Photo viewer & video player UI

mastodon/src/main/java/org/joinmastodon/android/ui/photoviewer/PhotoViewer.java

@@ -1,16 +1,34 @@
 package org.joinmastodon.android.ui.photoviewer;
 
+import android.Manifest;
+import android.annotation.SuppressLint;
 import android.app.Activity;
+import android.app.DownloadManager;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.content.res.ColorStateList;
+import android.graphics.Insets;
 import android.graphics.PixelFormat;
 import android.graphics.Rect;
 import android.graphics.SurfaceTexture;
 import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Drawable;
+import android.media.AudioManager;
 import android.media.MediaPlayer;
+import android.media.MediaScannerConnection;
 import android.net.Uri;
+import android.os.Build;
+import android.os.Environment;
+import android.os.SystemClock;
+import android.provider.MediaStore;
+import android.provider.Settings;
 import android.util.Log;
+import android.view.DisplayCutout;
 import android.view.Gravity;
 import android.view.KeyEvent;
+import android.view.MenuItem;
 import android.view.Surface;
 import android.view.TextureView;
 import android.view.View;
@@ -19,27 +37,47 @@ import android.view.ViewTreeObserver;
 import android.view.WindowInsets;
 import android.view.WindowManager;
 import android.widget.FrameLayout;
+import android.widget.ImageButton;
 import android.widget.ImageView;
+import android.widget.ProgressBar;
+import android.widget.SeekBar;
+import android.widget.TextView;
+import android.widget.Toast;
+import android.widget.Toolbar;
 
 import org.joinmastodon.android.R;
+import org.joinmastodon.android.api.MastodonAPIController;
 import org.joinmastodon.android.model.Attachment;
+import org.joinmastodon.android.ui.M3AlertDialogBuilder;
 
+import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.stream.Collectors;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.recyclerview.widget.RecyclerView;
 import androidx.viewpager2.widget.ViewPager2;
+import me.grishka.appkit.imageloader.ImageCache;
 import me.grishka.appkit.imageloader.ViewImageLoader;
 import me.grishka.appkit.imageloader.requests.UrlImageLoaderRequest;
 import me.grishka.appkit.utils.BindableViewHolder;
 import me.grishka.appkit.utils.CubicBezierInterpolator;
+import me.grishka.appkit.utils.V;
+import me.grishka.appkit.views.FragmentRootLinearLayout;
+import okio.BufferedSink;
+import okio.Okio;
+import okio.Sink;
+import okio.Source;
 
 public class PhotoViewer implements ZoomPanView.Listener{
 	private static final String TAG="PhotoViewer";
+	public static final int PERMISSION_REQUEST=926;
 
 	private Activity activity;
 	private List<Attachment> attachments;
@@ -48,10 +86,28 @@ public class PhotoViewer implements ZoomPanView.Listener{
 	private Listener listener;
 
 	private FrameLayout windowView;
+	private FragmentRootLinearLayout uiOverlay;
 	private ViewPager2 pager;
 	private ColorDrawable background=new ColorDrawable(0xff000000);
 	private ArrayList<MediaPlayer> players=new ArrayList<>();
 	private int screenOnRefCount=0;
+	private Toolbar toolbar;
+	private View toolbarWrap;
+	private SeekBar videoSeekBar;
+	private TextView videoTimeView;
+	private ImageButton videoPlayPauseButton;
+	private View videoControls;
+	private boolean uiVisible=true;
+	private AudioManager.OnAudioFocusChangeListener audioFocusListener=this::onAudioFocusChanged;
+	private Runnable uiAutoHider=()->{
+		if(uiVisible)
+			toggleUI();
+	};
+
+	private boolean videoPositionNeedsUpdating;
+	private Runnable videoPositionUpdater=this::updateVideoPosition;
+	private int videoDuration, videoInitialPosition, videoLastTimeUpdatePosition;
+	private long videoInitialPositionTime;
 
 	public PhotoViewer(Activity activity, List<Attachment> attachments, int index, Listener listener){
 		this.activity=activity;
@@ -75,7 +131,26 @@ public class PhotoViewer implements ZoomPanView.Listener{
 
