Android Adventures - Building The UI
Android Adventures - Building The UI
Written by Mike James   
Tuesday, 17 February 2015
Article Index
Android Adventures - Building The UI
Positioning multiple components
Simple Button Example
Calculator App
Going Further

If you can try it out on a real Android device do so - it is easier to find out what it really feels like. Also do have a look at what the layout looks like on a range of screens and orientations.

This isn't much of a calculator, but you could make it into a really good one. 

  • right align the text in the display
  • add a + and - button and implement the action
  • allow the user to enter multi-digit number
  • add a decimal point key and all a multi-digit float
  • add * an / keys
  • add a clear key 

and so on...

There are better ways to implement the layout and we will come back to the calculator program in later chapters.

Summary

  • You can create the XML layout file by hand, but using the Designer is easier.

  • It is still useful to know how the XML file works so that you can edit it when the Designer lets you down in some way.

  • The Designer modifies the way components look in the Layout by changing a component's properties.

  • How you position a component depends on the Layout you are using.

  • The RelativeLayout lets you position components relative to each other or to the container.

  • The Designer may change multiple properties to position the component where you want it.

  • Use the Component Tree to select components that are difficult to select in the Designer.

  • You can use the property window to select and directly set any property.

  • If you find positioning or sizing difficult in the Designer try zooming in. 

  • You can use Android Studio to view what your app looks like on various screen sizes and orientations. 

  • Different orientations and resolutions can be accommodated by creating additional layout files all with the same name. The system will pick which one to use at run time. 

  • You can copy and paste components in the Designer to quickly build up repeated UI designs. 

  • A single event handler can be attached to many components. 

 

NEW
Android Programming In Java:
Starting With an App
Third Edition

Covers Android Studio 3 and Constraint Layout.

Is now available as

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These articles are in the process of being updated to 3rd edition.

  1. Getting Started With Android Studio 3
  2. The Activity And The UI
  3. Building The UI and a Calculator App
  4. Android Events
  5. Basic Controls
  6. Layout Containers
  7. The ConstraintLayout
    1. Guidelines and Barriers
  1. UI Graphics A Deep Dive
  2. Menus & The Action Bar
  3. Menus, Context & Popup
  4. Resources
  5. Beginning Bitmap Graphics
  6. Staying Alive! Lifecycle & State
  7. Spinners
  8. Pickers
  9. ListView And Adapters

Earlier versions

2nd edition drafts:

  1. Getting Started With Android Studio 2
  2. The Activity And The UI
  3. Building The UI and a Calculator App
  4. Android Events
  5. Basic Controls
  6. Layout Containers - Updated Version in Print Book
  7. The ConstraintLayout - New In 2ed
  8. UI Graphics A Deep Dive
  9. Menus & The Action Bar
  10. Menus, Context & Popup
  11. Resources - Updated Version In Print Book 
  12. Beginning Bitmap Graphics
  13. Staying Alive! Lifecycle & State -Updated Version In Print Book
  14. Spinners
  15. Pickers
  16. ListView And Adapters

If you are interested in creating custom template also see:

Custom Projects In Android Studio

Androidgears

 

 

Coming Next

In the next chapter  we discover how to use more UI components and deal with the problem of implementing general event handling in Java.

Meanwhile if you have any questions on what we've covered so far please let me know using the comments.

You can download the code for this program and for the simple blank activity template from the CodeBin (note you have to register first).

 

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