Develop Reference

What am i doing wrong at my simple android app?

I am trying to make a app that has a switch a button and a text and if you turn the switch on and press the button; the number displayed on the text will be added by 1. But if the switch is turned off the number will be subtracted by 1.
but when i run my app and press the button, the app crashes...
i do not have much experience at programming and i do not know what im doing wrong. and i have only tried this code.
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TextView text = (TextView)findViewById(R.id.textView);
final Button button = (Button)findViewById(R.id.button);
Switch mySwitch = (Switch)findViewById(R.id.mySwitch);
mySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (isChecked== true){
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String text_string = text.getText().toString();
int text_int = Integer.parseInt(text_string);
text_int++;
text.setText(text_int);
}
});
}
if (isChecked == false) {
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String text_string = text.getText().toString();
int text_int = Integer.parseInt(text_string);
text_int++;
text.setText(text_int);
}
});
}
}
});
}
}
so this should behave as i described earlier but it doesn't.

Your app crashes because you are trying to set an int to a textview.setText()and when you pass an int to this method it expects it to be a resource id and which could not be found in your case that's why it will throw ResourceNotFoundException and crashes.
You should set text as following:
text.setText(String.valueOf(text_int));

You’re nesting listeners but that logic doesn’t work sequentially. You should declare your listeners separately. I suggest you create a boolean that holds the state of the switch and one button listener. Within the listener check if switch is enabled then run your calculations and do the same if the switch is disabled.
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(mySwitch.isChecked(){
String text_string = text.getText().toString();
int text_int = Integer.parseInt(text_string);
text_int++;
text.setText(String.valueOf(text_int));
} else {
String text_string = text.getText().toString();
int text_int = Integer.parseInt(text_string);
text_int++;
text.setText(String.valueOf(text_int));
}
}
});

You don't need a listener for the Switch, but only 1 listener for the Button:
final TextView text = (TextView)findViewById(R.id.textView);
final Button button = (Button)findViewById(R.id.button);
final Switch mySwitch = (Switch)findViewById(R.id.mySwitch);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String text_string = text.getText().toString();
int text_int = 0;
try {
text_int = Integer.parseInt(text_string);
} catch (NumberFormatException e) {
e.printStackTrace();
}
if (mySwitch.isChecked())
text_int++;
else
text_int--;
text.setText("" + text_int);
}
});
Every time you click the Button, in its listener the value in the TextView is increased or decreased depending on whether the Switch is checked or not.