 			@Override
 			public WindowInsets dispatchApplyWindowInsets(WindowInsets insets){
-				Log.w(TAG, "dispatchApplyWindowInsets() called with: insets = ["+insets+"]");
+				if(Build.VERSION.SDK_INT>=29){
+					DisplayCutout cutout=insets.getDisplayCutout();
+					if(cutout!=null){
+						// Make controls extend beneath the cutout, and replace insets to avoid cutout insets being filled with "navigation bar color"
+						Insets tappable=insets.getTappableElementInsets();
+						int leftInset=Math.max(0, cutout.getSafeInsetLeft()-tappable.left);
+						int rightInset=Math.max(0, cutout.getSafeInsetRight()-tappable.right);
+						insets=insets.replaceSystemWindowInsets(tappable.left, tappable.top, tappable.right, tappable.bottom);
+						toolbarWrap.setPadding(leftInset, 0, rightInset, 0);
+						videoControls.setPadding(leftInset, 0, rightInset, 0);
+					}else{
+						toolbarWrap.setPadding(0, 0, 0, 0);
+						videoControls.setPadding(0, 0, 0, 0);
+					}
+				}
+				uiOverlay.dispatchApplyWindowInsets(insets);
+				int bottomInset=insets.getSystemWindowInsetBottom();
+				if(bottomInset>0 && bottomInset<V.dp(36)){
+					uiOverlay.setPadding(uiOverlay.getPaddingLeft(), uiOverlay.getPaddingTop(), uiOverlay.getPaddingRight(), V.dp(36));
+				}
 				return insets.consumeSystemWindowInsets();
 			}
 		};
@@ -84,15 +159,47 @@ public class PhotoViewer implements ZoomPanView.Listener{
 		pager=new ViewPager2(activity);
 		pager.setAdapter(new PhotoViewAdapter());
 		pager.setCurrentItem(index, false);
+		pager.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback(){
+			@Override
+			public void onPageSelected(int position){
+				onPageChanged(position);
+			}
+		});
 		windowView.addView(pager);
 		pager.setMotionEventSplittingEnabled(false);
 
+		uiOverlay=activity.getLayoutInflater().inflate(R.layout.photo_viewer_ui, windowView).findViewById(R.id.photo_viewer_overlay);
+		uiOverlay.setStatusBarColor(0x80000000);
+		uiOverlay.setNavigationBarColor(0x80000000);
+		toolbarWrap=uiOverlay.findViewById(R.id.toolbar_wrap);
+		toolbar=uiOverlay.findViewById(R.id.toolbar);
+		toolbar.setNavigationOnClickListener(v->onStartSwipeToDismissTransition(0));
+		toolbar.getMenu().add(R.string.download).setIcon(R.drawable.ic_fluent_arrow_download_24_regular).setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
+		toolbar.setOnMenuItemClickListener(item->{
+			saveCurrentFile();
+			return true;
+		});
+		uiOverlay.setAlpha(0f);
+		videoControls=uiOverlay.findViewById(R.id.video_player_controls);
+		videoSeekBar=uiOverlay.findViewById(R.id.seekbar);
+		videoTimeView=uiOverlay.findViewById(R.id.time);
+		videoPlayPauseButton=uiOverlay.findViewById(R.id.play_pause_btn);
+		if(attachments.get(index).type!=Attachment.Type.VIDEO){
+			videoControls.setVisibility(View.GONE);
+		}else{
+			videoDuration=(int)Math.round(attachments.get(index).getDuration()*1000);
+			videoLastTimeUpdatePosition=-1;
+			updateVideoTimeText(0);
+		}
+
 		WindowManager.LayoutParams wlp=new WindowManager.LayoutParams(WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.MATCH_PARENT);
 		wlp.type=WindowManager.LayoutParams.TYPE_APPLICATION;
 		wlp.flags=WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR
 				| WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS;
 		wlp.format=PixelFormat.TRANSLUCENT;
 		wlp.setTitle(activity.getString(R.string.media_viewer));
+		if(Build.VERSION.SDK_INT>=28)
+			wlp.layoutInDisplayCutoutMode=Build.VERSION.SDK_INT>=30 ? WindowManager.LayoutParams.LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS : WindowManager.LayoutParams.LAYOUT_IN_DISPLAY_CUTOUT_MODE_SHORT_EDGES;
 		windowView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
 		wm.addView(windowView, wlp);
 
