Merge pull request #26 from informatik-ag-ngl/f/system_commands

Added system commands ( features: custom argument number, default values, system command builder, ...).
Fixed bug not copying attachment when using copy and send.

client/src/main/java/envoy/client/data/commands/OnCall.java

@@ -0,0 +1,34 @@
+package envoy.client.data.commands;
+
+import java.util.function.Supplier;
+
+/**
+ * This interface defines an action that should be performed when a system
+ * command gets called.
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>OnCall.java</strong><br>
+ * Created: <strong>23.07.2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public interface OnCall {
+
+	/**
+	 * Performs class specific actions when a {@link SystemCommand} has been called.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	void onCall();
+
+	/**
+	 * Performs actions that can only be performed by classes that are not
+	 * {@link SystemCommand}s when a SystemCommand has been called.
+	 *
+	 * @param consumer the action to perform when this {@link SystemCommand} has
+	 *                 been called
+	 * @since Envoy Client v0.2-beta
+	 */
+	void onCall(Supplier<Void> consumer);
+}

client/src/main/java/envoy/client/data/commands/SystemCommand.java

@@ -0,0 +1,135 @@
+package envoy.client.data.commands;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+
+/**
+ * This class is the base class of all {@code SystemCommands} and contains an
+ * action and a number of arguments that should be used as input for this
+ * function.
+ * No {@code SystemCommand} can return anything.
+ * Every {@code SystemCommand} must have as argument type {@code List<String>} so
+ * that the words following the indicator String can be used as input of the
+ * function. This approach has one limitation:<br>
+ * <b>Order matters!</b> Changing the order of arguments will likely result in
+ * unexpected behavior.
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>SystemCommand.java</strong><br>
+ * Created: <strong>16.07.2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public class SystemCommand implements OnCall {
+
+	protected int relevance;
+
+	/**
+	 * The argument count of the command.
+	 */
+	protected final int numberOfArguments;
+
+	/**
+	 * This function takes a {@code List<String>} as argument because automatically
+	 * {@code SystemCommand#numberOfArguments} words following the necessary command
+	 * will be put into this list.
+	 *
+	 * @see String#split(String)
+	 */
+	protected final Consumer<List<String>> action;
+
+	protected final String description;
+
+	protected final List<String> defaults;
+
+	/**
+	 * Constructs a new {@code SystemCommand}.
+	 *
+	 * @param action            the action performed by the command
+	 * @param numberOfArguments the argument count accepted by the action
+	 * @param defaults          the default values for the corresponding arguments
+	 * @param description       the description of this {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand(Consumer<List<String>> action, int numberOfArguments, List<String> defaults, String description) {
+		this.numberOfArguments	= numberOfArguments;
+		this.action				= action;
+		this.defaults			= defaults == null ? new ArrayList<>() : defaults;
+		this.description		= description;
+	}
+
+	/**
+	 * @return the action that should be performed
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Consumer<List<String>> getAction() { return action; }
+
+	/**
+	 * @return the argument count of the command
+	 * @since Envoy Client v0.2-beta
+	 */
+	public int getNumberOfArguments() { return numberOfArguments; }
+
+	/**
+	 * @return the description
+	 * @since Envoy Client v0.2-beta
+	 */
+	public String getDescription() { return description; }
+
+	/**
+	 * @return the relevance
+	 * @since Envoy Client v0.2-beta
+	 */
+	public int getRelevance() { return relevance; }
+
+	/**
+	 * @param relevance the relevance to set
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void setRelevance(int relevance) { this.relevance = relevance; }
+
+	/**
+	 * Increments the relevance of this {@code SystemCommand}.
+	 */
+	@Override
+	public void onCall() { relevance++; }
+
+	/**
+	 * Increments the relevance of this {@code SystemCommand} and executes the
+	 * supplier.
+	 */
+	@Override
+	public void onCall(Supplier<Void> consumer) {
+		onCall();
+		consumer.get();
+	}
+
+	/**
+	 * @return the defaults
+	 * @since Envoy Client v0.2-beta
+	 */
+	public List<String> getDefaults() { return defaults; }
+
+	@Override
+	public int hashCode() { return Objects.hash(action); }
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj) return true;
+		if (obj == null) return false;
+		if (getClass() != obj.getClass()) return false;
+		final SystemCommand other = (SystemCommand) obj;
+		return Objects.equals(action, other.action);
+	}
+
+	@Override
+	public String toString() {
+		return "SystemCommand [relevance=" + relevance + ", numberOfArguments=" + numberOfArguments + ", "
+				+ (action != null ? "action=" + action + ", " : "") + (description != null ? "description=" + description + ", " : "")
+				+ (defaults != null ? "defaults=" + defaults : "") + "]";
+	}
+}

