tmf/org.lttng.scope.tmf2.views.core/src/org/lttng/scope/tmf2/views/core/timegraph/model/render/tree/TimeGraphTreeElement.java

   1 /*******************************************************************************
   2  * Copyright (c) 2016 EfficiOS Inc., Alexandre Montplaisir
   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
  10 package org.lttng.scope.tmf2.views.core.timegraph.model.render.tree;
  11
  12 import java.util.Collections;
  13 import java.util.List;
  14 import java.util.Objects;
  15 import java.util.function.Predicate;
  16
  17 import org.eclipse.jdt.annotation.Nullable;
  18 import org.eclipse.tracecompass.tmf.core.event.ITmfEvent;
  19
  20 import com.google.common.base.MoreObjects;
  21 import com.google.common.collect.ImmutableList;
  22
  23 /**
  24  * The "tree element" is the unit of a timegraph represented by a single line.
  25  * State intervals are aligned with tree elements to represent the states of the
  26  * attribute represented by its tree element.
  27  *
  28  * Tree elements can have children, which allows representing them as a tree
  29  * structure. At the visualization layer, sub-trees could be allowed to be
  30  * expanded/collapsed, which can then change the number of visible tree elements
  31  * in the timegraph.
  32  *
  33  * @author Alexandre Montplaisir
  34  */
  35 public class TimeGraphTreeElement {
  36
  37     /** Non-null reference to a dummy element */
  38     public static final TimeGraphTreeElement DUMMY_ELEMENT = new TimeGraphTreeElement("Dummy", Collections.emptyList()); //$NON-NLS-1$
  39
  40     private final String fName;
  41     private final List<TimeGraphTreeElement> fChildElements;
  42
  43     /**
  44      * Constructor, build a tree element by specifying its name and children
  45      * elements.
  46      *
  47      * @param name
  48      *            The name this tree element should have.
  49      * @param children
  50      *            The children tree elements. You can pass an empty list for no
  51      *            children.
  52      */
  53     public TimeGraphTreeElement(String name, List<TimeGraphTreeElement> children) {
  54         fName = name;
  55         fChildElements = ImmutableList.copyOf(children);
  56     }
  57
  58     /**
  59      * Get the name of this tree element.
  60      *
  61      * @return The element's name
  62      */
  63     public String getName() {
  64         return fName;
  65     }
  66
  67     /**
  68      * Get the child elements of this tree element.
  69      *
  70      * @return The child elements
  71      */
  72     public List<TimeGraphTreeElement> getChildElements() {
  73         return fChildElements;
  74     }
  75
  76     /**
  77      * Determine if and how this tree element corresponds to a component of a
  78      * trace event.
  79      *
  80      * For example, if this tree element represents "CPU #2", then the predicate
  81      * should return true for all trace events belonging to CPU #2.
  82      *
  83      * The method returns null if this tree element does not correspond to a
  84      * particular aspect of trace events.
  85      *
  86      * @return The event matching predicate, if there is one
  87      */
  88     public @Nullable Predicate<ITmfEvent> getEventMatching() {
  89         /* Sub-classes can override */
  90         return null;
  91     }
  92
  93     @Override
  94     public int hashCode() {
  95         return Objects.hash(fName, fChildElements);
  96     }
  97
  98     @Override
  99     public boolean equals(@Nullable Object obj) {
 100         if (this == obj) {
 101             return true;
 102         }
 103         if (obj == null) {
 104             return false;
 105         }
 106         if (getClass() != obj.getClass()) {
 107             return false;
 108         }
 109         TimeGraphTreeElement other = (TimeGraphTreeElement) obj;
 110         return Objects.equals(fName, other.fName)
 111                 && Objects.equals(fChildElements, other.fChildElements);
 112     }
 113
 114     @Override
 115     public String toString() {
 116         return MoreObjects.toStringHelper(this)
 117             .add("fName", fName) //$NON-NLS-1$
 118             .add("fChildElements", fChildElements.toString()) //$NON-NLS-1$
 119             .toString();
 120     }
 121
 122 }