@@ -112,6 +219,44 @@ public class PhotoViewer implements ZoomPanView.Listener{
 				return true;
 			}
 		});
+
+		videoPlayPauseButton.setOnClickListener(v->{
+			MediaPlayer player=findCurrentVideoPlayer();
+			if(player!=null){
+				if(player.isPlaying())
+					pauseVideo();
+				else
+					resumeVideo();
+				hideUiDelayed();
+			}
+		});
+		videoSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener(){
+			@Override
+			public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser){
+				if(fromUser){
+					float p=progress/10000f;
+					updateVideoTimeText(Math.round(p*videoDuration));
+				}
+			}
+
+			@Override
+			public void onStartTrackingTouch(SeekBar seekBar){
+				stopUpdatingVideoPosition();
+				if(!uiVisible) // If dragging started during hide animation
+					toggleUI();
+				windowView.removeCallbacks(uiAutoHider);
+			}
+
+			@Override
+			public void onStopTrackingTouch(SeekBar seekBar){
+				MediaPlayer player=findCurrentVideoPlayer();
+				if(player!=null){
+					float progress=seekBar.getProgress()/10000f;
+					player.seekTo(Math.round(progress*player.getDuration()));
+				}
+				hideUiDelayed();
+			}
+		});
 	}
 
 	@Override
@@ -127,15 +272,22 @@ public class PhotoViewer implements ZoomPanView.Listener{
 	@Override
 	public void onSetBackgroundAlpha(float alpha){
 		background.setAlpha(Math.round(alpha*255f));
+		uiOverlay.setAlpha(Math.max(0f, alpha*2f-1f));
 	}
 
 	@Override
 	public void onStartSwipeToDismiss(){
 		listener.setPhotoViewVisibility(pager.getCurrentItem(), false);
+		if(!uiVisible){
+			windowView.setSystemUiVisibility(windowView.getSystemUiVisibility() & ~(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY | View.SYSTEM_UI_FLAG_FULLSCREEN));
+		}else{
+			windowView.removeCallbacks(uiAutoHider);
+		}
 	}
 
 	@Override
 	public void onStartSwipeToDismissTransition(float velocityY){
+		pauseVideo();
 		// stop receiving input events to allow the user to interact with the underlying UI while the animation is still running
 		WindowManager.LayoutParams wlp=(WindowManager.LayoutParams) windowView.getLayoutParams();
 		wlp.flags|=WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
@@ -163,17 +315,74 @@ public class PhotoViewer implements ZoomPanView.Listener{
 	@Override
 	public void onSwipeToDismissCanceled(){
 		listener.setPhotoViewVisibility(pager.getCurrentItem(), true);
+		if(!uiVisible){
+			windowView.setSystemUiVisibility(windowView.getSystemUiVisibility() | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY | View.SYSTEM_UI_FLAG_FULLSCREEN);
+		}else if(attachments.get(currentIndex).type==Attachment.Type.VIDEO){
+			hideUiDelayed();
+		}
 	}
 