client/src/main/java/envoy/client/data/commands/SystemCommandBuilder.java

@@ -0,0 +1,144 @@
+package envoy.client.data.commands;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+
+/**
+ * This class acts as a builder for {@link SystemCommand}s.
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>SystemCommandBuilder.java</strong><br>
+ * Created: <strong>23.07.2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public class SystemCommandBuilder {
+
+	private int						numberOfArguments;
+	private Consumer<List<String>>	action;
+	private List<String>			defaults;
+	private String					description;
+	private int						relevance;
+
+	/**
+	 * @param numberOfArguments the numberOfArguments to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setNumberOfArguments(int numberOfArguments) {
+		this.numberOfArguments = numberOfArguments;
+		return this;
+	}
+
+	/**
+	 * @param action the action to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setAction(Consumer<List<String>> action) {
+		this.action = action;
+		return this;
+	}
+
+	/**
+	 * @param description the description to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setDescription(String description) {
+		this.description = description;
+		return this;
+	}
+
+	/**
+	 * @param relevance the relevance to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setRelevance(int relevance) {
+		this.relevance = relevance;
+		return this;
+	}
+
+	/**
+	 * @param defaults the defaults to set
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder setDefaults(String... defaults) {
+		this.defaults = List.of(defaults);
+		return this;
+	}
+
+	/**
+	 * Resets all values stored.
+	 *
+	 * @return this {@code SystemCommandBuilder}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommandBuilder reset() {
+		numberOfArguments	= 0;
+		action				= null;
+		defaults			= new ArrayList<>();
+		description			= "";
+		relevance			= 0;
+		return this;
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.
+	 *
+	 * @return the built {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand build() { return build(true); }
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.<br>
+	 * {@code SystemCommand#numberOfArguments} will be set to 0, regardless of the
+	 * previous value.<br>
+	 * At the end, this {@code SystemCommandBuilder} will be reset.
+	 *
+	 * @return the built {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand buildNoArg() {
+		numberOfArguments = 0;
+		return build(true);
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.<br>
+	 * {@code SystemCommand#numberOfArguments} will be set to use the rest of the
+	 * string as argument, regardless of the previous value.<br>
+	 * At the end, this {@code SystemCommandBuilder} will be reset.
+	 *
+	 * @return the built {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand buildRemainingArg() {
+		numberOfArguments = -1;
+		return build(true);
+	}
+
+	/**
+	 * Builds a {@code SystemCommand} based upon the previously entered data.<br>
+	 * At the end, this {@code SystemCommandBuilder} <b>can</b> be reset but must
+	 * not be.
+	 *
+	 * @param reset whether this {@code SystemCommandBuilder} should be reset
+	 *              afterwards.<br>
+	 *              This can be useful if another command wants to execute something
+	 *              similar
+	 * @return the built {@code SystemCommand}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public SystemCommand build(boolean reset) {
+		final var sc = new SystemCommand(action, numberOfArguments, defaults, description);
+		sc.setRelevance(relevance);
+		if (reset) reset();
+		return sc;
+	}
+}

