Add notification subsystem

build.gradle

@@ -30,6 +30,7 @@ tasks.register("javadocAll", Javadoc) {
             ":base",
             ":ansi",
             ":slf4j-compat",
+            ":notification",
             ":windowing",
             ":windowing:glfw",
     ]

notification/README.md

@@ -0,0 +1,2 @@
+# The `slf4j-compat` subsystem
+This subsystems provides an extensive notification API. The only thing missing in the sandwich is your rendering implementation.

notification/build.gradle

@@ -0,0 +1,110 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+// Plugins
+plugins {
+    id("java")
+    id("io.freefair.lombok") version("${pluginLombok}")
+    id("maven-publish")
+}
+
+// Dependencies
+dependencies {
+    // -> Runtime <-
+    // Lombok
+    compileOnly("org.projectlombok:lombok:${dependencyLombok}")
+    annotationProcessor("org.projectlombok:lombok:${dependencyLombok}")
+
+    // JetBrains Annotations
+    compileOnly("org.jetbrains:annotations:${dependencyJetbrainsAnnotations}")
+
+    // -> Project <-
+    implementation(project(":base"))
+}
+
+// Fix delombok task
+delombok.doFirst {
+    File target = file("${project.projectDir}/src/main/module-info.java")
+    File source = file("${project.projectDir}/src/main/java/module-info.java")
+
+    target.delete()
+    source.renameTo(target)
+}
+delombok.doLast {
+    File target = file("${project.projectDir}/src/main/java/module-info.java")
+    File source = file("${project.projectDir}/src/main/module-info.java")
+
+    target.delete()
+    source.renameTo(target)
+}
+
+// Javadoc configuration
+javadoc {
+    outputs.upToDateWhen { false }  // Force task execution
+    dependsOn(delombok)  // Make sure the source is delomboked first
+
+    javadoc {
+        setClasspath(files(project.sourceSets.main.compileClasspath))  // Include dependencies
+
+        options {
+            if (new File(projectDir, "src/main/javadoc/theme.css").exists())
+                stylesheetFile = new File(projectDir, "src/main/javadoc/theme.css")  // Theming is cool :3
+            setMemberLevel(JavadocMemberLevel.PUBLIC)  // Only display public stuff
+            setOverview("src/main/javadoc/overview.html")  // We want a custom overview page to greet the visitor
+            setLocale("en_US")  // 你好
+            addStringOption("Xwerror", "-quiet") // Fail build on warning
+
+            setJFlags([
+                    "-Duser.language=en_US"  // See above
+            ])
+        }
+    }
+}
+
+// Include javadoc and source jar during publishing
+java {
+    withJavadocJar()
+    withSourcesJar()
+}
+
+// Build publishing configuration
+// Note: You can safely ignore any errors or warnings thrown by your IDE here
+publishing {
+    repositories {
+        maven {
+            name = "staropensource"
+            url = uri("https://mvn.staropensource.de/sosengine")
+            credentials(org.gradle.api.credentials.PasswordCredentials)
+            authentication {
+                //noinspection GroovyAssignabilityCheck
+                basic (BasicAuthentication)
+            }
+        }
+    }
+    publications {
+        //noinspection GroovyAssignabilityCheck
+        maven (MavenPublication) {
+            groupId = group
+            artifactId = project.getName()
+            version = version
+            //noinspection GroovyAssignabilityCheck
+            from components.java
+        }
+    }
+}

notification/gradle

@@ -0,0 +1 @@
+../gradle

notification/gradlew

@@ -0,0 +1 @@
+../gradlew

notification/gradlew.bat

@@ -0,0 +1 @@
+../gradlew.bat

notification/src/main/java/de/staropensource/engine/notification/NotificationManager.java