 	@Override
 	public void onDismissed(){
 		for(MediaPlayer player:players)
 			player.release();
+		if(!players.isEmpty()){
+			activity.getSystemService(AudioManager.class).abandonAudioFocus(audioFocusListener);
+		}
 		listener.setPhotoViewVisibility(pager.getCurrentItem(), true);
 		wm.removeView(windowView);
 		listener.photoViewerDismissed();
 	}
 
+	@Override
+	public void onSingleTap(){
+		toggleUI();
+	}
+
+	private void toggleUI(){
+		if(uiVisible){
+			uiOverlay.animate()
+					.alpha(0f)
+					.setDuration(250)
+					.setInterpolator(CubicBezierInterpolator.DEFAULT)
+					.withEndAction(()->uiOverlay.setVisibility(View.GONE))
+					.start();
+			windowView.setSystemUiVisibility(windowView.getSystemUiVisibility() | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY | View.SYSTEM_UI_FLAG_FULLSCREEN);
+		}else{
+			uiOverlay.setVisibility(View.VISIBLE);
+			uiOverlay.animate()
+					.alpha(1f)
+					.setDuration(300)
+					.setInterpolator(CubicBezierInterpolator.DEFAULT)
+					.start();
+			windowView.setSystemUiVisibility(windowView.getSystemUiVisibility() & ~(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY | View.SYSTEM_UI_FLAG_FULLSCREEN));
+			if(attachments.get(currentIndex).type==Attachment.Type.VIDEO)
+				hideUiDelayed(5000);
+		}
+		uiVisible=!uiVisible;
+	}
+
+	private void hideUiDelayed(){
+		hideUiDelayed(2000);
+	}
+
+	private void hideUiDelayed(long delay){
+		windowView.removeCallbacks(uiAutoHider);
+		windowView.postDelayed(uiAutoHider, delay);
+	}
+
+	private void onPageChanged(int index){
+		currentIndex=index;
+		Attachment att=attachments.get(index);
+		V.setVisibilityAnimated(videoControls, att.type==Attachment.Type.VIDEO ? View.VISIBLE : View.GONE);
+		if(att.type==Attachment.Type.VIDEO){
+			videoSeekBar.setSecondaryProgress(0);
+			videoDuration=(int)Math.round(att.getDuration()*1000);
+			videoLastTimeUpdatePosition=-1;
+			updateVideoTimeText(0);
+		}
+	}
+
 	/**
 	 * To be called when the list containing photo views is scrolled
 	 * @param x
@@ -189,6 +398,7 @@ public class PhotoViewer implements ZoomPanView.Listener{
 			WindowManager.LayoutParams wlp=(WindowManager.LayoutParams) windowView.getLayoutParams();
 			wlp.flags|=WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON;
 			wm.updateViewLayout(windowView, wlp);
+			activity.getSystemService(AudioManager.class).requestAudioFocus(audioFocusListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
 		}
 		screenOnRefCount++;
 	}
@@ -201,6 +411,185 @@ public class PhotoViewer implements ZoomPanView.Listener{
 			WindowManager.LayoutParams wlp=(WindowManager.LayoutParams) windowView.getLayoutParams();
 			wlp.flags&=~WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON;
 			wm.updateViewLayout(windowView, wlp);
+			activity.getSystemService(AudioManager.class).abandonAudioFocus(audioFocusListener);
+		}
+	}
+
+	public void onPause(){
+		pauseVideo();
+	}
+
+	private void saveCurrentFile(){
+		if(Build.VERSION.SDK_INT>=29){
+			doSaveCurrentFile();
+		}else{
+			if(activity.checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)!=PackageManager.PERMISSION_GRANTED){
+				listener.onRequestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE});
+			}else{
+				doSaveCurrentFile();
+			}
+		}
+	}