client/src/main/java/envoy/client/data/commands/SystemCommandsMap.java

@@ -0,0 +1,263 @@
+package envoy.client.data.commands;
+
+import java.util.*;
+import java.util.function.Function;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import envoy.util.EnvoyLog;
+
+/**
+ * This class stores all {@link SystemCommand}s used.
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>SystemCommandsMap.java</strong><br>
+ * Created: <strong>17.07.2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class SystemCommandsMap {
+
+	private final Map<String, SystemCommand> systemCommands = new HashMap<>();
+
+	private final Pattern commandPattern = Pattern.compile("^[a-zA-Z0-9_:!\\(\\)\\?\\.\\,\\;\\-]+$");
+
+	private static final Logger logger = EnvoyLog.getLogger(SystemCommandsMap.class);
+
+	/**
+	 * Adds a new command to the map if the command name is valid.
+	 *
+	 * @param command       the input string to execute the
+	 *                      given action
+	 * @param systemCommand the command to add - can be built using
+	 *                      {@link SystemCommandBuilder}
+	 * @see SystemCommandsMap#isValidKey(String)
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void add(String command, SystemCommand systemCommand) { if (isValidKey(command)) systemCommands.put(command, systemCommand); }
+
+	/**
+	 * This method checks if the input String is a key in the map and returns the
+	 * wrapped System command if present.
+	 * It will return an empty optional if the value after the slash is not a key in
+	 * the map, which is a valid case (i.e. input="3/4" and "4" is not a key in the
+	 * map).
+	 * <p>
+	 * Usage example:<br>
+	 * {@code SystemCommandsMap systemCommands = new SystemCommandsMap();}<br>
+	 * {@code Button button = new  Button();}
+	 * {@code systemCommands.add("example", text -> button.setText(text.get(0), 1);}<br>
+	 * {@code ....}<br>
+	 * user input: {@code "/example xyz ..."}<br>
+	 * {@code systemCommands.get("example xyz ...")} or
+	 * {@code systemCommands.get("/example xyz ...")}
+	 * result: {@code Optional<SystemCommand>}
+	 *
+	 * @param input the input string given by the user
+	 * @return the wrapped system command, if present
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Optional<SystemCommand> get(String input) { return Optional.ofNullable(systemCommands.get(getCommand(input))); }
+
+	/**
+	 * This method ensures that the "/" of a {@link SystemCommand} is stripped.<br>
+	 * It returns the command as (most likely) entered as key in the map for the
+	 * first word of the text.<br>
+	 * It should only be called on strings that contain a "/" at position 0/-1.
+	 *
+	 * @param raw the input
+	 * @return the command as entered in the map
+	 * @since Envoy Client v0.2-beta
+	 * @apiNote this method will (most likely) not return anything useful if
+	 *          whatever is entered after the slash is not a system command. Only
+	 *          exception: for recommendation purposes.
+	 */
+	public String getCommand(String raw) {
+		final var	trimmed	= raw.stripLeading();
+		final var	index	= trimmed.indexOf(' ');
+		return trimmed.substring(trimmed.charAt(0) == '/' ? 1 : 0, index < 1 ? trimmed.length() : index);
+	}
+
+	/**
+	 * Examines whether a key can be put in the map and logs it with
+	 * {@code Level.WARNING} if that key violates API constrictions.<br>
+	 * (allowed chars are <b>a-zA-Z0-9_:!()?.,;-</b>)
+	 * <p>
+	 * The approach to not throw an exception was taken so that an ugly try-catch
+	 * block for every addition to the system commands map could be avoided, an
+	 * error that should only occur during implementation and not in production.
+	 *
+	 * @param command the key to examine
+	 * @return whether this key can be used in the map
+	 * @since Envoy Client v0.2-beta
+	 */
+	public boolean isValidKey(String command) {
+		final boolean valid = commandPattern.matcher(command).matches();
+		if (!valid) logger.log(Level.WARNING,
+				"The command \"" + command
+						+ "\" is not valid. As it will cause problems in execution, it will not be entered into the map. Only the characters "
+						+ commandPattern + "are allowed");
+		return valid;
+	}
+
+	/**
+	 * Takes a 'raw' string (the whole input) and checks if "/" is the first visible
+	 * character and then checks if a command is present after that "/". If that is
+	 * the case, it will be executed.
+	 * <p>
+	 *
+	 * @param raw the raw input string
+	 * @return whether a command could be found
+	 * @since Envoy Client v0.2-beta
+	 */
+	public boolean executeIfAnyPresent(String raw) {
+		// possibly a command was detected and could be executed
+		final var	raw2			= raw.stripLeading();
+		final var	commandFound	= raw2.startsWith("/") ? executeIfPresent(raw2) : false;
+		// the command was executed successfully - no further checking needed
+		if (commandFound) logger.log(Level.FINE, "executed system command " + getCommand(raw2));
+		return commandFound;
+	}
+
+	/**
+	 * This method checks if the input String is a key in the map and executes the
+	 * wrapped System command if present.
+	 * Its intended usage is after a "/" has been detected in the input String.
+	 * It will do nothing if the value after the slash is not a key in
+	 * the map, which is a valid case (i.e. input="3/4" and "4" is not a key in the
+	 * map).
+	 * <p>
+	 * Usage example:<br>
+	 * {@code SystemCommandsMap systemCommands = new SystemCommandsMap();}<br>
+	 * {@code Button button = new Button();}<br>
+	 * {@code systemCommands.add("example", (words)-> button.setText(words.get(0), 1);}<br>
+	 * {@code ....}<br>
