allows to select a previous engineer or new crew member to activate large vessels

MekHQ/src/mekhq/campaign/Campaign.java

@@ -2447,19 +2447,29 @@ public List<Person> getTechs(final boolean noZeroMinute) {
         return getTechs(noZeroMinute, false);
     }
 
+    public List<Person> getTechsExpanded() {
+        return getTechsExpanded(false, false, true);
+    }
+
+    public List<Person> getTechs(final boolean noZeroMinute, final boolean eliteFirst) {
+        return getTechsExpanded(noZeroMinute, eliteFirst, false);
+    }
+
     /**
      * Returns a list of active technicians.
      *
      * @param noZeroMinute If TRUE, then techs with no time remaining will be
      *                     excluded from the list.
      * @param eliteFirst   If TRUE and sorted also TRUE, then return the list sorted
      *                     from best to worst
+     * @param expanded     If TRUE, then include techs with expanded roles (e.g. Tech/Vessel skill)
      * @return The list of active {@link Person}s who qualify as technicians
-     *         ({@link Person#isTech()}).
+     *         ({@link Person#isTech()}), or who qualify as expanded technicians ({@link Person#isTechExpanded()}).
      */
-    public List<Person> getTechs(final boolean noZeroMinute, final boolean eliteFirst) {
+    public List<Person> getTechsExpanded(final boolean noZeroMinute, final boolean eliteFirst, final boolean expanded) {
         final List<Person> techs = getActivePersonnel().stream()
-                .filter(person -> person.isTech() && (!noZeroMinute || (person.getMinutesLeft() > 0)))
+                .filter(person -> (expanded ? person.isTechExpanded() : person.isTech())
+                    && (!noZeroMinute || (person.getMinutesLeft() > 0)))
                 .collect(Collectors.toList());
 
         // also need to loop through and collect engineers on self-crewed vessels

MekHQ/src/mekhq/campaign/personnel/Person.java

@@ -3753,8 +3753,13 @@ public boolean canGun(final Entity entity) {
     }
 
     public boolean canTech(final Entity entity) {
+        if (entity == null) {
+            return false;
+        }
         if ((entity instanceof Mek) || (entity instanceof ProtoMek)) {
             return hasSkill(SkillType.S_TECH_MEK);
+        } else if (entity instanceof Dropship || entity instanceof Jumpship) {
+            return hasSkill(SkillType.S_TECH_VESSEL);
         } else if (entity instanceof Aero) {
             return hasSkill(SkillType.S_TECH_AERO);
         } else if (entity instanceof BattleArmor) {
@@ -3845,24 +3850,34 @@ public int getMinutesLeft() {
     public void setMinutesLeft(final int minutesLeft) {
         this.minutesLeft = minutesLeft;
         if (engineer && (getUnit() != null)) {
-            // set minutes for all crewmembers
-            for (Person p : getUnit().getActiveCrew()) {
-                p.setMinutesLeft(minutesLeft);
-            }
+            // set minutes for all crew members, except the engineer to not cause infinite recursion.
+            getUnit().getActiveCrew()
+                .stream()
+                .filter(this::isNotSelf)
+                .forEach(p -> p.setMinutesLeft(minutesLeft));
         }
     }
 
+    /**
+     * Checks if the other person is not the same person as this person, easy right?
+     * @param p Person to check against
+     * @return  true if the person is not the same person as this person
+     */
+    private boolean isNotSelf(Person p) {
+        return !this.equals(p);
+    }
+
     public int getOvertimeLeft() {
         return overtimeLeft;
     }
 
     public void setOvertimeLeft(final int overtimeLeft) {
         this.overtimeLeft = overtimeLeft;
         if (engineer && (getUnit() != null)) {
-            // set minutes for all crewmembers
-            for (Person p : getUnit().getActiveCrew()) {
-                p.setMinutesLeft(overtimeLeft);
-            }
+            getUnit().getActiveCrew()
+                .stream()
+                .filter(this::isNotSelf)
+                .forEach(p -> p.setOvertimeLeft(overtimeLeft));
         }
     }
 
