How to use a different drawable res folder (for eg. drawable-theme1) when the appTheme is selected as "theme1" from styles.xml? Is this possible?

Question

Currently I am having four themes in my styles.xml file. (theme1, theme2, theme3, theme4).

I am having a test_image.xml in both drawable & drawable-theme1 folders.

What I need is, for theme1 alone, I need resources from drawable-theme1, and for other themes (theme2, theme3, theme4), I need resources from normal drawable folder.

Finally, while setting the image view programmatically, I will be calling imageView.setResource(R.drawable.test_image). The resource file must be retrieved based on my selected theme.

Whether this is possible?

I could not get any questions or similar relevant to this. If anyone has provided a solution already, please help me finding that. Thanks

Answer 1

You can't use <themeName> as a qualifier.
It means that you can't use a drawable-themeName folder.

However you can define a custom attribute in the attrs.xml file:

<resources>
    <attr name="myDrawable" format="reference" />
</resources>

Then in styles.xml in the app theme you can define it:

<style name="AppTheme1" parent="Theme.MaterialComponents.DayNight">
    <!-- .....   -->
    <item name="myDrawable">@drawable/ic_add_24px</item>

</style>

Finally in a layout you can use something like:

<com.google.android.material.button.MaterialButton
    ....
    app:icon="?attr/myDrawable"/>

or programmatically:

    MaterialButton button = findViewById(R.id.button);

    TypedValue typedValue = new TypedValue();
    getTheme().resolveAttribute(R.attr.myDrawable, typedValue, true);
    button.setIcon(ContextCompat.getDrawable(this,typedValue.resourceId));