+	 * user input: {@code "/example xyz ..."}<br>
+	 * {@code systemCommands.executeIfPresent("example xyz ...")}
+	 * result: {@code button.getText()=="xyz"}
+	 *
+	 * @param input the input string given by the user
+	 * @return whether a command could be found
+	 * @since Envoy Client v0.2-beta
+	 */
+	public boolean executeIfPresent(String input) {
+		final var	command	= getCommand(input);
+		final var	value	= get(command);
+		value.ifPresent(systemCommand -> {
+			// Splitting the String so that the leading command including the first " " is
+			// removed and only as many following words as allowed by the system command
+			// persist
+			final var arguments = extractArguments(input, systemCommand);
+			// Executing the function
+			try {
+				systemCommand.getAction().accept(arguments);
+				systemCommand.onCall();
+			} catch (final Exception e) {
+				logger.log(Level.WARNING, "The system command " + command + " threw an exception: ", e);
+			}
+		});
+		return value.isPresent();
+	}
+
+	/**
+	 * Supplies missing values with default values.
+	 *
+	 * @param input         the input String
+	 * @param systemCommand the command that is expected
+	 * @return the list of arguments that can be used to parse the systemCommand
+	 * @since Envoy Client v0.2-beta
+	 */
+	private List<String> extractArguments(String input, SystemCommand systemCommand) {
+		// no more arguments follow after the command (e.g. text = "/DABR")
+		final var indexOfSpace = input.indexOf(" ");
+		if (indexOfSpace < 0) return supplementDefaults(new String[] {}, systemCommand);
+		// the arguments behind a system command
+		final var	remainingString		= input.substring(indexOfSpace + 1);
+		final var	numberOfArguments	= systemCommand.getNumberOfArguments();
+		// splitting those arguments and supplying default values
+		final var	textArguments		= remainingString.split(" ", -1);
+		final var	originalArguments	= numberOfArguments >= 0 ? Arrays.copyOfRange(textArguments, 0, numberOfArguments) : textArguments;
+		final var	arguments			= supplementDefaults(originalArguments, systemCommand);
+		return arguments;
+	}
+
+	/**
+	 * Retrieves the recommendations based on the current input entered.<br>
+	 * The first word is used for the recommendations and
+	 * it does not matter if the "/" is at its beginning or not.<br>
+	 * If none are present, nothing will be done.<br>
+	 * Otherwise the given function will be executed on the recommendations.<br>
+	 *
+	 * @param input  the input string
+	 * @param action the action that should be taken for the recommendations, if any
+	 *               are present
+	 * @since Envoy Client v0.2-beta
+	 */
+	public void requestRecommendations(String input, Function<Set<String>, Void> action) {
+		final var partialCommand = getCommand(input);
+		// Get the expected commands
+		final var recommendations = recommendCommands(partialCommand);
+		if (recommendations.isEmpty()) return;
+		// Execute the given action
+		else action.apply(recommendations);
+	}
+
+	/**
+	 * Recommends commands based upon the currently entered input.<br>
+	 * In the current implementation, all we check is whether a key contains this
+	 * input. This might be updated later on.
+	 *
+	 * @param partialCommand the partially entered command
+	 * @return a set of all commands that match this input
+	 * @since Envoy Client v0.2-beta
+	 */
+	private Set<String> recommendCommands(String partialCommand) {
+		// current implementation only looks if input is contained within a command,
+		// might be updated
+		return systemCommands.keySet()
+			.stream()
+			.filter(command -> command.contains(partialCommand))
+			.sorted((command1, command2) -> Integer.compare(systemCommands.get(command1).getRelevance(), systemCommands.get(command2).getRelevance()))
+			.collect(Collectors.toSet());
+	}
+
+	/**
+	 *
+	 * Supplies the default values for arguments if none are present in the text for
+	 * any argument. <br>
+	 * Will only work for {@code SystemCommand}s whose argument counter is bigger
+	 * than 1.
+	 *
+	 * @param textArguments the arguments that were parsed from the text
+	 * @param toEvaluate    the system command whose default values should be used
+	 * @return the final argument list
+	 * @since Envoy Client v0.2-beta
+	 * @apiNote this method will insert an empty String if the size of the list
+	 *          given to the {@code SystemCommand} is smaller than its argument
+	 *          counter and no more text arguments could be found.
+	 */
+	private List<String> supplementDefaults(String[] textArguments, SystemCommand toEvaluate) {
+		final var			defaults			= toEvaluate.getDefaults();
+		final var			numberOfArguments	= toEvaluate.getNumberOfArguments();
+		final List<String>	result				= new ArrayList<>();
+
+		if (toEvaluate.getNumberOfArguments() > 0) for (int index = 0; index < numberOfArguments; index++) {
+			String textArg = null;
+			if (index < textArguments.length) textArg = textArguments[index];
+			// Set the argument at position index to the current argument of the text, if it
+			// is present. Otherwise the default for that argument will be taken if present.
+			// In the worst case, an empty String will be used.
+			result.add(!(textArg == null) && !textArg.isBlank() ? textArg : index < defaults.size() ? defaults.get(index) : "");
+		}
+		return result;
+	}
+
+	/**
+	 * @return all {@link SystemCommand}s used with the underlying command as key
+	 * @since Envoy Client v0.2-beta
+	 */
+	public Map<String, SystemCommand> getSystemCommands() { return systemCommands; }
+}

