/sign ui compatibility with Paper 1.17

Now looks for the first public boolean in TileEntitySign. This should be
fine until upstream changes the public modifier of the boolean or makes
more drastic changes to how Minecraft signs are marked as editable.

Fixes: #21

CHANGELOG.md

@@ -7,6 +7,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## v1.12.8 (2021-06-21)
+
+### Fixed
+
+* `/sign ui` compatibility with Paper 1.17 (#21)
+
 ## v1.12.7 (2021-06-13)
 
 ### Fixed

build.gradle

@@ -1,5 +1,5 @@
 def name = 'SignEdit'
-version '1.12.7'
+version '1.12.8'
 
 /*
  * Copyright (C) 2017-2021 Deltik <https://www.deltik.org/>

src/org/deltik/mc/signedit/CraftBukkitReflector.java

@@ -54,16 +54,28 @@ public static Method getDeclaredMethodRecursive(Class<?> whateverClass, String n
     }
 
     public static Field getFirstFieldOfType(Object source, Class<?> desiredType) throws NoSuchFieldException {
-        return getFirstFieldOfType(source.getClass(), desiredType);
+        return getFirstFieldOfType(source, desiredType, ~0x0);
     }
 
-    public static Field getFirstFieldOfType(Class<?> source, Class<?> desiredType) throws NoSuchFieldException {
+    public static Field getFirstFieldOfType(
+            Object source,
+            Class<?> desiredType,
+            int modifierMask
+    ) throws NoSuchFieldException {
+        return getFirstFieldOfType(source.getClass(), desiredType, modifierMask);
+    }
+
+    public static Field getFirstFieldOfType(
+            Class<?> source,
+            Class<?> desiredType,
+            int modifierMask
+    ) throws NoSuchFieldException {
         Class<?> ancestor = source;
         while (ancestor != null) {
             Field[] fields = ancestor.getDeclaredFields();
             for (Field field : fields) {
                 Class<?> candidateType = field.getType();
-                if (desiredType.isAssignableFrom(candidateType)) {
+                if (desiredType.isAssignableFrom(candidateType) && (field.getModifiers() & modifierMask) > 0) {
                     field.setAccessible(true);
                     return field;
                 }

src/org/deltik/mc/signedit/interactions/UiSignEditInteraction.java

@@ -35,6 +35,7 @@
 import javax.inject.Inject;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
 import java.util.stream.IntStream;
 
 import static org.deltik.mc.signedit.CraftBukkitReflector.getDeclaredMethodRecursive;
@@ -144,10 +145,10 @@ private Object toRawTileEntity(BlockState blockState) throws Exception {
     }
 
     /**
-     * FIXME: Find a more reliable way than looking for the first boolean to mark the TileEntitySign as editable
+     * FIXME: Find a more reliable way than looking for the first public boolean to mark the TileEntitySign as editable
      */
     private void makeTileEntitySignEditable(Object tileEntitySign) throws Exception {
-        Field signIsEditable = getFirstFieldOfType(tileEntitySign, boolean.class);
+        Field signIsEditable = getFirstFieldOfType(tileEntitySign, boolean.class, Modifier.PUBLIC);
         signIsEditable.setAccessible(true);
         signIsEditable.set(tileEntitySign, true);
     }