Merge pull request #2 from erolaksoy/FixVisibilityCalculation

Fix visibility calculation and update compose versions

buildSrc/src/main/java/AppVersions.kt

@@ -1,3 +1,3 @@
 const val PUBLISHING_GROUP = "com.erolaksoy"
 const val PUBLISHING_ARTIFACT_ID = "compose-impression"
-const val VERSION = "0.1"
+const val VERSION = "0.1.1"

gradle/libraries.versions.toml

@@ -1,42 +1,41 @@
 [versions]
-agp = "8.0.2"
-androidx_activity_compose = "1.7.2"
+agp = "8.2.2"
+androidx_activity_compose = "1.8.2"
 androidx_test = "1.5.0"
 androidx_test_ext = "1.1.5"
 appcompat = "1.6.1"
-compile_sdk_version = "33"
-compose = "1.4.3"
-compose_compilerextension = "1.4.5"
-constraint_layout = "2.1.4"
+compile_sdk_version = "34"
+compose = "1.6.2"
+compose_compilerextension = "1.5.1"
 core_ktx = "1.10.1"
 detekt = "1.23.0"
 dokka = "1.8.10"
 espresso_core = "3.5.1"
 ksp = "1.8.20-1.0.11"
 junit = "4.13.2"
-kotlin = "1.8.20"
+kotlin = "1.9.0"
 ktlint = "0.45.2"
 ktlint_gradle = "10.2.1"
-min_sdk_version = "21"
-target_sdk_version = "33"
+min_sdk_version = "23"
+target_sdk_version = "34"
 
 [libraries]
 junit = { module = "junit:junit", version.ref = "junit" }
 androidx_activity_compose = { module = "androidx.activity:activity-compose", version.ref = "androidx_activity_compose" }
 androidx_appcompat = { module = "androidx.appcompat:appcompat", version.ref = "appcompat" }
 androidx_core_ktx = { module = "androidx.core:core-ktx", version.ref = "core.ktx" }
-androidx_test_rules = { module = "androidx.test:rules", version.ref = "androidx.test" }
-androidx_test_runner = { module = "androidx.test:runner", version.ref = "androidx.test" }
-androidx_test_ext_junit = { module = "androidx.test.ext:junit", version.ref = "androidx.test.ext" }
-androidx_test_ext_junit_ktx = { module = "androidx.test.ext:junit-ktx", version.ref = "androidx.test.ext" }
+androidx_test_rules = { module = "androidx.test:rules", version.ref = "androidx_test" }
+androidx_test_runner = { module = "androidx.test:runner", version.ref = "androidx_test" }
+androidx_test_ext_junit = { module = "androidx.test.ext:junit", version.ref = "androidx_test_ext" }
+androidx_test_ext_junit_ktx = { module = "androidx.test.ext:junit-ktx", version.ref = "androidx_test_ext" }
 compose_material = { module = "androidx.compose.material:material", version.ref = "compose" }
 compose_foundation = { module = "androidx.compose.foundation:foundation", version.ref = "compose" }
 compose_ui = { module = "androidx.compose.ui:ui", version.ref = "compose" }
 compose_ui_tooling = { module = "androidx.compose.ui:ui-tooling", version.ref = "compose" }
 compose_ui_test_junit4 = { module = "androidx.compose.ui:ui-test-junit4", version.ref = "compose" }
 compose_ui_test_manifest = { module = "androidx.compose.ui:ui-test-manifest", version.ref = "compose" }
 detekt_formatting = { module = "io.gitlab.arturbosch.detekt:detekt-formatting", version.ref = "detekt" }
-espressoCore = { module = "androidx.test.espresso:espresso-core", version.ref = "espresso.core" }
+espressoCore = { module = "androidx.test.espresso:espresso-core", version.ref = "espresso_core" }
 agp = { module = "com.android.tools.build:gradle", version.ref = "agp" }
 kgp = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin", version.ref = "kotlin" }
 dokkaCore = { module = "org.jetbrains.dokka:dokka-core", version.ref = "dokka" }
@@ -46,6 +45,6 @@ kotlin-gradlePlugin = { group = "org.jetbrains.kotlin", name = "kotlin-gradle-pl
 [plugins]
 detekt = { id = "io.gitlab.arturbosch.detekt", version.ref = "detekt" }
 dokka = { id = "org.jetbrains.dokka:dokka-gradle-plugin", version.ref = "dokka" }
-ktlint = { id = "org.jlleitschuh.gradle.ktlint", version.ref = "ktlint.gradle" }
+ktlint = { id = "org.jlleitschuh.gradle.ktlint", version.ref = "ktlint_gradle" }
 android-application = { id = "com.android.application", version.ref = "agp" }
 android-library = { id = "com.android.library", version.ref = "agp" }