+
+	public void onRequestPermissionsResult(String[] permissions, int[] results){
+		if(results[0]==PackageManager.PERMISSION_GRANTED){
+			doSaveCurrentFile();
+		}else if(!activity.shouldShowRequestPermissionRationale(Manifest.permission.WRITE_EXTERNAL_STORAGE)){
+			new M3AlertDialogBuilder(activity)
+					.setTitle(R.string.permission_required)
+					.setMessage(R.string.storage_permission_to_download)
+					.setPositiveButton(R.string.open_settings, (dialog, which)->activity.startActivity(new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS, Uri.fromParts("package", activity.getPackageName(), null))))
+					.setNegativeButton(R.string.cancel, null)
+					.show();
+		}
+	}
+
+	private String mimeTypeForFileName(String fileName){
+		int extOffset=fileName.lastIndexOf('.');
+		if(extOffset>0){
+			return switch(fileName.substring(extOffset+1).toLowerCase()){
+				case "jpg", "jpeg" -> "image/jpeg";
+				case "png" -> "image/png";
+				case "gif" -> "image/gif";
+				case "webp" -> "image/webp";
+				case "mp4" -> "video/mp4";
+				case "webm" -> "video/webm";
+				default -> null;
+			};
+		}
+		return null;
+	}
+
+	private OutputStream destinationStreamForFile(Attachment att) throws IOException{
+		String fileName=Uri.parse(att.url).getLastPathSegment();
+		if(Build.VERSION.SDK_INT>=29){
+			ContentValues values=new ContentValues();
+//			values.put(MediaStore.Downloads.DOWNLOAD_URI, att.url);
+			values.put(MediaStore.MediaColumns.DISPLAY_NAME, fileName);
+			values.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DOWNLOADS);
+			String mime=mimeTypeForFileName(fileName);
+			if(mime!=null)
+				values.put(MediaStore.MediaColumns.MIME_TYPE, mime);
+			ContentResolver cr=activity.getContentResolver();
+			Uri itemUri=cr.insert(MediaStore.Files.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY), values);
+			return cr.openOutputStream(itemUri);
+		}else{
+			return new FileOutputStream(new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), fileName));
+		}
+	}
+
+	private void doSaveCurrentFile(){
+		Attachment att=attachments.get(pager.getCurrentItem());
+		if(att.type==Attachment.Type.IMAGE){
+			UrlImageLoaderRequest req=new UrlImageLoaderRequest(att.url);
+			try{
+				File file=ImageCache.getInstance(activity).getFile(req);
+				if(file==null){
+					saveViaDownloadManager(att);
+					return;
+				}
+				MastodonAPIController.runInBackground(()->{
+					try(Source src=Okio.source(file); Sink sink=Okio.sink(destinationStreamForFile(att))){
+						BufferedSink buf=Okio.buffer(sink);
+						buf.writeAll(src);
+						buf.flush();
+						activity.runOnUiThread(()->Toast.makeText(activity, R.string.file_saved, Toast.LENGTH_SHORT).show());
+						if(Build.VERSION.SDK_INT<29){
+							String fileName=Uri.parse(att.url).getLastPathSegment();
+							File dstFile=new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), fileName);
+							MediaScannerConnection.scanFile(activity, new String[]{dstFile.getAbsolutePath()}, new String[]{mimeTypeForFileName(fileName)}, null);
+						}
+					}catch(IOException x){
+						Log.w(TAG, "doSaveCurrentFile: ", x);
+						activity.runOnUiThread(()->Toast.makeText(activity, R.string.error_saving_file, Toast.LENGTH_SHORT).show());
+					}
+				});