Update sharedpreference that uses checkbox

I want to update the changes when I uncheck and check the checkbox in the preference activity but when I press the back button it doesn't work. It only works when I close the activity and then open it
Main activity
public class MainActivity extends ActionBarActivity {
private ToggleButton togle;
private Camera camera;
private boolean isFlashOn;
private boolean hasFlash;
Parameters params;
private ShakeListener mShaker;
MediaPlayer mp;
ImageView anime;
int p=1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
anime = (ImageView) findViewById(R.id.Animation);
hasFlash = getApplicationContext().getPackageManager()
.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
if (!hasFlash) {
// device doesn't support flash
// Show alert message and close the application
AlertDialog alert = new AlertDialog.Builder(MainActivity.this)
.create();
alert.setTitle("Error");
alert.setMessage("Sorry, your device doesn't support flash light!");
alert.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// closing the application
finish(); }
});
alert.show();
return;}
getCamera();
togle = (ToggleButton) findViewById(R.id.ToggleButton01);
togle.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
boolean checked = ((ToggleButton) v).isChecked();
if (checked){
turnOffFlash();
}
else{
getCamera();
turnOnFlash();
}
}
});
SharedPreferences getprefs = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
boolean stopshake = getprefs.getBoolean("checkbox", true);
if (stopshake == true ){
mShaker = new ShakeListener(this);
mShaker.setOnShakeListener(new ShakeListener.OnShakeListener () {
public void onShake()
{ if (!isFlashOn) {
Toast.makeText(MainActivity.this, "On" , Toast.LENGTH_SHORT).show();
getCamera();
turnOnFlash();
}
else{
turnOffFlash();
Toast.makeText(MainActivity.this, "Off" , Toast.LENGTH_SHORT).show();
} }
});
}
}
private void getCamera() {
// TODO Auto-generated method stub
if (camera == null) {
try {
camera = Camera.open();
params = camera.getParameters();
} catch (RuntimeException e) {
Log.e("Camera Error. Failed to Open. Error: ", e.getMessage());
}
} }
private void turnOnFlash() {
if (!isFlashOn) {
if (camera == null || params == null) {
return;
}
// play sound
getCamera();
playSound();
params = camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_TORCH);
camera.setParameters(params);
camera.startPreview();
isFlashOn = true;
anime.setImageResource(R.drawable.anim);
anime.post(new Runnable() {
#Override
public void run() {
AnimationDrawable frameAnimation =
(AnimationDrawable) anime.getDrawable();
frameAnimation.start();
}
});
// changing button/switch image
}
}
private void turnOffFlash() {
if (isFlashOn) {
if (camera == null || params == null) {
return;
}
// play sound
playSound();
params = camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_OFF);
camera.setParameters(params);
camera.stopPreview();
camera.setPreviewCallback(null);
camera.release();
camera = null;
isFlashOn = false;
anime.setImageResource(R.drawable.off);
// changing button/switch image
}
}
private void playSound() {
// TODO Auto-generated method stub
if(isFlashOn){
mp = MediaPlayer.create(MainActivity.this, R.raw.off1);
}else{
mp = MediaPlayer.create(MainActivity.this, R.raw.on1);
}
mp.setOnCompletionListener(new OnCompletionListener() {
#Override
public void onCompletion(MediaPlayer mp) {
// TODO Auto-generated method stub
mp.release();
}
});
mp.start();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
Intent intent = new Intent(MainActivity.this, Prefsetting.class);
startActivity(intent);
return true;
}
return super.onOptionsItemSelected(item);
}
}
Preference activity
public class Prefsetting extends PreferenceActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.prefset);
}
}

You access SharedPreferences in the onCreate() of your MainActivity, which is only called when that activity is created from scratch (i.e. when you first start your app). As you (presumably) navigate to and from your Prefsetting Activity fairly quickly, MainActivity is likely only in a paused or stopped state when it is resumed. Take a look at the diagram here to see what happens to Activity classes as they move into and out of the foreground.
You have a couple of options. Either place this:
#Override
public void onResume() {
super.onResume();
SharedPreferences getprefs = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
boolean stopshake = getprefs.getBoolean("checkbox", true);
if (stopshake) {
mShaker = new ShakeListener(this);
mShaker.setOnShakeListener(new ShakeListener.OnShakeListener () {
public void onShake() {
if (!isFlashOn) {
Toast.makeText(MainActivity.this, "On" , Toast.LENGTH_SHORT).show();
getCamera();
turnOnFlash();
} else {
turnOffFlash();
Toast.makeText(MainActivity.this, "Off" , Toast.LENGTH_SHORT).show();
}
}
});
} else {
if (mShaker != null) {
mShaker.setOnShakeListener(null);
mShaker = null;
}
}
}
Into somewhere like onResume().
Or, use an EventBus like LocalBrodcastManager to update your Preferences when onPause() is called in your PreferenceActivity.

From the code snippet it appears that you never actually commit your changes to the SharedPreferences of the application. Somewhere in the code when that boolean is flipped you need to do something like this:
prefs.put("checkbox", currentBooleanState).commit();

