Make PlotFlag more generic to allow generic flag creation

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/flags/FlagContainer.java

@@ -11,7 +11,7 @@ import java.util.Map;
 @EqualsAndHashCode(of = "flagMap") public class FlagContainer {
 
     private final FlagContainer parentContainer;
-    private final Map<Class<?>, PlotFlag<?>> flagMap = new HashMap<>();
+    private final Map<Class<?>, PlotFlag<?, ?>> flagMap = new HashMap<>();
 
     public FlagContainer(@Nullable final FlagContainer parentContainer) {
         this.parentContainer = parentContainer;
@@ -21,25 +21,25 @@ import java.util.Map;
         return this.parentContainer;
     }
 
-    protected Map<Class<?>, PlotFlag<?>> getInternalPlotFlagMap() {
+    protected Map<Class<?>, PlotFlag<?, ?>> getInternalPlotFlagMap() {
         return this.flagMap;
     }
 
-    public Map<Class<?>, PlotFlag<?>> getFlagMap() {
+    public Map<Class<?>, PlotFlag<?, ?>> getFlagMap() {
-        return ImmutableMap.<Class<?>, PlotFlag<?>>builder().putAll(this.flagMap).build();
+        return ImmutableMap.<Class<?>, PlotFlag<?, ?>>builder().putAll(this.flagMap).build();
     }
 
-    public void addFlag(final PlotFlag<?> flag) {
+    public void addFlag(final PlotFlag<?, ? extends PlotFlag<?, ?>> flag) {
         this.flagMap.put(flag.getClass(), flag);
     }
 
-    public void addAll(final Collection<PlotFlag<?>> flags) {
+    public void addAll(final Collection<PlotFlag<?, ?>> flags) {
-        for (final PlotFlag<?> flag : flags) {
+        for (final PlotFlag<?, ?> flag : flags) {
             this.addFlag(flag);
         }
     }
 
-    public Collection<PlotFlag<?>> getRecognizedPlotFlags() {
+    public Collection<PlotFlag<?, ?>> getRecognizedPlotFlags() {
         return this.getHighestClassContainer().getFlagMap().values();
     }
 
@@ -50,8 +50,8 @@ import java.util.Map;
         return this;
     }
 
-    public PlotFlag<?> getFlagErased(Class<?> flagClass) {
+    public PlotFlag<?, ?> getFlagErased(Class<?> flagClass) {
-        final PlotFlag<?> flag = this.flagMap.get(flagClass);
+        final PlotFlag<?, ?> flag = this.flagMap.get(flagClass);
         if (flag != null) {
             return flag;
         } else {
@@ -62,10 +62,10 @@ import java.util.Map;
         return null;
     }
 
-    public <T> PlotFlag<T> getFlag(final Class<? extends PlotFlag<T>> flagClass) {
+    public <T> PlotFlag<T, ?> getFlag(final Class<? extends PlotFlag<T, ?>> flagClass) {
-        final PlotFlag<?> flag = this.flagMap.get(flagClass);
+        final PlotFlag<?, ?> flag = this.flagMap.get(flagClass);
         if (flag != null) {
-            return (PlotFlag<T>) flag;
+            return (PlotFlag<T, ?>) flag;
         } else {
             if (getParentContainer() != null) {
                 return getParentContainer().getFlag(flagClass);

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/flags/GlobalFlagContainer.java

@@ -14,8 +14,8 @@ public final class GlobalFlagContainer extends FlagContainer {
 
     private final Map<String, Class<?>> stringClassMap = new HashMap<>();
 
-    @Override public PlotFlag<?> getFlagErased(Class<?> flagClass) {
+    @Override public PlotFlag<?, ?> getFlagErased(Class<?> flagClass) {
-        final PlotFlag<?> flag = super.getFlagErased(flagClass);
+        final PlotFlag<?, ?> flag = super.getFlagErased(flagClass);
         if (flag != null) {
             return flag;
         } else {
@@ -24,10 +24,10 @@ public final class GlobalFlagContainer extends FlagContainer {
         }
     }
 