@@ -0,0 +1,146 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.engine.notification;
+
+import de.staropensource.engine.base.type.immutable.ImmutableHashMap;
+import de.staropensource.engine.notification.type.Notification;
+import de.staropensource.engine.notification.type.NotificationState;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Manages and handles {@link Notification}s.
+ *
+ * @since v1-alpha6
+ */
+public final class NotificationManager {
+    /**
+     * Contains a list of all notifications and their states.
+     *
+     * @since v1-alpha6
+     */
+    private static final @NotNull Map<@NotNull Notification, @NotNull NotificationState> notifications = new HashMap<>();
+
+    /**
+     * Creates and initializes an instance of this class.
+     *
+     * @since v1-alpha6
+     */
+    private NotificationManager() {}
+
+    /**
+     * Returns an {@link ImmutableHashMap} containing all
+     * registered notifications and their current states.
+     *
+     * @return map of registered notifications
+     * @since v1-alpha6
+     */
+    public static @NotNull Map<@NotNull Notification, @NotNull NotificationState> getNotifications() {
+        return new ImmutableHashMap<>(notifications);
+    }
+
+    /**
+     * Returns whether the specified notification
+     * is registered and if so, which state
+     * it is in.
+     *
+     * @param notification notification to check
+     * @return state or {@code null} if unregistered
+     * @since v1-alpha6
+     */
+    public static @Nullable NotificationState getState(@NotNull Notification notification) {
+        if (notifications.containsKey(notification))
+            return notifications.get(notification);
+
+        return null;
+    }
+
+    /**
+     * Fires the specified notification.
+     * Will simply set it's state to
+     * {@link NotificationState#SHOWN}
+     * if it is already registered.
+     *
+     * @param notification notification to fire
+     * @since v1-alpha6
+     */
+    public static void fire(@NotNull Notification notification) {
+        updateNotification(notification, NotificationState.SHOWN, false);
+    }
+
+    /**
+     * Hides the specified notification.
+     * Does nothing if it isn't shown.
+     *
+     * @param notification notification to update
+     * @since v1-alpha6
+     */
+    public static void hide(@NotNull Notification notification) {
+        if (notifications.getOrDefault(notification, NotificationState.HIDDEN) == NotificationState.SHOWN)
+            updateNotification(notification, NotificationState.HIDDEN, false);
+    }
+
+    /**
+     * Dismisses the specified notification.
+     * Does nothing if it is already dismissed.
+     * <p>
+     * Note: Dismissing a notification does not
+     * necessarily mean it removes it. Depending
+     * on the {@link Notification#}
+     *
+     * @param notification notification to update
+     * @since v1-alpha6
+     */
+    public static void dismiss(@NotNull Notification notification) {
+        if (notifications.getOrDefault(notification, NotificationState.HIDDEN) == NotificationState.SHOWN) {
+            updateNotification(notification, NotificationState.DISMISSED, false);
+
+            switch (notification.getDismissalAction()) {
+                case UNREGISTER -> updateNotification(notification, notifications.get(notification), true);
+                case EXECUTE -> notification.dismiss();
+                case EXECUTE_UNREGISTER -> {
+                    notification.dismiss();
+                    updateNotification(notification, notifications.get(notification), true);
+                }
+            }
+        }
+    }
+
+    /**
+     * Adds or updates the specified notification
+     * in the {@link #notifications} map.
+     *
+     * @param notification notification to add or update
+     * @param state        state to set
+     * @since v1-alpha6
+     */
+    private static synchronized void updateNotification(@NotNull Notification notification, @NotNull NotificationState state, boolean removeOnly) {
+        if (removeOnly)
+            notifications.remove(notification);
+        else
+            if (notifications.containsKey(notification))
+                notifications.replace(notification, state);
+            else
+                notifications.put(notification, state);
+    }
+}

notification/src/main/java/de/staropensource/engine/notification/NotificationSubsystem.java

@@ -0,0 +1,83 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.engine.notification;
+
+import de.staropensource.engine.base.annotation.EngineSubsystem;
+import de.staropensource.engine.base.implementable.SubsystemClass;
+import de.staropensource.engine.base.implementation.versioning.StarOpenSourceVersioningSystem;
+import de.staropensource.engine.base.type.DependencyVector;
+import de.staropensource.engine.base.utility.information.EngineInformation;
+import lombok.Getter;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Main class of the {@code notification} subsystem.
+ *
+ * @since v1-alpha6
+ */
+@EngineSubsystem
+@SuppressWarnings({ "JavadocDeclaration" })
+public final class NotificationSubsystem extends SubsystemClass {
+    /**
+     * Contains the class instance.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns the class instance.
+     *
+     * @return class instance unless the subsystem is uninitialized
+     * @since v1-alpha6
+     */
+    @Getter
+    private static NotificationSubsystem instance = null;
+
+    /**
+     * Initializes this subsystem.
+     *
+     * @since v1-alpha6
+     */
+    public NotificationSubsystem() {
+        // Check if subsystem has already initialized
+        if (instance == null)
+            instance = this;
+        else
+            logger.crash("Only one instance of this class is allowed, use getInstance() instead of creating a new instance");
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public @NotNull String getName() {
+        return "notification";
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public void initializeSubsystem() {}
+
+    /** {@inheritDoc} */
+    @Override
+    public @NotNull DependencyVector getDependencyVector() {
+        return new DependencyVector.Builder()
+                .setIdentifier("notification")
+                .setVersioningSystem(StarOpenSourceVersioningSystem.class)
+                .setVersion(EngineInformation.getVersioningString())
+                .build();
+    }
+}

notification/src/main/java/de/staropensource/engine/notification/type/Notification.java

