Improves some variable names and adds some comments

src/main/java/net/knarcraft/stargate/utility/PermissionHelper.java

@@ -1,6 +1,7 @@
 package net.knarcraft.stargate.utility;
 
 import net.knarcraft.stargate.Stargate;
+import net.knarcraft.stargate.event.StargateAccessEvent;
 import net.knarcraft.stargate.portal.Portal;
 import net.knarcraft.stargate.portal.PortalOption;
 import org.bukkit.entity.Player;
@@ -14,6 +15,102 @@ public final class PermissionHelper {
 
     }
 
+    /**
+     * Opens a portal if the given player is allowed to, and if the portal is not already open
+     *
+     * @param player <p>The player opening the portal</p>
+     * @param portal <p>The portal to open</p>
+     */
+    public static void openPortal(Player player, Portal portal) {
+        Portal destination = portal.getDestination();
+
+        //Always-open gate -- Do nothing
+        if (portal.isAlwaysOn()) {
+            return;
+        }
+
+        //Random gate -- Do nothing
+        if (portal.isRandom()) {
+            return;
+        }
+
+        //Invalid destination
+        if ((destination == null) || (destination == portal)) {
+            Stargate.sendErrorMessage(player, Stargate.getString("invalidMsg"));
+            return;
+        }
+
+        //Gate is already open
+        if (portal.isOpen()) {
+            // Close if this player opened the gate
+            if (portal.getActivePlayer() == player) {
+                portal.close(false);
+            }
+            return;
+        }
+
+        //Gate that someone else is using -- Deny access
+        if ((!portal.isFixed()) && portal.isActive() && (portal.getActivePlayer() != player)) {
+            Stargate.sendErrorMessage(player, Stargate.getString("denyMsg"));
+            return;
+        }
+
+        //Check if the player can use the private gate
+        if (portal.isPrivate() && !PermissionHelper.canPrivate(player, portal)) {
+            Stargate.sendErrorMessage(player, Stargate.getString("denyMsg"));
+            return;
+        }
+
+        //Destination blocked
+        if ((destination.isOpen()) && (!destination.isAlwaysOn())) {
+            Stargate.sendErrorMessage(player, Stargate.getString("blockMsg"));
+            return;
+        }
+
+        //Open gate
+        portal.open(player, false);
+    }
+
+    /**
+     * Creates a StargateAccessPortal and gives the result
+     *
+     * <p>The event is used for other plugins to bypass the permission checks</p>
+     *
+     * @param player <p>The player trying to use the portal</p>
+     * @param portal <p>The portal the player is trying to use</p>
+     * @param deny   <p>Whether the player's access has already been denied by a check</p>
+     * @return <p>False if the player should be allowed through the portal</p>
+     */
+    public static boolean cannotAccessPortal(Player player, Portal portal, boolean deny) {
+        StargateAccessEvent event = new StargateAccessEvent(player, portal, deny);
+        Stargate.server.getPluginManager().callEvent(event);
+        return event.getDeny();
+    }
+
+    /**
+     * Checks whether a given user cannot travel between two portals
+     *
+     * @param player         <p>The player to check</p>
+     * @param entrancePortal <p>The portal the user wants to enter</p>
+     * @param destination    <p>The portal the user wants to exit</p>
+     * @return <p>False if the user is allowed to access the portal</p>
+     */
+    public static boolean cannotAccessPortal(Player player, Portal entrancePortal, Portal destination) {
+        boolean deny = false;
+        // Check if player has access to this server for Bungee gates
+        if (entrancePortal.isBungee() && !PermissionHelper.canAccessServer(player, entrancePortal.getNetwork())) {
+            Stargate.debug("cannotAccessPortal", "Cannot access server");
+            deny = true;
+        } else if (PermissionHelper.cannotAccessNetwork(player, entrancePortal.getNetwork())) {
+            Stargate.debug("cannotAccessPortal", "Cannot access network");
+            deny = true;
+        } else if (!entrancePortal.isBungee() && PermissionHelper.cannotAccessWorld(player, destination.getWorld().getName())) {
+            Stargate.debug("cannotAccessPortal", "Cannot access world");
+            deny = true;
+        }
+        return cannotAccessPortal(player, entrancePortal, deny);
+    }
+
     /**
      * Checks whether a player has the given permission
      *
@@ -55,8 +152,9 @@ public final class PermissionHelper {
 
     /**
      * Checks whether a player can access the given world
+     *
      * @param player <p>The player trying to access the world</p>
-     * @param world <p>The world the player is trying to access</p>
+     * @param world  <p>The world the player is trying to access</p>
      * @return <p>False if the player should be allowed to access the world</p>
      */
     public static boolean cannotAccessWorld(Player player, String world) {
@@ -96,6 +194,7 @@ public final class PermissionHelper {
 
     /**
      * Checks whether a player can access the given bungee server
+     *
      * @param player <p>The player trying to teleport</p>
      * @param server <p>The server the player is trying to connect to</p>
      * @return <p>True if the player is allowed to access the given server</p>