test: display branched events inside HashgraphGui (#18618)

Signed-off-by: Ivan Kavaldzhiev <[email protected]>

Author: IvanKavaldzhiev

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/gui/BranchedEventMetadata.java

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: Apache-2.0
+package com.swirlds.platform.gui;
+
+/**
+ * Metadata for an event that is part of a branched event.
+ * <p>
+ * This metadata contains the index of the branch and the generation of the event.
+ */
+public record BranchedEventMetadata(Integer branchIndex, Long generation) {
+
+    /**
+     * Get the index of the branch that the linked event is on.
+     */
+    public Integer getBranchIndex() {
+        return branchIndex;
+    }
+
+    /**
+     * Get the generation of the event linked to this metadata.
+     */
+    public Long getGeneration() {
+        return generation;
+    }
+}

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/gui/GuiEventStorage.java

@@ -3,6 +3,7 @@
 
 import static org.hiero.consensus.model.event.EventConstants.FIRST_GENERATION;
 
+import com.hedera.hapi.platform.event.GossipEvent;
 import com.hedera.hapi.platform.state.ConsensusSnapshot;
 import com.swirlds.common.context.PlatformContext;
 import com.swirlds.config.api.Configuration;
@@ -17,7 +18,9 @@
 import com.swirlds.platform.system.address.AddressBook;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import edu.umd.cs.findbugs.annotations.Nullable;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import org.hiero.consensus.config.EventConfig;
 import org.hiero.consensus.model.event.PlatformEvent;
@@ -37,6 +40,7 @@ public class GuiEventStorage {
     private final SimpleLinker linker;
     private final Configuration configuration;
     private ConsensusRound lastConsensusRound;
+    private Map<GossipEvent, BranchedEventMetadata> branchedEventsMetadata = new HashMap<>();
 
     /**
      * Creates an empty instance
@@ -143,4 +147,19 @@ public synchronized List<EventImpl> getNonAncientEvents() {
     public synchronized @Nullable ConsensusRound getLastConsensusRound() {
         return lastConsensusRound;
     }
+
+    /**
+     * Get map with a link between a branched event and its metadata
+     *
+     * @return the map
+     */
+    @NonNull
+    public Map<GossipEvent, BranchedEventMetadata> getBranchedEventsMetadata() {
+        return branchedEventsMetadata;
+    }
+
+    public void setBranchedEventsMetadata(
+            @NonNull final Map<GossipEvent, BranchedEventMetadata> branchedEventsMetadata) {
+        this.branchedEventsMetadata = branchedEventsMetadata;
+    }
 }

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/gui/hashgraph/HashgraphPictureOptions.java

@@ -55,6 +55,11 @@ public interface HashgraphPictureOptions {
      */
     boolean writeBirthRound();
 
+    /**
+     * @return should branch numbers be written for every branched event (if any)
+     */
+    boolean writeBranches();
+
     /**
      * @return should simple colors be used in the picture
      */

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/gui/hashgraph/internal/EventSelector.java

@@ -76,7 +76,7 @@ public void mouseClicked(final MouseEvent me) {
             final int xEvent = metadata.xpos(null, e);
             final int yEvent = metadata.ypos(e);
             final double distanceSquared = Math.pow(xEvent - xClicked, 2) + Math.pow(yEvent - yClicked, 2);
-            if (distanceSquared <= rSquared) {
+            if (distanceSquared <= rSquared - 20) {
                 if (selectedEvent == e) {
                     selectedEvent = null;
                 } else {

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/gui/hashgraph/internal/GenerationCoordinates.java

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: Apache-2.0
+package com.swirlds.platform.gui.hashgraph.internal;
+
+import com.hedera.hapi.platform.event.GossipEvent;
+import edu.umd.cs.findbugs.annotations.NonNull;
+import java.util.Map;
+
+/**
+ * Class holding X coordinates for branched events with a specific generation for a given node.
+ * Note that it's normal the branch to contain events with different generations.
+ */
+public class GenerationCoordinates {
+
+    // the X coordinates of all branched events with the same generation
+    private Map<GossipEvent, Integer> xCoordinates;
+    // the X coordinate of the most right branched event for a given generation
+    private Integer rightMostX = 0;
+
+    /**
+     * Return the X coordinates of all branched events with the same generation.
+     *
+     * @return the coordinates
+     */
+    public Map<GossipEvent, Integer> getXCoordinates() {
+        return xCoordinates;
+    }
+
+    /**
+     * Set updated X coordinates of all branched events with the same generation.
+     *
+     * @param xCoordinates the coordinates to set
+     */
+    public void setXCoordinates(@NonNull final Map<GossipEvent, Integer> xCoordinates) {
+        this.xCoordinates = xCoordinates;
+    }
+
+    /**
+     * Return the X coordinate of the most right branched event for a given generation.
+     *
+     * @return the coordinate
+     */
+    public Integer getRightMostX() {
+        return rightMostX;
+    }
+
+    /**
+     * Set the X coordinate of the most right branched event for a given generation.
+     *
+     * @param rightMostX the coordinate to set
+     */
+    public void setRightMostX(@NonNull final Integer rightMostX) {
+        this.rightMostX = rightMostX;
+    }
+}

