Ignore unpressed events during velocity calculation on iOS (#848)

compose/ui/ui/src/androidMain/kotlin/androidx/compose/ui/input/pointer/util/VelocityTracker.android.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package androidx.compose.ui.input.pointer.util
+
+/**
+ * Some platforms (e.g. iOS) ignore certain events during velocity calculation.
+ */
+internal actual fun VelocityTracker.shouldUse(event: PointerInputChange): Boolean = true

compose/ui/ui/src/commonMain/kotlin/androidx/compose/ui/input/pointer/util/VelocityTracker.kt

@@ -285,6 +285,11 @@ private fun Array<DataPointAtTime?>.set(index: Int, time: Long, dataPoint: Float
     }
 }
 
+/**
+ * Some platforms (e.g. iOS) ignore certain events during velocity calculation.
+ */
+internal expect fun VelocityTracker.shouldUse(event: PointerInputChange): Boolean
+
 /**
  * Track the positions and timestamps inside this event change.
  *
@@ -308,6 +313,10 @@ fun VelocityTracker.addPointerInputChange(event: PointerInputChange) {
         resetTracking()
     }
 
+    if (!shouldUse(event)) {
+        return
+    }
+
     // To calculate delta, for each step we want to  do currentPosition - previousPosition.
     // Initially the previous position is the previous position of the current event
     var previousPointerPosition = event.previousPosition

compose/ui/ui/src/notMobileMain/kotlin/androidx/compose/ui/input/pointer/util/VelocityTracker.notMobile.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package androidx.compose.ui.input.pointer.util
+
+import androidx.compose.ui.input.pointer.PointerInputChange
+
+/**
+ * Some platforms (e.g. iOS) ignore certain events during velocity calculation.
+ */
+internal actual fun VelocityTracker.shouldUse(event: PointerInputChange): Boolean = true

compose/ui/ui/src/uikitMain/kotlin/androidx/compose/ui/input/pointer/util/VelocityTracker.uikit.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package androidx.compose.ui.input.pointer.util
+
+import androidx.compose.ui.input.pointer.PointerInputChange
+
+/**
+ * Some platforms (e.g. iOS) ignore certain events during velocity calculation.
+ */
+internal actual fun VelocityTracker.shouldUse(event: PointerInputChange): Boolean = event.pressed