Add a mechanism for printing debug reports.

ProtocolLib/src/main/java/com/comphenix/protocol/async/PacketProcessingQueue.java

@@ -23,7 +23,10 @@ import java.util.PriorityQueue;
 import java.util.Queue;
 import java.util.concurrent.Semaphore;
 
+import com.comphenix.protocol.ProtocolLibrary;
 import com.comphenix.protocol.concurrency.AbstractConcurrentListenerMultimap;
+import com.comphenix.protocol.error.Report;
+import com.comphenix.protocol.error.ReportType;
 import com.comphenix.protocol.events.PacketEvent;
 import com.comphenix.protocol.injector.PrioritizedListener;
 import com.google.common.collect.MinMaxPriorityQueue;
@@ -35,6 +38,8 @@ import com.google.common.collect.MinMaxPriorityQueue;
  * @author Kristian
  */
 class PacketProcessingQueue extends AbstractConcurrentListenerMultimap<AsyncListenerHandler> {
+	public static final ReportType REPORT_GUAVA_CORRUPT_MISSING = 
+			new ReportType("Guava is either missing or corrupt. Reverting to PriorityQueue.");
 
 	// Initial number of elements
 	public static final int INITIAL_CAPACITY = 64;
@@ -74,8 +79,9 @@ class PacketProcessingQueue extends AbstractConcurrentListenerMultimap<AsyncList
 					maximumSize(maximumSize).
 					<PacketEventHolder>create(), null);
 		} catch (IncompatibleClassChangeError e) {
-			System.out.println("[ProtocolLib] Guava is either missing or corrupt. Reverting to PriorityQueue.");
-			e.printStackTrace();
+			// Print in the console
+			ProtocolLibrary.getErrorReporter().reportWarning(
+				this, Report.newBuilder(REPORT_GUAVA_CORRUPT_MISSING).error(e));
 			
 			// It's a Beta class after all
 			this.processingQueue = Synchronization.queue(

ProtocolLib/src/main/java/com/comphenix/protocol/async/PacketSendingQueue.java

@@ -27,6 +27,10 @@ import java.util.concurrent.PriorityBlockingQueue;
 import org.bukkit.entity.Player;
 
 import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.ProtocolLibrary;
+import com.comphenix.protocol.error.ErrorReporter;
+import com.comphenix.protocol.error.Report;
+import com.comphenix.protocol.error.ReportType;
 import com.comphenix.protocol.events.PacketEvent;
 import com.comphenix.protocol.injector.PlayerLoggedOutException;
 import com.comphenix.protocol.reflect.FieldAccessException;
@@ -36,17 +40,16 @@ import com.comphenix.protocol.reflect.FieldAccessException;
  * @author Kristian
  */
 abstract class PacketSendingQueue {
-
+	public static final ReportType REPORT_DROPPED_PACKET = new ReportType("Warning: Dropped packet index %s of type %s.");
+	
 	public static final int INITIAL_CAPACITY = 10;
 	
 	private PriorityBlockingQueue<PacketEventHolder> sendingQueue;
 	
 	// Asynchronous packet sending
 	private Executor asynchronousSender;
-	
 	// Whether or not packet transmission must occur on a specific thread
 	private final boolean notThreadSafe;
-
 	// Whether or not we've run the cleanup procedure
 	private boolean cleanedUp = false;
 	
@@ -279,10 +282,10 @@ abstract class PacketSendingQueue {
 			}
 		
 		} catch (PlayerLoggedOutException e) {
-			System.out.println(String.format(
-					"[ProtocolLib] Warning: Dropped packet index %s of type %s",
-					marker.getOriginalSendingIndex(), event.getPacketType()
-			));
+			ProtocolLibrary.getErrorReporter().reportDebug(this, Report.newBuilder(REPORT_DROPPED_PACKET).
+				messageParam(marker.getOriginalSendingIndex(), event.getPacketType()).
+				callerParam(event)
+			);
 			
 		} catch (IOException e) {
 			// Just print the error

ProtocolLib/src/main/java/com/comphenix/protocol/error/BasicErrorReporter.java

@@ -45,6 +45,16 @@ public class BasicErrorReporter implements ErrorReporter {
 		printParameters(parameters);
 	}
 
+	@Override
+	public void reportDebug(Object sender, Report report) {
+		// We just have to swallow it
+	}
+
+	@Override
+	public void reportDebug(Object sender, ReportBuilder builder) {
+		// As above
+	}
+	
 	@Override
 	public void reportWarning(Object sender, Report report) {
 		// Basic warning

ProtocolLib/src/main/java/com/comphenix/protocol/error/DelegatedErrorReporter.java

@@ -37,6 +37,15 @@ public class DelegatedErrorReporter implements ErrorReporter {
 		delegated.reportMinimal(sender, methodName, error, parameters);
 	}
 
+	@Override
+	public void reportDebug(Object sender, Report report) {
+		Report transformed = filterReport(sender, report, false);
+		
+		if (transformed != null) {
+			delegated.reportDebug(sender, transformed);
+		}
+	}
+	
 	@Override
 	public void reportWarning(Object sender, Report report) {
 		Report transformed = filterReport(sender, report, false);
@@ -77,4 +86,9 @@ public class DelegatedErrorReporter implements ErrorReporter {
 	public void reportDetailed(Object sender, ReportBuilder reportBuilder) {
 		reportDetailed(sender, reportBuilder.build());
 	}
+	
+	@Override
+	public void reportDebug(Object sender, ReportBuilder builder) {
+		reportDebug(sender, builder.build());
+	}
 }