@@ -0,0 +1,327 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.engine.notification.type;
+
+import de.staropensource.engine.base.type.Color;
+import de.staropensource.engine.notification.NotificationManager;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.Setter;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.Range;
+
+import java.util.LinkedHashMap;
+
+/**
+ * A notification!
+ *
+ * @since v1-alpha6
+ */
+@Getter
+@Setter
+@SuppressWarnings({ "JavadocDeclaration" })
+public class Notification {
+    /**
+     * Contains the class from where
+     * this notification was emitted.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns the class from where
+     * this notification was emitted.
+     *
+     * @return origin
+     * @since v1-alpha6
+     */
+    @Setter(value = AccessLevel.NONE)
+    private final @NotNull Class<?> origin;
+
+    /**
+     * Contains what to do when the notification is dismissed.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns what to do when the notification is dismissed.
+     *
+     * @return dismissal action
+     * @since v1-alpha6
+     * -- SETTER --
+     * Sets what to do when the notification is dismissed.
+     *
+     * @param dismissalAction new dismissal action
+     * @since v1-alpha6
+     */
+    private @NotNull NotificationDismissalAction dismissalAction = NotificationDismissalAction.UNREGISTER;
+
+    /**
+     * Contains the priority of this notification.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns the priority of this notification.
+     *
+     * @return priority
+     * @since v1-alpha6
+     * -- SETTER --
+     * Sets the priority of this notification.
+     *
+     * @param priority new priority
+     * @since v1-alpha6
+     */
+    private @NotNull NotificationPriority priority = NotificationPriority.DEFAULT;
+
+    /**
+     * Contains the type of this notification.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns the type of this notification.
+     *
+     * @return type
+     * @since v1-alpha6
+     * -- SETTER --
+     * Sets the type of this notification.
+     *
+     * @param type new type
+     * @since v1-alpha6
+     */
+    private @NotNull NotificationType type = NotificationType.INFORMATIONAL;
+
+    /**
+     * Contains the title of this notification.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns the title of this notification.
+     *
+     * @return title
+     * @since v1-alpha6
+     * -- SETTER --
+     * Sets the title of this notification.
+     *
+     * @param title new title
+     * @since v1-alpha6
+     */
+    private @NotNull String title;
+
+    /**
+     * Contains the content of this notification.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns the content of this notification.
+     *
+     * @return content
+     * @since v1-alpha6
+     * -- SETTER --
+     * Sets the content of this notification.
+     *
+     * @param message new content
+     * @since v1-alpha6
+     */
+    private @Nullable String content = null;
+
+    /**
+     * Contains the color of this notification.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns the theme color of this notification.
+     *
+     * @return theme color
+     * @since v1-alpha6
+     * -- SETTER --
+     * Sets the theme color of this notification.
+     *
+     * @param color new theme color
+     * @since v1-alpha6
+     */
+    private @Nullable Color color = null;
+
+    /**
+     * Contains whether this notification shall be closable or not.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns whether this notification shall be closable or not.
+     *
+     * @return closable flag state
+     * @since v1-alpha6
+     * -- SETTER --
+     * Sets whether this notification shall be closable or not.
+     *
+     * @param closable new closable flag state
+     * @since v1-alpha6
+     */
+    private boolean closable = true;
+
+    /**
+     * Contains whether the notification has a progress bar attached,
+     * and if so, to which percentage it is filled.
+     * <p>
+     * If it contains {@code -1} then this notification does not have
+     * a progress bar. If it doesn't, it must contain a percentage
+     * between {@code 0} and {@code 100}.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns whether the notification has a progress bar attached,
+     * and if so, to which percentage it is filled.
+     * <p>
+     * If it contains {@code -1} then this notification does not have
+     * a progress bar. If it doesn't, it must contain a percentage
+     * between {@code 0} and {@code 100}.
+     *
+     * @return progress bar filled in %, or {@code -1} if disabled
+     * @since v1-alpha6
+     * -- SETTER --
+     * Sets whether the notification has a progress bar attached,
+     * and if so, to which percentage it is filled.
+     * <p>
+     * If it contains {@code -1} then this notification does not have
+     * a progress bar. If it doesn't, it must contain a percentage
+     * between {@code 0} and {@code 100}.
+     *
+     * @param bar new % value to which the progress bar is filled, or {@code -1} to mark it as disabled
+     * @since v1-alpha6
+     */
+    private @Range(from = -1, to = 100) int bar = -1;
+
+    /**
+     * Contains the {@link Runnable} which shall be executed
+     * when the notification is clicked/interacted with.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Contains the {@link Runnable} which shall be executed
+     * when the notification is clicked/interacted with.
+     *
+     * @return {@link Runnable} executed if clicked
+     * @since v1-alpha6
+     * -- SETTER --
+     * Sets the {@link Runnable} which shall be executed
+     * when the notification is clicked/interacted with.
+     *
+     * @param clickCode {@link Runnable} executed if clicked
+     * @since v1-alpha6
+     */
+    private @Nullable Runnable clickCode = null;
+
+    /**
+     * Contains all buttons and their associated
+     * {@link Runnable}s on this notification.
+     *
+     * @since v1-alpha6
+     * -- GETTER --
+     * Returns all buttons and their associated
+     * {@link Runnable}s on this notification.
+     *
+     * @return linked button map
+     * @since v1-alpha6
+     */
+    private @NotNull LinkedHashMap<@NotNull String, @NotNull Runnable> buttons = new LinkedHashMap<>();
+
+    /**
+     * Creates and initializes an instance of this class.
+     *
+     * @since v1-alpha6
+     */
+    public Notification(@NotNull Class<?> origin, @NotNull String title) {
+        this.origin = origin;
+        this.title = title;
+    }
+
+    /**
+     * Sets the percentage of which the progress bar is filled.
+     * This method calculates the percentage between two values,
+     * saving you the simple math.
+     *
+     * @param min   minimum value
+     * @param max   maximum value
+     * @param value value
+     * @since v1-alpha6
+     */
+    public void setBar(int min, int max, int value) {
+        if (min >= value)
+            bar = 0;
+        else
+            bar = max / value;
+
+        if (bar < 0)
+            bar = 0;
+        else if (bar > 100)
+            bar = 100;
+    }
+
+    /**
+     * Sets the percentage of which the progress bar is filled.
+     * This method calculates the percentage between two values,
+     * saving you the simple math.
+     * <p>
+     * Note: This method assumes the minimum value is {@code 0}.
+     * If you want control over this, see {@link #setBar(int, int, int)}.
+     *
+     * @param max   maximum value
+     * @param value value
+     * @since v1-alpha6
+     */
+    public void setBar(int max, int value) {
+        setBar(0, max, value);
+    }
+
+    /**
+     * Returns the state of this notification.
+     *
+     * @return state or {@code null} if not registered
+     * @since v1-alpha6
+     */
+    public final @Nullable NotificationState getState() {
+        return NotificationManager.getState(this);
+    }
+
+    /**
+     * Fires this notification.
+     * <p>
+     * If this notification has just been created,
+     * invoking this method will register it and
+     * make it work. If this method has been called
+     * already however, it will simply display
+     * the notification again, even if hidden or
+     * dismissed.
+     *
+     * @since v1-alpha6
+     */
+    public final void fire() {
+        NotificationManager.fire(this);
+    }
+
+    /**
+     * Dismisses this notification.
+     * <p>
+     * This method will only be executed if
+     * {@link #dismissalAction} is either set
+     * to {@link NotificationDismissalAction#EXECUTE}
+     * or {@link NotificationDismissalAction#EXECUTE_UNREGISTER}.
+     *
+     * @since v1-alpha6
+     */
+    public void dismiss() {}
+}