client/src/main/java/envoy/client/data/commands/package-info.java

@@ -0,0 +1,12 @@
+/**
+ * This package contains all classes that can be used as system commands.<br>
+ * Every system command can be called using a specific syntax:"/&lt;command&gt;"
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>package-info.java</strong><br>
+ * Created: <strong>16.07.2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+package envoy.client.data.commands;

client/src/main/java/envoy/client/ui/controller/ChatScene.java

@@ -30,6 +30,8 @@ import javafx.util.Duration;
 
 import envoy.client.data.*;
 import envoy.client.data.audio.AudioRecorder;
+import envoy.client.data.commands.SystemCommandBuilder;
+import envoy.client.data.commands.SystemCommandsMap;
 import envoy.client.event.MessageCreationEvent;
 import envoy.client.net.Client;
 import envoy.client.net.WriteProxy;
@@ -107,6 +109,8 @@ public final class ChatScene implements Restorable {
 	private Attachment		pendingAttachment;
 	private boolean			postingPermanentlyDisabled;
 
+	private final SystemCommandsMap messageTextAreaCommands = new SystemCommandsMap();
+
 	private static final Settings	settings	= Settings.getInstance();
 	private static final EventBus	eventBus	= EventBus.getInstance();
 	private static final Logger		logger		= EnvoyLog.getLogger(ChatScene.class);
@@ -193,7 +197,7 @@ public final class ChatScene implements Restorable {
 			switch (e.getOperationType()) {
 				case ADD:
 					if (contact instanceof User) localDB.getUsers().put(contact.getName(), (User) contact);
-					Chat chat = contact instanceof User ? new Chat(contact) : new GroupChat(client.getSender(), contact);
+					final Chat chat = contact instanceof User ? new Chat(contact) : new GroupChat(client.getSender(), contact);
 					Platform.runLater(() -> chatList.getItems().add(chat));
 					break;
 				case REMOVE:
@@ -203,6 +207,22 @@ public final class ChatScene implements Restorable {
 		});
 	}
 