Custom Dialog not cancelling even after setting cancellable true

I have a custom ActivityIndicator defined as this
public class ActivityIndicator extends Dialog
{
private ImageView progress;
private ImageView bottomProgress;
private int type = INDICATOR_SIMPLE;
public static final int INDICATOR_SIMPLE = 0;
public static final int INDICATOR_BOTTOM = 1;
public ActivityIndicator(Context context, int theme, int type)
{
super(context, theme);
this.type = type;
onCreate(null);
}
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.dialog_indicator);
progress = (ImageView) findViewById(R.id.progress);
bottomProgress = (ImageView) findViewById(R.id.bottomProgress);
if(type == INDICATOR_BOTTOM)
{
progress.setVisibility(View.INVISIBLE);
}
else if(type == INDICATOR_SIMPLE)
{
bottomProgress.setVisibility(View.INVISIBLE);
}
this.setCancelable(false);
}
#Override
public void show()
{
progress.clearAnimation();
bottomProgress.clearAnimation();
if(type == INDICATOR_BOTTOM)
{
progress.setVisibility(View.INVISIBLE);
new Handler().postDelayed(new Runnable()
{
#Override
public void run()
{
Animation anim = AnimationUtils.loadAnimation(getContext(), R.anim.rotating_img);
bottomProgress.startAnimation(anim);
}
},400);
}
if(type == INDICATOR_SIMPLE)
{
bottomProgress.setVisibility(View.INVISIBLE);
new Handler().postDelayed(new Runnable()
{
#Override
public void run()
{
Animation anim = AnimationUtils.loadAnimation(getContext(), R.anim.rotating_img);
progress.startAnimation(anim);
}
},400);
}
super.show();
}
#Override
public void dismiss()
{
super.dismiss();
progress.clearAnimation();
bottomProgress.clearAnimation();
}
}
In my activity I initialize it as:
indicator = new ActivityIndicator(this, android.R.style.Theme_Translucent_NoTitleBar_Fullscreen, ActivityIndicator.INDICATOR_SIMPLE);
Now as seen in code , default style cancelable is false.
However at some point i do want to put it cancelable , here is my code:
indicator.setCancelable(true);
indicator.setOnCancelListener(new DialogInterface.OnCancelListener()
{
#Override
public void onCancel(DialogInterface dialog)
{
finish();
}
});
indicator.show();
When I try to press the back button, nothing happens, the dialog doesn't cancel nor the cancel listener. What is wrong here? Why is it not cancelling automatically on back key pressed

Don't Override onCreate(). That onCreate(null) method that you invoke is what's screwing up your code. Rather use an initializer pattern to initialize the Dialog.
If you change your onCreate to an initialize() and invoke that from the constructor the code will work.
Look at the following.
public ActivityIndicator(Context context, int theme, int type)
{
super(context, theme);
this.type = type;
initialize();
}
protected void initialize()
{
setContentView(R.layout.dialog_indicator);
setCancelable(false);
progress = (ImageView) findViewById(R.id.progress);
bottomProgress = (ImageView) findViewById(R.id.bottomProgress);
if(type == INDICATOR_BOTTOM)
{
progress.setVisibility(View.INVISIBLE);
}
else if(type == INDICATOR_SIMPLE)
{
bottomProgress.setVisibility(View.INVISIBLE);
}
}

Please comment your seton cancellabel and use below code and check.
indicator.setOnKeyListener(new OnKeyListener() {
#Override
public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK){
finish();
}
}
}

When you are creating an instance of ActivityIndicator, in the OnCreate method, setCancelable is set to false.
Try removing that..

Got you problem just change your constructor like below and you would get your cancel listner called:
public ActivityIndicator(Context context, int theme, int type, boolean isCancelable)
{
super(context, theme);
this.type = type;
onCreate(null);
this.setCancelable(isCancelable); //setcancelable here on the basis of boolean value and remove setcancelable from onCreate()
}
Call the constructor with one more argument which is boolean true/false
Note: Don't forget to remove setCancelable() from onCreate() method.

How to stop a Splash Screen with a click before the end?