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/gui/hashgraph/internal/HashgraphGuiControls.java

@@ -49,6 +49,8 @@ public class HashgraphGuiControls implements HashgraphPictureOptions {
     private final Checkbox labelGenerationCheckbox;
     /** the birth round number for the event */
     private final Checkbox labelBirthroundCheckbox;
+    /** the branch number for the event */
+    private final Checkbox labelBranchNumberCheckbox;
     /** check to display the latest events available */
     private final Checkbox displayLatestEvents;
 
@@ -71,6 +73,7 @@ public HashgraphGuiControls(final ItemListener freezeListener) {
         labelConsTimestampCheckbox = new Checkbox("Labels: Timestamp (consensus)");
         labelGenerationCheckbox = new Checkbox("Labels: Generation");
         labelBirthroundCheckbox = new Checkbox("Labels: Birth round");
+        labelBranchNumberCheckbox = new Checkbox("Labels: Branch number");
         displayLatestEvents = new Checkbox("Display latest events");
         displayLatestEvents.setState(true);
 
@@ -109,6 +112,7 @@ public HashgraphGuiControls(final ItemListener freezeListener) {
             labelConsTimestampCheckbox,
             labelGenerationCheckbox,
             labelBirthroundCheckbox,
+            labelBranchNumberCheckbox,
             displayLatestEvents
         };
     }
@@ -196,7 +200,8 @@ public JPanel createPanel() {
                                 - Non-famous witnesses are yellow\s
                                 - Famous witnesses are green\s
                                 - Undecided witnesses are red\s
-                                - The selected event is magenta\s
+                                - The selected event is magenta with green border\s
+                                - The parents of the selected event have magenta borders\s
                                 - The events the selected event can strongly see are cyan\s""")),
                 constr);
         constr.gridy++;
@@ -282,6 +287,11 @@ public boolean displayLatestEvents() {
         return displayLatestEvents.getState();
     }
 
+    @Override
+    public boolean writeBranches() {
+        return labelBranchNumberCheckbox.getState();
+    }
+
     @Override
     public void setStartGeneration(final long startGeneration) {
         this.startGeneration.setValue(startGeneration);

platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/gui/hashgraph/internal/HashgraphPicture.java

@@ -4,6 +4,7 @@
 import static com.swirlds.logging.legacy.LogMarker.EXCEPTION;
 import static com.swirlds.platform.gui.hashgraph.HashgraphGuiConstants.HASHGRAPH_PICTURE_FONT;
 
+import com.hedera.hapi.platform.event.GossipEvent;
 import com.swirlds.platform.Consensus;
 import com.swirlds.platform.consensus.CandidateWitness;
 import com.swirlds.platform.gui.hashgraph.HashgraphGuiConstants;
@@ -27,12 +28,15 @@
 import java.awt.image.BufferedImage;
 import java.io.Serial;
 import java.time.Instant;
+import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
 import javax.swing.JPanel;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.hiero.consensus.model.event.EventConstants;
+import org.hiero.consensus.model.node.NodeId;
 
 /**
  * This panel has the hashgraph picture, and appears in the window to the right of all the settings.
@@ -52,6 +56,9 @@ public class HashgraphPicture extends JPanel {
     private AddressBookMetadata nonExpandedMetadata;
     private AddressBookMetadata expandedMetadata;
 
+    /** used to store coordinates for branched events with a given generation for each forking node */
+    private final Map<Long, Map<Long, GenerationCoordinates>> nodeIdToBranchIndexToCoordinates = new HashMap<>();
+
     public HashgraphPicture(final HashgraphGuiSource hashgraphSource, final HashgraphPictureOptions options) {
         this.hashgraphSource = hashgraphSource;
         this.options = options;
@@ -105,7 +112,8 @@ public void paintComponent(final Graphics g) {
                     .filter(e -> addressBook.getIndexOfNodeId(e.getCreatorId()) < numMem)
                     .toList();
 
-            pictureMetadata = new PictureMetadata(fm, this.getSize(), currentMetadata, events);
+            pictureMetadata = new PictureMetadata(
+                    fm, this.getSize(), currentMetadata, events, hashgraphSource, nodeIdToBranchIndexToCoordinates);
 
             selector.setMetadata(pictureMetadata);
             selector.setEventsInPicture(events);
@@ -128,6 +136,12 @@ public void paintComponent(final Graphics g) {
 
             final int d = pictureMetadata.getD();
 
