Android: How to pass reference of a Button in Adapter to Activity

Question

All,

I have a listview filled with Buttons that start and stop a chronometer timer. Each timer is also set inside each row of the listview. Inside the activity, I have a global start and stop button. These buttons are supposed to stop and start all the timers in the listview. I can't seem to get a reference to all the timers in the listview in order to stop them. I can't even get a reference to the buttons inside each row of the listview.

Below is my code. Please help!

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="fill_parent"
android:layout_height="fill_parent">

<TextView android:layout_width="wrap_content" android:id="@+id/timerPositionName"
    android:layout_height="wrap_content" android:text="blocker" />

<TextView android:layout_width="wrap_content" android:id="@+id/timerTime"
    android:layout_height="wrap_content" />

<Button android:layout_width="wrap_content" android:id="@+id/timerResetTime"
    android:layout_height="wrap_content" android:text="@string/timerResetTime"></Button>

<Button android:layout_width="wrap_content" android:id="@+id/timerStartStopTime"
    android:layout_height="wrap_content"></Button>


<Chronometer android:id="@+id/chrono"
    android:layout_height="wrap_content" android:layout_width="wrap_content"
    android:textStyle="bold" android:textSize="14sp" android:visibility="gone" />

Here is the Adapter:

public class TimersAdapter extends BaseAdapter {

final static String START = "Start";
final static String STOP = "Stop";
private PenaltyBoxTimerActivity activity;
private ArrayList<TimerController> _controllers;
private static LayoutInflater inflater = null;

public TimersAdapter(PenaltyBoxTimerActivity a, ArrayList<TimerController> controllers) {
    activity = a;
    _controllers = controllers;
    inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

public int getCount() {
    return _controllers.size();
}

public Object getItem(int position) {
    return _controllers.get(position);
}

public long getItemId(int position) {
    return position;
}

public static class ViewHolder {
    public Button startStopButton;
    public Button resetButton;
    public TextView timeView;
    public TextView timerName;
    public Chronometer stopWatch;

    public long length = 0;
    public long startTime = 0;
    public long currentTime = 0;
    public long timeElapsed = 0;
    public long timeRemaining = 0;
    public long prevTimeRemaining = 0;
    public boolean isCurrentlyRunning = false;
}

public View getView(final int position, View convertView, ViewGroup parent) {
    View vi = convertView;
    final ViewHolder holder;

    if (convertView == null) {
        vi = inflater.inflate(R.layout.timer_item, null);
        holder = new ViewHolder();

        holder.timeView = (TextView) vi.findViewById(R.id.timerTime);
        holder.startStopButton = (Button) vi.findViewById(R.id.timerStartStopTime);
        holder.resetButton = (Button) vi.findViewById(R.id.timerResetTime);
        holder.timerName = (TextView) vi.findViewById(R.id.timerPositionName);

        holder.stopWatch = (Chronometer) vi.findViewById(R.id.chrono);

        vi.setTag(holder);
    } else
        holder = (ViewHolder) vi.getTag();

    holder.length = _controllers.get(position).getLength();
    holder.startTime = _controllers.get(position).getStartTime();
    holder.currentTime = _controllers.get(position).getCurrentTime();
    holder.timeElapsed = _controllers.get(position).getTimeElapsed();
    holder.timeRemaining = _controllers.get(position).getTimeRemaining();
    holder.prevTimeRemaining = _controllers.get(position).getPrevTimeRemaining();
    holder.isCurrentlyRunning = _controllers.get(position).getIsCurrentlyRunning();
    holder.timerName.setText(_controllers.get(position).getPositionName());
    holder.timeView.setText(DateTimes.formatTime(holder.length));

    holder.stopWatch.setOnChronometerTickListener(new OnChronometerTickListener() {
        @Override
        public void onChronometerTick(Chronometer arg0) {
            AndroidLogger.logMessage("time remaining " + DateTimes.formatTime(holder.timeRemaining), Log.INFO);
            activity.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    holder.currentTime = SystemClock.elapsedRealtime();
                    holder.isCurrentlyRunning = true;
                    holder.timeElapsed = holder.currentTime - holder.startTime;
                    if (holder.prevTimeRemaining == 0)
                        holder.timeRemaining = holder.length - holder.timeElapsed;
                    else
                        holder.timeRemaining = holder.prevTimeRemaining - holder.timeElapsed;
                    holder.timeView.setText(DateTimes.formatTime(holder.timeRemaining));
                }
            });
        }
    });

    holder.resetButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            AndroidLogger.logMessage("reset single Timer", Log.INFO);
            holder.prevTimeRemaining = 0;
            holder.isCurrentlyRunning = false;
            AndroidLogger.logMessage("RESET clicked ", Log.INFO);
            holder.stopWatch.setBase(SystemClock.elapsedRealtime());
            holder.timeView.setText(DateTimes.formatTime(0000));
        }
    });

    holder.startStopButton.setText(START);
    holder.startStopButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            if (holder.startStopButton.getText().toString().equalsIgnoreCase(START)) {
                AndroidLogger.logMessage("start single Timer", Log.INFO);
                holder.startTime = SystemClock.elapsedRealtime();
                holder.isCurrentlyRunning = true;

