Proper context implementation - WIP

api/src/main/java/me/lucko/luckperms/api/LuckPermsApi.java

@@ -22,6 +22,8 @@
 
 package me.lucko.luckperms.api;
 
+import me.lucko.luckperms.api.context.ContextListener;
+import me.lucko.luckperms.api.context.IContextCalculator;
 import me.lucko.luckperms.api.event.LPListener;
 
 import java.util.Optional;
@@ -218,4 +220,18 @@ public interface LuckPermsApi {
      */
     Node.Builder buildNode(String permission) throws IllegalArgumentException;
 
+    /**
+     * Register a custom context calculator to the server
+     * @param contextCalculator the context calculator to register. The type MUST be the player class of the platform.
+     * @throws ClassCastException if the type is not the player class of the platform.
+     */
+    void registerContextCalculator(IContextCalculator<?> contextCalculator);
+
+    /**
+     * Registers a custom context listener to the server,
+     * @param contextListener the context listener to register. The type MUST be the player class of the platform.
+     * @throws ClassCastException if the type is not the player class of the platform.
+     */
+    void registerContextListener(ContextListener<?> contextListener);
+
 }

api/src/main/java/me/lucko/luckperms/api/Node.java

@@ -105,7 +105,15 @@ public interface Node extends Map.Entry<String, Boolean> {
     boolean shouldApplyOnWorld(String world, boolean includeGlobal, boolean applyRegex);
 
     /**
-     * If this node should apply given the specific context
+     * If this node should apply in the given context
+     * @param context the context key value pairs
+     * @param worldAndServer if world and server contexts should be checked
+     * @return true if the node should apply
+     */
+    boolean shouldApplyWithContext(Map<String, String> context, boolean worldAndServer);
+
+    /**
+     * If this node should apply in the given context
      * @param context the context key value pairs
      * @return true if the node should apply
      */

api/src/main/java/me/lucko/luckperms/api/context/ContextCalculator.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2016 Lucko (Luck) <luck@lucko.me>
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.api.context;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * A simple implementation of the listener aspects of {@link IContextCalculator<T>}
+ * @param <T> the subject type
+ */
+public abstract class ContextCalculator<T> implements IContextCalculator<T> {
+    private final List<ContextListener<T>> listeners = new CopyOnWriteArrayList<>();
+
+    /**
+     * Pushes an update to all registered {@link ContextListener}s.
+     * Make sure any changes are applied internally before this method is called.
+     * @param subject the subject that changed
+     * @param before the context state before the change
+     * @param current the context state after the change (now)
+     * @throws NullPointerException if any parameters are null
+     */
+    protected void pushUpdate(T subject, Map.Entry<String, String> before, Map.Entry<String, String> current) {
+        if (subject == null) {
+            throw new NullPointerException("subject");
+        }
+        if (before == null) {
+            throw new NullPointerException("before");
+        }
+        if (current == null) {
+            throw new NullPointerException("current");
+        }
+
+        for (ContextListener<T> listener : listeners) {
+            try {
+                listener.onContextChange(subject, before, current);
+            } catch (Exception e) {
+                System.out.println("Exception whilst passing context change to listener: " + listener);
+                e.printStackTrace();
+            }
+        }
+    }
+
+    @Override
+    public void addListener(ContextListener<T> listener) {
+        if (listener == null) {
+            throw new NullPointerException("listener");
+        }
+
+        listeners.add(listener);
+    }
+
+}

api/src/main/java/me/lucko/luckperms/api/context/ContextListener.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2016 Lucko (Luck) <luck@lucko.me>
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.api.context;
+
+import java.util.Map;
+
+/**
+ * Listens to context changes
+ * @param <T> the subject type, Is ALWAYS the player class of the platform.
+ */
+public interface ContextListener<T> {
+
+    /**
+     * Called whenever a context changes on the
+     * @param subject the subject that had context changed
+     * @param before the context state before the change
+     * @param current the context state after the change (now)
+     */
+    void onContextChange(T subject, Map.Entry<String, String> before, Map.Entry<String, String> current) throws Exception;
+
+}

api/src/main/java/me/lucko/luckperms/api/context/IContextCalculator.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2016 Lucko (Luck) <luck@lucko.me>
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.api.context;
+
+import java.util.Map;
+
+/**
+ * Calculates whether contexts are applicable to {@link T}
+ *
+ * <p>Somewhat inspired by the system used on Sponge.
+ * @param <T> the subject type. Is ALWAYS the player class of the platform.
+ */
+public interface IContextCalculator<T> {
+
+    /**
+     * Gives the subject all of the applicable contexts they meet
+     * @param subject the subject to add contexts tp
+     * @param accumulator a map of contexts to add to
+     * @return the map
+     */
+    Map<String, String> giveApplicableContext(T subject, Map<String, String> accumulator);
+
+    /**
+     * Checks to see if a context is applicable to a subject
+     * @param subject the subject to check against
+     * @param context the context to check for
+     * @return true if met, or false if not. If this calculator does not calculate the given context, return false.
+     */
+    boolean isContextApplicable(T subject, Map.Entry<String, String> context);
+
+    /**
+     * Adds a listener to be called whenever a context handled by this calculator changes
+     * @param listener the listener instance
+     * @throws NullPointerException if listener is null
+     */
+    void addListener(ContextListener<T> listener);
+
+}