CastEnabledActivity.java

package de.danoeh.antennapod.activity;

import android.content.SharedPreferences;
import android.media.AudioManager;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.annotation.CallSuper;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;

import com.google.android.gms.cast.ApplicationMetadata;

import de.danoeh.antennapod.R;
import de.danoeh.antennapod.core.cast.CastConsumer;
import de.danoeh.antennapod.core.cast.CastManager;
import de.danoeh.antennapod.core.cast.DefaultCastConsumer;
import de.danoeh.antennapod.core.cast.SwitchableMediaRouteActionProvider;
import de.danoeh.antennapod.core.preferences.UserPreferences;
import de.danoeh.antennapod.core.service.playback.PlaybackService;

/**
 * Activity that allows for showing the MediaRouter button whenever there's a cast device in the
 * network.
 */
public abstract class CastEnabledActivity extends AppCompatActivity
        implements SharedPreferences.OnSharedPreferenceChangeListener {
    public static final String TAG = "CastEnabledActivity";

    protected CastManager castManager;
    protected SwitchableMediaRouteActionProvider mediaRouteActionProvider;
    private final CastButtonVisibilityManager castButtonVisibilityManager = new CastButtonVisibilityManager();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).
                registerOnSharedPreferenceChangeListener(this);

        castManager = CastManager.getInstance();
        castManager.addCastConsumer(castConsumer);
        castButtonVisibilityManager.setPrefEnabled(UserPreferences.isCastEnabled());
        onCastConnectionChanged(castManager.isConnected());
    }

    @Override
    protected void onDestroy() {
        PreferenceManager.getDefaultSharedPreferences(getApplicationContext())
                .unregisterOnSharedPreferenceChangeListener(this);
        castManager.removeCastConsumer(castConsumer);
        super.onDestroy();
    }

    @Override
    @CallSuper
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        getMenuInflater().inflate(R.menu.cast_enabled, menu);
        castButtonVisibilityManager.setMenu(menu);
        return true;
    }

    @Override
    @CallSuper
    public boolean onPrepareOptionsMenu(Menu menu) {
        super.onPrepareOptionsMenu(menu);
        mediaRouteActionProvider = castManager
                .addMediaRouterButton(menu.findItem(R.id.media_route_menu_item));
        mediaRouteActionProvider.setEnabled(castButtonVisibilityManager.shouldEnable());
        return true;
    }

    @Override
    protected void onResume() {
        super.onResume();
        castButtonVisibilityManager.setResumed(true);
    }

    @Override
    protected void onPause() {
        super.onPause();
        castButtonVisibilityManager.setResumed(false);
    }

    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
        if (UserPreferences.PREF_CAST_ENABLED.equals(key)) {
            boolean newValue = UserPreferences.isCastEnabled();
            Log.d(TAG, "onSharedPreferenceChanged(), isCastEnabled set to " + newValue);
            castButtonVisibilityManager.setPrefEnabled(newValue);
            // PlaybackService has its own listener, so if it's active we don't have to take action here.
            if (!newValue && !PlaybackService.isRunning) {
                CastManager.getInstance().disconnect();
            }
        }
    }

    CastConsumer castConsumer = new DefaultCastConsumer() {
        @Override
        public void onApplicationConnected(ApplicationMetadata appMetadata, String sessionId, boolean wasLaunched) {
            onCastConnectionChanged(true);
        }

        @Override
        public void onDisconnected() {
            onCastConnectionChanged(false);
        }
    };

    private void onCastConnectionChanged(boolean connected) {
        if (connected) {
            castButtonVisibilityManager.onConnected();
            setVolumeControlStream(AudioManager.USE_DEFAULT_STREAM_TYPE);
        } else {
            castButtonVisibilityManager.onDisconnected();
            setVolumeControlStream(AudioManager.STREAM_MUSIC);
        }
    }

    /**
     * Should be called by any activity or fragment for which the cast button should be shown.
     *
     * @param showAsAction refer to {@link MenuItem#setShowAsAction(int)}
     */
    public final void requestCastButton(int showAsAction) {
        castButtonVisibilityManager.requestCastButton(showAsAction);
    }

    private class CastButtonVisibilityManager {
        private volatile boolean prefEnabled = false;
        private volatile boolean viewRequested = false;
        private volatile boolean resumed = false;
        private volatile boolean connected = false;
        private volatile int showAsAction = MenuItem.SHOW_AS_ACTION_IF_ROOM;
        private Menu menu;

        public synchronized void setPrefEnabled(boolean newValue) {
            if (prefEnabled != newValue && resumed && (viewRequested || connected)) {
                if (newValue) {
                    castManager.incrementUiCounter();
                } else {
                    castManager.decrementUiCounter();
                }
            }
            prefEnabled = newValue;
            if (mediaRouteActionProvider != null) {
                mediaRouteActionProvider.setEnabled(prefEnabled && (viewRequested || connected));
            }
        }

        public synchronized void setResumed(boolean newValue) {
            if (resumed == newValue) {
                Log.e(TAG, "resumed should never change to the same value");
                return;
            }
            resumed = newValue;
            if (prefEnabled && (viewRequested || connected)) {
                if (resumed) {
                    castManager.incrementUiCounter();
                } else {
                    castManager.decrementUiCounter();
                }
            }
        }

        public synchronized void setViewRequested(boolean newValue) {
            if (viewRequested != newValue && resumed && prefEnabled && !connected) {
                if (newValue) {
                    castManager.incrementUiCounter();
                } else {
                    castManager.decrementUiCounter();
                }
            }
            viewRequested = newValue;
            if (mediaRouteActionProvider != null) {
                mediaRouteActionProvider.setEnabled(prefEnabled && (viewRequested || connected));
            }
        }

        public synchronized void setConnected(boolean newValue) {
            if (connected != newValue && resumed && prefEnabled && !prefEnabled) {
                if (newValue) {
                    castManager.incrementUiCounter();
                } else {
                    castManager.decrementUiCounter();
                }
            }
            connected = newValue;
            if (mediaRouteActionProvider != null) {
                mediaRouteActionProvider.setEnabled(prefEnabled && (viewRequested || connected));
            }
        }

        public synchronized boolean shouldEnable() {
            return prefEnabled && viewRequested;
        }

        public void setMenu(Menu menu) {
            setViewRequested(false);
            showAsAction = MenuItem.SHOW_AS_ACTION_IF_ROOM;
            this.menu = menu;
            setShowAsAction();
        }

        public void requestCastButton(int showAsAction) {
            setViewRequested(true);
            this.showAsAction = showAsAction;
            setShowAsAction();
        }

        public void onConnected() {
            setConnected(true);
            setShowAsAction();
        }

        public void onDisconnected() {
            setConnected(false);
            setShowAsAction();
        }

        private void setShowAsAction() {
            if (menu == null) {
                Log.d(TAG, "setShowAsAction() without a menu");
                return;
            }
            MenuItem item = menu.findItem(R.id.media_route_menu_item);
            if (item == null) {
                Log.e(TAG, "setShowAsAction(), but cast button not inflated");
                return;
            }
            MenuItemCompat.setShowAsAction(item, connected? MenuItem.SHOW_AS_ACTION_ALWAYS : showAsAction);
        }
    }
}