# Building RingQt Applications for Mobile¶

In this chapter we will learn about Building RingQt Applications for Mobile.

Check the next link : http://doc.qt.io/qt-5/androidgs.html

• The Android SDK Tools

• The Android NDK

• Apache Ant v1.8 or later

• Java SE Development Kit (JDK) v6 or later

## Update the Android SDK¶

Update the Android SDK to get the API and tools packages required for development

## Install Qt for Android¶

• You can install Qt for Android from the next link

• Run Qt Creator, Select Tools > Options > Android to add the

Android NDK and SDK paths.

• Using Qt Creator Open the project

Folder : ring/android/ringqt/project

Project file : project.pro

• You will find the code in resourcestest.ring

You can modify the code then build and run for Desktop or Mobile.

## Comments about developing for Android using RingQt¶

1. The main project file is main.cpp

This file load Ring Compiler/Virtual Machine and RingQt

Then copy files during the runtime from the resources to temp. folder

Then run the test.ring

Through main.cpp you can extract more files from the resources to temp. folder once you add them (create projects with many files).

2. The next functions are missing from this Ring edition

• Database (ODBC, SQLite & MySQL)
• Security and Internet functions (LibCurl & OpenSSL)
• RingAllegro (Allegro Library)
• RingLibSDL (LibSDL Library)

Just use Qt Classes through RingQt.

For database access use the QSqlDatabase Class

Note

All of the missing libraries ((LibCurl, OpenSSL & Allegro) can be compiled for Android, but they are not included in this Qt project.

1. use if isandroid() when you want to modify the code just for android

Example:

if isandroid()
// Android code
else
// other platforms
ok


(4) Sometimes you will find that the button text/image is repeated in drawing ! it’s Qt problem that you can avoid using the next code.

if isandroid()
setStyleSheet("
border-style: outset;
border-width: 2px;
border-color: black;
ok

1. Always use Layouts instead of manual setting of controls position and size.

This is the best way to get the expected user interface to avoid problems like (controls with small/extra size)

1. When you deal with Qt Classes you can determine the images from resources (you don’t need to copy them using main.cpp)

Example:

if isandroid()
mypic = new QPixmap(":/resources/cardsimage")
else
mypic = new QPixmap("cards.jpg")
ok


In the previous example, cards.jpg is added to the resources then we write the “cardsimage” as alias for “cards.jpg”