feat: allow closing photos and videos with a swipe gesture (#5609)

Signed-off-by: Enrique López Mañas <eenriquelopez@gmail.com>

Author: kikoso

app/src/main/java/com/nextcloud/talk/fullscreenfile/FullScreenImageActivity.kt

@@ -12,6 +12,7 @@ package com.nextcloud.talk.fullscreenfile
 import android.content.Intent
 import android.os.Bundle
 import android.util.Log
+import com.nextcloud.talk.ui.SwipeToCloseLayout
 import android.view.Menu
 import android.view.MenuItem
 import android.view.View
@@ -133,6 +134,12 @@ class FullScreenImageActivity : AppCompatActivity() {
             binding.photoView.visibility = View.VISIBLE
             displayImage(path)
         }
+
+        binding.swipeToCloseLayout.setOnSwipeToCloseListener(object : SwipeToCloseLayout.OnSwipeToCloseListener {
+            override fun onSwipeToClose() {
+                finish()
+            }
+        })
     }
 
     private fun displayImage(path: String) {

app/src/main/java/com/nextcloud/talk/fullscreenfile/FullScreenMediaActivity.kt

@@ -39,6 +39,7 @@ import com.nextcloud.talk.BuildConfig
 import com.nextcloud.talk.R
 import com.nextcloud.talk.application.NextcloudTalkApplication
 import com.nextcloud.talk.databinding.ActivityFullScreenMediaBinding
+import com.nextcloud.talk.ui.SwipeToCloseLayout
 import com.nextcloud.talk.ui.dialog.SaveToStorageDialogFragment
 import com.nextcloud.talk.utils.Mimetype.VIDEO_PREFIX_GENERIC
 import java.io.File
@@ -135,6 +136,12 @@ class FullScreenMediaActivity : AppCompatActivity() {
                 }
             }
         )
+
+        binding.swipeToCloseLayout.setOnSwipeToCloseListener(object : SwipeToCloseLayout.OnSwipeToCloseListener {
+            override fun onSwipeToClose() {
+                finish()
+            }
+        })
     }
 
     override fun onStart() {

app/src/main/java/com/nextcloud/talk/ui/SwipeToCloseLayout.kt

@@ -0,0 +1,86 @@
+package com.nextcloud.talk.ui
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.MotionEvent
+import android.view.View
+import android.widget.FrameLayout
+import androidx.customview.widget.ViewDragHelper
+import kotlin.math.abs
+
+class SwipeToCloseLayout @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null,
+    defStyleAttr: Int = 0
+) : FrameLayout(context, attrs, defStyleAttr) {
+
+    private var dragHelper: ViewDragHelper
+    private var swipeListener: OnSwipeToCloseListener? = null
+
+    interface OnSwipeToCloseListener {
+        fun onSwipeToClose()
+    }
+
+    init {
+        dragHelper = ViewDragHelper.create(this, 1.0f, DragCallback())
+    }
+
+    fun setOnSwipeToCloseListener(listener: OnSwipeToCloseListener) {
+        this.swipeListener = listener
+    }
+
+    override fun onInterceptTouchEvent(ev: MotionEvent): Boolean {
+        val action = ev.actionMasked
+        if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
+            dragHelper.cancel()
+            return false
+        }
+        return dragHelper.shouldInterceptTouchEvent(ev)
+    }
+
+    override fun onTouchEvent(ev: MotionEvent): Boolean {
+        dragHelper.processTouchEvent(ev)
+        return true
+    }
+
+    private inner class DragCallback : ViewDragHelper.Callback() {
+        override fun tryCaptureView(child: View, pointerId: Int): Boolean {
+            return true // Capture any child view
+        }
+
+        override fun getViewVerticalDragRange(child: View): Int {
+            return height
+        }
+
+        override fun clampViewPositionVertical(child: View, therapeutic: Int, dy: Int): Int {
+            return therapeutic
+        }
+
+        override fun onViewReleased(releasedChild: View, xvel: Float, yvel: Float) {
+            val totalDragDistance = abs(releasedChild.top)
+            if (totalDragDistance > height * DRAG_THRESHOLD || abs(yvel) > dragHelper.minVelocity) {
+                swipeListener?.onSwipeToClose()
+            } else {
+                dragHelper.settleCapturedViewAt(0, 0)
+                invalidate()
+            }
+        }
+
+        override fun onViewPositionChanged(changedView: View, left: Int, top: Int, dx: Int, dy: Int) {
+            val progress = 1f - (abs(top).toFloat() / height)
+            alpha = progress.coerceIn(MIN_ALPHA, MAX_ALPHA)
+        }
+    }
+
+    override fun computeScroll() {
+        if (dragHelper.continueSettling(true)) {
+            postInvalidateOnAnimation()
+        }
+    }
+
+    companion object {
+        private const val DRAG_THRESHOLD = 0.3f
+        private const val MIN_ALPHA = 0.5f
+        private const val MAX_ALPHA = 1.0f
+    }
+}

app/src/main/res/layout/activity_full_screen_image.xml

@@ -7,10 +7,10 @@
   ~ SPDX-FileCopyrightText: 2021 Dariusz Olszewski <starypatyk@gmail.com>
   ~ SPDX-License-Identifier: GPL-3.0-or-later
 -->
-<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<com.nextcloud.talk.ui.SwipeToCloseLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    android:id="@+id/image_wrapper_view"
+    android:id="@+id/swipe_to_close_layout"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".fullscreenfile.FullScreenImageActivity">
@@ -35,4 +35,4 @@
         android:layout_height="match_parent"
         android:visibility="invisible" />
 
-</FrameLayout>
+</com.nextcloud.talk.ui.SwipeToCloseLayout>

app/src/main/res/layout/activity_full_screen_media.xml

@@ -6,9 +6,10 @@
   ~ SPDX-FileCopyrightText: 2021 Marcel Hibbe <dev@mhibbe.de>
   ~ SPDX-License-Identifier: GPL-3.0-or-later
 -->
-<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<com.nextcloud.talk.ui.SwipeToCloseLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/swipe_to_close_layout"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".fullscreenfile.FullScreenMediaActivity">
@@ -28,4 +29,4 @@
         app:show_buffering="when_playing"
         app:show_shuffle_button="true" />
 
-</FrameLayout>
+</com.nextcloud.talk.ui.SwipeToCloseLayout>