I have two buttons that increment and decrement a value by one with each press and they're working just fine with the onClickListener. I see that an onLongClickListener exists, which I assume is for touch and hold events. How would I have the number rapidly increment/decrement if the button is held?
Am I correct in assuming that onLongClickListener only fires once per long click? Is there a more appropriate listener or a property somewhere that I'm not aware of?
For example, to move an app icon on your home screen, touch & hold, then drag it to the new location. Sometimes touch & hold is called a "long press."
"Touch slop" refers to the distance in pixels a user's touch can wander before the gesture is interpreted as scrolling.
You may implement it as in the following code.
package org.me.rapidchange;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnKeyListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.TextView;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
public class MainActivity extends Activity implements OnKeyListener,
OnTouchListener, OnClickListener {
private class UpdateCounterTask implements Runnable {
private boolean mInc;
public UpdateCounterTask(boolean inc) {
mInc = inc;
}
public void run() {
if (mInc) {
mHandler.sendEmptyMessage(MSG_INC);
} else {
mHandler.sendEmptyMessage(MSG_DEC);
}
}
}
private static final int MSG_INC = 0;
private static final int MSG_DEC = 1;
private Button mIncButton;
private Button mDecButton;
private TextView mText;
private int mCounter;
private Handler mHandler;
private ScheduledExecutorService mUpdater;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_INC:
inc();
return;
case MSG_DEC:
dec();
return;
}
super.handleMessage(msg);
}
};
mIncButton = (Button) findViewById(R.id.inc_button);
mDecButton = (Button) findViewById(R.id.dec_button);
mText = (TextView) findViewById(R.id.text);
mIncButton.setOnTouchListener(this);
mIncButton.setOnKeyListener(this);
mIncButton.setOnClickListener(this);
mDecButton.setOnTouchListener(this);
mDecButton.setOnKeyListener(this);
mDecButton.setOnClickListener(this);
}
private void inc() {
mCounter++;
mText.setText(Integer.toString(mCounter));
}
private void dec() {
mCounter--;
mText.setText(Integer.toString(mCounter));
}
private void startUpdating(boolean inc) {
if (mUpdater != null) {
Log.e(getClass().getSimpleName(), "Another executor is still active");
return;
}
mUpdater = Executors.newSingleThreadScheduledExecutor();
mUpdater.scheduleAtFixedRate(new UpdateCounterTask(inc), 200, 200,
TimeUnit.MILLISECONDS);
}
private void stopUpdating() {
mUpdater.shutdownNow();
mUpdater = null;
}
public void onClick(View v) {
if (mUpdater == null) {
if (v == mIncButton) {
inc();
} else {
dec();
}
}
}
public boolean onKey(View v, int keyCode, KeyEvent event) {
boolean isKeyOfInterest = keyCode == KeyEvent.KEYCODE_DPAD_CENTER || keyCode == KeyEvent.KEYCODE_ENTER;
boolean isReleased = event.getAction() == KeyEvent.ACTION_UP;
boolean isPressed = event.getAction() == KeyEvent.ACTION_DOWN
&& event.getAction() != KeyEvent.ACTION_MULTIPLE;
if (isKeyOfInterest && isReleased) {
stopUpdating();
} else if (isKeyOfInterest && isPressed) {
startUpdating(v == mIncButton);
}
return false;
}
public boolean onTouch(View v, MotionEvent event) {
boolean isReleased = event.getAction() == MotionEvent.ACTION_UP || event.getAction() == MotionEvent.ACTION_CANCEL;
boolean isPressed = event.getAction() == MotionEvent.ACTION_DOWN;
if (isReleased) {
stopUpdating();
} else if (isPressed) {
startUpdating(v == mIncButton);
}
return false;
}
}
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With