                holder.stopWatch.setBase(SystemClock.elapsedRealtime());
                holder.stopWatch.start();
                holder.startStopButton.setText(STOP);
                AndroidLogger.logMessage("start clicked ", Log.INFO);
                OnTimerStartClickEvent(true);
            } else {
                AndroidLogger.logMessage("stop single Timer", Log.INFO);
                holder.currentTime = SystemClock.elapsedRealtime();
                holder.timeElapsed = holder.currentTime - holder.startTime;
                if (holder.prevTimeRemaining == 0) {
                    holder.timeRemaining = holder.length - holder.timeElapsed;
                } else {
                    holder.timeRemaining = holder.prevTimeRemaining - holder.timeElapsed;
                }
                holder.prevTimeRemaining = holder.timeRemaining;
                holder.timeView.setText(DateTimes.formatTime(holder.timeRemaining));

                holder.stopWatch.stop();

                holder.startStopButton.setText(START);
                AndroidLogger.logMessage("stop clicked ", Log.INFO);
                OnTimerStopClickEvent(false);
            }
        }
    });

    activity.setOnTimerStartClickListener(new OnTimerStartStopClickListener() {
        @Override
        public void onTimerStartStopButtonClick() {
            AndroidLogger.logMessage("is currently running:" + holder.isCurrentlyRunning, Log.INFO);
            if (holder.isCurrentlyRunning) {
                AndroidLogger.logMessage("start single Timer", Log.INFO);
                holder.startTime = SystemClock.elapsedRealtime();
                holder.isCurrentlyRunning = true;

                holder.stopWatch.setBase(SystemClock.elapsedRealtime());
                holder.stopWatch.start();
                holder.startStopButton.setText(STOP);
                AndroidLogger.logMessage("start clicked ", Log.INFO);
            }
        }
    });
    activity.setOnTimerStopClickListener(new OnTimerStartStopClickListener() {
        @Override
        public void onTimerStartStopButtonClick() {
            AndroidLogger.logMessage("is currently running:" + holder.isCurrentlyRunning, Log.INFO);
            // if (_holder.isCurrentlyRunning) {
            AndroidLogger.logMessage("stop single Timer", Log.INFO);
            holder.currentTime = SystemClock.elapsedRealtime();
            holder.timeElapsed = holder.currentTime - holder.startTime;
            if (holder.prevTimeRemaining == 0) {
                holder.timeRemaining = holder.length - holder.timeElapsed;
            } else {
                holder.timeRemaining = holder.prevTimeRemaining - holder.timeElapsed;
            }
            holder.prevTimeRemaining = holder.timeRemaining;
            holder.timeView.setText(DateTimes.formatTime(holder.timeRemaining));

            holder.stopWatch.stop();
            holder.startStopButton.setText(START);
            AndroidLogger.logMessage("stop clicked ", Log.INFO);
            // }
        }
    });

    return vi;
}

private OnTimerStartStopClickListener _onTimerStopClickListener = null;

public void setOnTimerStopClickListener(OnTimerStartStopClickListener listener) {
    _onTimerStopClickListener = listener;
}

private void OnTimerStopClickEvent(boolean isTimerCurrentlyActive) {
    if (_onTimerStopClickListener != null) {
        _onTimerStopClickListener.onTimerStartStopButtonClick();
    }
}

private OnTimerStartStopClickListener _onTimerStartClickListener = null;

public void setOnTimerStartClickListener(OnTimerStartStopClickListener listener) {
    _onTimerStartClickListener = listener;
}

private void OnTimerStartClickEvent(boolean isTimerCurrentlyActive) {
    if (_onTimerStartClickListener != null) {
        _onTimerStartClickListener.onTimerStartStopButtonClick();
    }
}}

Here is my Activity:

public class PenaltyBoxTimerActivity extends Activity { private Button _startTimersButton; private Button _stopTimersButton; private ListView _manageTimersList; TimersListAdapter _adapter;

private ArrayList<TimerController> _timerList = new ArrayList<TimerController>();

private boolean _areCountersActive = false;
long countUp;

private OnTimerStartStopClickListener _onTimerStopClickListener = null;

public void setOnTimerStopClickListener(OnTimerStartStopClickListener listener) {
    _onTimerStopClickListener = listener;
}

private void OnTimerStopClickEvent() {
    if (_onTimerStopClickListener != null) {
        _onTimerStopClickListener.onTimerStartStopButtonClick();
    }
}

private OnTimerStartStopClickListener _onTimerStartClickListener = null;

public void setOnTimerStartClickListener(OnTimerStartStopClickListener listener) {
    _onTimerStartClickListener = listener;
}

private void OnTimerStartClickEvent() {
    if (_onTimerStartClickListener != null) {
        _onTimerStartClickListener.onTimerStartStopButtonClick();
    }
}

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    initializeGoToSettingsButton();
    initializeStartTimerButton();
    initializeStopTimerButton();

