debounce with coroutines (#1107)

commons/build.gradle.kts

@@ -10,6 +10,7 @@ plugins {
 
 val mockkVersion = extra["mockk_version"] as String
 val kotlinLoggingVersion = extra["kotlinLogging_version"] as String
+val kotlinxCoroutinesVersion = extra["kotlinx_coroutines_version"] as String
 val hamcrestVersion = extra["hamcrest_version"] as String
 val mockitoVersion = extra["mockito_version"] as String
 val assertjVersion = extra["assertj_version"] as String
@@ -24,6 +25,14 @@ kotlin {
  }
 
  sourceSets {
+ commonMain {
+ dependencies {
+ // Can't use compileOnly
+ // > Task :commons:compileTestDevelopmentExecutableKotlinJs FAILED
+ //e: Could not find "org.jetbrains.kotlinx:kotlinx-coroutines-core" in [/home/me/.local/share/kotlin/daemon]
+ implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlinxCoroutinesVersion")
+ }
+ }
  commonTest {
  dependencies {
  implementation(kotlin("test"))

commons/src/commonMain/kotlin/org/jetbrains/letsPlot/commons/Debounce.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2024. JetBrains s.r.o.
+ * Use of this source code is governed by the MIT license that can be found in the LICENSE file.
+ */
+
+package org.jetbrains.letsPlot.commons
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+
+
+// Not thread-safe
+fun <T> debounce(
+ delayMs: Long,
+ scope: CoroutineScope,
+ action: (T) -> Unit
+): (T) -> Unit {
+ var activeJob: Job? = null
+
+ return { v: T ->
+ activeJob?.cancel()
+ activeJob = scope.launch {
+ delay(delayMs)
+ action(v)
+ }
+ }
+}

demo/plot/build.gradle.kts

@@ -28,6 +28,7 @@ kotlin {
  val batikVersion = extra["batik_version"] as String
  val kotlinLoggingVersion = extra["kotlinLogging_version"] as String
  val kotlinxHtmlVersion = extra["kotlinx_html_version"] as String
+ val kotlinxCoroutinesVersion = extra["kotlinx_coroutines_version"] as String
  val ktorVersion = extra["ktor_version"] as String
  val jfxPlatform = extra["jfxPlatformResolved"] as String
  val jfxVersion = extra["jfx_version"] as String
@@ -39,6 +40,7 @@ kotlin {
  commonMain {
  dependencies {
  implementation(kotlin("stdlib-common"))
+ implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlinxCoroutinesVersion")
 
  implementation(project(":commons"))
  implementation(project(":datamodel"))

gradle.properties

@@ -10,6 +10,7 @@ kotlin_version=1.9.23
 kotlinLogging_version=2.0.5
 
 kotlinx_html_version=0.7.3
+kotlinx_coroutines_version=1.7.1
 
 slf4j_version=1.7.29
 

plot-builder/build.gradle.kts

@@ -9,6 +9,7 @@ plugins {
 
 val mockkVersion = extra["mockk_version"] as String
 val kotlinLoggingVersion = extra["kotlinLogging_version"] as String
+val kotlinxCoroutinesVersion = extra["kotlinx_coroutines_version"] as String
 val hamcrestVersion = extra["hamcrest_version"] as String
 val mockitoVersion = extra["mockito_version"] as String
 val assertjVersion = extra["assertj_version"] as String
@@ -22,6 +23,11 @@ kotlin {
  sourceSets {
  commonMain {
  dependencies {
+ // Can't use compileOnly
+ // > Task :commons:compileTestDevelopmentExecutableKotlinJs FAILED
+ //e: Could not find "org.jetbrains.kotlinx:kotlinx-coroutines-core" in [/home/me/.local/share/kotlin/daemon]
+ implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlinxCoroutinesVersion")
+
  compileOnly(project(":commons"))
  compileOnly(project(":datamodel"))
  compileOnly(project(":plot-base"))

plot-builder/src/commonMain/kotlin/org/jetbrains/letsPlot/core/plot/builder/interact/PlotToolEventDispatcher.kt

@@ -5,6 +5,9 @@
 
 package org.jetbrains.letsPlot.core.plot.builder.interact
 
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import org.jetbrains.letsPlot.commons.debounce
 import org.jetbrains.letsPlot.commons.geometry.DoubleRectangle
 import org.jetbrains.letsPlot.commons.registration.Registration
 import org.jetbrains.letsPlot.core.interact.DrawRectFeedback
@@ -47,6 +50,11 @@ internal class PlotToolEventDispatcher(
  deactivateOverlappingInteractions(origin, interactionSpec)
 
  val interactionName = interactionSpec.getValue(ToolInteractionSpec.NAME) as String
+ val completeInteractionDebounced =
+ debounce<DoubleRectangle>(DEBOUNCE_DELAY_MS, CoroutineScope(Dispatchers.Default)) { dataBounds ->
+ println("Debounced interaction: $interactionName, dataBounds: $dataBounds")
+ completeInteraction(origin, interactionName, dataBounds)
+ }
 
  // ToDo: sent "completed" event in "onCompleted"
  val feedback = when (interactionName) {
@@ -66,7 +74,7 @@ internal class PlotToolEventDispatcher(
 
  ToolInteractionSpec.WHEEL_ZOOM -> WheelZoomFeedback(
  onCompleted = { dataBounds ->
- completeInteraction(origin, interactionName, dataBounds)
+ completeInteractionDebounced(dataBounds)
  }
  )
 
@@ -151,4 +159,8 @@ internal class PlotToolEventDispatcher(
  ) {
  val interactionName = interactionSpec.getValue(ToolInteractionSpec.NAME) as String
  }
+
+ companion object {
+ private const val DEBOUNCE_DELAY_MS = 30L
+ }
 }