+            if (nodeIdToBranchIndexToCoordinates.isEmpty()) {
+                for (final NodeId nodeId : hashgraphSource.getAddressBook().getNodeIdSet()) {
+                    nodeIdToBranchIndexToCoordinates.put(nodeId.id(), new HashMap<>());
+                }
+            }
+
             // for each event, draw 2 downward lines to its parents
             for (final EventImpl event : events) {
                 drawLinksToParents(g, event);
@@ -137,13 +151,42 @@ public void paintComponent(final Graphics g) {
             for (final EventImpl event : events) {
                 drawEventCircle(g, event, options, d);
             }
+
+            final List<EventImpl> selectedEvents =
+                    events.stream().filter(selector::isSelected).toList();
+            if (!selectedEvents.isEmpty()) {
+                final EventImpl selectedEvent = selectedEvents.getFirst();
+                if (selectedEvent != null) {
+                    // if we have a selected event draw the circle and its parent links last, so that all labels and
+                    // lines connected to it can be easily seen
+                    drawLinksToParents(g, selectedEvent);
+                    drawEventCircle(g, selectedEvent, options, d);
+                }
+            }
         } catch (final Exception e) {
             logger.error(EXCEPTION.getMarker(), "error while painting", e);
         }
     }
 
+    /**
+     * Draws a border around the event circle.
+     *
+     * @param g    the graphics context
+     * @param d    the diameter of the event circle
+     * @param event the selected event
+     * @param borderColor the color of the border
+     */
+    private void drawBorderAroundEvent(final Graphics g, final int d, final EventImpl event, final Color borderColor) {
+        final int xPos =
+                pictureMetadata.xpos(event.getOtherParent() != null ? event.getOtherParent() : event, event) - d / 2;
+        final int yPos = pictureMetadata.ypos(event) - d / 2;
+        g.setColor(borderColor);
+        g.fillOval(xPos - 5, yPos - 5, d + 10, d + 10);
+    }
+
     private void drawLinksToParents(final Graphics g, final EventImpl event) {
-        Graphics2D g2d = (Graphics2D) g;
+        final int d = pictureMetadata.getD();
+        final Graphics2D g2d = (Graphics2D) g;
         Stroke savedStroke = null;
         g.setColor(HashgraphGuiUtils.eventColor(event, options));
         boolean selectedLines = selector.isSelected(event);
@@ -168,15 +211,29 @@ private void drawLinksToParents(final Graphics g, final EventImpl event) {
             g.drawLine(
                     pictureMetadata.xpos(e2, event),
                     pictureMetadata.ypos(event),
-                    pictureMetadata.xpos(e2, event),
+                    pictureMetadata.xpos(e2, e1),
                     pictureMetadata.ypos(e1));
+
+            if (selectedLines) {
+                final Color currentColor = g.getColor();
+                drawBorderAroundEvent(g, d, e1, Color.MAGENTA);
+                drawEventCircle(g, e1, options, d);
+                g.setColor(currentColor);
+            }
         }
         if (e2 != null && e2.getGeneration() >= pictureMetadata.getMinGen()) {
             g.drawLine(
                     pictureMetadata.xpos(e2, event),
                     pictureMetadata.ypos(event),
                     pictureMetadata.xpos(event, e2),
                     pictureMetadata.ypos(e2));
+
+            if (selectedLines) {
+                final Color currentColor = g.getColor();
+                drawBorderAroundEvent(g, d, e2, Color.MAGENTA);
+                drawEventCircle(g, e2, options, d);
+                g.setColor(currentColor);
+            }
         }
 
         if (selectedLines) {
@@ -204,11 +261,15 @@ private void drawEventCircle(
         } else {
             color = HashgraphGuiUtils.eventColor(event, options);
         }
-        g.setColor(color);
 
         final int xPos = pictureMetadata.xpos(e2, event) - d / 2;
         final int yPos = pictureMetadata.ypos(event) - d / 2;
 
+        if (selector.isSelected(event)) {
+            drawBorderAroundEvent(g, d, event, Color.GREEN);
+        }
+
+        g.setColor(color);
         g.fillOval(xPos, yPos, d, d);
         g.setFont(g.getFont().deriveFont(Font.BOLD));
 
@@ -254,8 +315,21 @@ private void drawEventCircle(
         if (options.writeBirthRound()) {
             s += " " + event.getBirthRound();
         }
+
+        final GossipEvent gossipEvent = event.getBaseEvent().getGossipEvent();
+        if (options.writeBranches()
+                && hashgraphSource.getEventStorage().getBranchedEventsMetadata().containsKey(gossipEvent)) {
+            s += " " + "\\/ "
+                    + hashgraphSource
+                            .getEventStorage()
+                            .getBranchedEventsMetadata()
+                            .get(gossipEvent)
+                            .branchIndex();
+        }
+
         if (!s.isEmpty()) {
             final Rectangle2D rect = fm.getStringBounds(s, g);
+
             final int x = (int) (pictureMetadata.xpos(e2, event) - rect.getWidth() / 2. - fa / 4.);
             final int y = (int) (pictureMetadata.ypos(event) + rect.getHeight() / 2. - fd / 2);
             g.setColor(HashgraphGuiConstants.LABEL_OUTLINE);