SCaLE Mobile App

Mobile App for Southern California Linux Expo.

Getting Started

Qt is a cross-platform software development kit written in C++. This project uses Qt Quick which allows us to write an application that can run on any desktop and mobile platform. You'll need to have Qt installed as well as the mobile SDKs in order to compile for mobile. Windows and Linux users can compile for Android and desktop only because iOS SDK is not available for those platforms. OSX users can compile for all platforms.

Clone the repo and update submodules:

git clone https://github.com/KnowikiApps/scale-conf-app.git
git submodule update --init

Installing Qt

You willl need to install Qt SDK and Qt Creator. This project uses Qt SDK version 5.15.x LTS

For Android

In order to compile for Android you will need to set up the Android development tools. http://doc.qt.io/qt-5/androidgs.html

For iOS (OSX Users Only)

http://doc.qt.io/qt-5/ios-support.html

Building and running

Everything you need is in the Qt Creator IDE. It has a built in compiler and debugger, and a ton of other tools.

http://doc.qt.io/qtcreator/

Project settings are defined in a .pro file in the project root. Open the file with Qt Creator to import the project.

Configuring the project

Depending on what OS you're using, and if you have all of the dependencies, you will be prompted to choose a list of kits for compile and run.

Qt Versioning is pretty specific, so it's important to use the correct Qt version. We're using version 5.15.2 for this project.

Android

If you have installed the Android SDK and tools necessary, you should have an option that looks something like this: Android for armeabi_v7a (GCC 4.9, Qt 5.x.x)

SSL Support

Qt Networking libraries (like the one we use to pull data from api endpoints) use OpenSSL, but Android no longer supports it. In order to get this to work you need to provide the binaries. They are included with the git submodule from the convenience repository https://github.com/KDAB/android_openssl

This is the official Qt Article on the topic: http://doc.qt.io/qt-5/opensslsupport.html

Desktop

For most development work, you can get away with not using a mobile virtual device or simulator. The app should run basically the same as a desktop app. You should at least have this option, if you dont have any others. Desktop Qt 5.x.x <compiler>

iOS

If you're using Mac OS, then you should be able to run the app on the iOS simulator or an actual iOS device.

iphonesimulator-clang Qt 5.x.x for iOS3 iphoneos-clang Qt 5.x.x for iOS3

Building for iOS

iOS devices require a lot of images for icons and launch screens. In the ios directory you'll find the SVG source images which need to be rendered to png before build. There is a python script that uses CairoSVG to render the png files and puts them in the assets catalog (which is just a directory).

To install cairosvg:

pip3 install cairosvg

To run the render script (from within the ios directory):

python3 render-images.py

Building for Android

Android needs fewer image assets than iOS does, but there is a render script for some of the image assets anyway.

From the project root:

cd android/img/

python3 render-images.py

(EXPERIMENTAL) Android Docker Container

Currently there is a project underway to containerize the Android build environement. It is being hosted on Docker hub here:

https://hub.docker.com/r/knowikiapps/scale-conf/tags

The container can be run using this command:

docker run -it --rm knowikiapps/scale-conf:android-build-env

Qt Documentation

Qt Quick has changed a lot over the years. With so many versions floating out there, you'll need to be sure that you're looking at the proper documentation. If you're doing Google searches be sure to check the version of Qt Quick Controls. An example of a search that will give you want you want: QtQuick.Controls 2 ApplicationWindow Prefacing your search with "QtQuick.Controls 2" will help make sure you're getting the right version of the docs. Previous versions of QtQuick Controls are very different. The example above illustrates this, previous versions of ApplicationWindow have properties that v2 doesnt have.

Javascript

QML uses javascript to manipulate the graphical objects. This implementation of ECMAScript is not exactly the same as javascript for browsers, but it's close. Here's more info:

http://doc.qt.io/qt-5/qtqml-javascript-expressions.html

http://doc.qt.io/qt-5/qtqml-javascript-resources.html

http://doc.qt.io/qt-5/qtqml-javascript-imports.html

http://doc.qt.io/qt-5/qtqml-javascript-qmlglobalobject.html

https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest