ViewModel refactoring.

.idea/inspectionProfiles/Project_Default.xml

@@ -1,6 +1,7 @@
 <component name="InspectionProjectProfileManager">
   <profile version="1.0">
     <option name="myName" value="Project Default" />
+    <inspection_tool class="FieldCanBeLocal" enabled="false" level="WARNING" enabled_by_default="false" />
     <inspection_tool class="TrivialIf" enabled="false" level="WARNING" enabled_by_default="false" />
   </profile>
 </component>

app/src/main/java/com/majinnaibu/monstercards/ui/collections/CollectionsFragment.java

@@ -12,7 +12,7 @@ import androidx.lifecycle.Observer;
 import androidx.lifecycle.ViewModelProvider;
 
 import com.majinnaibu.monstercards.R;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 
 public class CollectionsFragment extends MCFragment {
 

app/src/main/java/com/majinnaibu/monstercards/ui/dashboard/DashboardFragment.java

@@ -7,12 +7,10 @@ import android.view.ViewGroup;
 import android.widget.TextView;
 
 import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.lifecycle.Observer;
 import androidx.lifecycle.ViewModelProvider;
 
 import com.majinnaibu.monstercards.R;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 
 public class DashboardFragment extends MCFragment {
 
@@ -23,12 +21,7 @@ public class DashboardFragment extends MCFragment {
         dashboardViewModel = new ViewModelProvider(this).get(DashboardViewModel.class);
         View root = inflater.inflate(R.layout.fragment_dashboard, container, false);
         final TextView textView = root.findViewById(R.id.text_dashboard);
-        dashboardViewModel.getText().observe(getViewLifecycleOwner(), new Observer<String>() {
+        dashboardViewModel.getText().observe(getViewLifecycleOwner(), textView::setText);
-            @Override
-            public void onChanged(@Nullable String s) {
-                textView.setText(s);
-            }
-        });
         return root;
     }
 }

app/src/main/java/com/majinnaibu/monstercards/ui/dashboard/DashboardViewModel.java

@@ -5,8 +5,7 @@ import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModel;
 
 public class DashboardViewModel extends ViewModel {
-
+    private final MutableLiveData<String> mText;
-    private MutableLiveData<String> mText;
 
     public DashboardViewModel() {
         mText = new MutableLiveData<>();

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditAbilityScoresFragment.java

@@ -11,8 +11,8 @@ import androidx.navigation.NavController;
 import androidx.navigation.Navigation;
 
 import com.majinnaibu.monstercards.R;
-import com.majinnaibu.monstercards.ui.MCFragment;
 import com.majinnaibu.monstercards.ui.components.Stepper;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 
 public class EditAbilityScoresFragment extends MCFragment {
     private final String ABILITY_SCORE_FORMAT = "%d (%+d)";

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditArmorFragment.java

@@ -21,10 +21,9 @@ import androidx.navigation.Navigation;
 import com.majinnaibu.monstercards.R;
 import com.majinnaibu.monstercards.data.enums.ArmorType;
 import com.majinnaibu.monstercards.helpers.ArrayHelper;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.utils.TextChangedListener;
 
-@SuppressWarnings("FieldCanBeLocal")
 public class EditArmorFragment extends MCFragment {
     private EditMonsterViewModel mViewModel;
     private ViewHolder mHolder;

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditBasicInfoFragment.java

@@ -13,10 +13,9 @@ import androidx.navigation.Navigation;
 
 import com.google.android.material.switchmaterial.SwitchMaterial;
 import com.majinnaibu.monstercards.R;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.utils.TextChangedListener;
 
-@SuppressWarnings("FieldCanBeLocal")
 public class EditBasicInfoFragment extends MCFragment {
     private EditMonsterViewModel mViewModel;
     private ViewHolder mHolder;

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditChallengeRatingFragment.java

@@ -20,7 +20,7 @@ import androidx.navigation.Navigation;
 import com.majinnaibu.monstercards.R;
 import com.majinnaibu.monstercards.data.enums.ChallengeRating;
 import com.majinnaibu.monstercards.helpers.ArrayHelper;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.utils.TextChangedListener;
 
 public class EditChallengeRatingFragment extends MCFragment {

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditConditionImmunitiesFragment.java

@@ -29,7 +29,6 @@ import org.jetbrains.annotations.NotNull;
 /**
  * A fragment representing a list of Items.
  */
-@SuppressWarnings("FieldCanBeLocal")
 public class EditConditionImmunitiesFragment extends Fragment {
     private EditMonsterViewModel mViewModel;
     private ViewHolder mHolder;

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditConditionImmunitiesRecyclerViewAdapter.java

@@ -26,7 +26,7 @@ public class EditConditionImmunitiesRecyclerViewAdapter extends RecyclerView.Ada
 
     @NotNull
     @Override
-    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+    public ViewHolder onCreateViewHolder(@NotNull ViewGroup parent, int viewType) {
         return new ViewHolder(FragmentEditConditionImmunitiesListItemBinding.inflate(LayoutInflater.from(parent.getContext()), parent, false));
     }
 

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditConditionImmunityFragment.java

@@ -19,22 +19,21 @@ import com.majinnaibu.monstercards.R;
 import com.majinnaibu.monstercards.utils.Logger;
 import com.majinnaibu.monstercards.utils.TextChangedListener;
 
-@SuppressWarnings("FieldCanBeLocal")
 public class EditConditionImmunityFragment extends Fragment {
     private EditMonsterViewModel mEditMonsterViewModel;
-    private EditConditionImmunityViewModel mViewModel;
+    private EditStringViewModel mViewModel;
     private ViewHolder mHolder;
     private String mOldValue;
 
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
-        mViewModel = new ViewModelProvider(this).get(EditConditionImmunityViewModel.class);
+        mViewModel = new ViewModelProvider(this).get(EditStringViewModel.class);
         if (getArguments() != null) {
             EditConditionImmunityFragmentArgs args = EditConditionImmunityFragmentArgs.fromBundle(getArguments());
             mOldValue = args.getCondition();
-            mViewModel.reset(mOldValue);
+            mViewModel.resetValue(mOldValue);
         } else {
-            Logger.logWTF("This should never happen. EditConditionImmunityFragment needs arguments");
+            Logger.logWTF("EditConditionImmunityFragment needs arguments");
             mOldValue = null;
         }
 
@@ -49,14 +48,14 @@ public class EditConditionImmunityFragment extends Fragment {
         mEditMonsterViewModel = new ViewModelProvider(backStackEntry).get(EditMonsterViewModel.class);
         View root = inflater.inflate(R.layout.fragment_edit_condition_immunity, container, false);
         mHolder = new ViewHolder(root);
-        mHolder.description.setText(mViewModel.getDescription().getValue());
+        mHolder.description.setText(mViewModel.getValueAsString());
-        mHolder.description.addTextChangedListener(new TextChangedListener((TextChangedListener.OnTextChangedCallback) (s, start, before, count) -> mViewModel.setDescription(s.toString())));
+        mHolder.description.addTextChangedListener(new TextChangedListener((TextChangedListener.OnTextChangedCallback) (s, start, before, count) -> mViewModel.setValue(s.toString())));
 
         requireActivity().getOnBackPressedDispatcher().addCallback(getViewLifecycleOwner(), new OnBackPressedCallback(true) {
             @Override
             public void handleOnBackPressed() {
                 if (mViewModel.hasChanges()) {
-                    mEditMonsterViewModel.replaceConditionImmunity(mOldValue, mViewModel.getDescription().getValue());
+                    mEditMonsterViewModel.replaceConditionImmunity(mOldValue, mViewModel.getValueAsString());
                 }
                 Navigation.findNavController(requireView()).navigateUp();
             }

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditConditionImmunityViewModel.java

@@ -1,36 +0,0 @@
-package com.majinnaibu.monstercards.ui.editmonster;
-
-import androidx.lifecycle.LiveData;
-import androidx.lifecycle.MutableLiveData;
-import androidx.lifecycle.ViewModel;
-
-import com.majinnaibu.monstercards.utils.ChangeTrackedLiveData;
-
-public class EditConditionImmunityViewModel extends ViewModel {
-    private final ChangeTrackedLiveData<String> mDescription;
-    private final MutableLiveData<Boolean> mHasChanges;
-
-    public EditConditionImmunityViewModel() {
-        mHasChanges = new MutableLiveData<>(false);
-        ChangeTrackedLiveData.OnValueDirtiedCallback onDirtied = () -> mHasChanges.setValue(true);
-        mDescription = new ChangeTrackedLiveData<>("", onDirtied);
-    }
-
-    public void reset(String description) {
-        mHasChanges.setValue(false);
-        mDescription.resetValue(description);
-    }
-
-    public LiveData<String> getDescription() {
-        return mDescription;
-    }
-
-    public void setDescription(String description) {
-        mDescription.setValue(description);
-    }
-
-    public boolean hasChanges() {
-        Boolean value = mHasChanges.getValue();
-        return value != null && value;
-    }
-}

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditMonsterFragment.java

@@ -20,8 +20,8 @@ import com.google.android.material.snackbar.Snackbar;
 import com.majinnaibu.monstercards.R;
 import com.majinnaibu.monstercards.data.MonsterRepository;
 import com.majinnaibu.monstercards.models.Monster;
-import com.majinnaibu.monstercards.ui.MCFragment;
 import com.majinnaibu.monstercards.ui.monster.MonsterDetailFragmentArgs;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.utils.Logger;
 
 import java.util.Objects;
@@ -32,7 +32,6 @@ import io.reactivex.rxjava3.observers.DisposableCompletableObserver;
 import io.reactivex.rxjava3.observers.DisposableSingleObserver;
 import io.reactivex.rxjava3.schedulers.Schedulers;
 
-@SuppressWarnings("FieldCanBeLocal")
 public class EditMonsterFragment extends MCFragment {
 
     private EditMonsterViewModel mViewModel;

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditMonsterViewModel.java

@@ -3,7 +3,6 @@ package com.majinnaibu.monstercards.ui.editmonster;
 import androidx.annotation.NonNull;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
-import androidx.lifecycle.ViewModel;
 
 import com.majinnaibu.monstercards.data.enums.AbilityScore;
 import com.majinnaibu.monstercards.data.enums.AdvantageType;
@@ -15,6 +14,7 @@ import com.majinnaibu.monstercards.models.Language;
 import com.majinnaibu.monstercards.models.Monster;
 import com.majinnaibu.monstercards.models.Skill;
 import com.majinnaibu.monstercards.models.Trait;
+import com.majinnaibu.monstercards.ui.shared.ChangeTrackedViewModel;
 import com.majinnaibu.monstercards.utils.ChangeTrackedLiveData;
 
 import java.util.ArrayList;
@@ -26,11 +26,10 @@ import java.util.Objects;
 import java.util.UUID;
 
 @SuppressWarnings({"ConstantConditions", "unused"})
-public class EditMonsterViewModel extends ViewModel {
+public class EditMonsterViewModel extends ChangeTrackedViewModel {
     private final ChangeTrackedLiveData<UUID> mMonsterId;
     private final MutableLiveData<Boolean> mHasError;
     private final MutableLiveData<Boolean> mHasLoaded;
-    private final MutableLiveData<Boolean> mHasChanges;
     private final ChangeTrackedLiveData<Boolean> mHasCustomHitPoints;
     private final ChangeTrackedLiveData<Boolean> mHasShield;
     private final ChangeTrackedLiveData<Boolean> mCanHover;
@@ -91,70 +90,69 @@ public class EditMonsterViewModel extends ViewModel {
     private final ChangeTrackedLiveData<List<Trait>> mRegionalActions;
 
     public EditMonsterViewModel() {
+        super();
         mErrorMessage = new MutableLiveData<>("");
         mHasError = new MutableLiveData<>(false);
         mHasLoaded = new MutableLiveData<>(false);
-        mHasChanges = new MutableLiveData<>(false);
-        ChangeTrackedLiveData.OnValueDirtiedCallback onDirtied = () -> mHasChanges.setValue(true);
 
