Private const val batterySaverMode = 'battery' Now, to update the theme dynamically we have to use, tDefaultNightMode(/**Your Mode**/) System default (the recommended default option for Android Q).Set by Battery Saver (the recommended default option for Android P or before).

We can also let user to change the theme while using the app. Note : If you want to replace the color in the app, you need to create a custom values directory, called values-night and for image resources as well we will create drawables-night. So while still viewing the text box properties, change the right margin to 0, as indicated by callout 2 in figure 8.The above is the screenshot when you convert your style to Dark Mode.

However, the two views are separated by 32dp instead of 16dp, because both views have margins.

Therefore, the text box stretches to fill the horizontal space. 'Match constraints' means that the width is now determined by the horizontal constraints and margins. Open the Properties window for the text box and then click the width indicator until set to Match Constraints, as indicated by callout 1 in figure 8.This is called a chain (as indicated by the chain betwen the views), and it enables some extra layout options. So both views are constrained to each other. It might look like that's already there, but you're actually adding a bidirectional constraint between the two views.

Add a constraint from the right side of the text box to the left side of the button.This now defines the total width that the two views have available (which you can now fill with the text box). Create a constraint from the right side of the button to the right side of the parent layout.Figure 9. The text box stretches to fill the remaining space

Change text editor theme android studio