@@ -3901,6 +3916,19 @@ public boolean isTech() {
         return isTechMek() || isTechAero() || isTechMechanic() || isTechBA();
     }
 
+    /**
+     * Checks if the person is a tech, includes mektek, mechanic, aerotek, BAtek and the non-cannon "large vessel tek"
+     * @return true if the person is a tech
+     */
+    public boolean isTechExpanded() {
+        return isTechMek() || isTechAero() || isTechMechanic() || isTechBA() || isTechLargeVessel();
+    }
+
+    public boolean isTechLargeVessel() {
+        boolean hasSkill = hasSkill(SkillType.S_TECH_VESSEL);
+        return hasSkill && (getPrimaryRole().isVesselCrew() || getSecondaryRole().isVesselCrew());
+    }
+
     public boolean isTechMek() {
         boolean hasSkill = hasSkill(SkillType.S_TECH_MEK);
         return hasSkill && (getPrimaryRole().isMekTech() || getSecondaryRole().isMekTech());

MekHQ/src/mekhq/campaign/unit/MothballInfo.java

@@ -38,7 +38,7 @@
  * This class is used to store information about a particular unit that is
  * lost when a unit is mothballed, so that it may be restored to as close to
  * its prior state as possible when the unit is reactivated.
- * 
+ *
  * @author NickAragua
  */
 public class MothballInfo {
@@ -61,9 +61,17 @@ private MothballInfo() {
         vesselCrew = new ArrayList<>();
     }
 
+    /**
+     * Who was the original tech of this vessel?
+     * @return The original tech
+     */
+    public Person getTech() {
+        return tech;
+    }
+
     /**
      * Creates a set of mothball info for a given unit
-     * 
+     *
      * @param unit The unit to work with
      */
     public MothballInfo(Unit unit) {
@@ -78,7 +86,7 @@ public MothballInfo(Unit unit) {
 
     /**
      * Restore a unit's pilot, assigned tech and force, to the best of our ability
-     * 
+     *
      * @param unit     The unit to restore
      * @param campaign The campaign in which this is happening
      */
@@ -158,7 +166,7 @@ public void writeToXML(final PrintWriter pw, int indent) {
 
     /**
      * Deserializer method implemented in standard MekHQ pattern.
-     * 
+     *
      * @return Instance of MothballInfo
      */
     public static MothballInfo generateInstanceFromXML(Node wn, Version version) {

MekHQ/src/mekhq/campaign/unit/Unit.java

@@ -4821,6 +4821,29 @@ public void startMothballing(@Nullable Person mothballTech, boolean isGM) {
         }
     }
 
+    /**
+     * Returns the engineer responsible for the mothballing or activation of this unit.
+     * @return Person the previous engineer that worked on this vessel, or an empty object.
+     */
+    public Optional<Person> engineerResponsible() {
+        // if it is NOT self crewed or it is NOT mothballed, just get the tech
+        if (!isMothballed() || !isSelfCrewed()) {
+            return Optional.ofNullable(getTech());
+        } else {
+            // if it is self crewed AND is mothballed and has a mothball info, get the tech
+            if (isSelfCrewed() && isMothballed() && (this.mothballInfo != null)) {
+                var previousTech = this.mothballInfo.getTech();
+                var previousTechExists = previousTech != null;
+                var previousTechIsActive = previousTechExists && previousTech.getStatus().isActive();
+                if (previousTechIsActive) {
+                    return Optional.of(previousTech);
+                }
+            }
+        }
+
+        return Optional.empty();
+    }
+
     /**
      * Completes the mothballing of a unit.
      */
@@ -4858,8 +4881,25 @@ public void startActivating(@Nullable Person activationTech, boolean isGM) {
         // set this person as tech
         if (!isSelfCrewed() && (tech != null) && !tech.equals(activationTech)) {
             remove(tech, true);
+            tech = activationTech;
+        } else if (!isSelfCrewed() && (null == tech)) {
+            tech = activationTech;
+        }
+
+        if (isSelfCrewed() && !isConventionalInfantry()) {
+            if (engineerResponsible().isPresent() && engineerResponsible().get().getStatus().isActive()) {
+                var assignedEngineer = engineerResponsible().get();
+                addVesselCrew(assignedEngineer);
+            } else if (activationTech != null && activationTech.isTechLargeVessel()) {
+                addVesselCrew(activationTech);
+            } else {
+                // In this case there is nothing to be done, we cant activate this unit.
+                return;
+            }
+            resetEngineer();
+        } else {
+            tech = activationTech;
         }
-        tech = activationTech;
 
