Merge lib package into the main one in the Android implementation (#2270)

## Description

This PR changes the structure of the Gesture Handler's Android code. For
some time GH could have been used as a native Android library for
handling gestures, but it has been removed since. The split into two
packages that was required by it is still there, along some of the now
redundant files (another `build.gradle` and `AndroidManifest`).

This PR removes the two-package split and moves the core files into a
new `core` subpackage, like the `react` one.

## Test plan

Build the example app.

Author: j-piasecki

android/build.gradle

@@ -172,13 +172,8 @@ android {
         exclude "**/libreact_render*.so"
     }
 
-    // Include "lib/" as sources, unfortunately react-native link can't handle
-    // setting up alternative gradle modules. We still have "lib" defined as a
-    // standalone gradle module just to be used in AndroidNativeExample
     sourceSets.main {
         java {
-            srcDirs += 'lib/src/main/java'
-
             // Include "common/" only when it's not provided by Reanimated to mitigate
             // multiple definitions of the same class preventing build
             if (shouldUseCommonInterfaceFromReanimated()) {

android/lib/src/main/AndroidManifest.xml

@@ -4,7 +4,7 @@ import com.facebook.react.bridge.ReactContext
 import com.facebook.react.uimanager.events.Event
 
 class ReanimatedEventDispatcher {
-    fun <T : Event<T>>sendEvent(event: T, reactApplicationContext: ReactContext) {
-        // no-op
-    }
+  fun <T : Event<T>>sendEvent(event: T, reactApplicationContext: ReactContext) {
+    // no-op
+  }
 }

android/lib/src/test/java/com/swmansion/gesturehandler/ExampleUnitTest.java

@@ -5,13 +5,13 @@ import com.facebook.react.uimanager.events.Event
 import com.swmansion.reanimated.ReanimatedModule
 
 class ReanimatedEventDispatcher {
-    private var reanimatedModule: ReanimatedModule? = null
+  private var reanimatedModule: ReanimatedModule? = null
 
-    fun <T : Event<T>>sendEvent(event: T, reactApplicationContext: ReactContext) {
-        if (reanimatedModule == null) {
-            reanimatedModule = reactApplicationContext.getNativeModule(ReanimatedModule::class.java)
-        }
-
-        reanimatedModule?.nodesManager?.onEventDispatch(event)
+  fun <T : Event<T>>sendEvent(event: T, reactApplicationContext: ReactContext) {
+    if (reanimatedModule == null) {
+      reanimatedModule = reactApplicationContext.getNativeModule(ReanimatedModule::class.java)
     }
+
+    reanimatedModule?.nodesManager?.onEventDispatch(event)
+  }
 }

android/noreanimated/src/main/java/com/swmansion/gesturehandler/ReanimatedEventDispatcher.kt

@@ -2,7 +2,7 @@ apply plugin: "com.diffplug.spotless"
 
 spotless {
     kotlin {
-        target "src/**/*.kt"
+        target "src/**/*.kt", "reanimated/**/*.kt", "noreanimated/**/*.kt", "common/**/*.kt"
         ktlint().editorConfigOverride([indent_size: 2])
         trimTrailingWhitespace()
         indentWithSpaces()

android/reanimated/src/main/java/com/swmansion/gesturehandler/ReanimatedEventDispatcher.kt

@@ -1,4 +1,4 @@
-package com.swmansion.gesturehandler
+package com.swmansion.gesturehandler.core
 
 import android.os.Handler
 import android.os.Looper
@@ -37,14 +37,17 @@ class FlingGestureHandler : GestureHandler<FlingGestureHandler>() {
 
   private fun tryEndFling(event: MotionEvent) = if (
     maxNumberOfPointersSimultaneously == numberOfPointersRequired &&
-    (direction and DIRECTION_RIGHT != 0 &&
-      event.rawX - startX > minAcceptableDelta ||
-      direction and DIRECTION_LEFT != 0 &&
-      startX - event.rawX > minAcceptableDelta ||
-      direction and DIRECTION_UP != 0 &&
-      startY - event.rawY > minAcceptableDelta ||
-      direction and DIRECTION_DOWN != 0 &&
-      event.rawY - startY > minAcceptableDelta)) {
+    (
+      direction and DIRECTION_RIGHT != 0 &&
+        event.rawX - startX > minAcceptableDelta ||
+        direction and DIRECTION_LEFT != 0 &&
+        startX - event.rawX > minAcceptableDelta ||
+        direction and DIRECTION_UP != 0 &&
+        startY - event.rawY > minAcceptableDelta ||
+        direction and DIRECTION_DOWN != 0 &&
+        event.rawY - startY > minAcceptableDelta
+      )
+  ) {
     handler!!.removeCallbacksAndMessages(null)
     activate()
     true

