From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Mon, 4 Jan 2021 22:40:34 -0800
Subject: [PATCH] Add worldborder events


diff --git a/src/main/java/net/minecraft/world/level/border/WorldBorder.java b/src/main/java/net/minecraft/world/level/border/WorldBorder.java
index dd49122fada9729a44fc040ffa1f57eb6ac5a124..6028e65c7e5afeea87f14edb16415defe89ebffa 100644
--- a/src/main/java/net/minecraft/world/level/border/WorldBorder.java
+++ b/src/main/java/net/minecraft/world/level/border/WorldBorder.java
@@ -109,15 +109,19 @@ public class WorldBorder {
     }
 
     public void setCenter(double x, double z) {
-        this.centerX = x;
-        this.centerZ = z;
+        // Paper start
+        io.papermc.paper.event.world.border.WorldBorderCenterChangeEvent event = new io.papermc.paper.event.world.border.WorldBorderCenterChangeEvent(world.getWorld(), world.getWorld().getWorldBorder(), new org.bukkit.Location(world.getWorld(), this.getCenterX(), 0, this.getCenterZ()), new org.bukkit.Location(world.getWorld(), x, 0, z));
+        if (!event.callEvent()) return;
+        this.centerX = event.getNewCenter().getX();
+        this.centerZ = event.getNewCenter().getZ();
+        // Paper end
         this.extent.onCenterChange();
         Iterator iterator = this.getListeners().iterator();
 
         while (iterator.hasNext()) {
             BorderChangeListener iworldborderlistener = (BorderChangeListener) iterator.next();
 
-            iworldborderlistener.onBorderCenterSet(this, x, z);
+            iworldborderlistener.onBorderCenterSet(this, event.getNewCenter().getX(), event.getNewCenter().getZ()); // Paper
         }
 
     }
@@ -135,25 +139,43 @@ public class WorldBorder {
     }
 
     public void setSize(double size) {
-        this.extent = new WorldBorder.StaticBorderExtent(size);
+        // Paper start
+        io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent event = new io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent(world.getWorld(), world.getWorld().getWorldBorder(), io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent.Type.INSTANT_MOVE, getSize(), size, 0);
+        if (!event.callEvent()) return;
+        if (event.getType() == io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent.Type.STARTED_MOVE && event.getDuration() > 0) { // If changed to a timed transition
+            lerpSizeBetween(event.getOldSize(), event.getNewSize(), event.getDuration());
+            return;
+        }
+        this.extent = new WorldBorder.StaticBorderExtent(event.getNewSize());
+        // Paper end
         Iterator iterator = this.getListeners().iterator();
 
         while (iterator.hasNext()) {
             BorderChangeListener iworldborderlistener = (BorderChangeListener) iterator.next();
 
-            iworldborderlistener.onBorderSizeSet(this, size);
+            iworldborderlistener.onBorderSizeSet(this, event.getNewSize()); // Paper
         }
 
     }
 
     public void lerpSizeBetween(double fromSize, double toSize, long time) {
-        this.extent = (WorldBorder.BorderExtent) (fromSize == toSize ? new WorldBorder.StaticBorderExtent(toSize) : new WorldBorder.MovingBorderExtent(fromSize, toSize, time));
+        // Paper start
+        io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent.Type type;
+        if (fromSize == toSize) { // new size = old size
+            type = io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent.Type.INSTANT_MOVE; // Use INSTANT_MOVE because below it creates a Static border if they are equal.
+        } else {
+            type = io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent.Type.STARTED_MOVE;
+        }
+        io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent event = new io.papermc.paper.event.world.border.WorldBorderBoundsChangeEvent(world.getWorld(), world.getWorld().getWorldBorder(), type, fromSize, toSize, time);
+        if (!event.callEvent()) return;
+        this.extent = (WorldBorder.BorderExtent) (fromSize == event.getNewSize() ? new WorldBorder.StaticBorderExtent(event.getNewSize()) : new WorldBorder.MovingBorderExtent(fromSize, event.getNewSize(), event.getDuration()));
+        // Paper end
         Iterator iterator = this.getListeners().iterator();
 
         while (iterator.hasNext()) {
             BorderChangeListener iworldborderlistener = (BorderChangeListener) iterator.next();
 
-            iworldborderlistener.onBorderSizeLerping(this, fromSize, toSize, time);
+            iworldborderlistener.onBorderSizeLerping(this, fromSize, event.getNewSize(), event.getDuration()); // Paper
         }
 
     }
@@ -458,6 +480,7 @@ public class WorldBorder {
 
         @Override
         public WorldBorder.BorderExtent update() {
+            if (this.getLerpRemainingTime() <= 0L) new io.papermc.paper.event.world.border.WorldBorderBoundsChangeFinishEvent(world.getWorld(), world.getWorld().getWorldBorder(), this.from, this.to, this.lerpDuration).callEvent(); // Paper
             return (WorldBorder.BorderExtent) (this.getLerpRemainingTime() <= 0L ? WorldBorder.this.new StaticBorderExtent(this.to) : this);
         }