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 #Tue Jun 06 20:46:26 TRT 2023
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.2-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

impression/src/main/java/com/erolaksoy/impression/Impression.kt

@@ -2,13 +2,13 @@ package com.erolaksoy.impression
 
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.Stable
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.composed
-import androidx.compose.ui.layout.onPlaced
+import androidx.compose.ui.layout.onGloballyPositioned
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharedFlow
@@ -25,15 +25,34 @@ fun <T : Any> Modifier.impression(
 
     val coroutineScope = rememberCoroutineScope()
 
-    LaunchedEffect(key) {
-        impressionState.seenEvent.collect {
-            if (key == it) {
-                onImpressionHappened(key)
+    DisposableEffect(key) {
+        val job = coroutineScope.launch {
+            impressionState.seenEvent.collect {
+                if (key == it) {
+                    onImpressionHappened(key)
+                }
             }
         }
+        onDispose { job.cancel() }
     }
 
-    onPlaced {
+    onGloballyPositioned {
+        coroutineScope.launch {
+            if (it.isAttached.not()) return@launch
+            impressionState.onItemPlaced(key = key)
+        }
+    }
+}
+
+@Stable
+fun <T : Any> Modifier.impression(
+    key: T,
+    impressionState: ImpressionState,
+) = composed {
+
+    val coroutineScope = rememberCoroutineScope()
+
+    onGloballyPositioned {
         coroutineScope.launch {
             if (it.isAttached.not()) return@launch
             impressionState.onItemPlaced(key = key)
@@ -44,13 +63,17 @@ fun <T : Any> Modifier.impression(
 @Composable
 fun rememberImpressionState(
     lazyListState: LazyListState,
-    block: ImpressionState.() -> Unit = {},
+    block: ImpressionState.() -> Unit = defaultImpressionStateBlock,
 ): ImpressionState {
     return remember {
         ImpressionStateImpl(lazyListState).apply(block)
     }
 }
 
+internal val defaultImpressionStateBlock: ImpressionState.() -> Unit = {
+    addValidator(VisibilityPercentImpressionValidator())
+}
+
 class ImpressionStateImpl(private val state: LazyListState) : ImpressionState {
     private val _seenEvent = MutableSharedFlow<Any>(extraBufferCapacity = 1)
     override val seenEvent: SharedFlow<Any> = _seenEvent.asSharedFlow()
@@ -63,8 +86,12 @@ class ImpressionStateImpl(private val state: LazyListState) : ImpressionState {
     override suspend fun onItemPlaced(key: Any) = withContext(Dispatchers.Default) {
         if (_recordedItems.contains(key)) return@withContext
 
-        val filteredList = state.layoutInfo.visibleItemsInfo.filter {
-            _validators.any { it.isValid(state, key) }
+        val visibleItemsInfo = state.layoutInfo.visibleItemsInfo
+
+        val filteredList = if (_validators.isEmpty()) {
+            visibleItemsInfo
+        } else {
+            visibleItemsInfo.filter { _validators.any { it.isValid(state, key) } }
         }
 
         val isItemInList = filteredList.any { it.key == key }
@@ -79,6 +106,10 @@ class ImpressionStateImpl(private val state: LazyListState) : ImpressionState {
         _validators.add(validator)
     }
 
+    override fun clearValidators() {
+        _validators.clear()
+    }
+
     override fun clearAll() {
         _recordedItems.clear()
     }

impression/src/main/java/com/erolaksoy/impression/ImpressionState.kt

@@ -28,6 +28,11 @@ interface ImpressionState {
      */
     fun addValidator(validator: ImpressionValidator)
 
+    /**
+     * Removes all validators from the impression state.
+     */
+    fun clearValidators()
+
     /**
      * Clears all state from the impression state.
      */

impression/src/main/java/com/erolaksoy/impression/VisibilityPercentImpressionValidator.kt

@@ -5,7 +5,7 @@ import androidx.compose.foundation.lazy.LazyListItemInfo
 import androidx.compose.foundation.lazy.LazyListState
 
 class VisibilityPercentImpressionValidator(
-    @FloatRange(0.0, 1.0) private val visibilityPercentThreshold: Float,
+    @FloatRange(0.0, 1.0) private val visibilityPercentThreshold: Float = VISIBILITY_THRESHOLD,
 ) : ImpressionValidator {
 
     override suspend fun isValid(state: LazyListState, key: Any): Boolean {
@@ -23,6 +23,11 @@ class VisibilityPercentImpressionValidator(
     private fun LazyListState.visibilityPercent(itemInfo: LazyListItemInfo): Float {
         val start = (layoutInfo.viewportStartOffset - itemInfo.offset).coerceAtLeast(0)
         val end = (itemInfo.offset + itemInfo.size - layoutInfo.viewportEndOffset).coerceAtLeast(0)
-        return (1f - (start + end).toFloat() / itemInfo.size).coerceAtLeast(0f)
+        val visibleArea = maxOf(0f, (start + end).toFloat())
+        return 1f - (visibleArea / itemInfo.size.toFloat())
+    }
+
+    companion object {
+        private const val VISIBILITY_THRESHOLD = 0.5F
     }
 }