feat: Auto-hide Image Viewer toolbar (#507)

Previous code showed the toolbar and caption when displaying the image,
and the user has to tap the screen to dismiss it.

New code is consistent with the video viewer; the toolbar and caption
is displayed for two seconds, and then auto-hides.

- Tapping after the hide displays the toolbar and caption, which will
  not auto-hide and requires a second tap to dismiss.

- Tapping the caption before it's hidden cancels the auto-hide

Fixes #505

app/src/main/java/app/pachli/fragment/ViewImageFragment.kt

@@ -28,10 +28,10 @@ import android.view.MotionEvent
 import android.view.View
 import android.view.ViewGroup
 import android.widget.ImageView
+import androidx.coordinatorlayout.widget.CoordinatorLayout
 import androidx.core.view.GestureDetectorCompat
 import androidx.lifecycle.lifecycleScope
 import app.pachli.R
-import app.pachli.ViewMediaActivity
 import app.pachli.core.common.extensions.hide
 import app.pachli.core.common.extensions.viewBinding
 import app.pachli.core.common.extensions.visible
@@ -41,6 +41,8 @@ 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.google.android.material.bottomsheet.BottomSheetBehavior
+import com.google.android.material.bottomsheet.BottomSheetBehavior.BottomSheetCallback
 import com.ortiz.touchview.OnTouchCoordinatesListener
 import com.ortiz.touchview.TouchImageView
 import kotlin.math.abs
@@ -50,24 +52,29 @@ class ViewImageFragment : ViewMediaFragment() {
 
     private val binding by viewBinding(FragmentViewImageBinding::bind)
 
-    private lateinit var toolbar: View
-
     // Volatile: Image requests happen on background thread and we want to see updates to it
     // immediately on another thread. Atomic is an overkill for such thing.
     @Volatile
     private var startedTransition = false
 
-    override fun setupMediaView(showingDescription: Boolean) {
+    private var scheduleToolbarHide = false
+
+    override fun setupMediaView(
+        isToolbarVisible: Boolean,
+        showingDescription: Boolean,
+    ) {
         binding.photoView.transitionName = attachment.url
         binding.mediaDescription.text = attachment.description
         binding.captionSheet.visible(showingDescription)
 
         startedTransition = false
         loadImageFromNetwork(attachment.url, attachment.previewUrl, binding.photoView)
+
+        // Only schedule hiding the toolbar once
+        scheduleToolbarHide = isToolbarVisible
     }
 
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
-        toolbar = (requireActivity() as ViewMediaActivity).toolbar
         return inflater.inflate(R.layout.fragment_view_image, container, false)
     }
 
@@ -183,9 +190,19 @@ class ViewImageFragment : ViewMediaFragment() {
                 }
             },
         )
+
+        val captionSheetParams = (binding.captionSheet.layoutParams as CoordinatorLayout.LayoutParams)
+        (captionSheetParams.behavior as BottomSheetBehavior).addBottomSheetCallback(
+            object : BottomSheetCallback() {
+                override fun onStateChanged(bottomSheet: View, newState: Int) = cancelToolbarHide()
+                override fun onSlide(bottomSheet: View, slideOffset: Float) = cancelToolbarHide()
+            },
+        )
     }
 
     override fun onToolbarVisibilityChange(visible: Boolean) {
+        super.onToolbarVisibilityChange(visible)
+
         if (!userVisibleHint) return
 
         isDescriptionVisible = showingDescription && visible
@@ -203,6 +220,15 @@ class ViewImageFragment : ViewMediaFragment() {
             .start()
     }
 
+    override fun shouldScheduleToolbarHide(): Boolean {
+        return if (scheduleToolbarHide) {
+            scheduleToolbarHide = false
+            true
+        } else {
+            false
+        }
+    }
+
     override fun onStop() {
         super.onStop()
         Glide.with(this).clear(binding.photoView)

app/src/main/java/app/pachli/fragment/ViewMediaFragment.kt

@@ -17,15 +17,22 @@
 package app.pachli.fragment
 
 import android.content.Context
+import android.os.Build
 import android.os.Bundle
 import android.text.TextUtils
 import android.view.View
+import androidx.annotation.CallSuper
 import androidx.annotation.OptIn
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.lifecycleScope
 import androidx.media3.common.util.UnstableApi
 import app.pachli.ViewMediaActivity
 import app.pachli.core.network.model.Attachment
+import kotlin.time.Duration.Companion.seconds
 import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
 
