Roll back image viewer but retain swiping fix (#1863)

This fixes crashes with images which were too wide (aspect ratio wise).

app/build.gradle

@@ -159,7 +159,7 @@ dependencies {
 
     implementation "com.github.connyduck:sparkbutton:4.0.0"
 
-    implementation 'com.github.MikeOrtiz:TouchImageView:3.0.1'
+    implementation "com.github.chrisbanes:PhotoView:2.3.0"
 
     implementation "com.mikepenz:materialdrawer:$materialdrawerVersion"
     implementation "com.mikepenz:materialdrawer-iconics:$materialdrawerVersion"

app/src/main/java/com/keylesspalace/tusky/components/compose/dialog/CaptionDialog.kt

@@ -33,9 +33,9 @@ import at.connyduck.sparkbutton.helpers.Utils
 import com.bumptech.glide.Glide
 import com.bumptech.glide.request.target.CustomTarget
 import com.bumptech.glide.request.transition.Transition
+import com.github.chrisbanes.photoview.PhotoView
 import com.keylesspalace.tusky.R
 import com.keylesspalace.tusky.util.withLifecycleContext
-import com.ortiz.touchview.TouchImageView
 
 // https://github.com/tootsuite/mastodon/blob/1656663/app/models/media_attachment.rb#L94
 private const val MEDIA_DESCRIPTION_CHARACTER_LIMIT = 420
@@ -50,8 +50,8 @@ fun <T> T.makeCaptionDialog(existingDescription: String?,
     dialogLayout.setPadding(padding, padding, padding, padding)
 
     dialogLayout.orientation = LinearLayout.VERTICAL
-    val imageView = TouchImageView(this).apply {
-        maxZoom = 6f
+    val imageView = PhotoView(this).apply {
+        maximumScale = 6f
     }
 
     val displayMetrics = DisplayMetrics()

app/src/main/java/com/keylesspalace/tusky/fragment/ViewImageFragment.kt

@@ -29,6 +29,7 @@ import com.bumptech.glide.load.DataSource
 import com.bumptech.glide.load.engine.GlideException
 import com.bumptech.glide.request.RequestListener
 import com.bumptech.glide.request.target.Target
+import com.github.chrisbanes.photoview.PhotoViewAttacher
 import com.keylesspalace.tusky.R
 import com.keylesspalace.tusky.entity.Attachment
 import com.keylesspalace.tusky.util.hide
@@ -45,6 +46,7 @@ class ViewImageFragment : ViewMediaFragment() {
         fun onPhotoTap()
     }
 
+    private lateinit var attacher: PhotoViewAttacher
     private lateinit var photoActionsListener: PhotoActionsListener
     private lateinit var toolbar: View
     private var transition = BehaviorSubject.create<Unit>()
@@ -61,9 +63,68 @@ class ViewImageFragment : ViewMediaFragment() {
         photoActionsListener = context as PhotoActionsListener
     }
 
+    @SuppressLint("ClickableViewAccessibility")
     override fun setupMediaView(url: String, previewUrl: String?) {
         descriptionView = mediaDescription
         photoView.transitionName = url
+        attacher = PhotoViewAttacher(photoView).apply {
+            // This prevents conflicts with ViewPager
+            setAllowParentInterceptOnEdge(true)
+
+            // Clicking outside the photo closes the viewer.
+            setOnOutsidePhotoTapListener { photoActionsListener.onDismiss() }
+            setOnClickListener { onMediaTap() }
+
+            /* A vertical swipe motion also closes the viewer. This is especially useful when the photo
+             * mostly fills the screen so clicking outside is difficult. */
+            setOnSingleFlingListener { _, _, velocityX, velocityY ->
+                var result = false
+                if (abs(velocityY) > abs(velocityX)) {
+                    photoActionsListener.onDismiss()
+                    result = true
+                }
+                result
+            }
+        }
+
+        val gestureDetector = GestureDetector(requireContext(), object : GestureDetector.SimpleOnGestureListener() {
+            override fun onSingleTapConfirmed(e: MotionEvent?): Boolean {
+                onMediaTap()
+                return true
+            }
+        })
+
+        var lastY = 0f
+
+        photoView.setOnTouchListener { v, event ->
+            // This part is for scaling/translating on vertical move.
+            // We use raw coordinates to get the correct ones during scaling
+
+            gestureDetector.onTouchEvent(event)
+
+            if (event.action == MotionEvent.ACTION_DOWN) {
+                lastY = event.rawY
+            } else if (event.pointerCount == 1
+                    && attacher.scale == 1f
+                    && event.action == MotionEvent.ACTION_MOVE
+            ) {
+                val diff = event.rawY - lastY
+                // This code is to prevent transformations during page scrolling
+                // If we are already translating or we reached the threshold, then transform.
+                if (photoView.translationY != 0f || abs(diff) > 40) {
+                    photoView.translationY += (diff)
+                    val scale = (-abs(photoView.translationY) / 720 + 1).coerceAtLeast(0.5f)
+                    photoView.scaleY = scale
+                    photoView.scaleX = scale
+                    lastY = event.rawY
+                    return@setOnTouchListener true
+                }
+            } else if (event.action == MotionEvent.ACTION_UP || event.action == MotionEvent.ACTION_CANCEL) {
+                onGestureEnd()
+            }
+            attacher.onTouch(v, event)
+        }
+
         startedTransition = false
         loadImageFromNetwork(url, previewUrl, photoView)
     }
@@ -74,64 +135,9 @@ class ViewImageFragment : ViewMediaFragment() {
         return inflater.inflate(R.layout.fragment_view_image, container, false)
     }
 