android/spotless.gradle

@@ -1,4 +1,4 @@
-package com.swmansion.gesturehandler
+package com.swmansion.gesturehandler.core
 
 import android.app.Activity
 import android.content.Context
@@ -14,6 +14,7 @@ import com.facebook.react.bridge.Arguments
 import com.facebook.react.bridge.UiThreadUtil
 import com.facebook.react.bridge.WritableArray
 import com.facebook.react.uimanager.PixelUtil
+import com.swmansion.gesturehandler.BuildConfig
 import com.swmansion.gesturehandler.react.RNGestureHandlerTouchEvent
 import java.lang.IllegalStateException
 import java.util.*
@@ -48,7 +49,6 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
   private val trackedPointers: Array<PointerData?> = Array(MAX_POINTERS_COUNT) { null }
   var needsPointerData = false
 
-
   private var hitSlop: FloatArray? = null
   var eventCoalescingKey: Short = 0
     private set
@@ -127,11 +127,15 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
   }
 
   fun setManualActivation(manualActivation: Boolean): ConcreteGestureHandlerT =
-      applySelf { this.manualActivation = manualActivation }
+    applySelf { this.manualActivation = manualActivation }
 
   fun setHitSlop(
-    leftPad: Float, topPad: Float, rightPad: Float, bottomPad: Float,
-    width: Float, height: Float,
+    leftPad: Float,
+    topPad: Float,
+    rightPad: Float,
+    bottomPad: Float,
+    width: Float,
+    height: Float,
   ): ConcreteGestureHandlerT = applySelf {
     if (hitSlop == null) {
       hitSlop = FloatArray(6)
@@ -278,7 +282,7 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
     }
 
     // introduced in 1.11.0, remove if crashes are not reported
-    if(pointerProps.isEmpty()|| pointerCoords.isEmpty()){
+    if (pointerProps.isEmpty() || pointerCoords.isEmpty()) {
       throw IllegalStateException("pointerCoords.size=${pointerCoords.size}, pointerProps.size=${pointerProps.size}")
     }
 
@@ -289,8 +293,8 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
         event.eventTime,
         action,
         count,
-        pointerProps,  /* props are copied and hence it is safe to use static array here */
-        pointerCoords,  /* same applies to coords */
+        pointerProps, /* props are copied and hence it is safe to use static array here */
+        pointerCoords, /* same applies to coords */
         event.metaState,
         event.buttonState,
         event.xPrecision,
@@ -313,7 +317,8 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
     handler: GestureHandler<*>,
     event: MotionEvent,
     e: IllegalArgumentException
-  ) : Exception("""
+  ) : Exception(
+    """
     handler: ${handler::class.simpleName}
     state: ${handler.state}
     view: ${handler.view}
@@ -324,14 +329,17 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
     trackedPointersCount: ${handler.trackedPointersIDsCount}
     trackedPointers: ${handler.trackedPointerIDs.joinToString(separator = ", ")}
     while handling event: $event
-  """.trimIndent(), e) {}
+    """.trimIndent(),
+    e
+  )
 
   fun handle(transformedEvent: MotionEvent, sourceEvent: MotionEvent) {
-    if (!isEnabled
-      || state == STATE_CANCELLED
-      || state == STATE_FAILED
-      || state == STATE_END
-      || trackedPointersIDsCount < 1) {
+    if (!isEnabled ||
+      state == STATE_CANCELLED ||
+      state == STATE_FAILED ||
+      state == STATE_END ||
+      trackedPointersIDsCount < 1
+    ) {
       return
     }
 
