SPIGOT-7540, #1312: Add ServerTickManager API

By: Miles Holder <mwholder2005@gmail.com>

paper-server/src/main/java/org/bukkit/craftbukkit/CraftServerTickManager.java

@@ -0,0 +1,93 @@
+package org.bukkit.craftbukkit;
+
+import com.google.common.base.Preconditions;
+import net.minecraft.server.ServerTickRateManager;
+import org.bukkit.ServerTickManager;
+import org.bukkit.craftbukkit.entity.CraftEntity;
+import org.bukkit.entity.Entity;
+
+final class CraftServerTickManager implements ServerTickManager {
+
+    private final ServerTickRateManager manager;
+
+    CraftServerTickManager(ServerTickRateManager manager) {
+        this.manager = manager;
+    }
+
+    @Override
+    public boolean isRunningNormally() {
+        return manager.runsNormally();
+    }
+
+    @Override
+    public boolean isStepping() {
+        return manager.isSteppingForward();
+    }
+
+    @Override
+    public boolean isSprinting() {
+        return manager.isSprinting();
+    }
+
+    @Override
+    public boolean isFrozen() {
+        return manager.isFrozen();
+    }
+
+    @Override
+    public float getTickRate() {
+        return manager.tickrate();
+    }
+
+    @Override
+    public void setTickRate(final float tickRate) {
+        Preconditions.checkArgument(tickRate > 1 && tickRate < 10_000, "The given tick rate must not be less than one");
+        manager.setTickRate(tickRate);
+    }
+
+    @Override
+    public void setFrozen(final boolean frozen) {
+        if (frozen) {
+            if (manager.isSprinting()) {
+                manager.stopSprinting();
+            }
+
+            if (manager.isSteppingForward()) {
+                manager.stopStepping();
+            }
+        }
+
+        manager.setFrozen(frozen);
+    }
+
+    @Override
+    public boolean stepGameIfFrozen(final int ticks) {
+        return manager.stepGameIfPaused(ticks);
+    }
+
+    @Override
+    public boolean stopStepping() {
+        return manager.stopStepping();
+    }
+
+    @Override
+    public boolean requestGameToSprint(final int ticks) {
+        return manager.requestGameToSprint(ticks);
+    }
+
+    @Override
+    public boolean stopSprinting() {
+        return manager.stopSprinting();
+    }
+
+    @Override
+    public boolean isFrozen(final Entity entity) {
+        Preconditions.checkArgument(entity != null, "The given entity must not be null");
+        return manager.isEntityFrozen(((CraftEntity) entity).getHandle());
+    }
+
+    @Override
+    public int getFrozenTicksToRun() {
+        return manager.frozenTicksToRun();
+    }
+}