android widget Switch - on off event listener

Question

I would like to implement a switch button  android widget Switch  available from API v 14     lt Switch     android id    id switch1      android layout width  wrap content      android layout height  wrap content      android text  Switch    gt    But I m not sure how to add an event listener for the button  Should it be an  onClick  listener  And how would I know if it is toggled  on  or not

User · Answer

Use the following snippet to add a Switch to your layout via XML:

<Switch
     android:id="@+id/on_off_switch"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:textOff="OFF"
     android:textOn="ON"/>

Then in your Activity's onCreate method, get a reference to your Switch and set its OnCheckedChangeListener:

Switch onOffSwitch = (Switch)  findViewById(R.id.on_off_switch); 
onOffSwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    Log.v("Switch State=", ""+isChecked);
}       

});

User · Answer

The layout for Switch widget is something like this    lt LinearLayout     android layout width  match parent      android layout height  wrap content      android orientation  vertical  gt       lt Switch         android layout width  wrap content          android layout height  wrap content          android layout marginRight  20dp          android gravity  right          android text  All          android textStyle  bold          android textColor   color black          android textSize  20dp          android id    id list toggle    gt   lt  LinearLayout gt    In the Activity class  you can code by two ways  Depends on the use you can code   First Way  public class ActivityClass extends Activity implements CompoundButton OnCheckedChangeListener   Switch list toggle   Override protected void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       setContentView R layout return vehicle        list toggle  Switch findViewById R id list toggle       list toggle setOnCheckedChangeListener this            public void onCheckedChanged CompoundButton buttonView boolean isChecked        if isChecked            list toggle setText  Only Today s       To change the text near to switch         Log d  You are      Checked              else           list toggle setText  All List        To change the text near to switch         Log d  You are       Not Checked              Second way   public class ActivityClass extends Activity   Switch list toggle   Override protected void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       setContentView R layout return vehicle        list toggle  Switch findViewById R id list toggle       list toggle setOnCheckedChangeListener new CompoundButton OnCheckedChangeListener             Override        public void onCheckedChanged CompoundButton buttonView  boolean isChecked              if isChecked                 list toggle setText  Only Today s       To change the text near to switch              Log d  You are      Checked                          else                list toggle setText  All List       To change the text near to switch              Log d  You are       Not Checked

User · Answer

My solution  using a SwitchCompat and Kotlin  In my situation  i needed to react to a change only if the user triggered it through the UI  In fact  my switch reacts to a LiveData  and this made both setOnClickListener and setOnCheckedChangeListener unusable  setOnClickListener in fact reacts correctly to user interaction  but it s not triggered if the user drags the thumb across the switch  setOnCheckedChangeListener on the other end is triggered also if the switch is toggled programmatically  for example by an observer   Now in my case the switch was present on two fragments  and so onRestoreInstanceState would trigger in some cases the switch with an old value overwriting the correct value   So  i looked at the code of SwitchCompat  and was able to mimic it s behaviour successfully in distinguishing click and drag and used that to build a custom touchlistener that works as it should  Here we go          This function calls the lambda function passed with the right value of isChecked    when the switch is tapped with single click isChecked is relative to the current position so we pass  isChecked    when the switch is dragged instead  the position of the thumb centre where the user leaves the    thumb is compared to the middle of the switch  and we assume that left means false  right means true     there is no rtl or vertical switch management     The behaviour is extrapolated from the SwitchCompat source code     class SwitchCompatTouchListener private val v  SwitchCompat  private val lambda   Boolean - gt Unit     View OnTouchListener       companion object           private const val TOUCH MODE IDLE   0         private const val TOUCH MODE DOWN   1         private const val TOUCH MODE DRAGGING   2            private val vc   ViewConfiguration get v context      private val mScaledTouchSlop   vc scaledTouchSlop     private var mTouchMode   0     private var mTouchX   0f     private var mTouchY   0f                  return true if  x  y  is within the target area of the switch thumb        x y and rect are in view coordinates  0 0 is top left of the view             private fun hitThumb x  Float  y  Float   Boolean           val rect   v thumbDrawable bounds         return x  gt   rect left  amp  amp  x  lt   rect right  amp  amp  y  gt   rect top  amp  amp  y  lt   rect bottom            override fun onTouch view  View  event  MotionEvent   Boolean           if  view    v                when  MotionEventCompat getActionMasked event                     MotionEvent ACTION DOWN - gt                        val x   event x                     val y   event y                     if  v isEnabled  amp  amp  hitThumb x  y                             mTouchMode   TOUCH MODE DOWN                          mTouchX   x                          mTouchY   y                                                          MotionEvent ACTION MOVE - gt                        val x   event x                     val y   event y                     if  mTouchMode    TOUCH MODE DOWN  amp  amp                           abs x - mTouchX   gt  mScaledTouchSlop    abs y - mTouchY   gt  mScaledTouchSlop                                                mTouchMode   TOUCH MODE DRAGGING                                    MotionEvent ACTION UP                  MotionEvent ACTION CANCEL - gt                        if  mTouchMode    TOUCH MODE DRAGGING                            val r   v thumbDrawable bounds                         if  r left   r right  lt  v width  lambda false                          else lambda true                        else lambda  v isChecked                      mTouchMode   TOUCH MODE IDLE                                                    return v onTouchEvent event            How to use it   the actual touch listener that accepts a lambda with the code to execute   myswitch setOnTouchListener      SwitchCompatTouchListener myswitch               here goes all the code for your callback  in my case            i called a service which  when successful  in turn would             update my liveData          viewModel sendCommandToMyService it             For the sake of completeness  this is how the observer for the state switchstate  if you have it  looked like   switchstate observe this  Observer       myswitch isChecked   it

