Well, I have been looking up answers, but none have worked for me. I have a button that when it is HELD DOWN, is suppose to continue to move an image across the screen. But for some reason, it just keeps freezing my kindle when I tap the button. I think the thread is part of the problem, but i'm unsure. Here is the code:
package com.evilsea.darkages;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Color;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
public class MainActivity extends Activity implements OnTouchListener, Runnable {
ImageView leftImageButton;
boolean leftButtonDown = false;
ImageView knight;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Thread thread1 = new Thread(this);
thread1.start();
this.run();
}
public void addListenerOnLeftButton() {
leftImageButton = (ImageView) findViewById(R.id.left_button);
leftImageButton.setOnTouchListener(leftButtonlistener);
knight = (ImageView) findViewById(R.id.knight_image);
}
OnTouchListener leftButtonlistener = new OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
leftButtonDown = true;
try {
while(leftButtonDown) {
Thread.sleep(10);
moveLeft(5);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
break;
case MotionEvent.ACTION_UP:
leftButtonDown = false;
break;
}
return false;
}
};
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
return false;
}
@Override
public void run() {
addListenerOnLeftButton();
}
public void moveLeft(int speed) throws InterruptedException {
knight.setLeft(knight.getLeft() -speed);
}
}
BTW, I am just starting out w/ android, so I am sorry if this is an obvious question. Thanks! Much appreciated.
Firstly, you are making a UI thread sleep that's why your UI is getting freeze.Here, i have created a async task where i am sleeping background thread and running a UI update on main thread as you can see below in doInBackground method.Here is your solution -:
public class MainActivity extends Activity {
private ImageView leftImageButton;
private boolean leftButtonDown = false;
private ImageView knight;
private AsyncTask asyncTask = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
leftImageButton = (ImageView) findViewById(R.id.imageView2);
knight = (ImageView) findViewById(R.id.imageView1);
leftImageButton.setOnTouchListener(new LeftImageListener());
}
public void startTask() {
asyncTask = new AsyncTask<Void, Void, Void>() {
@Override
protected Void doInBackground(Void... params) {
if (leftButtonDown) {
while (leftButtonDown) {
try {
Thread.sleep(10);
runOnUiThread(new Runnable() {
@Override
public void run() {
try {
moveLeft(5);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
return null;
}
}.execute();
}
public void moveLeft(int speed) throws InterruptedException {
knight.setLeft(knight.getLeft() - speed);
}
public class LeftImageListener implements OnTouchListener {
public LeftImageListener() {
// TODO Auto-generated constructor stub
}
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
leftButtonDown = true;
startTask();
break;
case MotionEvent.ACTION_UP:
leftButtonDown = false;
break;
default:
break;
}
return true;
}
}
}