-        mName = new ChangeTrackedLiveData<>("", onDirtied);
+        mName = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mMonsterId = new ChangeTrackedLiveData<>(UUID.randomUUID(), onDirtied);
+        mMonsterId = new ChangeTrackedLiveData<>(UUID.randomUUID(), this::makeDirty);
-        mSize = new ChangeTrackedLiveData<>("", onDirtied);
+        mSize = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mType = new ChangeTrackedLiveData<>("", onDirtied);
+        mType = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mSubtype = new ChangeTrackedLiveData<>("", onDirtied);
+        mSubtype = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mAlignment = new ChangeTrackedLiveData<>("", onDirtied);
+        mAlignment = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mCustomHitPoints = new ChangeTrackedLiveData<>("", onDirtied);
+        mCustomHitPoints = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mHitDice = new ChangeTrackedLiveData<>(0, onDirtied);
+        mHitDice = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mNaturalArmorBonus = new ChangeTrackedLiveData<>(0, onDirtied);
+        mNaturalArmorBonus = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mHasCustomHitPoints = new ChangeTrackedLiveData<>(false, onDirtied);
+        mHasCustomHitPoints = new ChangeTrackedLiveData<>(false, this::makeDirty);
-        mArmorType = new ChangeTrackedLiveData<>(ArmorType.NONE, onDirtied);
+        mArmorType = new ChangeTrackedLiveData<>(ArmorType.NONE, this::makeDirty);
-        mHasShield = new ChangeTrackedLiveData<>(false, onDirtied);
+        mHasShield = new ChangeTrackedLiveData<>(false, this::makeDirty);
-        mShieldBonus = new ChangeTrackedLiveData<>(0, onDirtied);
+        mShieldBonus = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mCustomArmor = new ChangeTrackedLiveData<>("", onDirtied);
+        mCustomArmor = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mWalkSpeed = new ChangeTrackedLiveData<>(0, onDirtied);
+        mWalkSpeed = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mBurrowSpeed = new ChangeTrackedLiveData<>(0, onDirtied);
+        mBurrowSpeed = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mClimbSpeed = new ChangeTrackedLiveData<>(0, onDirtied);
+        mClimbSpeed = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mFlySpeed = new ChangeTrackedLiveData<>(0, onDirtied);
+        mFlySpeed = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mSwimSpeed = new ChangeTrackedLiveData<>(0, onDirtied);
+        mSwimSpeed = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mCanHover = new ChangeTrackedLiveData<>(false, onDirtied);
+        mCanHover = new ChangeTrackedLiveData<>(false, this::makeDirty);
-        mHasCustomSpeed = new ChangeTrackedLiveData<>(false, onDirtied);
+        mHasCustomSpeed = new ChangeTrackedLiveData<>(false, this::makeDirty);
-        mCustomSpeed = new ChangeTrackedLiveData<>("", onDirtied);
+        mCustomSpeed = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mStrength = new ChangeTrackedLiveData<>(10, onDirtied);
+        mStrength = new ChangeTrackedLiveData<>(10, this::makeDirty);
-        mDexterity = new ChangeTrackedLiveData<>(10, onDirtied);
+        mDexterity = new ChangeTrackedLiveData<>(10, this::makeDirty);
-        mConstitution = new ChangeTrackedLiveData<>(10, onDirtied);
+        mConstitution = new ChangeTrackedLiveData<>(10, this::makeDirty);
-        mIntelligence = new ChangeTrackedLiveData<>(10, onDirtied);
+        mIntelligence = new ChangeTrackedLiveData<>(10, this::makeDirty);
-        mWisdom = new ChangeTrackedLiveData<>(10, onDirtied);
+        mWisdom = new ChangeTrackedLiveData<>(10, this::makeDirty);
-        mCharisma = new ChangeTrackedLiveData<>(10, onDirtied);
+        mCharisma = new ChangeTrackedLiveData<>(10, this::makeDirty);
-        mStrengthProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, onDirtied);
+        mStrengthProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, this::makeDirty);
-        mStrengthAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, onDirtied);
+        mStrengthAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, this::makeDirty);
-        mDexterityProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, onDirtied);
+        mDexterityProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, this::makeDirty);
-        mDexterityAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, onDirtied);
+        mDexterityAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, this::makeDirty);
-        mConstitutionProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, onDirtied);
+        mConstitutionProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, this::makeDirty);
-        mConstitutionAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, onDirtied);
+        mConstitutionAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, this::makeDirty);
-        mIntelligenceProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, onDirtied);
+        mIntelligenceProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, this::makeDirty);
-        mIntelligenceAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, onDirtied);
+        mIntelligenceAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, this::makeDirty);
-        mWisdomProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, onDirtied);
+        mWisdomProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, this::makeDirty);
-        mWisdomAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, onDirtied);
+        mWisdomAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, this::makeDirty);
-        mCharismaProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, onDirtied);
+        mCharismaProficiency = new ChangeTrackedLiveData<>(ProficiencyType.NONE, this::makeDirty);
-        mCharismaAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, onDirtied);
+        mCharismaAdvantage = new ChangeTrackedLiveData<>(AdvantageType.NONE, this::makeDirty);
-        mChallengeRating = new ChangeTrackedLiveData<>(ChallengeRating.ONE_EIGHTH, onDirtied);
+        mChallengeRating = new ChangeTrackedLiveData<>(ChallengeRating.ONE_EIGHTH, this::makeDirty);
-        mCustomChallengeRatingDescription = new ChangeTrackedLiveData<>("", onDirtied);
+        mCustomChallengeRatingDescription = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mCustomProficiencyBonus = new ChangeTrackedLiveData<>(0, onDirtied);
+        mCustomProficiencyBonus = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mTelepathyRange = new ChangeTrackedLiveData<>(0, onDirtied);
+        mTelepathyRange = new ChangeTrackedLiveData<>(0, this::makeDirty);
-        mUnderstandsButDescription = new ChangeTrackedLiveData<>("", onDirtied);
+        mUnderstandsButDescription = new ChangeTrackedLiveData<>("", this::makeDirty);
-        mSkills = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mSkills = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mSenses = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mSenses = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mDamageImmunities = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mDamageImmunities = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mDamageResistances = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mDamageResistances = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mDamageVulnerabilities = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mDamageVulnerabilities = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mConditionImmunities = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mConditionImmunities = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mLanguages = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mLanguages = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mAbilities = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mAbilities = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mActions = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mActions = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mReactions = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mReactions = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mLairActions = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mLairActions = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mLegendaryActions = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mLegendaryActions = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
-        mRegionalActions = new ChangeTrackedLiveData<>(new ArrayList<>(), onDirtied);
+        mRegionalActions = new ChangeTrackedLiveData<>(new ArrayList<>(), this::makeDirty);
     }
 
     public void copyFromMonster(Monster monster) {
@@ -231,7 +229,7 @@ public class EditMonsterViewModel extends ViewModel {
         mLairActions.resetValue(new ArrayList<>(monster.lairActions));
         mLegendaryActions.resetValue(new ArrayList<>(monster.legendaryActions));
         mRegionalActions.resetValue(new ArrayList<>(monster.regionalActions));
-        mHasChanges.setValue(false);
+        makeClean();
     }
 
     public LiveData<String> getName() {
@@ -318,14 +316,6 @@ public class EditMonsterViewModel extends ViewModel {
         mCustomHitPoints.setValue(customHitPoints);
     }
 