-    @Nonnull @Override public <T> PlotFlag<T> getFlag(Class<? extends PlotFlag<T>> flagClass) {
+    @Nonnull @Override public <T> PlotFlag<T, ?> getFlag(Class<? extends PlotFlag<T, ?>> flagClass) {
-        final PlotFlag<?> flag = super.getFlag(flagClass);
+        final PlotFlag<?, ?> flag = super.getFlag(flagClass);
         if (flag != null) {
-            return (PlotFlag<T>) flag;
+            return (PlotFlag<T, ?>) flag;
         } else {
             throw new IllegalStateException(String.format("Unrecognized flag '%s'. All flag types"
                 + " must be present in the global flag container.", flagClass.getSimpleName()));
@@ -37,10 +37,10 @@ public final class GlobalFlagContainer extends FlagContainer {
     private GlobalFlagContainer() {
         super(null);
         // Register all default flags here
-        this.addFlag(new ExplosionFlag());
+        this.addFlag(ExplosionFlag.EXPLOSION_FALSE);
     }
 
-    @Override public void addFlag(PlotFlag<?> flag) {
+    @Override public void addFlag(PlotFlag<?, ?> flag) {
         super.addFlag(flag);
         this.stringClassMap.put(flag.getName().toLowerCase(Locale.ENGLISH), flag.getClass());
     }
@@ -49,7 +49,7 @@ public final class GlobalFlagContainer extends FlagContainer {
         return this.stringClassMap.get(name.toLowerCase(Locale.ENGLISH));
     }
 
-    public PlotFlag<?> getFlagFromString(final String name) {
+    public PlotFlag<?, ?> getFlagFromString(final String name) {
         final Class<?> flagClass = this.getFlagClassFromString(name);
         if (flagClass == null) {
             return null;

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/flags/PlotFlag.java

@@ -14,9 +14,9 @@ import java.util.Locale;
  *
  * @param <T> Value contained in the flag.
  */
-@EqualsAndHashCode(of = "value") public abstract class PlotFlag<T> {
+@EqualsAndHashCode(of = "value") public abstract class PlotFlag<T, F extends PlotFlag<T, F>> {
 
-    private T value;
+    private final T value;
     private final Captions flagCategory;
     private final Captions flagDescription;
 
@@ -42,33 +42,24 @@ import java.util.Locale;
     }
 
     /**
-     * Update the flag value.
+     * Parse a string into a flag, and throw an exception in the case that the
-     *
+     * string does not represent a valid flag value. This instance won't change its
-     * @param newValue New flag value.
+     * state, but instead an instance holding the parsed flag value will be returned.
-     */
-    public T setFlagValue(@NotNull final T newValue) {
-        return (this.value = Preconditions.checkNotNull(newValue, "flag values may not be null"));
-    }
-
-    /**
-     * Parse a string into a flag value, and throw an exception in the case that the
-     * string does not represent a valid flag value. The flag value will be updated to
-     * the newly parsed value.
      *
      * @param input String to parse.
      * @return Parsed value, if valid.
      * @throws FlagParseException If the value could not be parsed.
      */
-    public abstract T parse(@NotNull final String input) throws FlagParseException;
+    public abstract F parse(@NotNull final String input) throws FlagParseException;
 
     /**
-     * Merge two flag values into one and updates the flag value.
+     * Merge this flag's value with another value and return an instance
+     * holding the merged value.
      *
-     * @param oldValue Existing flag value.
      * @param newValue New flag value.
      * @return Flag containing parsed flag value.
      */
-    public abstract T merge(@NotNull final T oldValue, @NotNull final T newValue);
+    public abstract F merge(@NotNull final T newValue);
 
     /**
      * Returns a string representation of the flag instance, that when
@@ -93,4 +84,6 @@ import java.util.Locale;
 
     public abstract String getExample();
 
+    protected abstract F flagOf(@NotNull T value);
+
 }

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/flags/implementations/ExplosionFlag.java

@@ -2,15 +2,21 @@ package com.github.intellectualsites.plotsquared.plot.flags.implementations;
 
 import com.github.intellectualsites.plotsquared.plot.config.Captions;
 import com.github.intellectualsites.plotsquared.plot.flags.types.BooleanFlag;
+import org.jetbrains.annotations.NotNull;
 