notification/src/main/java/de/staropensource/engine/notification/type/NotificationDismissalAction.java

@@ -0,0 +1,69 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.engine.notification.type;
+
+/**
+ * Used for representing how a notification
+ * should act if it is dismissed.
+ *
+ * @since v1-alpha6
+ */
+public enum NotificationDismissalAction {
+    /**
+     * Makes the notification do nothing.
+     * It will simply sit there in loneliness,
+     * waiting to be interacted with.
+     * <p>
+     * <b>Not recommended as it will cause
+     * memory leaks if not cleaned up manually.</b>
+     *
+     * @since v1-alpha6
+     */
+    NOTHING,
+
+    /**
+     * Simply unregisters the notification,
+     * causing it to disappear. Most likely
+     * the option you want to choose.
+     *
+     * @since v1-alpha6
+     */
+    UNREGISTER,
+
+    /**
+     * Executes the {@link Notification#dismiss()}
+     * method on the notification.
+     * <p>
+     * <b>Not recommended as it will cause
+     * memory leaks if not cleaned up manually.</b>
+     *
+     * @since v1-alpha6
+     */
+    EXECUTE,
+
+    /**
+     * Executes the {@link Notification#dismiss()}
+     * method on the notification and
+     * unregisters it afterwards.
+     *
+     * @since v1-alpha6
+     */
+    EXECUTE_UNREGISTER,
+}

notification/src/main/java/de/staropensource/engine/notification/type/NotificationPriority.java