-    public LiveData<Boolean> getHasChanges() {
-        return mHasChanges;
-    }
-
-    public boolean hasChanges() {
-        return mHasChanges.getValue();
-    }
-
     public LiveData<Integer> getHitDice() {
         return mHitDice;
     }

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditSavingThrowsFragment.java

@@ -11,9 +11,9 @@ import androidx.navigation.NavController;
 import androidx.navigation.Navigation;
 
 import com.majinnaibu.monstercards.R;
-import com.majinnaibu.monstercards.ui.MCFragment;
 import com.majinnaibu.monstercards.ui.components.AdvantagePicker;
 import com.majinnaibu.monstercards.ui.components.ProficiencyPicker;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 
 public class EditSavingThrowsFragment extends MCFragment {
     private EditMonsterViewModel mViewModel;

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditSenseFragment.java

@@ -15,26 +15,25 @@ import androidx.navigation.NavController;
 import androidx.navigation.Navigation;
 
 import com.majinnaibu.monstercards.R;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.utils.Logger;
 import com.majinnaibu.monstercards.utils.TextChangedListener;
 
-@SuppressWarnings("FieldCanBeLocal")
 public class EditSenseFragment extends MCFragment {
     private EditMonsterViewModel mEditMonsterViewModel;
-    private EditSenseViewModel mViewModel;
+    private EditStringViewModel mViewModel;
     private ViewHolder mHolder;
     private String mOldSense;
 
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
-        mViewModel = new ViewModelProvider(this).get(EditSenseViewModel.class);
+        mViewModel = new ViewModelProvider(this).get(EditStringViewModel.class);
         if (getArguments() != null) {
             EditSenseFragmentArgs args = EditSenseFragmentArgs.fromBundle(getArguments());
             mOldSense = args.getSense();
-            mViewModel.reset(mOldSense);
+            mViewModel.resetValue(mOldSense);
         } else {
-            Logger.logWTF("This should never happen. EditSenseFragment needs arguments");
+            Logger.logWTF("EditSenseFragment needs arguments");
             mOldSense = null;
         }
         super.onCreate(savedInstanceState);
@@ -51,14 +50,14 @@ public class EditSenseFragment extends MCFragment {
 
         mHolder = new ViewHolder(root);
 
-        mHolder.description.setText(mViewModel.getDescription().getValue());
+        mHolder.description.setText(mViewModel.getValueAsString());
-        mHolder.description.addTextChangedListener(new TextChangedListener((TextChangedListener.OnTextChangedCallback) (s, start, before, count) -> mViewModel.setDescription(s.toString())));
+        mHolder.description.addTextChangedListener(new TextChangedListener((TextChangedListener.OnTextChangedCallback) (s, start, before, count) -> mViewModel.setValue(s.toString())));
 
         requireActivity().getOnBackPressedDispatcher().addCallback(getViewLifecycleOwner(), new OnBackPressedCallback(true) {
             @Override
             public void handleOnBackPressed() {
                 if (mViewModel.hasChanges()) {
-                    mEditMonsterViewModel.replaceSense(mOldSense, mViewModel.getDescription().getValue());
+                    mEditMonsterViewModel.replaceSense(mOldSense, mViewModel.getValueAsString());
                 }
                 Navigation.findNavController(requireView()).navigateUp();
             }

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditSenseViewModel.java

@@ -1,36 +0,0 @@
-package com.majinnaibu.monstercards.ui.editmonster;
-
-import androidx.lifecycle.LiveData;
-import androidx.lifecycle.MutableLiveData;
-import androidx.lifecycle.ViewModel;
-
-import com.majinnaibu.monstercards.utils.ChangeTrackedLiveData;
-
-public class EditSenseViewModel extends ViewModel {
-    private final ChangeTrackedLiveData<String> mDescription;
-    private final MutableLiveData<Boolean> mHasChanges;
-
-    public EditSenseViewModel() {
-        mHasChanges = new MutableLiveData<>(false);
-        ChangeTrackedLiveData.OnValueDirtiedCallback onDirtied = () -> mHasChanges.setValue(true);
-        mDescription = new ChangeTrackedLiveData<>("", onDirtied);
-    }
-
-    public void reset(String description) {
-        mHasChanges.setValue(false);
-        mDescription.resetValue(description);
-    }
-
-    public LiveData<String> getDescription() {
-        return mDescription;
-    }
-
-    public void setDescription(String description) {
-        mDescription.setValue(description);
-    }
-
-    public boolean hasChanges() {
-        Boolean value = mHasChanges.getValue();
-        return value != null && value;
-    }
-}

