[567517] Optimize Sequence Horizontal Layout

- Compute Message.getParentOperand() only if a lost message end is
found.
- Fast return the default reflexive message width if there is no
surrounded event on the same lifeline.

Bug: 567517
Change-Id: I2fab94b454824ff7fc4832d777d21687e55851ac
Signed-off-by: Maxime Porhel <maxime.porhel@obeo.fr>

2 files changed, 38 insertions, 35 deletions

diff --git a/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/elements/Message.java b/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/elements/Message.java
index 8f2f95b4f4..1540cb0ee6 100644
--- a/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/elements/Message.java
+++ b/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/elements/Message.java
@@ -421,40 +421,43 @@ public class Message extends AbstractSequenceElement implements ISequenceEvent {
      */
     public int getReflexiveMessageWidth() {
         Collection<ISequenceEvent> events = getSurroundedSameLifelineEvents();
-        final Range range = getVerticalRange();
-        Predicate<ISequenceEvent> toConsider = new Predicate<ISequenceEvent>() {
-            @Override
-            public boolean apply(ISequenceEvent input) {
-                boolean toConsider = range.includes(input.getVerticalRange());
-                if (input instanceof Message) {
-                    toConsider = toConsider && ((Message) input).isReflective();
+
+        int width = LayoutConstants.MESSAGE_TO_SELF_BENDPOINT_HORIZONTAL_GAP;
+        if (!events.isEmpty()) {
+
+            final Range range = getVerticalRange();
+            Predicate<ISequenceEvent> toConsider = new Predicate<ISequenceEvent>() {
+                @Override
+                public boolean apply(ISequenceEvent input) {
+                    boolean toConsider = range.includes(input.getVerticalRange());
+                    if (input instanceof Message) {
+                        toConsider = toConsider && ((Message) input).isReflective();
+                    }
+                    return toConsider;
                 }
-                return toConsider;
+            };
+
+            List<ISequenceEvent> impactingEvents = Lists.newArrayList(Iterables.filter(events, toConsider));
+            Collections.sort(impactingEvents, Ordering.natural().onResultOf(Functions.compose(RangeHelper.lowerBoundFunction(), ISequenceEvent.VERTICAL_RANGE)));
+            int subMessagesMaxRight = 0;
+            for (Message msg : Iterables.filter(impactingEvents, Message.class)) {
+                int reflexiveMessageWidth = msg.getReflexiveMessageWidth();
+                int origin = msg.getSourceElement().getProperLogicalBounds().right();
+                origin = Math.max(origin, msg.getTargetElement().getProperLogicalBounds().right());
+                subMessagesMaxRight = Math.max(subMessagesMaxRight, origin + reflexiveMessageWidth);
             }
-        };
-
-        List<ISequenceEvent> impactingEvents = Lists.newArrayList(Iterables.filter(events, toConsider));
-        Collections.sort(impactingEvents, Ordering.natural().onResultOf(Functions.compose(RangeHelper.lowerBoundFunction(), ISequenceEvent.VERTICAL_RANGE)));
-        int subMessagesMaxRight = 0;
-        for (Message msg : Iterables.filter(impactingEvents, Message.class)) {
-            int reflexiveMessageWidth = msg.getReflexiveMessageWidth();
-            int origin = msg.getSourceElement().getProperLogicalBounds().right();
-            origin = Math.max(origin, msg.getTargetElement().getProperLogicalBounds().right());
-            subMessagesMaxRight = Math.max(subMessagesMaxRight, origin + reflexiveMessageWidth);
-        }
 
-        int maxRight = 0;
-        for (AbstractNodeEvent node : Iterables.filter(impactingEvents, AbstractNodeEvent.class)) {
-            maxRight = Math.max(maxRight, node.getProperLogicalBounds().right());
-        }
-
-        int origin = getSourceElement().getProperLogicalBounds().right();
-        origin = Math.max(origin, getTargetElement().getProperLogicalBounds().right());
+            int maxRight = 0;
+            for (AbstractNodeEvent node : Iterables.filter(impactingEvents, AbstractNodeEvent.class)) {
+                maxRight = Math.max(maxRight, node.getProperLogicalBounds().right());
+            }
 