@@ -0,0 +1,62 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.engine.notification.type;
+
+/**
+ * Determines a notification's importance.
+ *
+ * @since v1-alpha6
+ */
+public enum NotificationPriority {
+    /**
+     * A very important notification.
+     *
+     * @since v1-alpha6
+     */
+    VERY_IMPORTANT,
+
+    /**
+     * An important notification.
+     *
+     * @since v1-alpha6
+     */
+    IMPORTANT,
+
+    /**
+     * The standard priority.
+     *
+     * @since v1-alpha6
+     */
+    DEFAULT,
+
+    /**
+     * An unimportant notification.
+     *
+     * @since v1-alpha6
+     */
+    UNIMPORTANT,
+
+    /**
+     * A very unimportant notification.
+     *
+     * @since v1-alpha6
+     */
+    VERY_UNIMPORTANT,
+}

notification/src/main/java/de/staropensource/engine/notification/type/NotificationState.java

@@ -0,0 +1,48 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.engine.notification.type;
+
+/**
+ * Used for representing the state of an notification.
+ *
+ * @since v1-alpha6
+ */
+public enum NotificationState {
+    /**
+     * A shown notification.
+     *
+     * @since v1-alpha6
+     */
+    SHOWN,
+
+    /**
+     * A hidden notification.
+     *
+     * @since v1-alpha6
+     */
+    HIDDEN,
+
+    /**
+     * A dismissed notification.
+     *
+     * @since v1-alpha6
+     */
+    DISMISSED,
+}

notification/src/main/java/de/staropensource/engine/notification/type/NotificationType.java

@@ -0,0 +1,48 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.engine.notification.type;
+
+/**
+ * Determines the type of a notification.
+ *
+ * @since v1-alpha6
+ */
+public enum NotificationType {
+    /**
+     * Marks a notification as an error notification.
+     *
+     * @since v1-alpha6
+     */
+    ERROR,
+
+    /**
+     * Marks a notification as a warning notification.
+     *
+     * @since v1-alpha6
+     */
+    WARNING,
+
+    /**
+     * Marks a notification as an informational notification.
+     *
+     * @since v1-alpha6
+     */
+    INFORMATIONAL,
+}

notification/src/main/java/module-info.java

@@ -0,0 +1,19 @@
+/**
+ * The {@code notification} subsystem, which
+ * provides an extensive notification API.
+ *
+ * @since v1-alpha6
+ */
+module sosengine.notification {
+    // Dependencies
+    // -> Engine
+    requires sosengine.base;
+
+    // API access
+    exports de.staropensource.engine.notification;
+    exports de.staropensource.engine.notification.type;
+
+    // Reflection access
+    opens de.staropensource.engine.notification;
+    opens de.staropensource.engine.notification.type;
+}

notification/src/main/javadoc/overview.html

@@ -0,0 +1,22 @@
+<!--
+  ~ STAROPENSOURCE ENGINE SOURCE FILE
+  ~ Copyright (c) 2024 The StarOpenSource Engine Authors
+  ~ Licensed under the GNU Affero General Public License v3
+  ~
+  ~ This program is free software: you can redistribute it and/or modify
+  ~ it under the terms of the GNU Affero General Public License as
+  ~ published by the Free Software Foundation, either version 3 of the
+  ~ License, or (at your option) any later version.
+  ~
+  ~ This program is distributed in the hope that it will be useful,
+  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of
+  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  ~ GNU Affero General Public License for more details.
+  ~
+  ~ You should have received a copy of the GNU Affero General Public License
+  ~ along with this program.  If not, see <https://www.gnu.org/licenses/>.
+  -->
+<body>
+<p>Welcome to the sos!engine API documentation!<br/>
+    You are currently in the documentation for the <b>notification</b> subsystem, which provides an extensive notification API.</p>
+</body>

notification/src/main/javadoc/theme.css

@@ -0,0 +1 @@
+../../../../src/main/javadoc/theme.css

settings.gradle

@@ -23,6 +23,7 @@ include("base")
 include("testing")
 include("ansi")
 include("slf4j-compat")
+include("notification")
 include("windowing")
 include("windowing:glfw")
 include("testapp")