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditSensesFragment.java

@@ -19,14 +19,13 @@ import androidx.recyclerview.widget.RecyclerView;
 
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import com.majinnaibu.monstercards.R;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.ui.shared.SwipeToDeleteCallback;
 import com.majinnaibu.monstercards.utils.Logger;
 
 /**
  * A fragment representing a list of Items.
  */
-@SuppressWarnings("FieldCanBeLocal")
 public class EditSensesFragment extends MCFragment {
     private EditMonsterViewModel mViewModel;
     private ViewHolder mHolder;

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditSkillFragment.java

@@ -16,10 +16,10 @@ import androidx.navigation.Navigation;
 
 import com.majinnaibu.monstercards.R;
 import com.majinnaibu.monstercards.models.Skill;
-import com.majinnaibu.monstercards.ui.MCFragment;
 import com.majinnaibu.monstercards.ui.components.AbilityScorePicker;
 import com.majinnaibu.monstercards.ui.components.AdvantagePicker;
 import com.majinnaibu.monstercards.ui.components.ProficiencyPicker;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.utils.Logger;
 import com.majinnaibu.monstercards.utils.TextChangedListener;
 
@@ -37,7 +37,7 @@ public class EditSkillFragment extends MCFragment {
             mOldSkill = new Skill(args.getName(), args.getAbilityScore(), args.getAdvantage(), args.getProficiency());
             mViewModel.copyFromSkill(mOldSkill);
         } else {
-            Logger.logWTF("This should never happen. EditSkillFragment needs arguments.");
+            Logger.logWTF("EditSkillFragment needs arguments.");
             mOldSkill = null;
         }
         super.onCreate(savedInstanceState);

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditSkillViewModel.java

@@ -1,32 +1,28 @@
 package com.majinnaibu.monstercards.ui.editmonster;
 
 import androidx.lifecycle.LiveData;
-import androidx.lifecycle.MutableLiveData;
-import androidx.lifecycle.ViewModel;
 
 import com.majinnaibu.monstercards.data.enums.AbilityScore;
 import com.majinnaibu.monstercards.data.enums.AdvantageType;
 import com.majinnaibu.monstercards.data.enums.ProficiencyType;
 import com.majinnaibu.monstercards.models.Skill;
+import com.majinnaibu.monstercards.ui.shared.ChangeTrackedViewModel;
 import com.majinnaibu.monstercards.utils.ChangeTrackedLiveData;
 
-public class EditSkillViewModel extends ViewModel {
+public class EditSkillViewModel extends ChangeTrackedViewModel {
     private final ChangeTrackedLiveData<AbilityScore> mAbilityScore;
     private final ChangeTrackedLiveData<AdvantageType> mAdvantageType;
-    private final MutableLiveData<Boolean> mHasChanges;
     private final ChangeTrackedLiveData<ProficiencyType> mProficiencyType;
     private final ChangeTrackedLiveData<String> mName;
     private final ChangeTrackedLiveData<Skill> mSkill;
 
     public EditSkillViewModel() {
-        mHasChanges = new MutableLiveData<>(false);
+        super();
-        ChangeTrackedLiveData.OnValueDirtiedCallback onDirtied = () -> mHasChanges.setValue(true);
+        mAbilityScore = new ChangeTrackedLiveData<>(AbilityScore.STRENGTH, this::makeDirty);
-
+        mAdvantageType = new ChangeTrackedLiveData<>(AdvantageType.NONE, this::makeDirty);
-        mAbilityScore = new ChangeTrackedLiveData<>(AbilityScore.STRENGTH, onDirtied);
+        mProficiencyType = new ChangeTrackedLiveData<>(ProficiencyType.NONE, this::makeDirty);
-        mAdvantageType = new ChangeTrackedLiveData<>(AdvantageType.NONE, onDirtied);
+        mName = new ChangeTrackedLiveData<>("Unknown Skill", this::makeDirty);
-        mProficiencyType = new ChangeTrackedLiveData<>(ProficiencyType.NONE, onDirtied);
+        mSkill = new ChangeTrackedLiveData<>(makeSkill(), this::makeDirty);
-        mName = new ChangeTrackedLiveData<>("Unknown Skill", onDirtied);
-        mSkill = new ChangeTrackedLiveData<>(makeSkill(), onDirtied);
     }
 
     public void copyFromSkill(Skill skill) {
@@ -76,11 +72,6 @@ public class EditSkillViewModel extends ViewModel {
         mSkill.setValue(makeSkill());
     }
 
-    public boolean hasChanges() {
-        Boolean value = mHasChanges.getValue();
-        return value != null && value;
-    }
-
     private Skill makeSkill() {
         return new Skill(mName.getValue(), mAbilityScore.getValue(), mAdvantageType.getValue(), mProficiencyType.getValue());
     }

