Toggle Buttons

A toggle button allows the user to change a setting between two states.

You can add a basic toggle button to your layout with theToggleButton object. Android 4.0 (API level 14) introduces another kind of toggle button called a switch that provides a slider control, which you can add with a Switch object.

Toggle buttons

Switches (in Android 4.0+)

The ToggleButton and Switch controls are subclasses ofCompoundButton and function in the same manner, so you can implement their behavior the same way.

Responding to Click Events

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When the user selects a ToggleButton and Switch, the object receives an on-click event.

To define the click event handler, add the android:onClick attribute to the <ToggleButton> or <Switch>element in your XML layout. The value for this attribute must be the name of the method you want to call in response to a click event. The Activity hosting the layout must then implement the corresponding method.

For example, here's a ToggleButton with the android:onClick attribute:

<ToggleButton 
    android:id="@+id/togglebutton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textOn="Vibrate on"
    android:textOff="Vibrate off"
    android:onClick="onToggleClicked"/>

Within the Activity that hosts this layout, the following method handles the click event:

public void onToggleClicked(View view) {
    // Is the toggle on?
    boolean on = ((ToggleButton) view).isChecked();
    
    if (on) {
        // Enable vibrate
    } else {
        // Disable vibrate
    }
}

The method you declare in the android:onClick attribute must have a signature exactly as shown above. Specifically, the method must:

• Be public
• Return void
• Define a View as its only parameter (this will be the View that was clicked)

Tip: If you need to change the state yourself, use the setChecked(boolean) or toggle() method to change the state.

Using an OnCheckedChangeListener

You can also declare a click event handler pragmatically rather than in an XML layout. This might be necessary if you instantiate the ToggleButton or Switch at runtime or you need to declare the click behavior in aFragment subclass.

To declare the event handler programmatically, create an CompoundButton.OnCheckedChangeListenerobject and assign it to the button by callingsetOnCheckedChangeListener(CompoundButton.OnCheckedChangeListener). For example:

ToggleButton toggle = (ToggleButton) findViewById(R.id.togglebutton);
toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        if (isChecked) {
            // The toggle is enabled
        } else {
            // The toggle is disabled
        }
    }
});