-public class ExplosionFlag extends BooleanFlag {
+public class ExplosionFlag extends BooleanFlag<ExplosionFlag> {
+    public static final ExplosionFlag EXPLOSION_TRUE = new ExplosionFlag(true);
+    public static final ExplosionFlag EXPLOSION_FALSE = new ExplosionFlag(false);
 
-    public ExplosionFlag() {
+    private ExplosionFlag(boolean value) {
-        super(Captions.FLAG_DESCRIPTION_EXPLOSION);
+        super(value, Captions.FLAG_DESCRIPTION_EXPLOSION);
     }
 
     @Override public String getExample() {
         return "true";
     }
 
+    @Override protected ExplosionFlag flagOf(@NotNull Boolean value) {
+        return value ? EXPLOSION_TRUE : EXPLOSION_FALSE;
+    }
 }

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/flags/types/BlockTypeListFlag.java

@@ -10,17 +10,17 @@ import org.jetbrains.annotations.NotNull;
 import java.util.ArrayList;
 import java.util.List;
 
-public class BlockTypeListFlag extends ListFlag<BlockType> {
+public class BlockTypeListFlag extends ListFlag<BlockType, BlockTypeListFlag> {
 
-    public BlockTypeListFlag(Captions description) {
+    public BlockTypeListFlag(List<BlockType> blockTypeList, Captions description) {
-        super(Captions.FLAG_CATEGORY_BLOCK_LIST, description);
+        super(blockTypeList, Captions.FLAG_CATEGORY_BLOCK_LIST, description);
     }
 
-    @Override public List<BlockType> parse(@NotNull String input) throws FlagParseException {
+    @Override public BlockTypeListFlag parse(@NotNull String input) throws FlagParseException {
         final List<BlockType> parsedBlocks = new ArrayList<>();
         final String[] split = input.split(",(?![^\\(\\[]*[\\]\\)])");
         if (split.length == 0) {
-            return parsedBlocks;
+            return this.flagOf(parsedBlocks);
         }
         for (final String blockString : split) {
             final BlockState blockState = BlockUtil.get(blockString);
@@ -30,11 +30,15 @@ public class BlockTypeListFlag extends ListFlag<BlockType> {
                 parsedBlocks.add(blockState.getBlockType());
             }
         }
-        return parsedBlocks;
+        return this.flagOf(parsedBlocks);
     }
 
     @Override public String getExample() {
         return "air,grass_block";
     }
 
+    @Override protected BlockTypeListFlag flagOf(@NotNull List<BlockType> value) {
+        return new BlockTypeListFlag(value, getFlagDescription()); // copy the description
+    }
+
 }

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/flags/types/BooleanFlag.java

@@ -9,7 +9,7 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Locale;
 
-public abstract class BooleanFlag extends PlotFlag<Boolean> {
+public abstract class BooleanFlag<F extends PlotFlag<Boolean, F>> extends PlotFlag<Boolean, F> {
 
     private static final Collection<String> positiveValues = Arrays.asList("1", "yes", "allow", "true");
     private static final Collection<String> negativeValues = Arrays.asList("0", "no", "deny", "disallow", "false");
@@ -34,18 +34,18 @@ public abstract class BooleanFlag extends PlotFlag<Boolean> {
         this(false, description);
     }
 
-    @Override public Boolean parse(@NotNull String input) throws FlagParseException {
+    @Override public F parse(@NotNull String input) throws FlagParseException {
         if (positiveValues.contains(input.toLowerCase(Locale.ENGLISH))) {
-            return true;
+            return this.flagOf(true);
         } else if (negativeValues.contains(input.toLowerCase(Locale.ENGLISH))) {
-            return false;
+            return this.flagOf(false);
         } else {
             throw new FlagParseException(this, input, Captions.FLAG_ERROR_BOOLEAN);
         }
     }
 
-    @Override public Boolean merge(@NotNull Boolean oldValue, @NotNull Boolean newValue) {
+    @Override public F merge(@NotNull Boolean newValue) {
-        return this.setFlagValue(oldValue || newValue);
+        return this.flagOf(getValue() || newValue);
     }
 
     @Override public String toString() {

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/flags/types/IntegerFlag.java