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditSkillsFragment.java

@@ -20,14 +20,13 @@ import androidx.recyclerview.widget.RecyclerView;
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import com.majinnaibu.monstercards.R;
 import com.majinnaibu.monstercards.models.Skill;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.ui.shared.SwipeToDeleteCallback;
 import com.majinnaibu.monstercards.utils.Logger;
 
 /**
  * A fragment representing a list of Items.
  */
-@SuppressWarnings("FieldCanBeLocal")
 public class EditSkillsFragment extends MCFragment {
     private EditMonsterViewModel mViewModel;
     private ViewHolder mHolder;

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditSpeedFragment.java

@@ -13,8 +13,8 @@ import androidx.navigation.NavController;
 import androidx.navigation.Navigation;
 
 import com.majinnaibu.monstercards.R;
-import com.majinnaibu.monstercards.ui.MCFragment;
 import com.majinnaibu.monstercards.ui.components.Stepper;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.utils.TextChangedListener;
 
 public class EditSpeedFragment extends MCFragment {

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/EditStringViewModel.java

@@ -0,0 +1,32 @@
+package com.majinnaibu.monstercards.ui.editmonster;
+
+import androidx.lifecycle.LiveData;
+
+import com.majinnaibu.monstercards.ui.shared.ChangeTrackedViewModel;
+import com.majinnaibu.monstercards.utils.ChangeTrackedLiveData;
+
+public class EditStringViewModel extends ChangeTrackedViewModel {
+    private final ChangeTrackedLiveData<String> mValue;
+
+    public EditStringViewModel() {
+        super();
+        mValue = new ChangeTrackedLiveData<>("", this::makeDirty);
+    }
+
+    public LiveData<String> getValue() {
+        return mValue;
+    }
+
+    public void setValue(String value) {
+        mValue.setValue(value);
+    }
+
+    public String getValueAsString() {
+        return mValue.getValue();
+    }
+
+    public void resetValue(String value) {
+        makeClean();
+        mValue.resetValue(value);
+    }
+}

app/src/main/java/com/majinnaibu/monstercards/ui/editmonster/placeholder/PlaceholderContent.java

@@ -1,72 +0,0 @@
-package com.majinnaibu.monstercards.ui.editmonster.placeholder;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-/**
- * Helper class for providing sample content for user interfaces created by
- * Android template wizards.
- * <p>
- * TODO: Replace all uses of this class before publishing your app.
- */
-public class PlaceholderContent {
-
-    /**
-     * An array of sample (placeholder) items.
-     */
-    public static final List<PlaceholderItem> ITEMS = new ArrayList<PlaceholderItem>();
-
-    /**
-     * A map of sample (placeholder) items, by ID.
-     */
-    public static final Map<String, PlaceholderItem> ITEM_MAP = new HashMap<String, PlaceholderItem>();
-
-    private static final int COUNT = 25;
-
-    static {
-        // Add some sample items.
-        for (int i = 1; i <= COUNT; i++) {
-            addItem(createPlaceholderItem(i));
-        }
-    }
-
-    private static void addItem(PlaceholderItem item) {
-        ITEMS.add(item);
-        ITEM_MAP.put(item.id, item);
-    }
-
-    private static PlaceholderItem createPlaceholderItem(int position) {
-        return new PlaceholderItem(String.valueOf(position), "Item " + position, makeDetails(position));
-    }
-
-    private static String makeDetails(int position) {
-        StringBuilder builder = new StringBuilder();
-        builder.append("Details about Item: ").append(position);
-        for (int i = 0; i < position; i++) {
-            builder.append("\nMore details information here.");
-        }
-        return builder.toString();
-    }
-
-    /**
-     * A placeholder item representing a piece of content.
-     */
-    public static class PlaceholderItem {
-        public final String id;
-        public final String content;
-        public final String details;
-
-        public PlaceholderItem(String id, String content, String details) {
-            this.id = id;
-            this.content = content;
-            this.details = details;
-        }
-
-        @Override
-        public String toString() {
-            return content;
-        }
-    }
-}

app/src/main/java/com/majinnaibu/monstercards/ui/library/LibraryFragment.java

@@ -19,7 +19,7 @@ import com.google.android.material.snackbar.Snackbar;
 import com.majinnaibu.monstercards.R;
 import com.majinnaibu.monstercards.data.MonsterRepository;
 import com.majinnaibu.monstercards.models.Monster;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.ui.shared.SwipeToDeleteCallback;
 import com.majinnaibu.monstercards.utils.Logger;
 

app/src/main/java/com/majinnaibu/monstercards/ui/monster/MonsterDetailFragment.java