    // add some test data
    _timerList = new ArrayList<TimerController>();
    TimerController a = new TimerController(UUID.randomUUID(), "hello", 100000);
    TimerController b = new TimerController(UUID.randomUUID(), "hello", 60000);
    TimerController c = new TimerController(UUID.randomUUID(), "hello", 10000);
    TimerController d = new TimerController(UUID.randomUUID(), "hello", 10000);
    TimerController e = new TimerController(UUID.randomUUID(), "hello", 10000);
    TimerController f = new TimerController(UUID.randomUUID(), "hello", 10000);
    _timerList.add(a);
    _timerList.add(b);
    _timerList.add(c);
    _timerList.add(d);
    _timerList.add(e);
    _timerList.add(f);

    initializeListView();
    intializeTimerButtons();
}

private void initializeGoToSettingsButton() {
    Button goToSettingsButton = (Button) findViewById(R.id.goToSettingsButton);
    goToSettingsButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {

            Intent myIntent = new Intent(getApplicationContext(), SettingsActivity.class);
            startActivity(myIntent);

        }
    });
}

private void initializeStopTimerButton() {
    _stopTimersButton = (Button) findViewById(R.id.stopTimersButton);
    _stopTimersButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            enableStartTimerButton();
            // OnTimerStopClickEvent();
            AndroidLogger.logMessage("stop all timers", Log.INFO);

            for (int i = 0; i < _timerList.size(); i++) {
                if (_timerList.get(i).getIsCurrentlyRunning()) {
                    // _timerList.get(i).getStopWatch().stop();

                    _timerList.get(i).setCurrentTime(SystemClock.elapsedRealtime());
                    _timerList.get(i).setTimeElapsed(
                            _timerList.get(i).getCurrentTime() - _timerList.get(i).getStartTime());

                    if (_timerList.get(i).getPrevTimeRemaining() == 0) {
                        _timerList.get(i).setTimeRemaining(
                                _timerList.get(i).getLength() - _timerList.get(i).getTimeElapsed());
                    } else {
                        _timerList.get(i).setTimeRemaining(
                                _timerList.get(i).getPrevTimeRemaining() - _timerList.get(i).getTimeElapsed());
                    }
                    _timerList.get(i).setPrevTimeRemaining(_timerList.get(i).getTimeRemaining());
                    // holder.timeView.setText(DateTimes.formatTime(holder.timeRemaining));
                }
            }

            _adapter.notifyDataSetChanged();
        }
    });
}

private void initializeStartTimerButton() {
    _startTimersButton = (Button) findViewById(R.id.startTimersButton);
    _startTimersButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            AndroidLogger.logMessage("start all Timers", Log.INFO);
            enableStopTimerButton();

        }
    });
}

private void initializeListView() {
    _manageTimersList = (ListView) findViewById(R.id.manageTimersList);
    // TimersAdapter adapter = new TimersAdapter(this, R.layout.timer_item,
    // _timerList, this);
    _adapter = new TimersListAdapter(this, _timerList);
    _adapter.setOnTimerStartClickListener(new OnTimerStartStopClickListener() {
        @Override
        public void onTimerStartStopButtonClick() {
            if (!_areCountersActive) {
                enableStopTimerButton();
            }
        }
    });
    _adapter.setOnTimerStopClickListener(new OnTimerStartStopClickListener() {
        @Override
        public void onTimerStartStopButtonClick() {
            // stopTimer();
        }
    });

    _manageTimersList.setAdapter(_adapter);
    _manageTimersList.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            if (!_areCountersActive) {
                enableStopTimerButton();
            }
        }
    });
}

private void enableStartTimerButton() {
    AndroidLogger.logMessage("start All Timers", Log.INFO);
    _startTimersButton.setEnabled(true);
    _stopTimersButton.setEnabled(false);

}

private void enableStopTimerButton() {
    AndroidLogger.logMessage("stop all Timers", Log.INFO);
    _startTimersButton.setEnabled(false);
    _stopTimersButton.setEnabled(true);

}

private void intializeTimerButtons() {
    AndroidLogger.logMessage("create timer buttons", Log.INFO);
    _startTimersButton.setEnabled(false);
    _stopTimersButton.setEnabled(false);

}}

Answer 1

You could try these three options to try getting the reference out to your activity:

1. Use the method getChildAt() on your ListView (_manageTimersList). This should get the child at a specific position. You could access your chronometer from here using findViewById then stop it
2. You can expose the stopAll() and startAll() to the your activity via your adapter. In the implementation of this method, you would add any chronometers added by getView() and then just stop it when the button call stopAll() or start them all using startAll(). Note: this is not my preferred method
3. Each TimerController that you pass to the adapter can have reference to the Chronometer that you set during getView(). In essence TimerController becomes the wrapper of it (which I think might be your intention, but I am not sure). You basically will be doing something like

    TimerController timerController = _controllers.get(position);
    timerController.setChronometer(holder.stopWatch);

Once you set this reference, you could do what you have implemented in the code. Just make sure to check for null for each TimerController in the list.

Answer 2

I think button references must be incapsulated in _adapter. You should store button views in array (which can be initialized or reinitialized within getView() method) in TimersListAdapter class and create special public method to toggle all buttons. The method you will be able to invoke from your activity.

Hope it will help you.