 /** Interface for actions that may happen while media is being displayed */
 interface MediaActionsListener {
@@ -51,16 +58,56 @@ abstract class ViewMediaFragment : Fragment() {
      * Called after [onResume], subclasses should override this and update
      * the contents of views (including loading any media).
      *
+     * @param isToolbarVisible True if the toolbar is visible
      * @param showingDescription True if the media's description should be shown
      */
-    abstract fun setupMediaView(showingDescription: Boolean)
+    abstract fun setupMediaView(
+        isToolbarVisible: Boolean,
+        showingDescription: Boolean,
+    )
 
     /**
      * Called when the visibility of the toolbar changes.
      *
      * @param visible True if the toolbar is visible
      */
-    abstract fun onToolbarVisibilityChange(visible: Boolean)
+    @CallSuper
+    protected open fun onToolbarVisibilityChange(visible: Boolean) {
+        if (visible && shouldScheduleToolbarHide()) {
+            hideToolbarAfterDelay()
+        } else {
+            hideToolbarJob?.cancel()
+        }
+    }
+
+    /**
+     * Called when the toolbar becomes visible, returns whether or not to schedule hiding the toolbar
+     */
+    protected abstract fun shouldScheduleToolbarHide(): Boolean
+
+    /** Hoist toolbar hiding to activity so it can track state across different fragments */
+    private var hideToolbarJob: Job? = null
+
+    /**
+     * Schedule hiding the toolbar after a delay
+     */
+    protected fun hideToolbarAfterDelay() {
+        hideToolbarJob?.cancel()
+        hideToolbarJob = lifecycleScope.launch {
+            delay(CONTROLS_TIMEOUT)
+            mediaActionsListener.onMediaTap()
+        }
+    }
+
+    /**
+     * Cancel previously scheduled hiding of the toolbar
+     */
+    protected fun cancelToolbarHide() {
+        hideToolbarJob?.cancel()
+    }
+
+    protected lateinit var mediaActivity: ViewMediaActivity
+        private set
 
     protected var showingDescription = false
     protected var isDescriptionVisible = false
@@ -82,6 +129,7 @@ abstract class ViewMediaFragment : Fragment() {
 
     override fun onAttach(context: Context) {
         super.onAttach(context)
+        mediaActivity = activity as ViewMediaActivity
         mediaActionsListener = context as MediaActionsListener
     }
 
@@ -109,18 +157,36 @@ abstract class ViewMediaFragment : Fragment() {
     }
 
     private fun finalizeViewSetup() {
-        val mediaActivity = activity as ViewMediaActivity
-
         showingDescription = !TextUtils.isEmpty(attachment.description)
         isDescriptionVisible = showingDescription
-        setupMediaView(showingDescription && mediaActivity.isToolbarVisible)
+        setupMediaView(mediaActivity.isToolbarVisible, showingDescription && mediaActivity.isToolbarVisible)
 
-        removeToolbarListener = (activity as ViewMediaActivity)
+        removeToolbarListener = mediaActivity
             .addToolbarVisibilityListener { isVisible ->
                 onToolbarVisibilityChange(isVisible)
             }
     }
 
+    override fun onPause() {
+        super.onPause()
+
+        // If <= API 23 then multi-window mode is not available, so this is a good time to
+        // pause everything
+        if (Build.VERSION.SDK_INT <= 23) {
+            hideToolbarJob?.cancel()
+        }
+    }
+
+    override fun onStop() {
+        super.onStop()
+
+        // If > API 23 then this might be multi-window, and definitely wasn't paused in onPause,
+        // so pause everything now.
+        if (Build.VERSION.SDK_INT > 23) {
+            hideToolbarJob?.cancel()
+        }
+    }
+
     override fun onDestroyView() {
         removeToolbarListener?.invoke()
         transitionComplete = null
@@ -132,6 +198,9 @@ abstract class ViewMediaFragment : Fragment() {
 
         protected const val ARG_ATTACHMENT = "attach"
 