@@ -26,7 +26,7 @@ import com.majinnaibu.monstercards.data.MonsterRepository;
 import com.majinnaibu.monstercards.helpers.CommonMarkHelper;
 import com.majinnaibu.monstercards.helpers.StringHelper;
 import com.majinnaibu.monstercards.models.Monster;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 import com.majinnaibu.monstercards.utils.Logger;
 
 import java.util.UUID;
@@ -241,10 +241,15 @@ public class MonsterDetailFragment extends MCFragment {
     @Override
     public boolean onOptionsItemSelected(@NonNull MenuItem item) {
         if (item.getItemId() == R.id.menu_action_edit_monster) {
-            NavDirections action = MonsterDetailFragmentDirections.actionNavigationMonsterToEditMonsterFragment(monsterDetailViewModel.getId().getValue().toString());
+            UUID monsterId = monsterDetailViewModel.getId().getValue();
+            if (monsterId != null) {
+                NavDirections action = MonsterDetailFragmentDirections.actionNavigationMonsterToEditMonsterFragment(monsterId.toString());
                 View view = getView();
                 assert view != null;
                 Navigation.findNavController(view).navigate(action);
+            } else {
+                Logger.logWTF("monsterId cannot be null.");
+            }
             return true;
         }
         return super.onOptionsItemSelected(item);

app/src/main/java/com/majinnaibu/monstercards/ui/search/SearchFragment.java

@@ -14,7 +14,7 @@ import androidx.recyclerview.widget.RecyclerView;
 
 import com.majinnaibu.monstercards.R;
 import com.majinnaibu.monstercards.data.MonsterRepository;
-import com.majinnaibu.monstercards.ui.MCFragment;
+import com.majinnaibu.monstercards.ui.shared.MCFragment;
 
 public class SearchFragment extends MCFragment {
 

app/src/main/java/com/majinnaibu/monstercards/ui/search/SearchResultsRecyclerViewAdapter.java

@@ -13,6 +13,8 @@ import com.majinnaibu.monstercards.data.MonsterRepository;
 import com.majinnaibu.monstercards.models.Monster;
 import com.majinnaibu.monstercards.utils.Logger;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -20,16 +22,11 @@ import io.reactivex.rxjava3.core.Flowable;
 import io.reactivex.rxjava3.disposables.Disposable;
 
 public class SearchResultsRecyclerViewAdapter extends RecyclerView.Adapter<SearchResultsRecyclerViewAdapter.ViewHolder> {
-    public interface ItemCallback {
-        void onItem(Monster monster);
-    }
-
     private final MonsterRepository mRepository;
+    private final ItemCallback mOnClickHandler;
     private String mSearchText;
     private List<Monster> mValues;
     private Disposable mSubscriptionHandler;
-    private final ItemCallback mOnClickHandler;
-
     public SearchResultsRecyclerViewAdapter(MonsterRepository repository,
                                             ItemCallback onClick) {
         mRepository = repository;
@@ -54,6 +51,7 @@ public class SearchResultsRecyclerViewAdapter extends RecyclerView.Adapter<Searc
                 throwable -> Logger.logError("Error performing search", throwable));
     }
 
+    @NotNull
     @Override
     public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         View view = LayoutInflater.from(parent.getContext())
@@ -79,7 +77,11 @@ public class SearchResultsRecyclerViewAdapter extends RecyclerView.Adapter<Searc
         return mValues.size();
     }
 
-    class ViewHolder extends RecyclerView.ViewHolder {
+    public interface ItemCallback {
+        void onItem(Monster monster);
+    }
+
+    public static class ViewHolder extends RecyclerView.ViewHolder {
         final TextView mIdView;
         final TextView mContentView;
 

app/src/main/java/com/majinnaibu/monstercards/ui/shared/ChangeTrackedViewModel.java

@@ -0,0 +1,25 @@
+package com.majinnaibu.monstercards.ui.shared;
+
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+
+public class ChangeTrackedViewModel extends ViewModel {
+    private final MutableLiveData<Boolean> mHasChanges;
+
+    public ChangeTrackedViewModel() {
+        mHasChanges = new MutableLiveData<>(false);
+    }
+
+    public boolean hasChanges() {
+        Boolean value = mHasChanges.getValue();
+        return value != null && value;
+    }
+
+    protected void makeDirty() {
+        mHasChanges.setValue(true);
+    }
+
+    protected void makeClean() {
+        mHasChanges.setValue(false);
+    }
+}

app/src/main/java/com/majinnaibu/monstercards/ui/shared/MCFragment.java

@@ -1,4 +1,4 @@
-package com.majinnaibu.monstercards.ui;
+package com.majinnaibu.monstercards.ui.shared;
 
 import android.app.Activity;
 
@@ -11,7 +11,7 @@ import com.majinnaibu.monstercards.data.MonsterRepository;
 
 public class MCFragment extends Fragment {
     public MonsterCardsApplication getApplication() {
-        return (MonsterCardsApplication) this.getActivity().getApplication();
+        return (MonsterCardsApplication) requireActivity().getApplication();
     }
 
     protected MonsterRepository getMonsterRepository() {