CurrentSessionTimerRetainedFragment.java

package com.pluscubed.plustimer.ui.currentsessiontimer;

import android.app.Fragment;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;

import com.pluscubed.plustimer.model.PuzzleType;
import com.pluscubed.plustimer.model.ScrambleAndSvg;

import net.gnehzr.tnoodle.scrambles.InvalidScrambleException;

/**
 * Retained fragment alongside CurrentSTimerFragment
 */
public class CurrentSessionTimerRetainedFragment extends Fragment {

    private static final String STATE_CURRENT_SCRAMBLE = "current_scramble";
    private static final String STATE_CURRENT_SVG = "current_svg";
    private static final String STATE_NEXT_SCRAMBLE = "next_scramble";
    private static final String STATE_NEXT_SVG = "next_svg";
    private static final String STATE_SCRAMBLING = "scrambling";

    private Handler mScramblerThreadHandler;
    private HandlerThread mScramblerThread;

    private ScrambleAndSvg mCurrentScrambleAndSvg;
    private ScrambleAndSvg mNextScrambleAndSvg;

    private boolean mScrambling;

    public boolean isScrambling() {
        return mScrambling;
    }

    public void generateNextScramble() {
        postToScrambleThread(() -> {
            mScrambling = true;
            mNextScrambleAndSvg = generateScramble();
            mScrambling = false;
        });

    }

    public void postSetScrambleViewsToCurrent() {
        postToScrambleThread(() -> {
            mCurrentScrambleAndSvg = mNextScrambleAndSvg;
            mNextScrambleAndSvg = null;
            if (getTargetFragment() != null) {
                final CurrentSessionTimerFragment targetFragment =
                        (CurrentSessionTimerFragment) getTargetFragment();
                targetFragment.getUiHandler().post(() -> {
                    targetFragment.setScrambleTextAndImageToCurrent();
                    targetFragment.enableMenuItems(true);
                });
            }
        });

    }

    //Generate scramble image and text
    private ScrambleAndSvg generateScramble() {
        ScrambleAndSvg scrambleAndSvg = null;
        try {
            PuzzleType puzzleType = PuzzleType.getCurrent(getActivity()).toBlocking().value();
            String scramble = puzzleType.getPuzzle().generateScramble();
            String svg = puzzleType.getPuzzle().drawScramble(scramble, null).toString();
            scrambleAndSvg = new ScrambleAndSvg(scramble, svg);
        } catch (InvalidScrambleException e) {
            e.printStackTrace();
        }

        return scrambleAndSvg;
    }

    public ScrambleAndSvg getCurrentScrambleAndSvg() {
        return mCurrentScrambleAndSvg;
    }

    private void postToScrambleThread(Runnable r) {

        mScramblerThreadHandler.post(r);

    }

    private void startScramblerThread() {
        mScramblerThread = new HandlerThread("ScramblerThread");
        mScramblerThread.start();
        mScramblerThreadHandler = new Handler(mScramblerThread.getLooper());
    }

    private void stopScramblerThread() {
        if (mScramblerThread != null) {
            mScramblerThread.quit();
            mScramblerThread = null;
            mScramblerThreadHandler = null;
        }
    }

    public void resetScramblerThread() {
        stopScramblerThread();
        startScramblerThread();
        mScrambling = false;
        mCurrentScrambleAndSvg = null;
        mNextScrambleAndSvg = null;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRetainInstance(true);

        startScramblerThread();

        if (savedInstanceState != null) {
            String current_scramble = savedInstanceState.getString
                    (STATE_CURRENT_SCRAMBLE);
            if (current_scramble != null) {
                mCurrentScrambleAndSvg = new ScrambleAndSvg(current_scramble,
                        savedInstanceState.getString(STATE_CURRENT_SVG));
            }
            String next_scramble = savedInstanceState.getString
                    (STATE_NEXT_SCRAMBLE);
            if (next_scramble != null) {
                mNextScrambleAndSvg = new ScrambleAndSvg(next_scramble,
                        savedInstanceState.getString(STATE_NEXT_SVG));
            }
            mScrambling = savedInstanceState.getBoolean(STATE_SCRAMBLING);
            if (mScrambling) {
                generateNextScramble();
                postSetScrambleViewsToCurrent();
            }
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        stopScramblerThread();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        if (mCurrentScrambleAndSvg != null) {
            outState.putString(STATE_CURRENT_SCRAMBLE, mCurrentScrambleAndSvg
                    .getScramble());
            outState.putString(STATE_CURRENT_SVG, mCurrentScrambleAndSvg
                    .getSvg());
        }
        if (mNextScrambleAndSvg != null) {
            outState.putString(STATE_NEXT_SCRAMBLE,
                    mNextScrambleAndSvg.getScramble());
            outState.putString(STATE_NEXT_SVG, mNextScrambleAndSvg.getSvg());
        }
        outState.putBoolean(STATE_SCRAMBLING, mScrambling);
    }
}