(SWT.BEGINNING, SWT.CENTER, false, true);
 481         buttonComposite.setLayoutData(data);
 482
 483         fFunctionActivateButton = new Button(buttonComposite, SWT.RADIO);
 484         fFunctionActivateButton.setText(Messages.TraceControl_EnableGroupSelectionName);
 485         fFunctionActivateButton.setSelection(false);
 486         data = new GridData(GridData.FILL_HORIZONTAL);
 487         fFunctionActivateButton.setLayoutData(data);
 488         fFunctionActivateButton.addSelectionListener(new SelectionAdapter() {
 489             @Override
 490             public void widgetSelected(SelectionEvent e) {
 491                 setKernelEnablements(KernelGroupEnum.FUNCTION);
 492             }
 493         });
 494
 495         Group functionGroup = new Group(functionMainGroup, SWT.SHADOW_NONE);
 496         layout = new GridLayout(4, true);
 497         functionGroup.setLayout(layout);
 498         functionGroup.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
 499
 500         Label functionNameLabel = new Label(functionGroup, SWT.LEFT);
 501         functionNameLabel.setText(Messages.TraceControl_EnableEventsEventNameLabel);
 502         data = new GridData(GridData.FILL_BOTH);
 503         data.horizontalSpan = 1;
 504         functionNameLabel.setLayoutData(data);
 505
 506         fFunctionEventNameText = new Text(functionGroup, SWT.LEFT);
 507         fFunctionEventNameText.setToolTipText(Messages.TraceControl_EnableEventsFunctionEventNameTooltip);
 508         data = new GridData(GridData.FILL_BOTH);
 509         data.horizontalSpan = 3;
 510         fFunctionEventNameText.setLayoutData(data);
 511
 512         Label functionLabel = new Label(functionGroup, SWT.LEFT);
 513         functionLabel.setText(Messages.TraceControl_EnableEventsFunctionNameLabel);
 514         data = new GridData(GridData.FILL_BOTH);
 515         data.horizontalSpan = 1;
 516         functionLabel.setLayoutData(data);
 517
 518         fFunctionText = new Text(functionGroup, SWT.LEFT);
 519         fFunctionText.setToolTipText(Messages.TraceControl_EnableEventsProbeNameTooltip);
 520         data = new GridData(GridData.FILL_BOTH);
 521         data.horizontalSpan = 3;
 522         fFunctionText.setLayoutData(data);
 523     }
 524
 525     /**
 526      * Enable/selects widgets depending on the group specified.
 527      * @param group - group to enable.
 528      */
 529     private void setKernelEnablements(KernelGroupEnum group) {
 530         fTracepointsActivateButton.setSelection(group == KernelGroupEnum.TRACEPOINTS);
 531         fTracepointsViewer.getTree().setEnabled(group == KernelGroupEnum.TRACEPOINTS);
 532
 533         fSysCallsActivateButton.setSelection(group == KernelGroupEnum.SYSCALLS);
 534
 535         fProbeActivateButton.setSelection(group == KernelGroupEnum.PROBE);
 536         fProbeEventNameText.setEnabled(group == KernelGroupEnum.PROBE);
 537         fProbeText.setEnabled(group == KernelGroupEnum.PROBE);
 538
 539         fFunctionActivateButton.setSelection(group == KernelGroupEnum.FUNCTION);
 540         fFunctionEventNameText.setEnabled(group == KernelGroupEnum.FUNCTION);
 541         fFunctionText.setEnabled(group == KernelGroupEnum.FUNCTION);
 542     }
 543
 544     // ------------------------------------------------------------------------
 545     // Local classes
 546     // ------------------------------------------------------------------------
 547     /**
 548      * Content provider for the tracepoints tree.
 549      */
 550     public static final class KernelContentProvider extends TraceControlContentProvider {
 551         @Override
 552         public Object[] getChildren(Object parentElement) {
 553             if (parentElement instanceof TraceProviderGroup) {
 554                 List<ITraceControlComponent> children = ((ITraceControlComponent)parentElement).getChildren(KernelProviderComponent.class);
 555                 return children.toArray(new ITraceControlComponent[children.size()]);
 556             }
 557             if (parentElement instanceof ITraceControlComponent) {
 558                 return ((ITraceControlComponent)parentElement).getChildren();
 559             }
 560             return new Object[0];
 561         }
 562     }
 563
 564     /**
 565      * Content label for the tracepoints tree.
 566      */
 567     public static final class KernelLabelProvider extends TraceControlLabelProvider {
 568         @Override
 569         public Image getImage(Object element) {
 570             return null;
 571         }
 572         @Override
 573         public String getText(Object element) {
 574             if ((element != null) && (element instanceof KernelProviderComponent)) {
 575                 return Messages.TraceControl_EnableEventsTracepointTreeAllLabel;
 576             }
 577             return super.getText(element);
 578         }
 579     }
 580
 581     /**
 582      * Check state listener for the tracepoints tree.
 583      */
 584     public final class KernelCheckListener implements ICheckStateListener {
 585         @Override
 586         public void checkStateChanged(CheckStateChangedEvent event) {
 587           if (event.getChecked()) {
 588               if (event.getElement() instanceof KernelProviderComponent) {
 589                   fTracepointsViewer.setSubtreeChecked(event.getElement(), true);
 590               }
 591           } else {
 592               if (event.getElement() instanceof KernelProviderComponent) {
 593                   fTracepointsViewer.setSubtreeChecked(event.getElement(), false);
 594               } else {
 595                   ITraceControlComponent component = (ITraceControlComponent) event.getElement();
 596                   fTracepointsViewer.setChecked(component.getParent(), false);
 597               }
 598           }
 599         }
 600     }
 601 }