Font size of TextView in Android application changes on changing font size from native settings

Question

I want to specify my own text size in my application, but I am having a problem doing this.

When I change the font size in the device settings, the font size of my

Answer 1

It is not a good thing to have to specify DIP or SP again by code when already defined in a dimen.xml file.

I think that the best option is to use PX when using a dimen.xml value :

tv.setTextSize(TypedValue.COMPLEX_UNIT_PX, getResources().getDimensionPixelSize(R.dimen.txt_size));

This way, you can switch from DP to SP if needed in dimen.xml file without having to change any code.

Answer 2

this may help. add the code in your custom Application or BaseActivity

/**
 * 重写 getResource 方法，防止系统字体影响
 *
 * @return
 */
@Override
public Resources getResources() {
    Resources resources = super.getResources();
    if (resources != null && resources.getConfiguration().fontScale != 1) {
        Configuration configuration = resources.getConfiguration();
        configuration.fontScale = 1;
        resources.updateConfiguration(configuration, resources.getDisplayMetrics());
    }
    return resources;
}

however, Resource#updateConfiguration is deplicated in API level 25, which means it will be unsupported some day in the future.

Answer 3

this solutions is with Kotlin and without using the deprecated function resources.updateConfiguration

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        adjustFontScale(resources.configuration)
    }

    private fun adjustFontScale(configuration: Configuration?) {
        configuration?.let {
            it.fontScale = 1.0F
            val metrics: DisplayMetrics = resources.displayMetrics
            val wm: WindowManager = getSystemService(Context.WINDOW_SERVICE) as WindowManager
            wm.defaultDisplay.getMetrics(metrics)
            metrics.scaledDensity = configuration.fontScale * metrics.density

            baseContext.applicationContext.createConfigurationContext(it)
            baseContext.resources.displayMetrics.setTo(metrics)

        }
    }

Observation: this is the same solution as the above but udpated with Kotlin

Answer 4

Use the dimension type of resources like you use string resources (DOCS).

In your dimens.xml file, declare your dimension variables:

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <dimen name="textview_height">25dp</dimen>
  <dimen name="textview_width">150dp</dimen>
  <dimen name="ball_radius">30dp</dimen>
  <dimen name="font_size">16sp</dimen>
</resources>

Then you can use these values like this:

<TextView
   android:layout_height="@dimen/textview_height"
   android:layout_width="@dimen/textview_width"
   android:textSize="@dimen/font_size"/>

You can declare different dimens.xml files for different types of screens. Doing this will guarantee the desired look of your app on different devices.

When you don't specify android:textSize the system uses the default values.

Answer 5

Override getResources() in Activity.

Set TextView's size in sp as usual like android:textSize="32sp"

override fun getResources(): Resources {
    return super.getResources().apply {
        configuration.fontScale = 1F
        updateConfiguration(configuration, displayMetrics)
    }
}

Answer 6

for kotlin, it works for me

priceTextView.textSize = 12f