+			}catch(IOException x){
+				Log.w(TAG, "doSaveCurrentFile: ", x);
+				Toast.makeText(activity, R.string.error_saving_file, Toast.LENGTH_SHORT).show();
+			}
+		}else{
+			saveViaDownloadManager(att);
+		}
+	}
+
+	private void saveViaDownloadManager(Attachment att){
+		DownloadManager.Request req=new DownloadManager.Request(Uri.parse(att.url));
+		activity.getSystemService(DownloadManager.class).enqueue(req);
+		Toast.makeText(activity, R.string.downloading, Toast.LENGTH_SHORT).show();
+	}
+
+	private void onAudioFocusChanged(int change){
+		if(change==AudioManager.AUDIOFOCUS_LOSS || change==AudioManager.AUDIOFOCUS_LOSS_TRANSIENT || change==AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK){
+			pauseVideo();
+		}
+	}
+
+	private MediaPlayer findCurrentVideoPlayer(){
+		RecyclerView rv=(RecyclerView) pager.getChildAt(0);
+		if(rv.findViewHolderForAdapterPosition(pager.getCurrentItem()) instanceof GifVViewHolder vvh && vvh.playerReady){
+			return vvh.player;
+		}
+		return null;
+	}
+
+	private void pauseVideo(){
+		MediaPlayer player=findCurrentVideoPlayer();
+		if(player==null || !player.isPlaying())
+			return;
+		player.pause();
+		videoPlayPauseButton.setImageResource(R.drawable.ic_play_24);
+		videoPlayPauseButton.setContentDescription(activity.getString(R.string.play));
+		stopUpdatingVideoPosition();
+		windowView.removeCallbacks(uiAutoHider);
+	}
+
+	private void resumeVideo(){
+		MediaPlayer player=findCurrentVideoPlayer();
+		if(player==null || player.isPlaying())
+			return;
+		player.start();
+		videoPlayPauseButton.setImageResource(R.drawable.ic_pause_24);
+		videoPlayPauseButton.setContentDescription(activity.getString(R.string.pause));
+		startUpdatingVideoPosition(player);
+	}
+
+	private void startUpdatingVideoPosition(MediaPlayer player){
+		videoInitialPosition=player.getCurrentPosition();
+		videoInitialPositionTime=SystemClock.uptimeMillis();
+		videoDuration=player.getDuration();
+		videoPositionNeedsUpdating=true;
+		windowView.postOnAnimation(videoPositionUpdater);
+	}
+
+	private void stopUpdatingVideoPosition(){
+		videoPositionNeedsUpdating=false;
+		windowView.removeCallbacks(videoPositionUpdater);
+	}
+
+	private String formatTime(int timeSec, boolean includeHours){
+		if(includeHours)
+			return String.format(Locale.getDefault(), "%d:%02d:%02d", timeSec/3600, timeSec%3600/60, timeSec%60);
+		else
+			return String.format(Locale.getDefault(), "%d:%02d", timeSec/60, timeSec%60);
+	}
+
+	private void updateVideoPosition(){
+		if(videoPositionNeedsUpdating){
+			int currentPosition=videoInitialPosition+(int)(SystemClock.uptimeMillis()-videoInitialPositionTime);
+			videoSeekBar.setProgress(Math.round((float)currentPosition/videoDuration*10000f));
+			updateVideoTimeText(currentPosition);
+			windowView.postOnAnimation(videoPositionUpdater);
+		}
+	}
+
+	@SuppressLint("SetTextI18n")
+	private void updateVideoTimeText(int currentPosition){
+		int currentPositionSec=currentPosition/1000;
+		if(currentPositionSec!=videoLastTimeUpdatePosition){
+			videoLastTimeUpdatePosition=currentPositionSec;
+			boolean includeHours=videoDuration>=3600_000;
+			videoTimeView.setText(formatTime(currentPositionSec, includeHours)+" / "+formatTime(videoDuration/1000, includeHours));
 		}
 	}
 
