disable flinging on preview view

- only change camera mode when fling happens on the bottom tab
- so zoom gestures do not interfere with the fling

app/src/main/kotlin/com/simplemobiletools/camera/activities/MainActivity.kt

@@ -1,5 +1,6 @@
 package com.simplemobiletools.camera.activities
 
+import android.annotation.SuppressLint
 import android.app.Activity
 import android.content.Intent
 import android.content.res.ColorStateList
@@ -39,16 +40,24 @@ import com.simplemobiletools.camera.views.FocusCircleView
 import com.simplemobiletools.commons.extensions.*
 import com.simplemobiletools.commons.helpers.*
 import com.simplemobiletools.commons.models.Release
-import kotlinx.android.synthetic.main.activity_main.*
-import kotlinx.android.synthetic.main.layout_flash.*
-import kotlinx.android.synthetic.main.layout_top.*
 import java.util.concurrent.TimeUnit
+import kotlin.math.abs
+import kotlinx.android.synthetic.main.activity_main.*
+import kotlinx.android.synthetic.main.layout_flash.flash_auto
+import kotlinx.android.synthetic.main.layout_flash.flash_off
+import kotlinx.android.synthetic.main.layout_flash.flash_on
+import kotlinx.android.synthetic.main.layout_flash.flash_toggle_group
+import kotlinx.android.synthetic.main.layout_top.change_resolution
+import kotlinx.android.synthetic.main.layout_top.default_icons
+import kotlinx.android.synthetic.main.layout_top.settings
+import kotlinx.android.synthetic.main.layout_top.toggle_flash
 
 class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener, CameraXPreviewListener {
     private companion object {
         const val CAPTURE_ANIMATION_DURATION = 500L
         const val PHOTO_MODE_INDEX = 1
         const val VIDEO_MODE_INDEX = 0
+        private const val MIN_SWIPE_DISTANCE_X = 100
     }
 
     lateinit var mTimerHandler: Handler
@@ -288,6 +297,7 @@ class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener, Camera
     private fun initializeCamera() {
         setContentView(R.layout.activity_main)
         initButtons()
+        initModeSwitcher()
         defaultScene = Scene(top_options, default_icons)
         flashModeScene = Scene(top_options, flash_toggle_group)
 
@@ -376,6 +386,43 @@ class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener, Camera
         flash_auto.setOnClickListener { selectFlashMode(FLASH_AUTO) }
     }
 
+    @SuppressLint("ClickableViewAccessibility")
+    private fun initModeSwitcher(){
+        val gestureDetector = GestureDetector(this, object : GestureDetector.SimpleOnGestureListener() {
+            override fun onFling(event1: MotionEvent, event2: MotionEvent, velocityX: Float, velocityY: Float): Boolean {
+                val deltaX = event1.x - event2.x
+                val deltaXAbs = abs(deltaX)
+
+                if (deltaXAbs >= MIN_SWIPE_DISTANCE_X) {
+                    if (deltaX > 0) {
+                        onSwipeLeft()
+                    } else {
+                        onSwipeRight()
+                    }
+                }
+
+                return true
+            }
+        })
+
+        camera_mode_tab.setOnTouchListener { _, event ->
+            gestureDetector.onTouchEvent(event)
+        }
+    }
+
+    private fun onSwipeLeft() {
+        if (!is3rdPartyIntent() && camera_mode_tab.isVisible()) {
+            selectPhotoTab(triggerListener = true)
+        }
+    }
+
+    private fun onSwipeRight() {
+        if (!is3rdPartyIntent() && camera_mode_tab.isVisible()) {
+            selectVideoTab(triggerListener = true)
+        }
+    }
+
+
     private fun selectFlashMode(flashMode: Int) {
         closeOptions()
         mPreview?.setFlashlightState(flashMode)
@@ -715,18 +762,6 @@ class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener, Camera
         mFocusCircleView.drawFocusCircle(xPos, yPos)
     }
 
-    override fun onSwipeLeft() {
-        if (!is3rdPartyIntent() && camera_mode_tab.isVisible()) {
-            selectPhotoTab(triggerListener = true)
-        }
-    }
-
-    override fun onSwipeRight() {
-        if (!is3rdPartyIntent() && camera_mode_tab.isVisible()) {
-            selectVideoTab(triggerListener = true)
-        }
-    }
-
     override fun onTouchPreview() {
         closeOptions()
     }

app/src/main/kotlin/com/simplemobiletools/camera/implementations/CameraXPreview.kt

@@ -31,7 +31,6 @@ import com.simplemobiletools.camera.models.MySize
 import com.simplemobiletools.camera.models.ResolutionOption
 import com.simplemobiletools.commons.extensions.toast
 import com.simplemobiletools.commons.helpers.ensureBackgroundThread
-import kotlin.math.abs
 
 class CameraXPreview(
     private val activity: AppCompatActivity,
@@ -46,7 +45,6 @@ class CameraXPreview(
         // Auto focus is 1/6 of the area.
         private const val AF_SIZE = 1.0f / 6.0f
         private const val AE_SIZE = AF_SIZE * 1.5f
-        private const val MIN_SWIPE_DISTANCE_X = 100
     }
 
     private val config = activity.config
@@ -293,21 +291,6 @@ class CameraXPreview(
                     true
                 } ?: false
             }
-
-            override fun onFling(event1: MotionEvent, event2: MotionEvent, velocityX: Float, velocityY: Float): Boolean {
-                val deltaX = event1.x - event2.x
-                val deltaXAbs = abs(deltaX)
-
-                if (deltaXAbs >= MIN_SWIPE_DISTANCE_X) {
-                    if (deltaX > 0) {
-                        listener.onSwipeLeft()
-                    } else {
-                        listener.onSwipeRight()
-                    }
-                }
-
-                return true
-            }
         })
         previewView.setOnTouchListener { _, event ->
             val handledGesture = gestureDetector.onTouchEvent(event)

app/src/main/kotlin/com/simplemobiletools/camera/implementations/CameraXPreviewListener.kt

@@ -18,8 +18,6 @@ interface CameraXPreviewListener {
     fun onVideoRecordingStopped()
     fun onVideoDurationChanged(durationNanos: Long)
     fun onFocusCamera(xPos: Float, yPos: Float)
-    fun onSwipeLeft()
-    fun onSwipeRight()
     fun onTouchPreview()
     fun displaySelectedResolution(resolutionOption: ResolutionOption)
     fun showImageSizes(