@@ -380,11 +388,11 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
     val offsetY = event.rawY - event.y
 
     trackedPointers[pointerId] = PointerData(
-        pointerId,
-        event.getX(event.actionIndex),
-        event.getY(event.actionIndex),
-        event.getX(event.actionIndex) + offsetX - windowOffset[0],
-        event.getY(event.actionIndex) + offsetY - windowOffset[1],
+      pointerId,
+      event.getX(event.actionIndex),
+      event.getY(event.actionIndex),
+      event.getX(event.actionIndex) + offsetX - windowOffset[0],
+      event.getY(event.actionIndex) + offsetY - windowOffset[1],
     )
     trackedPointersCount++
     addChangedPointer(trackedPointers[pointerId]!!)
@@ -402,11 +410,11 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
     val offsetY = event.rawY - event.y
 
     trackedPointers[pointerId] = PointerData(
-        pointerId,
-        event.getX(event.actionIndex),
-        event.getY(event.actionIndex),
-        event.getX(event.actionIndex) + offsetX - windowOffset[0],
-        event.getY(event.actionIndex) + offsetY - windowOffset[1],
+      pointerId,
+      event.getX(event.actionIndex),
+      event.getY(event.actionIndex),
+      event.getX(event.actionIndex) + offsetX - windowOffset[0],
+      event.getY(event.actionIndex) + offsetY - windowOffset[1],
     )
     addChangedPointer(trackedPointers[pointerId]!!)
     trackedPointers[pointerId] = null
@@ -545,11 +553,11 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
   }
 
   fun wantEvents(): Boolean {
-    return isEnabled
-      && state != STATE_FAILED
-      && state != STATE_CANCELLED
-      && state != STATE_END
-      && trackedPointersIDsCount > 0
+    return isEnabled &&
+      state != STATE_FAILED &&
+      state != STATE_CANCELLED &&
+      state != STATE_END &&
+      trackedPointersIDsCount > 0
   }
 
   open fun shouldRequireToWaitForFailure(handler: GestureHandler<*>): Boolean {
@@ -745,7 +753,7 @@ open class GestureHandler<ConcreteGestureHandlerT : GestureHandler<ConcreteGestu
     private lateinit var pointerCoords: Array<PointerCoords?>
     private fun initPointerProps(size: Int) {
       var size = size
-      if (!::pointerProps.isInitialized) {
+      if (!Companion::pointerProps.isInitialized) {
         pointerProps = arrayOfNulls(MAX_POINTERS_COUNT)
         pointerCoords = arrayOfNulls(MAX_POINTERS_COUNT)
       }

android/lib/src/main/java/com/swmansion/gesturehandler/FlingGestureHandler.kt renamed to android/src/main/java/com/swmansion/gesturehandler/core/FlingGestureHandler.kt

@@ -1,4 +1,4 @@
-package com.swmansion.gesturehandler
+package com.swmansion.gesturehandler.core
 
 interface GestureHandlerInteractionController {
   fun shouldWaitForHandlerFailure(handler: GestureHandler<*>, otherHandler: GestureHandler<*>): Boolean

android/lib/src/main/java/com/swmansion/gesturehandler/GestureHandler.kt renamed to android/src/main/java/com/swmansion/gesturehandler/core/GestureHandler.kt

@@ -1,4 +1,4 @@
-package com.swmansion.gesturehandler
+package com.swmansion.gesturehandler.core
 
 import android.graphics.Matrix
 import android.graphics.PointF
@@ -134,7 +134,10 @@ class GestureHandlerOrchestrator(
               // their state is set to END and when the gesture they are waiting for activates they
               // should be cancelled, however `cancel` was never sent as gestures were already in the END state.
               // Send synthetic BEGAN -> CANCELLED to properly handle JS logic
-              otherHandler.dispatchStateChange(GestureHandler.STATE_CANCELLED, GestureHandler.STATE_BEGAN)
+              otherHandler.dispatchStateChange(
+                GestureHandler.STATE_CANCELLED,
+                GestureHandler.STATE_BEGAN
+              )
             }
             otherHandler.isAwaiting = false
           } else {
@@ -253,10 +256,10 @@ class GestureHandlerOrchestrator(
 
     val action = sourceEvent.actionMasked
     val event = transformEventToViewCoords(handler.view, MotionEvent.obtain(sourceEvent))
-    
+
     // Touch events are sent before the handler itself has a chance to process them,
     // mainly because `onTouchesUp` shoul be send befor gesture finishes. This means that
-    // the first `onTouchesDown` event is sent before a gesture begins, activation in 
+    // the first `onTouchesDown` event is sent before a gesture begins, activation in
     // callback for this event causes problems because the handler doesn't have a chance
     // to initialize itself with starting values of pointer (in pan this causes translation
     // to be equal to the coordinates of the pointer). The simplest solution is to send
@@ -475,9 +478,10 @@ class GestureHandlerOrchestrator(
 