-        int width = LayoutConstants.MESSAGE_TO_SELF_BENDPOINT_HORIZONTAL_GAP;
-        width = Math.max(width, maxRight - origin + LayoutConstants.MESSAGE_TO_SELF_HORIZONTAL_GAP);
-        width = Math.max(width, subMessagesMaxRight - origin + LayoutConstants.MESSAGE_TO_SELF_HORIZONTAL_GAP);
+            int origin = getSourceElement().getProperLogicalBounds().right();
+            origin = Math.max(origin, getTargetElement().getProperLogicalBounds().right());
 
+            width = Math.max(width, maxRight - origin + LayoutConstants.MESSAGE_TO_SELF_HORIZONTAL_GAP);
+            width = Math.max(width, subMessagesMaxRight - origin + LayoutConstants.MESSAGE_TO_SELF_HORIZONTAL_GAP);
+        }
         return width;
     }
 
diff --git a/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/layout/horizontal/LostMessageEndHorizontalLayoutHelper.java b/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/layout/horizontal/LostMessageEndHorizontalLayoutHelper.java
index 8ab3d331c3..69b39335e6 100644
--- a/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/layout/horizontal/LostMessageEndHorizontalLayoutHelper.java
+++ b/plugins/org.eclipse.sirius.diagram.sequence/src/org/eclipse/sirius/diagram/sequence/business/internal/layout/horizontal/LostMessageEndHorizontalLayoutHelper.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2010 THALES GLOBAL SERVICES.
+ * Copyright (c) 2010, 2020 THALES GLOBAL SERVICES.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
@@ -44,8 +44,8 @@ import com.google.common.collect.Iterables;
 import com.google.common.collect.Multimap;
 
 /**
- * Computes the appropriate graphical locations of sequence events and lifelines
- * on a sequence diagram to reflect the semantic order.
+ * Computes the appropriate graphical locations of sequence events and lifelines on a sequence diagram to reflect the
+ * semantic order.
  * 
  * @author pcdavid, mporhel
  */
@@ -71,8 +71,7 @@ public class LostMessageEndHorizontalLayoutHelper {
      * Constructor.
      * 
      * @param diagram
-     *            the sequence diagram for which to compute the horizontal
-     *            locations.
+     *            the sequence diagram for which to compute the horizontal locations.
      */
     public LostMessageEndHorizontalLayoutHelper(SequenceDiagram diagram) {
         this.sequenceDiagram = diagram;
@@ -132,7 +131,6 @@ public class LostMessageEndHorizontalLayoutHelper {
         ISequenceNode sourceElement = msg.getSourceElement();
         ISequenceNode targetElement = msg.getTargetElement();
 
-        Option<Operand> parentOperand = msg.getParentOperand();
         if (sourceElement != null && targetElement != null) {
             Option<Lifeline> sourceLifeline = sourceElement.getLifeline();
             Option<Lifeline> targetLifeline = targetElement.getLifeline();
@@ -142,6 +140,7 @@ public class LostMessageEndHorizontalLayoutHelper {
                 LostMessageEnd sourceLME = (LostMessageEnd) sourceElement;
                 lostSources.put(targetLifeline.get(), sourceLME);
                 lostMessages.put(sourceLME, msg);
+                Option<Operand> parentOperand = msg.getParentOperand();
                 if (parentOperand.some()) {
                     operands.put(sourceLME, parentOperand.get());
                     operands2lostEnds.put(parentOperand.get(), sourceLME);
@@ -152,6 +151,7 @@ public class LostMessageEndHorizontalLayoutHelper {
                 LostMessageEnd targetLME = (LostMessageEnd) targetElement;
                 lostTargets.put(sourceLifeline.get(), targetLME);
                 lostMessages.put(targetLME, msg);
+                Option<Operand> parentOperand = msg.getParentOperand();
                 if (parentOperand.some()) {
                     operands.put(targetLME, parentOperand.get());
                     operands2lostEnds.put(parentOperand.get(), targetLME);