@@ -5,26 +5,26 @@ import com.github.intellectualsites.plotsquared.plot.flags.FlagParseException;
 import com.github.intellectualsites.plotsquared.plot.flags.PlotFlag;
 import org.jetbrains.annotations.NotNull;
 
-public class IntegerFlag extends PlotFlag<Integer> {
+public class IntegerFlag extends PlotFlag<Integer, IntegerFlag> {
 
-    protected IntegerFlag(final int defaultValue, @NotNull Captions flagDescription) {
+    protected IntegerFlag(final int value, @NotNull Captions flagDescription) {
-        super(defaultValue, Captions.FLAG_CATEGORY_INTEGERS, flagDescription);
+        super(value, Captions.FLAG_CATEGORY_INTEGERS, flagDescription);
     }
 
     protected IntegerFlag(@NotNull Captions flagDescription) {
         this(0, flagDescription);
     }
 
-    @Override public Integer parse(@NotNull String input) throws FlagParseException {
+    @Override public IntegerFlag parse(@NotNull String input) throws FlagParseException {
         try {
-            return Integer.parseInt(input);
+            return flagOf(Integer.parseInt(input));
         } catch (final Throwable throwable) {
             throw new FlagParseException(this, input, Captions.FLAG_ERROR_INTEGER);
         }
     }
 
-    @Override public Integer merge(@NotNull Integer oldValue, @NotNull Integer newValue) {
+    @Override public IntegerFlag merge(@NotNull Integer newValue) {
-        return oldValue + newValue;
+        return flagOf(getValue() + newValue);
     }
 
     @Override public String toString() {
@@ -35,4 +35,8 @@ public class IntegerFlag extends PlotFlag<Integer> {
         return "10";
     }
 
+    @Override protected IntegerFlag flagOf(@NotNull Integer value) {
+        return new IntegerFlag(value, getFlagDescription());
+    }
+
 }

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/flags/types/ListFlag.java

@@ -8,17 +8,17 @@ import org.jetbrains.annotations.NotNull;
 import java.util.ArrayList;
 import java.util.List;
 
-public abstract class ListFlag<V> extends PlotFlag<List<V>> {
+public abstract class ListFlag<V, F extends PlotFlag<List<V>, F>> extends PlotFlag<List<V>, F> {
 
-    public ListFlag(final Captions category, final Captions description) {
+    public ListFlag(final List<V> valueList, final Captions category, final Captions description) {
-        super(new ArrayList<>(), category, description);
+        super(valueList, category, description);
     }
 
-    @Override public List<V> merge(@NotNull List<V> oldValue, @NotNull List<V> newValue) {
+    @Override public F merge(@NotNull List<V> newValue) {
         final List<V> mergedList = new ArrayList<>();
-        mergedList.addAll(oldValue);
+        mergedList.addAll(getValue());
         mergedList.addAll(newValue);
-        return this.setFlagValue(mergedList);
+        return this.flagOf(mergedList);
     }
 
     @Override public String toString() {

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/object/Plot.java

@@ -213,7 +213,7 @@ public class Plot {
      * @see Plot#getPlot(Location) for existing plots
      */
     public Plot(@NotNull PlotId id, UUID owner, HashSet<UUID> trusted, HashSet<UUID> members,
-        HashSet<UUID> denied, String alias, BlockLoc position, Collection<PlotFlag<?>> flags,
+        HashSet<UUID> denied, String alias, BlockLoc position, Collection<PlotFlag<?, ?>> flags,
         PlotArea area, boolean[] merged, long timestamp, int temp) {
         this.id = id;
         this.area = area;
@@ -229,7 +229,7 @@ public class Plot {
         this.temp = temp;
         this.flagContainer = new FlagContainer(area.getFlagContainer());
         if (flags != null) {
-            for (PlotFlag<?> flag : flags) {
+            for (PlotFlag<?, ?> flag : flags) {
                 this.flagContainer.addFlag(flag);
             }
         }
@@ -3148,7 +3148,7 @@ public class Plot {
         return getMerged(direction.getIndex());
     }
 
-    public <T> T getFlag(final Class<? extends PlotFlag<T>> flagClass) {
+    public <T> T getFlag(final Class<? extends PlotFlag<T, ?>> flagClass) {
         return this.flagContainer.getFlag(flagClass).getValue();
     }