     // if the pointer is inside the view but it overflows its parent, handlers attached to the parent
     // might not have been extracted (pointer might be in a child, but may be outside parent)
-    if (coords[0] in 0f..view.width.toFloat() && coords[1] in 0f..view.height.toFloat()
-      && isViewOverflowingParent(view) && extractAncestorHandlers(view, coords, pointerId)) {
-        found = true
+    if (coords[0] in 0f..view.width.toFloat() && coords[1] in 0f..view.height.toFloat() &&
+      isViewOverflowingParent(view) && extractAncestorHandlers(view, coords, pointerId)
+    ) {
+      found = true
     }
 
     return found
@@ -527,8 +531,10 @@ class GestureHandlerOrchestrator(
       }
       PointerEventsConfig.BOX_ONLY -> {
         // This view is the target, its children don't matter
-        (recordViewHandlersForPointer(view, coords, pointerId)
-          || shouldHandlerlessViewBecomeTouchTarget(view, coords))
+        (
+          recordViewHandlersForPointer(view, coords, pointerId) ||
+            shouldHandlerlessViewBecomeTouchTarget(view, coords)
+          )
       }
       PointerEventsConfig.BOX_NONE -> {
         // This view can't be the target, but its children might
@@ -557,8 +563,10 @@ class GestureHandlerOrchestrator(
           extractGestureHandlers(view, coords, pointerId)
         } else false
 
-        (recordViewHandlersForPointer(view, coords, pointerId)
-          || found || shouldHandlerlessViewBecomeTouchTarget(view, coords))
+        (
+          recordViewHandlersForPointer(view, coords, pointerId) ||
+            found || shouldHandlerlessViewBecomeTouchTarget(view, coords)
+          )
       }
     }
 
@@ -570,7 +578,6 @@ class GestureHandlerOrchestrator(
   private fun isClipping(view: View) =
     view !is ViewGroup || viewConfigHelper.isViewClippingChildren(view)
 
-
   companion object {
     // The limit doesn't necessarily need to exists, it was just simpler to implement it that way
     // it is also more allocation-wise efficient to have a fixed limit
@@ -637,14 +644,15 @@ class GestureHandlerOrchestrator(
       x in 0f..child.width.toFloat() && y in 0f..child.height.toFloat()
 
     private fun shouldHandlerWaitForOther(handler: GestureHandler<*>, other: GestureHandler<*>): Boolean {
-      return handler !== other && (handler.shouldWaitForHandlerFailure(other)
-        || other.shouldRequireToWaitForFailure(handler))
+      return handler !== other && (
+        handler.shouldWaitForHandlerFailure(other) ||
+          other.shouldRequireToWaitForFailure(handler)
+        )
     }
 
     private fun canRunSimultaneously(a: GestureHandler<*>, b: GestureHandler<*>) =
       a === b || a.shouldRecognizeSimultaneously(b) || b.shouldRecognizeSimultaneously(a)
 
-
     private fun shouldHandlerBeCancelledBy(handler: GestureHandler<*>, other: GestureHandler<*>): Boolean {
       if (!handler.hasCommonPointers(other)) {
         // if two handlers share no common pointer one can never trigger cancel for the other
@@ -656,16 +664,17 @@ class GestureHandlerOrchestrator(
         return false
       }
       return if (handler !== other &&
-        (handler.isAwaiting || handler.state == GestureHandler.STATE_ACTIVE)) {
+        (handler.isAwaiting || handler.state == GestureHandler.STATE_ACTIVE)
+      ) {
         // in every other case as long as the handler is about to be activated or already in active
         // state, we delegate the decision to the implementation of GestureHandler#shouldBeCancelledBy
         handler.shouldBeCancelledBy(other)
       } else true
     }
 
     private fun isFinished(state: Int) =
-      state == GestureHandler.STATE_CANCELLED
-        || state == GestureHandler.STATE_FAILED
-        || state == GestureHandler.STATE_END
+      state == GestureHandler.STATE_CANCELLED ||
+        state == GestureHandler.STATE_FAILED ||
+        state == GestureHandler.STATE_END
   }
 }