How to change the font across the whole app

Either for the branding or to make the app look cooler or different, you might wonder how to change the font across the whole app? And all this in one go, without setting something for each view. So let’s do a step by step with this.

I made a simple app that has a list of articles from floridaman.com (some of the articles are quite funny) and a details screen for the article that it looks like this:

Step 1. Download the font

What I did, was go to Google Fonts and download a font. When I pick a font I look for one that has multiple styles. For this guide, I choose Source Code Pro, because it has a lot of styles and it looks quite different from the default app font.

Once you picked your font, download it and you should have a folder with a lot of .ttf files like this:

Step 2. Adding font to project

The font will be added to the project like a resource so we should rename the fonts we want to match the android naming requirements.

For this demo I picked just two fonts and renamed them:

  • SourceCodePro-Regular to source_code_pro_regular
  • SourceCodePro-Italic to source_code_pro_italic

Now we will go in Android Studio to the res folder, right-click on it, and create a new Android Resource Directory

And when the Dialog pops up we will choose to create a font directory

Now we take our fonts and copy them in the newly created font directory. The result should look like this.

Step 3. Creating the font family resource

After we’ve done this we need to create a font family resource that we will use to set the font across the whole app and to tell it how to use different types of fonts.

For that, we right-click on the font directory in Android Studio and create a new resource file, that will have the root as font-family. Something like this:

I named it default_font, because it will be a default everywhere in the app, and know we should tell them what font to use, so we change the content of the XML file to this:

<?xml version="1.0" encoding="utf-8"?> <font-family xmlns:android="http://schemas.android.com/apk/res/android"> <font android:font="@font/source_code_pro_regular" android:fontStyle="normal" /> <font android:font="@font/source_code_pro_italic" android:fontStyle="italic" /> </font-family>

Basically we set the font and pick the style for each font. There is also a font-weight attribute in case you need that.

Now you might notice a warning in the XML file and if you hover over it you will see that it says:

Attribute font is only used in API level 26 and higher

So this will only work for API level 26 or higher. To fix that we can click on the warning suggestion and choose to override Resource in font-v26. This will create a folder with two default_font.xml files. One for API level 26 and higher and the other one for below API level 26.

Now the one with the (v26) we will leave it as it is and on the other one we will replace android: namespace with the app: namespace in order to take advantage of the Support Library that can set the font below API level 26. More details you can find here.

<?xml version="1.0" encoding="utf-8"?> <font-family xmlns:app="http://schemas.android.com/apk/res-auto"> <font app:font="@font/source_code_pro_regular" app:fontStyle="normal" /> <font app:font="@font/source_code_pro_italic" app:fontStyle="italic" /> </font-family>

Step 4. Setting the font in the app

Now to set the font in the app all we have to do is go to styles.xml file and set the font family in our app theme like this:

<item name="android:fontFamily">@font/default_font</item>

Now if you run the app the result will look like this:

Conclusion

This is how you change the font across the whole app, even below API level 26, in 4 simple steps. Hope this helped you and if you are interested in more guides you can find here.

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