ProtocolLib/src/main/java/com/comphenix/protocol/error/DetailedErrorReporter.java

@@ -37,6 +37,7 @@ import org.bukkit.plugin.Plugin;
 import com.comphenix.protocol.error.Report.ReportBuilder;
 import com.comphenix.protocol.events.PacketAdapter;
 import com.comphenix.protocol.reflect.PrettyPrinter;
+import com.google.common.base.Preconditions;
 import com.google.common.primitives.Primitives;
 
 /**
@@ -144,7 +145,7 @@ public class DetailedErrorReporter implements ErrorReporter {
 	public void setDetailedReporting(boolean detailedReporting) {
 		this.detailedReporting = detailedReporting;
 	}
-
+	
 	@Override
 	public void reportMinimal(Plugin sender, String methodName, Throwable error, Object... parameters) {
 		if (reportMinimalNoSpam(sender, methodName, error)) {
@@ -210,6 +211,18 @@ public class DetailedErrorReporter implements ErrorReporter {
 	    return (number & (number - 1)) == 0;
 	}
 	
+	@Override
+	public void reportDebug(Object sender, ReportBuilder builder) {
+		reportDebug(sender, Preconditions.checkNotNull(builder, "builder cannot be NULL").build());
+	}
+	
+	@Override
+	public void reportDebug(Object sender, Report report) {
+		if (logger.isLoggable(Level.FINE)) {
+			reportLevel(Level.FINE, sender, report);
+		}
+	}
+	
 	@Override
 	public void reportWarning(Object sender, ReportBuilder reportBuilder) {
 		if (reportBuilder == null)
@@ -220,24 +233,30 @@ public class DetailedErrorReporter implements ErrorReporter {
 	
 	@Override
 	public void reportWarning(Object sender, Report report) {
+		if (logger.isLoggable(Level.WARNING)) {
+			reportLevel(Level.WARNING, sender, report);
+		}
+	}
+	
+	private void reportLevel(Level level, Object sender, Report report) {
 		String message = "[" + pluginName + "] [" + getSenderName(sender) + "] " + report.getReportMessage();
 		
 		// Print the main warning
 		if (report.getException() != null) {
-			logger.log(Level.WARNING, message, report.getException());
+			logger.log(level, message, report.getException());
 		} else {			
-			logger.log(Level.WARNING, message);
+			logger.log(level, message);
 			
 			// Remember the call stack
 			if (detailedReporting) {
-				printCallStack(Level.WARNING, logger);
+				printCallStack(level, logger);
 			}
 		}
 		
 		// Parameters?
 		if (report.hasCallerParameters()) {
 			// Write it
-			logger.log(Level.WARNING, printParameters(report.getCallerParameters()));
+			logger.log(level, printParameters(report.getCallerParameters()));
 		}
 	}
 	

ProtocolLib/src/main/java/com/comphenix/protocol/error/ErrorReporter.java

@@ -44,6 +44,22 @@ public interface ErrorReporter {
 	 */
 	public abstract void reportMinimal(Plugin sender, String methodName, Throwable error, Object... parameters);
 	
+	/**
+	 * Prints a debug message from the current sender.
+	 * <p>
+	 * Most users will not see this message.
+	 * @param sender - the sender.
+	 * @param report - the report.
+	 */
+	public abstract void reportDebug(Object sender, Report report);
+	
+	/**
+	 * Prints a debug message from the current sender.
+	 * @param sender - the sender.
+	 * @param report - the report builder.
+	 */
+	public abstract void reportDebug(Object sender, ReportBuilder builder);
+	
 	/**
 	 * Prints a warning message from the current plugin.
 	 * @param sender - the object containing the caller method. 

ProtocolLib/src/main/java/com/comphenix/protocol/error/RethrowErrorReporter.java

@@ -21,6 +21,16 @@ public class RethrowErrorReporter implements ErrorReporter {
 				"Minimal error by " + sender + " in " + methodName + " with " + Joiner.on(",").join(parameters), error);
 	}
 
+	@Override
+	public void reportDebug(Object sender, Report report) {
+		// Do nothing - this is just a debug
+	}
+
+	@Override
+	public void reportDebug(Object sender, ReportBuilder builder) {
+		// As above
+	}
+	
 	@Override
 	public void reportWarning(Object sender, ReportBuilder reportBuilder) {
 		reportWarning(sender, reportBuilder.build());

ProtocolLib/src/main/java/com/comphenix/protocol/injector/PacketFilterBuilder.java

@@ -20,6 +20,7 @@ import com.google.common.util.concurrent.Futures;
 
 public class PacketFilterBuilder {
 	public static final ReportType REPORT_TEMPORARY_EVENT_ERROR = new ReportType("Unable to register or handle temporary event.");
+	public static final ReportType REPORT_SPIGOT_IS_DELAYING_INJECTOR = new ReportType("Delaying due to Spigot.");
 	
 	private ClassLoader classLoader;
 	private Server server;
@@ -218,8 +219,8 @@ public class PacketFilterBuilder {
 							}
 						});
 				
-				System.out.println("Delaying due to Spigot");
-				
+				reporter.reportWarning(this, Report.newBuilder(REPORT_SPIGOT_IS_DELAYING_INJECTOR));
+
 				// Let plugins use this version instead
 				return delayed;
 			} else {