I created an activity splashScreen in my application.
This works very well with animation is my code :
public class SpalshScreenActivity extends Activity {
private static final int STOPSPLASH = 0;
private static final long SPLASHTIME = 3000;
private boolean flagBack = false;
private final transient Handler splashHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
if (msg.what == STOPSPLASH && !flagBack) {
StartMainActivity();
}
super.handleMessage(msg);
}
};
public void onAttachedToWindow() {
super.onAttachedToWindow();
Window window = getWindow();
window.setFormat(PixelFormat.RGBA_8888);
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTheme(R.style.HideActionBar);
setContentView(R.layout.splash);
StartAnimations();
final Message msg = new Message();
msg.what = STOPSPLASH;
splashHandler.sendMessageDelayed(msg, SPLASHTIME);
}
private void StartAnimations() {
Animation anim = AnimationUtils.loadAnimation(this, R.anim.alpha);
anim.reset();
LinearLayout l=(LinearLayout) findViewById(R.id.lin_lay);
l.clearAnimation();
l.startAnimation(anim);
anim = AnimationUtils.loadAnimation(this, R.anim.translate);
anim.reset();
ImageView iv = (ImageView) findViewById(R.id.logo);
iv.clearAnimation();
iv.startAnimation(anim);
}
private void StartMainActivity() {
final Intent intent = new Intent(SpalshScreenActivity.this, MainFragmentActivity.class);
startActivity(intent);
finish();
}
public boolean onKeyDown(int keyCode, KeyEvent evt) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
flagBack = true;
finish();
return true;
}
return false;
}}
Now I would like to add the ability to click on the screen to stop the SplashScreen.
I tried this way, it works but I think it is not an optimal solution (slow) :
#Override
public boolean onTouchEvent(MotionEvent evt) {
if(evt.getAction() == MotionEvent.ACTION_DOWN) {
flagBack = true;
StartMainActivity();
}
return true;
}
Thank you in advance!

set an OnClickListener to the activity with the same code as in the onTouchEvent

Animation don't work with a changing of the ImageView Drawable

Hi have a problem with Animation, actually i want to fade my ImageView while it's changing it resource.
It's not working, i can change the resource but without any animation.
private void checkX() {
// TODO Auto-generated method stub
switch (x) {
case (1): {
startingAnimation();
xImg.setImageResource(R.drawable.test_uno);
endingAnimation();
break;
}
case (2): {
startingAnimation();
xImg.setImageResource(R.drawable.test_due);
endingAnimation();
break;
}
case (3): {
startingAnimation();
xImg.setImageResource(R.drawable.test_tre);
endingAnimation();
break;
}
case (4): {
startingAnimation();
xImg.setImageResource(R.drawable.test_quattro);
endingAnimation();
break;
}
case (5): {
x = 1;
checkX();
break;
}
case (0): {
x = 4;
checkX();
break;
}
}
}
private void endingAnimation() {
// TODO Auto-generated method stub
ObjectAnimator animation2 = ObjectAnimator.ofFloat(xImg, "alpha", 255);
animation2.setDuration(1000);
animation2.start();
}
private void startingAnimation() {
// TODO Auto-generated method stub
ObjectAnimator animation = ObjectAnimator.ofFloat(xImg, "alpha", 0);
animation.setDuration(1000);
animation.start();
}
checkX is called each time i press a button(that add or subtract 1 to X).
How i can make both animations and ImageView resource change?

Try changing the image source when the animation's onAnimationEnd is called. For example:
animation.addListener(new AnimatorListener() {
#Override
public void onAnimationStart(Animator animation) { }
#Override
public void onAnimationRepeat(Animator animation) { }
#Override
public void onAnimationEnd(Animator animation) {
// change your ImageView's source here
}
#Override
public void onAnimationCancel(Animator animation) { }
});

Apply fade out animation on your ImageView and set animationListener to it. on animation end change your views resource and set fade in animation on it
For fade in animation
Animation fadeIn = new AlphaAnimation(0, 1);
fadeIn.setInterpolator(new DecelerateInterpolator());
fadeIn.setDuration(1000);
final AnimationSet animation = new AnimationSet(false);
animation.addAnimation(fadeIn);
For fade out animation
Animation fadeOut = new AlphaAnimation(1, 0);
fadeOut.setInterpolator(new AccelerateInterpolator());
fadeOut.setDuration(300);
final AnimationSet animation = new AnimationSet(false);
animation.addAnimation(fadeOut);
Thats how you implement listner on animation
fadeout.setAnimationListener(new Animation.AnimationListener(){
#Override
public void onAnimationStart(Animation arg0) {
}
#Override
public void onAnimationRepeat(Animation arg0) {
}
#Override
public void onAnimationEnd(Animation arg0) {
//change resource of Imageview here
}
});