-    @SuppressLint("ClickableViewAccessibility")
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
-        val gestureDetector = GestureDetector(requireContext(), object : GestureDetector.SimpleOnGestureListener() {
-            override fun onSingleTapConfirmed(e: MotionEvent?): Boolean {
-                onMediaTap()
-                return true
-            }
-        })
-
-        var lastY = 0f
-        photoView.setOnTouchListener { _, event ->
-            // This part is for scaling/translating on vertical move.
-            // We use raw coordinates to get the correct ones during scaling
-            var result = true
-
-            gestureDetector.onTouchEvent(event)
-
-            if (event.action == MotionEvent.ACTION_DOWN) {
-                lastY = event.rawY
-            } else if (!photoView.isZoomed && event.action == MotionEvent.ACTION_MOVE) {
-                val diff = event.rawY - lastY
-                // This code is to prevent transformations during page scrolling
-                // If we are already translating or we reached the threshold, then transform.
-                if (photoView.translationY != 0f || abs(diff) > 40) {
-                    photoView.translationY += (diff)
-                    val scale = (-abs(photoView.translationY) / 720 + 1).coerceAtLeast(0.5f)
-                    photoView.scaleY = scale
-                    photoView.scaleX = scale
-                    lastY = event.rawY
-                }
-                return@setOnTouchListener true
-            } else if (event.action == MotionEvent.ACTION_UP || event.action == MotionEvent.ACTION_CANCEL) {
-                onGestureEnd()
-            } else if (event.pointerCount >= 2 || photoView.canScrollHorizontally(1) && photoView.canScrollHorizontally(-1)) {
-                // Starting from here is adapted code from TouchImageView to play nice with pager.
-
-                // Can scroll horizontally checks if there's still a part of the image.
-                // That can be scrolled until you reach the edge multi-touch event.
-                val parent = view.parent
-                result = when (event.action) {
-                    MotionEvent.ACTION_DOWN, MotionEvent.ACTION_MOVE -> {
-                        // Disallow RecyclerView to intercept touch events.
-                        parent.requestDisallowInterceptTouchEvent(true)
-                        // Disable touch on view
-                        false
-                    }
-                    MotionEvent.ACTION_UP -> {
-                        // Allow RecyclerView to intercept touch events.
-                        parent.requestDisallowInterceptTouchEvent(false)
-                        true
-                    }
-                    else -> true
-                }
-            }
-            result
-        }
 
         val arguments = this.requireArguments()
         val attachment = arguments.getParcelable<Attachment>(ARG_ATTACHMENT)
@@ -267,7 +273,13 @@ class ViewImageFragment : ViewMediaFragment() {
                 // another branch. take() will unsubscribe after we have it to not leak menmory
                 transition
                         .take(1)
-                        .subscribe { target.onResourceReady(resource, null) }
+                        .subscribe {
+                            target.onResourceReady(resource, null)
+                            // It's needed. Don't ask why, I don't know, setImageDrawable() should
+                            // do it by itself but somehow it doesn't work automatically.
+                            // Just do it. If you don't, image will jump around when touched.
+                            attacher.update()
+                        }
             }
             return true
         }

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

@@ -7,7 +7,7 @@
     android:clickable="true"
     android:focusable="true">
 
-    <com.ortiz.touchview.TouchImageView
+    <com.github.chrisbanes.photoview.PhotoView
         android:id="@+id/photoView"
         android:layout_width="match_parent"
         android:layout_height="match_parent" />