         if (!isGM) {
             setMothballTime(getMothballOrActivationTime());

MekHQ/src/mekhq/gui/CampaignGUI.java

@@ -1614,7 +1614,7 @@ public void refitUnit(Refit r, boolean selectModelName) {
                 StringBuilder nameBuilder = new StringBuilder(128);
                 nameBuilder.append("<html>")
                     .append(tech.getFullName())
-                    .append(", <b>") 
+                    .append(", <b>")
                     .append(SkillType.getColoredExperienceLevelName(tech.getSkillLevel(getCampaign(), false)))
                     .append("</b> ")
                     .append(tech.getPrimaryRoleDesc())
@@ -1722,7 +1722,7 @@ public void refitUnit(Refit r, boolean selectModelName) {
     public @Nullable UUID selectTech(Unit u, String desc, boolean ignoreMaintenance) {
         String name;
         Map<String, Person> techHash = new LinkedHashMap<>();
-        for (Person tech : getCampaign().getTechs()) {
+        for (Person tech : getCampaign().getTechsExpanded()) {
             if (!tech.isMothballing() && tech.canTech(u.getEntity())) {
                 int time = tech.getMinutesLeft();
                 if (!ignoreMaintenance) {

MekHQ/src/mekhq/gui/adapter/UnitTableMouseAdapter.java

@@ -205,7 +205,7 @@ public void actionPerformed(ActionEvent action) {
             String quality = (String) JOptionPane.showInputDialog(gui.getFrame(), "Choose the new quality level",
                     "Set Quality", JOptionPane.PLAIN_MESSAGE, null, possibilities,
                     PartQuality.QUALITY_D.toName(reverse));
-            
+
             PartQuality q = PartQuality.fromName(quality, reverse);
             for (Unit unit : units) {
                 if (null != unit) {
@@ -526,7 +526,7 @@ public void actionPerformed(ActionEvent action) {
 
     private @Nullable Person pickTechForMothballOrActivation(Unit unit, String description) {
         Person tech = null;
-        if (!unit.isSelfCrewed()) {
+        if (!unit.isSelfCrewed() || isSelfCrewedButHasNoTech(unit)) {
             UUID id = gui.selectTech(unit, description, true);
             if (null != id) {
                 tech = gui.getCampaign().getPerson(id);
@@ -544,6 +544,10 @@ public void actionPerformed(ActionEvent action) {
         return tech;
     }
 
+    private boolean isSelfCrewedButHasNoTech(Unit unit) {
+        return unit.isSelfCrewed() && unit.engineerResponsible().isEmpty();
+    }
+
     @Override
     protected Optional<JPopupMenu> createPopupMenu() {
         if (unitTable.getSelectedRowCount() == 0) {

MekHQ/unittests/mekhq/campaign/CampaignTest.java

@@ -133,6 +133,7 @@ void testGetTechs() {
         when(testCampaign.getTechs()).thenCallRealMethod();
         when(testCampaign.getTechs(anyBoolean())).thenCallRealMethod();
         when(testCampaign.getTechs(anyBoolean(), anyBoolean())).thenCallRealMethod();
+        when(testCampaign.getTechsExpanded(anyBoolean(), anyBoolean(), anyBoolean())).thenCallRealMethod();
 
         // Test just getting the list of active techs.
         List<Person> expected = new ArrayList<>(3);