Additional work towards 1.16 compatibility

- Very basic implementation of the SideEffects system. Will definitely need fine tuning for it to be functional, but is not considered a priority in my opinion.
- Minor changes to the World interface and World implementations related to the SideEffects system. Shouldn't be the cause of any new bugs but be on the lookout.
- Included debug in BukkitImplLoader.java to assist contributors in understanding what needs to be implemented for the adapter to load properly.

Still very WIP but we're a few steps closer. So far, this is coming along better than I anticipated. Hopefully we can keep the momentum.

worldedit-core/src/main/java/com/sk89q/worldedit/util/SideEffect.java

@@ -0,0 +1,68 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util;
+
+import java.util.Locale;
+
+public enum SideEffect {
+    LIGHTING(State.ON),
+    NEIGHBORS(State.ON),
+    CONNECTIONS(State.ON),
+    ENTITY_AI(State.OFF),
+    PLUGIN_EVENTS(State.OFF);
+
+    private final String displayName;
+    private final String description;
+    private final State defaultValue;
+
+    SideEffect(State defaultValue) {
+        this.displayName = "worldedit.sideeffect." + this.name().toLowerCase(Locale.US);
+        this.description = "worldedit.sideeffect." + this.name().toLowerCase(Locale.US) + ".description";
+        this.defaultValue = defaultValue;
+    }
+
+    public String getDisplayName() {
+        return this.displayName;
+    }
+
+    public String getDescription() {
+        return this.description;
+    }
+
+    public State getDefaultValue() {
+        return this.defaultValue;
+    }
+
+    public enum State {
+        OFF,
+        ON,
+        DELAYED;
+
+        private final String displayName;
+
+        State() {
+            this.displayName = "worldedit.sideeffect.state." + this.name().toLowerCase(Locale.US);
+        }
+
+        public String getDisplayName() {
+            return this.displayName;
+        }
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/SideEffectSet.java

@@ -0,0 +1,94 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Maps;
+
+import java.util.Arrays;
+import java.util.EnumMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+public class SideEffectSet {
+    private static final SideEffectSet DEFAULT = new SideEffectSet(
+            Arrays.stream(SideEffect.values()).collect(Collectors.toMap(Function.identity(), SideEffect::getDefaultValue))
+    );
+    private static final SideEffectSet NONE = new SideEffectSet();
+
+    private final Map<SideEffect, SideEffect.State> sideEffects;
+    private final Set<SideEffect> appliedSideEffects;
+    private final boolean appliesAny;
+
+    private SideEffectSet() {
+        this(ImmutableMap.of());
+    }
+
+    public SideEffectSet(Map<SideEffect, SideEffect.State> sideEffects) {
+        this.sideEffects = Maps.immutableEnumMap(sideEffects);
+
+        appliedSideEffects = sideEffects.entrySet()
+                .stream()
+                .filter(entry -> entry.getValue() != SideEffect.State.OFF)
+                .map(Map.Entry::getKey)
+                .collect(Collectors.toSet());
+        appliesAny = !appliedSideEffects.isEmpty();
+    }
+
+    public SideEffectSet with(SideEffect sideEffect, SideEffect.State state) {
+        Map<SideEffect, SideEffect.State> entries = this.sideEffects.isEmpty() ? Maps.newEnumMap(SideEffect.class) : new EnumMap<>(this.sideEffects);
+        entries.put(sideEffect, state);
+        return new SideEffectSet(entries);
+    }
+
+    public boolean doesApplyAny() {
+        return this.appliesAny;
+    }
+
+    public SideEffect.State getState(SideEffect effect) {
+        return sideEffects.getOrDefault(effect, effect.getDefaultValue());
+    }
+
+    /**
+     * Gets whether this side effect is not off.
+     *
+     * This returns whether it is either delayed or on.
+     *
+     * @param effect The side effect
+     * @return Whether it should apply
+     */
+    public boolean shouldApply(SideEffect effect) {
+        return getState(effect) != SideEffect.State.OFF;
+    }
+
+    public Set<SideEffect> getSideEffectsToApply() {
+        return this.appliedSideEffects;
+    }
+
+    public static SideEffectSet defaults() {
+        return DEFAULT;
+    }
+
+    public static SideEffectSet none() {
+        return NONE;
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/formatting/component/SideEffectBox.java

@@ -0,0 +1,88 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.formatting.component;
+
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
+import com.sk89q.worldedit.util.formatting.text.Component;
+import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
+import com.sk89q.worldedit.util.formatting.text.event.ClickEvent;
+import com.sk89q.worldedit.util.formatting.text.event.HoverEvent;
+import com.sk89q.worldedit.util.formatting.text.format.TextColor;
+
+import java.util.Comparator;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.Collectors;
+
+public class SideEffectBox extends PaginationBox {
+
+    private static List<SideEffect> sideEffects;
+
+    private SideEffectSet sideEffectSet;
+
+    private static List<SideEffect> getSideEffects() {
+        if (sideEffects == null) {
+            sideEffects = WorldEdit.getInstance().getPlatformManager().getSupportedSideEffects()
+                    .stream()
+                    .sorted(Comparator.comparing(Enum::name))
+                    .collect(Collectors.toList());
+        }
+
+        return sideEffects;
+    }
+
+    public SideEffectBox(SideEffectSet sideEffectSet) {
+        super("Side Effects");
+
+        this.sideEffectSet = sideEffectSet;
+    }
+
+    private static final SideEffect.State[] SHOWN_VALUES = {SideEffect.State.OFF, SideEffect.State.ON};
+
+    @Override
+    public Component getComponent(int number) {
+        SideEffect effect = getSideEffects().get(number);
+        SideEffect.State state = this.sideEffectSet.getState(effect);
+
+        TextComponent.Builder builder = TextComponent.builder();
+        builder = builder.append(TranslatableComponent.of(effect.getDisplayName(), TextColor.YELLOW)
+                .hoverEvent(HoverEvent.of(HoverEvent.Action.SHOW_TEXT, TranslatableComponent.of(effect.getDescription()))));
+        for (SideEffect.State uiState : SHOWN_VALUES) {
+            builder = builder.append(TextComponent.space());
+            builder = builder.append(TranslatableComponent.of(uiState.getDisplayName(), uiState == state ? TextColor.WHITE : TextColor.GRAY)
+                    .clickEvent(ClickEvent.runCommand("//fast -h " + effect.name().toLowerCase(Locale.US) + " " + uiState.name().toLowerCase(Locale.US)))
+                    .hoverEvent(HoverEvent.showText(uiState == state
+                            ? TranslatableComponent.of("worldedit.sideeffect.box.current")
+                            : TranslatableComponent.of("worldedit.sideeffect.box.change-to", TranslatableComponent.of(uiState.getDisplayName()))
+                    ))
+            );
+        }
+
+        return builder.build();
+    }
+
+    @Override
+    public int getComponentsSize() {
+        return getSideEffects().size();
+    }
+}