Building RingQt Applications for Mobile

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

Update the Android SDK

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

Install Qt for Android

RingQt for Android

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


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


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

(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()
                border-style: outset;
                border-width: 2px;
                border-radius: 4px;
                border-color: black;
                padding: 6px;")
  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)


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

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