Simplify GestureListener

lawnchair/src/app/lawnchair/gestures/DirectionalGestureListener.kt

@@ -1,17 +1,17 @@
 package app.lawnchair.gestures
 
-import android.view.View.OnTouchListener
-import android.view.GestureDetector
 import android.annotation.SuppressLint
 import android.content.Context
-import android.view.MotionEvent
+import android.view.GestureDetector
 import android.view.GestureDetector.SimpleOnGestureListener
+import android.view.MotionEvent
 import android.view.View
-import java.lang.Exception
+import android.view.View.OnTouchListener
 import kotlin.math.abs
 
 open class DirectionalGestureListener(ctx: Context?) : OnTouchListener {
     private val mGestureDetector: GestureDetector
+
     @SuppressLint("ClickableViewAccessibility")
     override fun onTouch(v: View, event: MotionEvent): Boolean {
         return mGestureDetector.onTouchEvent(event)
@@ -26,32 +26,29 @@ open class DirectionalGestureListener(ctx: Context?) : OnTouchListener {
             return true
         }
 
+        private fun shouldReactToSwipe(diff: Float, velocity: Float): Boolean =
+            abs(diff) > SWIPE_THRESHOLD && abs(velocity) > SWIPE_VELOCITY_THRESHOLD
+
         override fun onFling(e1: MotionEvent, e2: MotionEvent, velocityX: Float, velocityY: Float): Boolean {
-            var result = false
-            try {
+            return try {
                 val diffY = e2.y - e1.y
                 val diffX = e2.x - e1.x
-                if (abs(diffX) > abs(diffY)) {
-                    if (abs(diffX) > SWIPE_THRESHOLD && abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
-                        if (diffX > 0) {
-                            onSwipeRight()
-                        } else {
-                            onSwipeLeft()
-                        }
-                        result = true
+
+                when {
+                    abs(diffX) > abs(diffY) && shouldReactToSwipe(diffX, velocityX) -> {
+                        if (diffX > 0) onSwipeRight() else onSwipeLeft()
+                        true
                     }
-                } else if (abs(diffY) > SWIPE_THRESHOLD && abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
-                    if (diffY > 0) {
-                        onSwipeBottom()
-                    } else {
-                        onSwipeTop()
+                    shouldReactToSwipe(diffY, velocityY) -> {
+                        if (diffY > 0) onSwipeBottom() else onSwipeTop()
+                        true
                     }
-                    result = true
+                    else -> false
                 }
             } catch (exception: Exception) {
                 exception.printStackTrace()
+                false
             }
-            return result
         }
     }