@@ -240,6 +629,7 @@ public class PhotoViewer implements ZoomPanView.Listener{
 		Drawable getPhotoViewCurrentDrawable(int index);
 
 		void photoViewerDismissed();
+		void onRequestPermissions(String[] permissions);
 	}
 
 	private class PhotoViewAdapter extends RecyclerView.Adapter<BaseHolder>{
@@ -334,13 +724,15 @@ public class PhotoViewer implements ZoomPanView.Listener{
 		}
 	}
 
-	private class GifVViewHolder extends BaseHolder implements MediaPlayer.OnPreparedListener, MediaPlayer.OnErrorListener, TextureView.SurfaceTextureListener{
+	private class GifVViewHolder extends BaseHolder implements MediaPlayer.OnPreparedListener, MediaPlayer.OnErrorListener, MediaPlayer.OnCompletionListener,
+			MediaPlayer.OnVideoSizeChangedListener, MediaPlayer.OnBufferingUpdateListener, MediaPlayer.OnInfoListener, MediaPlayer.OnSeekCompleteListener, TextureView.SurfaceTextureListener{
 		public TextureView textureView;
 		public FrameLayout wrap;
 		public MediaPlayer player;
 		private Surface surface;
 		private boolean playerReady;
 		private boolean keepingScreenOn;
+		private ProgressBar progressBar;
 
 		public GifVViewHolder(){
 			textureView=new TextureView(activity);
@@ -348,6 +740,10 @@ public class PhotoViewer implements ZoomPanView.Listener{
 			zoomPanView.addView(wrap, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, Gravity.CENTER));
 			wrap.addView(textureView);
 
+			progressBar=new ProgressBar(activity);
+			progressBar.setIndeterminateTintList(ColorStateList.valueOf(0xffffffff));
+			zoomPanView.addView(progressBar, new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, Gravity.CENTER));
+
 			textureView.setSurfaceTextureListener(this);
 		}
 
@@ -359,6 +755,7 @@ public class PhotoViewer implements ZoomPanView.Listener{
 			params.width=item.getWidth();
 			params.height=item.getHeight();
 			wrap.setBackground(listener.getPhotoViewCurrentDrawable(getAbsoluteAdapterPosition()));
+			progressBar.setVisibility(item.type==Attachment.Type.VIDEO ? View.VISIBLE : View.GONE);
 			if(itemView.isAttachedToWindow()){
 				reset();
 				prepareAndStartPlayer();
@@ -369,6 +766,7 @@ public class PhotoViewer implements ZoomPanView.Listener{
 		public void onPrepared(MediaPlayer mp){
 			Log.d(TAG, "onPrepared() called with: mp = ["+mp+"]");
 			playerReady=true;
+			progressBar.setVisibility(View.GONE);
 			if(surface!=null)
 				startPlayer();
 		}
@@ -398,19 +796,24 @@ public class PhotoViewer implements ZoomPanView.Listener{
 
 		private void startPlayer(){
 			player.setSurface(surface);
-			player.setLooping(true);
-			player.start();
 			if(item.type==Attachment.Type.VIDEO){
 				incKeepScreenOn();
 				keepingScreenOn=true;
+				if(getAbsoluteAdapterPosition()==currentIndex){
+					player.start();
+					startUpdatingVideoPosition(player);
+					hideUiDelayed();
+				}
 			}else{
 				keepingScreenOn=false;
+				player.setLooping(true);
+				player.start();
 			}
 		}
 
 		@Override
 		public boolean onError(MediaPlayer mp, int what, int extra){
-			Log.e(TAG, "gif player onError() called with: mp = ["+mp+"], what = ["+what+"], extra = ["+extra+"]");
+			Log.e(TAG, "video player onError() called with: mp = ["+mp+"], what = ["+what+"], extra = ["+extra+"]");
 			return false;
 		}
 