+	/**
+	 * Initializes all {@code SystemCommands} used in {@code ChatScene}.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	private void initializeSystemCommandsMap() {
+		final var builder = new SystemCommandBuilder();
+		// Do A Barrel roll initialization
+		final var random = new Random();
+		builder.setAction(text -> doABarrelRoll(Integer.parseInt(text.get(0)), Double.parseDouble(text.get(1))))
+			.setDefaults(Integer.toString(random.nextInt(3) + 1), Double.toString(random.nextDouble() * 3 + 1))
+			.setDescription("See for yourself :)")
+			.setNumberOfArguments(2);
+		messageTextAreaCommands.add("DABR", builder.build());
+	}
+
 	/**
 	 * Initializes all necessary data via dependency injection-
 	 *
@@ -225,6 +245,7 @@ public final class ChatScene implements Restorable {
 		if (!client.isOnline()) updateInfoLabel("You are offline", "infoLabel-info");
 
 		recorder = new AudioRecorder();
+		initializeSystemCommandsMap();
 	}
 
 	@Override
@@ -376,20 +397,34 @@ public final class ChatScene implements Restorable {
 	}
 
 	/**
-	 * Rotates every element in our application by 360° in at most 2.75s.
+	 * Rotates every element in our application by (at most 4 *) 360° in at most
+	 * 2.75s.
 	 *
 	 * @since Envoy Client v0.1-beta
 	 */
 	@FXML
 	private void doABarrelRoll() {
+		final var random = new Random();
+		doABarrelRoll(random.nextInt(3) + 1, random.nextDouble() * 3 + 1);
+	}
+
+	/**
+	 * Rotates every element in our application by {@code rotations}*360° in
+	 * {@code an}.
+	 *
+	 * @param rotations     the amount of times the scene is rotated by 360°
+	 * @param animationTime the time in seconds that this animation lasts
+	 * @since Envoy Client v0.1-beta
+	 */
+	private void doABarrelRoll(int rotations, double animationTime) {
 		// contains all Node objects in ChatScene in alphabetical order
-		final var	rotatableNodes	= new Node[] { attachmentButton, attachmentView, contactLabel, infoLabel, messageList, messageTextArea,
-				postButton, remainingChars, rotateButton, scene, settingsButton, chatList, voiceButton };
-		final var	random			= new Random();
+		final var rotatableNodes = new Node[] { attachmentButton, attachmentView, contactLabel, infoLabel, messageList, messageTextArea, postButton,
+				remainingChars, rotateButton, scene, settingsButton, chatList, voiceButton };
 		for (final var node : rotatableNodes) {
-			// Defines at most four whole rotation in at most 4s
-			final var rotateTransition = new RotateTransition(Duration.seconds(random.nextDouble() * 3 + 1), node);
-			rotateTransition.setByAngle((random.nextInt(3) + 1) * 360);
+			// Sets the animation duration to {animationTime}
+			final var rotateTransition = new RotateTransition(Duration.seconds(animationTime), node);
+			// rotates every element {rotations} times
+			rotateTransition.setByAngle(rotations * 360);
 			rotateTransition.play();
 			// This is needed as for some strange reason objects could stop before being
 			// rotated back to 0°
@@ -480,8 +515,8 @@ public final class ChatScene implements Restorable {
 			updateInfoLabel("You need to go online to send more messages", "infoLabel-error");
 			return;
 		}
-		final var text = messageTextArea.getText().strip();
-		try {
+		final var	text					= messageTextArea.getText().strip();
+		if (!messageTextAreaCommands.executeIfAnyPresent(text)) try {
 			// Creating the message and its metadata
 			final var builder = new MessageBuilder(localDB.getUser().getID(), currentChat.getRecipient().getID(), localDB.getIDGenerator())
 				.setText(text);
@@ -569,9 +604,14 @@ public final class ChatScene implements Restorable {
 	private void copyAndPostMessage() {
 		final var messageText = messageTextArea.getText();
 		Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new StringSelection(messageText), null);
+		final var	image				= attachmentView.getImage();
+		final var	messageAttachment	= pendingAttachment;
 		postMessage();
 		messageTextArea.setText(messageText);
 		updateRemainingCharsLabel();
 		postButton.setDisable(messageText.isBlank());
+		attachmentView.setImage(image);
+		if (attachmentView.getImage() != null) attachmentView.setVisible(true);
+		pendingAttachment = messageAttachment;
 	}
 }