Table of Contents

About

Responsive UI in Android.

See also: Android - GUI (Layout)

See https://material.io/guidelines/layout/responsive-ui.html

Flexible UI with fragment

A modular fragment allows you to change your fragment combinations for different screen sizes.

Android Tablet Handset Design

See Building a flexible UI with fragments.

Why not always create one Activity with a lots of fragments ?

  • Increased complexity of the code
  • Harder intent handling
  • Difficult to read, maintain and test
  • Risk of tight coupling
  • Security concerns (???)

Create a new activity when the context changes. For example:

  • displaying different kind of data
  • of switching from viewing to entering data

Code example:

  • get a transaction (from FragmentManager)
  • code that handle the back button if the user want to go back to the previous fragment.
  • replace the contents of fragment_container with a new DetailsFragment. 
FragmentManager fm = getFragmentManager();

Fragment fragB = new DetailsFragement();
int containerID = R.id.fragement_container;
String tag = null;

FragmentTransaction ft = fm.beginTransaction();
ft.addToBackStack(tag); // when the user hits the back button, they go back to the previous fragment.
ft.replace(containerID, fragB);
ft.commit; // The transaction is executed by calling commit

Density-Independent Pixels (dp or dip)

Multiple screens - ConfigurationExamples

Android Screen Buckets

Density-Independent Pixels (dp or dip) is the consistent unit of measure to define physical size.

The measure is consistent between:

  • tablet physical size
  • and pixel density. dpi = dots per inch

For example, A 48 dp button will be the same physical size across all different screen densities.

Documentation / Reference