Added AddClassicBeatEvent.

core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/events/AddClassicBeatEvent.kt

@@ -0,0 +1,60 @@
+package cn.rdlevel.rdkt.core.events
+
+
+import cn.rdlevel.rdkt.core.data.sound.AudioData
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlin.jvm.JvmStatic
+
+/**
+ * Plays a classy beat on the specified row.
+ *
+ * @property tick The duration to advance a pulse in beats.
+ * @property swing The duration between an odd pulse and its previous pulse in beats. Setting this to 0 will disable swing. The value should be between 0 and the doubled value of [tick].
+ * @property hold The duration to hold the beat in beats. Setting this to 0 will disable hold.
+ * @property setXs The pattern of Xs to set on the row when [hold] is on.
+ * @property length The number of pulses to have.
+ * @property sound The sound to play. Setting this to null will use the row's current sound.
+ */
+@Serializable
+public data class AddClassicBeatEvent(
+    var tick: Double = 1.0,
+    var swing: Double = 0.0,
+    var hold: Double = 0.0,
+    var setXs: SetXMode = SetXMode.NO_CHANGE,
+    var length: Int = 7,
+    var sound: AudioData? = null,
+) : RowEvent() {
+    /**
+     * Represents the pattern of Xs to set on the row when [hold] is on.
+     */
+    public enum class SetXMode {
+        /**
+         * Do not change the pattern on the row.
+         */
+        @SerialName("NoChange")
+        NO_CHANGE,
+
+        /**
+         * Sets pattern to -xx-xx.
+         */
+        @SerialName("ThreeBeat")
+        THREE_BEAT,
+
+        /**
+         * Sets pattern to -x-x-x.
+         */
+        @SerialName("FourBeat")
+        FOUR_BEAT,
+    }
+
+    public companion object {
+        /**
+         * Creates a new [AddClassicBeatEvent] using the provided block to set its properties.
+         */
+        @JvmStatic
+        public fun of(block: AddClassicBeatEvent.() -> Unit): AddClassicBeatEvent {
+            return AddClassicBeatEvent().apply(block)
+        }
+    }
+}

core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/events/EventProperties.kt

@@ -12,6 +12,13 @@ public interface BeatSpecificEvent : Event {
      * This property is mutable, allowing the beat to be set directly.
      */
     override var beat: Double
+
+    public companion object {
+        @JvmStatic
+        public fun requireBeatInBound(beat: Double) {
+            require(beat >= 1) { "Beat must be greater than or equal to 1." }
+        }
+    }
 }
 
 /**

core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/events/EventTabs.kt

@@ -1,5 +1,6 @@
 package cn.rdlevel.rdkt.core.events
 
+import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
 /**
@@ -17,7 +18,7 @@ public sealed class SoundEvent : AbstractEvent(), YSpecificEvent {
 public sealed class BeatSpecificSoundEvent : BeatSpecificEvent, SoundEvent() {
     override var beat: Double = 1.0
         set(value) {
-            require(value >= 1) { "Beat must be greater than or equal to 1." }
+            BeatSpecificEvent.requireBeatInBound(value)
             field = value
         }
 }
@@ -26,7 +27,26 @@ public sealed class BeatSpecificSoundEvent : BeatSpecificEvent, SoundEvent() {
  * An event that belongs to the rows tab.
  */
 @Serializable
-public sealed class RowEvent : AbstractEvent()
+public sealed class RowEvent : AbstractEvent(), BeatSpecificEvent, RowSpecificEvent, YSpecificEvent {
+    override var beat: Double = 1.0
+        set(value) {
+            BeatSpecificEvent.requireBeatInBound(value)
+            field = value
+        }
+
+    @SerialName("row")
+    override var rowId: Int = 0
+        set(value) {
+            RowSpecificEvent.requireRowInBound(value)
+            field = value
+        }
+
+    /**
+     * This property does not affect the actual position in the editor for [RowEvent].
+     */
+    override var y: Int = 0
+
+}
 
 /**
  * An event that belongs to the actions tab.

core/src/commonMain/kotlin/cn/rdlevel/rdkt/core/settings/LevelSettings.kt

@@ -124,7 +124,7 @@ public class LevelSettings {
         }
 
     /**
-     * Whether the use grayscale for the syringe strip.
+     * Whether to use grayscale for the syringe strip.
      */
     public var songLabelGrayscale: Boolean = false