+        @JvmStatic
+        protected val CONTROLS_TIMEOUT = 2.seconds // Consistent with YouTube player
+
         /**
          * @param attachment The media attachment to display in the fragment
          * @param shouldCallMediaReady If true this fragment should call

app/src/main/java/app/pachli/fragment/ViewVideoFragment.kt

@@ -47,14 +47,12 @@ import androidx.media3.exoplayer.util.EventLogger
 import androidx.media3.ui.AspectRatioFrameLayout
 import app.pachli.BuildConfig
 import app.pachli.R
-import app.pachli.ViewMediaActivity
 import app.pachli.core.common.extensions.hide
 import app.pachli.core.common.extensions.show
 import app.pachli.core.common.extensions.viewBinding
 import app.pachli.core.common.extensions.visible
 import app.pachli.core.network.model.Attachment
 import app.pachli.databinding.FragmentViewVideoBinding
-import app.pachli.fragment.ViewVideoFragment.Companion.CONTROLS_TIMEOUT
 import com.bumptech.glide.Glide
 import com.bumptech.glide.request.target.CustomTarget
 import com.bumptech.glide.request.transition.Transition
@@ -62,9 +60,6 @@ import com.google.android.material.snackbar.Snackbar
 import dagger.hilt.android.AndroidEntryPoint
 import javax.inject.Inject
 import kotlin.math.abs
-import kotlin.time.Duration.Companion.seconds
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import okhttp3.OkHttpClient
 
@@ -89,10 +84,6 @@ class ViewVideoFragment : ViewMediaFragment() {
 
     private lateinit var toolbar: View
 
-    /** Hoist toolbar hiding to activity so it can track state across different fragments */
-    private var hideToolbarJob: Job? = null
-
-    private lateinit var mediaActivity: ViewMediaActivity
     private lateinit var mediaPlayerListener: Player.Listener
     private var isAudio = false
 
@@ -116,7 +107,6 @@ class ViewVideoFragment : ViewMediaFragment() {
 
     @SuppressLint("PrivateResource", "MissingInflatedId")
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
-        mediaActivity = activity as ViewMediaActivity
         toolbar = mediaActivity.toolbar
         val rootView = inflater.inflate(R.layout.fragment_view_video, container, false)
 
@@ -243,7 +233,7 @@ class ViewVideoFragment : ViewMediaFragment() {
                 if (isPlaying) {
                     hideToolbarAfterDelay()
                 } else {
-                    hideToolbarJob?.cancel()
+                    cancelToolbarHide()
                 }
             }
 
@@ -301,7 +291,6 @@ class ViewVideoFragment : ViewMediaFragment() {
         if (Build.VERSION.SDK_INT <= 23) {
             binding.videoView.onPause()
             releasePlayer()
-            hideToolbarJob?.cancel()
         }
     }
 
@@ -313,7 +302,6 @@ class ViewVideoFragment : ViewMediaFragment() {
         if (Build.VERSION.SDK_INT > 23) {
             binding.videoView.onPause()
             releasePlayer()
-            hideToolbarJob?.cancel()
         }
     }
 
@@ -365,7 +353,10 @@ class ViewVideoFragment : ViewMediaFragment() {
     }
 
     @SuppressLint("ClickableViewAccessibility")
-    override fun setupMediaView(showingDescription: Boolean) {
+    override fun setupMediaView(
+        isToolbarVisible: Boolean,
+        showingDescription: Boolean,
+    ) {
         startedTransition = false
 
         binding.mediaDescription.text = attachment.description
@@ -389,15 +380,9 @@ class ViewVideoFragment : ViewMediaFragment() {
         binding.videoView.requestFocus()
     }
 
-    private fun hideToolbarAfterDelay() {
-        hideToolbarJob?.cancel()
-        hideToolbarJob = lifecycleScope.launch {
-            delay(CONTROLS_TIMEOUT)
-            mediaActivity.onMediaTap()
-        }
-    }
-
     override fun onToolbarVisibilityChange(visible: Boolean) {
+        super.onToolbarVisibilityChange(visible)
+
         if (!userVisibleHint) return
         view ?: return
 
@@ -420,16 +405,13 @@ class ViewVideoFragment : ViewMediaFragment() {
                 },
             )
             .start()
-
-        if (visible && (binding.videoView.player?.isPlaying == true) && !isAudio) {
-            hideToolbarAfterDelay()
-        } else {
-            hideToolbarJob?.cancel()
     }
+
+    override fun shouldScheduleToolbarHide(): Boolean {
+        return (binding.videoView.player?.isPlaying == true) && !isAudio
     }
 
     companion object {
-        private val CONTROLS_TIMEOUT = 2.seconds // Consistent with YouTube player
         private const val SEEK_POSITION = "seekPosition"
     }
 }