@@ -420,6 +823,13 @@ public class PhotoViewer implements ZoomPanView.Listener{
 			players.add(player);
 			player.setOnPreparedListener(this);
 			player.setOnErrorListener(this);
+			player.setOnVideoSizeChangedListener(this);
+			if(item.type==Attachment.Type.VIDEO){
+				player.setOnBufferingUpdateListener(this);
+				player.setOnInfoListener(this);
+				player.setOnSeekCompleteListener(this);
+				player.setOnCompletionListener(this);
+			}
 			try{
 				player.setDataSource(activity, Uri.parse(item.url));
 				player.prepareAsync();
@@ -438,5 +848,53 @@ public class PhotoViewer implements ZoomPanView.Listener{
 				keepingScreenOn=false;
 			}
 		}
+
+		@Override
+		public void onVideoSizeChanged(MediaPlayer mp, int width, int height){
+			FrameLayout.LayoutParams params=(FrameLayout.LayoutParams) wrap.getLayoutParams();
+			params.width=width;
+			params.height=height;
+			zoomPanView.updateLayout();
+		}
+
+		@Override
+		public void onBufferingUpdate(MediaPlayer mp, int percent){
+			if(getAbsoluteAdapterPosition()==currentIndex){
+				videoSeekBar.setSecondaryProgress(percent*100);
+			}
+		}
+
+		@Override
+		public boolean onInfo(MediaPlayer mp, int what, int extra){
+			return switch(what){
+				case MediaPlayer.MEDIA_INFO_BUFFERING_START -> {
+					progressBar.setVisibility(View.VISIBLE);
+					stopUpdatingVideoPosition();
+					yield true;
+				}
+				case MediaPlayer.MEDIA_INFO_BUFFERING_END -> {
+					progressBar.setVisibility(View.GONE);
+					startUpdatingVideoPosition(player);
+					yield true;
+				}
+				default -> false;
+			};
+		}
+
+		@Override
+		public void onSeekComplete(MediaPlayer mp){
+			if(getAbsoluteAdapterPosition()==currentIndex && player.isPlaying())
+				startUpdatingVideoPosition(player);
+		}
+
+		@Override
+		public void onCompletion(MediaPlayer mp){
+			videoPlayPauseButton.setImageResource(R.drawable.ic_play_24);
+			videoPlayPauseButton.setContentDescription(activity.getString(R.string.play));
+			stopUpdatingVideoPosition();
+			if(!uiVisible)
+				toggleUI();
+			windowView.removeCallbacks(uiAutoHider);
+		}
 	}
 }

mastodon/src/main/java/org/joinmastodon/android/ui/photoviewer/ZoomPanView.java

@@ -53,6 +53,7 @@ public class ZoomPanView extends FrameLayout implements ScaleGestureDetector.OnS
 	private float cropAnimationValue, rawCropAndFadeValue;
 	private float lastFlingVelocityY;
 	private float backgroundAlphaForTransition=1f;
+	private boolean forceUpdateLayout;
 
 	private static final String TAG="ZoomPanView";
 
@@ -106,6 +107,8 @@ public class ZoomPanView extends FrameLayout implements ScaleGestureDetector.OnS
 	@Override
 	protected void onLayout(boolean changed, int left, int top, int right, int bottom){
 		super.onLayout(changed, left, top, right, bottom);
+		if(!changed && child!=null && !forceUpdateLayout)
+			return;
 		child=getChildAt(0);
 		if(child==null)
 			return;
@@ -120,6 +123,13 @@ public class ZoomPanView extends FrameLayout implements ScaleGestureDetector.OnS
 			updateViewTransform(false);
 		updateLimits(scale);
 		transX=transY=0;
+		if(forceUpdateLayout)
+			forceUpdateLayout=false;
+	}
+
+	public void updateLayout(){
+		forceUpdateLayout=true;
+		requestLayout();
 	}
 
 	private float interpolate(float a, float b, float k){
@@ -445,7 +455,8 @@ public class ZoomPanView extends FrameLayout implements ScaleGestureDetector.OnS
 
 	@Override
 	public boolean onSingleTapConfirmed(MotionEvent e){
-		return false;
+		listener.onSingleTap();
+		return true;
 	}
 
 	@Override
@@ -589,5 +600,6 @@ public class ZoomPanView extends FrameLayout implements ScaleGestureDetector.OnS
 		void onStartSwipeToDismissTransition(float velocityY);
 		void onSwipeToDismissCanceled();
 		void onDismissed();
+		void onSingleTap();
 	}
 }