Android - How to dynamically change the thumb/track color of a SwitchPreference's switch

Question

So far, I can only change the summary/title text color of a preference with setSpan() on the text, but I couldn't find anything that can change the Switch's color in a SwitchPreference, I considered several plans including set a custom layout, or set a custom adapter for the preference, but I don't have a clear idea of how to achieve them yet, so, your help will be greatly appreciated.

PS: I considered simply set a custom layout, but that won't work in my case because I need to change the color of a SwitchPreference when the app is running, and users can set a custom color for the Switches, so themes also won't work in this case.

Answer 1

OK, I found the solution by myself:

Create a custom SwitchPreference class, then apply that to all the SwitchPreference widgets that you got, the class looks like this:

    class ColorSwitchPreference extends SwitchPreference {
    Switch aSwitch;
    SharedPreferences sharedPreferences;

    public ColorSwitchPreference(Context context){
        super(context);
    }

    public ColorSwitchPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public ColorSwitchPreference(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public ColorSwitchPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }


    @Override
    protected void onBindView(View view) {
        super.onBindView(view);
        aSwitch = findSwitchInChildViews((ViewGroup) view);
        if (aSwitch!=null) {
            //do change color here
            changeColor(aSwitch.isChecked(),aSwitch.isEnabled());
            aSwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    changeColor(isChecked, aSwitch.isEnabled());
                }
            });
        }
    }

    private void changeColor(boolean checked, boolean enabled){
        try {
            sharedPreferences = getContext().getSharedPreferences("settings_data",MODE_PRIVATE);
            //apply the colors here
            int thumbCheckedColor = sharedPreferences.getInt("theme_color_key",Color.parseColor("#3F51B5"));
            int thumbUncheckedColor = Color.parseColor("#ECECEC");
            int trackCheckedColor = sharedPreferences.getInt("theme_color_key",Color.parseColor("#3F51B5"));
            int trackUncheckedColor = Color.parseColor("#B9B9B9");
            if(enabled){
                aSwitch.getThumbDrawable().setColorFilter(checked ? thumbCheckedColor : thumbUncheckedColor, PorterDuff.Mode.MULTIPLY);
                aSwitch.getTrackDrawable().setColorFilter(checked ? trackCheckedColor : trackUncheckedColor, PorterDuff.Mode.MULTIPLY);
            }else {
                aSwitch.getThumbDrawable().setColorFilter(Color.parseColor("#B9B9B9"), PorterDuff.Mode.MULTIPLY);
                aSwitch.getTrackDrawable().setColorFilter(Color.parseColor("#E9E9E9"), PorterDuff.Mode.MULTIPLY);
            }
        }catch (NullPointerException e){
            e.printStackTrace();
        }
    }

    private Switch findSwitchInChildViews(ViewGroup view) {// find the Switch widget in the SwitchPreference
        for (int i=0;i<view.getChildCount();i++) {
            View thisChildview = view.getChildAt(i);
            if (thisChildview instanceof Switch) {
                return (Switch)thisChildview;
            }
            else if (thisChildview instanceof  ViewGroup) {
                Switch theSwitch = findSwitchInChildViews((ViewGroup) thisChildview);
                if (theSwitch!=null) return theSwitch;
            }
        }
        return null;
    }
}

Basically, you use findSwitchInChildViews() to get the Switch widget in the SwitchPreference, and then change the color from there.

That's it! it's actually a pretty straightforward approach, but I just didn't think about it before, hope this post can help someone in the future to avoid my struggle.

(PS: I got the code for finding Switch from here, changing Switch color from here, thanks!)