User · Answer

For those using Kotlin  you can set a listener for a switch  in this case having the ID mySwitch  as follows       mySwitch setOnCheckedChangeListener      isChecked - gt              do whatever you need to do when the switch is toggled here         isChecked is true if the switch is currently checked  ON   and false otherwise

User · Answer

Define your XML layout    lt RelativeLayout xmlns android  http   schemas android com apk res android      xmlns tools  http   schemas android com tools      android layout width  match parent      android layout height  match parent      tools context  com neoecosystem samplex SwitchActivity  gt        lt Switch         android id    id myswitch          android layout height  wrap content          android layout width  wrap content    gt    lt  RelativeLayout gt     Then create an Activity  public class SwitchActivity extends ActionBarActivity implements CompoundButton OnCheckedChangeListener        Switch mySwitch   null         Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout activity switch             mySwitch    Switch  findViewById R id myswitch           mySwitch setOnCheckedChangeListener this               Override     public void onCheckedChanged CompoundButton buttonView  boolean isChecked            if  isChecked                   do something when check is selected           else                 do something when unchecked                                        For below API 14 use SwitchCompat            XML   lt RelativeLayout xmlns android  http   schemas android com apk res android      xmlns tools  http   schemas android com tools      android layout width  match parent      android layout height  match parent      tools context  com neoecosystem samplex SwitchActivity  gt        lt android support v7 widget SwitchCompat         android id    id myswitch          android layout height  wrap content          android layout width  wrap content    gt    lt  RelativeLayout gt    Activity  public class SwitchActivity extends ActionBarActivity implements CompoundButton OnCheckedChangeListener        SwitchCompat mySwitch   null         Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout activity switch             mySwitch    SwitchCompat  findViewById R id myswitch           mySwitch setOnCheckedChangeListener this               Override     public void onCheckedChanged CompoundButton buttonView  boolean isChecked            if  isChecked                   do something when checked is selected           else                 do something when unchecked

User · Answer

there are two ways    using xml onclick view Add Switch in XML as below     lt Switch android id    id switch1  android onClick  toggle   gt     In YourActivity Class  For E g MainActivity java       Switch toggle    outside oncreate     toggle   Switch  findViewById R id switch1      inside oncreate      public void toggle View view    outside oncreate               if  toggle isChecked                  if  Build VERSION SDK INT  gt   Build VERSION CODES M                    start setBackgroundColor getColor R color gold                    stop setBackgroundColor getColor R color white                                    else                       if  Build VERSION SDK INT  gt   Build VERSION CODES M                    stop setBackgroundColor getColor R color gold                    start setBackgroundColor getColor R color white                                     using on click listener   Add Switch in XML as below             In YourActivity Class  For E g MainActivity java       Switch toggle     outside oncreate     toggle   Switch  findViewById R id switch1       inside oncreate       toggle setOnClickListener new View OnClickListener          inside oncreate          Override         public void onClick View view                 if  toggle isChecked                      if  Build VERSION SDK INT  gt   Build VERSION CODES M                        start setBackgroundColor getColor R color gold                                                else                               if  Build VERSION SDK INT  gt   Build VERSION CODES M                        stop setBackgroundColor getColor R color gold

User · Answer

You can use DataBinding and ViewModel for Switch Checked Change event   lt layout xmlns android  http   schemas android com apk res android      xmlns app  http   schemas android com apk res-auto      xmlns tools  http   schemas android com tools  gt        lt data gt            lt variable                 name  viewModel                  type  com example ui ViewModel    gt       lt  data gt       lt Switch             android id    id on off switch              android layout width  wrap content              android layout height  wrap content              android onCheckedChanged     button  on  - gt  viewModel onCheckedChange on           gt

User · Answer

Switch inherits CompoundButton s attributes  so I would recommend the OnCheckedChangeListener  mySwitch setOnCheckedChangeListener new CompoundButton OnCheckedChangeListener         public void onCheckedChanged CompoundButton buttonView  boolean isChecked               do something  the isChecked will be            true if the switch is in the On position

User · Answer

In Kotlin           switch button setOnCheckedChangeListener   buttonView  isChecked - gt          if  isChecked                   The switch enabled             text view text    Switch on             else                  The switch disabled             text view text    Switch off

User · Answer

September 2020 - Programmatically Answer You can do it with programmatically for Switch Widget and Material Design  Switch yourSwitchButton   findViewById R id switch id    yourSwitchButton setChecked true      true is open  false is close   yourSwitchButton setOnCheckedChangeListener  compoundButton  b  - gt            if  b               open job                      else                close job                      canerkaseler

[android] android.widget.Switch - on/off event listener?

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