More Win Screen API (#8805)

Adds methods to get and set whether a player has seen the win screen before.

patches/api/Win-Screen-API.patch

@@ -18,10 +18,39 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +     * and exits the end for the first time.
 +     * In vanilla, the win screen starts with a poem and then continues with the credits but its content can be
 +     * changed by using a resource pack.
++     * <br>
++     * Calling this method does not change the value of {@link #hasSeenWinScreen()}.
++     * That means that the win screen is still displayed to a player if they leave the end for the first time, even though
++     * they have seen it before because this method was called.
++     * Note this method does not make the player invulnerable, which is normally expected when viewing credits.
 +     *
++     * @see #hasSeenWinScreen() 
++     * @see #setHasSeenWinScreen(boolean) 
 +     * @see <a href="https://minecraft.fandom.com/wiki/End_Poem#Technical_details">https://minecraft.fandom.com/wiki/End_Poem#Technical_details</a>
 +     */
 +    public void showWinScreen();
++
++    /**
++     * Returns whether this player has seen the win screen before.
++     * When a player leaves the end the win screen is shown to them if they have not seen it before.
++     *
++     * @return Whether this player has seen the win screen before
++     * @see #setHasSeenWinScreen(boolean)
++     * @see #showWinScreen()
++     * @see <a href="https://minecraft.fandom.com/wiki/End_Poem">https://minecraft.fandom.com/wiki/End_Poem</a>
++     */
++    public boolean hasSeenWinScreen();
++
++    /**
++     * Changes whether this player has seen the win screen before.
++     * When a player leaves the end the win screen is shown to them if they have not seen it before.
++     *
++     * @param hasSeenWinScreen Whether this player has seen the win screen before
++     * @see #hasSeenWinScreen()
++     * @see #showWinScreen()
++     * @see <a href="https://minecraft.fandom.com/wiki/End_Poem">https://minecraft.fandom.com/wiki/End_Poem</a>
++     */
++    public void setHasSeenWinScreen(boolean hasSeenWinScreen);
 +    // Paper end
 +
      // Paper start

patches/server/Win-Screen-API.patch

@@ -3,6 +3,8 @@ From: Lama06 <andreasprues36@gmail.com>
 Date: Sat, 21 Jan 2023 13:53:23 +0100
 Subject: [PATCH] Win Screen API
 
+== AT ==
+public net.minecraft.server.level.ServerPlayer seenCredits
 
 diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
@@ -19,6 +21,16 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +        var packet = new ClientboundGameEventPacket(ClientboundGameEventPacket.WIN_GAME, 1);
 +        getHandle().connection.send(packet);
 +    }
++
++    @Override
++    public boolean hasSeenWinScreen() {
++        return getHandle().seenCredits;
++    }
++
++    @Override
++    public void setHasSeenWinScreen(boolean hasSeenWinScreen) {
++        getHandle().seenCredits = hasSeenWinScreen;
++    }
 +    // Paper end
 +
      @Override