AudioPlayerController.java

/**
 * Controls the Audio Player and adapts to the quirks of the Android AudioPlayer. 
 */
package org.androiddaisyreader.controller;

import java.util.logging.Logger;

import org.androiddaisyreader.AudioPlayer;
import org.androiddaisyreader.player.SegmentTimeInfo;
import org.androiddaisyreader.model.Audio;
import org.androiddaisyreader.model.AudioPlayerState;

/**
 * OK, let's go...
 * 
 * @author Julian Harty
 */
public class AudioPlayerController {

    private AudioPlayer player;
    private Logger log = Logger.getLogger("AudioPlayerController");

    @SuppressWarnings("unused")
    private AudioPlayerController() {
        // Stop people from calling me without providing a player.
    }

    public AudioPlayerController(AudioPlayer player) {
        this.player = player;
    }

    /**
     * Play the audio from part of a file. Starts at the time specified in the
     * from parameter. Finishes when the duration has been reached, or at the
     * end of the file, whichever's sooner.
     * 
     * Android's MediaPlayer does not include a facility to 'stop' at a
     * particular duration. Instead it plays to the end of the file. Therefore
     * we want to emulate the behaviour of the Android player in this Mock audio
     * player.
     * 
     * @param segment The audio segment to play
     */
    public void playFileSegment(Audio audioSegment) {

        Audio currentSegment = player.getCurrentSegment();
        if (currentSegment == null) {
            log.info("Starting to play a new file");
            player.setInternalPlayerState(AudioPlayerState.PLAY_NEW_FILE);
            player.setCurrentSegment(audioSegment);
            player.play();
            return;
        }

        // Note: if we are able to determine the overall duration of the
        // fileToPlay
        // we could check whether the duration is valid. For now, we'll assume
        // it is.

        if (currentSegment.getAudioFilename().matches(audioSegment.getAudioFilename())) {
            int newClipStartsAt = audioSegment.getClipBegin();
            int previousClipEndsAt = currentSegment.getClipEnd();
            SegmentTimeInfo interval = SegmentTimeInfo.compareTimesForAudioSegments(
                    newClipStartsAt, previousClipEndsAt);

            // Update the Player with details of the new segment.
            player.setCurrentSegment(audioSegment);
            switch (interval) {
            case CONTIGUOUS:
                log.info("The player will continue playing the existing audio, without interruption.");
                player.setInternalPlayerState(AudioPlayerState.CONTINUE_PLAYING_EXISTING_FILE);
                break;
            case GAP:
                log.warning(String.format("There is a gap between the audio segments, last "
                        + "segment finished at %d, next segment starts at %d", newClipStartsAt,
                        previousClipEndsAt));
                player.setInternalPlayerState(AudioPlayerState.GAP_BETWEEN_CONTENTS);
                player.seekTo(audioSegment.getClipBegin());
                player.play();
                break;
            case OVERLAPPING:
                log.warning(String.format(
                        "The player was asked to play earlier in the file than expected."
                                + " Generally the next request %d should be contiguous with the"
                                + " end of the previous section %d", newClipStartsAt,
                        previousClipEndsAt));
                player.setInternalPlayerState(AudioPlayerState.OVERLAPPING_CONTENTS);
                player.seekTo(audioSegment.getClipBegin());
                player.play();
                break;
            }
        } else {
            log.info(String.format(
                    "Stop playing the current file %s & start playing the newly specified file %s",
                    currentSegment.getAudioFilename(), audioSegment.getAudioFilename()));
            player.setInternalPlayerState(AudioPlayerState.PLAY_NEW_FILE);
            player.setCurrentSegment(audioSegment);
            player.play();
            log.warning("Why aren't you playing?");
        }
        currentSegment = audioSegment;
        log.info(String.format("Playing %s from %d to %d", currentSegment.getAudioFilename(),
                currentSegment.getClipBegin(), currentSegment.getClipEnd()));
    }

}