Scandium

Introduction

Scandium is a replacement for Appcelerator's Titanium Desktop that enables deployment of Python web applications on the desktop.

A scandium app is basically just a Flask app inside a chromeless QtWebKit widget.

Installation

Scandium depends on:

• twisted
• flask
• qt4reactor
• PySide
• py2exe

The most hassle-free installation method is to download and install twisted, qt4reactor, PySide and py2exe separately. Setuptools will install Flask for you.

Creating a Project

Running scadmin.py startproject projectname will produce the following in the current directory::

- scandium-projectname
| - runapp.py
| - setup.py
\ - projectname
  | - __init__.py
  | - settings.py
  | - static
  | | - css
  | | - icons
  | \ - js
  | - templates
  |  \ - index.html
  \ views.py

Getting Started

If you've got your dependencies in order, python runapp.py will generate a Scandium 'hello world' application from a blank project.

Add views, templates and static content in the obvious places.

Configuration

You can override the default configuration by modifying settings.py. Available settings and defaults are as follows:

DEBUG

Debug flag for the Scandium app. Enables

Default: True

FLASK_DEBUG

Sets the debug flag on the Flask app. Enables in-browser tracebacks etc.

Default: True

HTTP_PORT

Port to listen for HTTP connections.

Default: 8080

STATIC_RESOURCE

Defines where to find static resources. Can be a filepath or a tuple of (package, directoryname). You must use the latter format if you want to deploy your application using a compressed or bundled distributable. The default value for this setting is defined in settings.py because the project name is required.

Default: (projectname, 'static')

TEMPLATE_RESOURCE

Defines where to find templates. Can be a filepath or a tuple of (package, directoryname). You must use the latter format if you want to deploy your application using a compressed or bundled distributable. The default value for this setting is defined in settings.py because the project name is required.

Default: (projectname, 'templates')

ALLOW_DEFERREDS

If enabled, views may return twisted deferred objects. The response will be returned to the browser when the deferred fires.

Default: False

ICON_RESOURCE

Defines the image to use for the application icon. Can be a filepath or a tuple of (package, directoryname). You must use the latter format if you want to deploy your application using a compressed or bundled distributable.

Default: None

WINDOW_TITLE

Title to be displayed in the browser window. Adding a <title></title> tag to your HTML page won't affect this.

Default: "Scandium Browser"

WINDOW_GEOMETRY

Size and position for the application window, specified as (x, y, width, height).

Default: (100, 100, 800, 500)

Custom Settings

It is possible to define custom settings in settings.py for use in your web application code. Just do from projectname import sc and reference the settings using sc.conf.SETTING_NAME.

Building with py2exe

The template project layout includes a setup.py file that will generate an executable using py2exe when invoked. Running python setup.py py2exe will generate a dist directory containing::

- projectname.exe
- QtGui4.dll
- QtNetwork4.dll
- QtCore4.dll
\ - imageformats
  | - qgif4.dll
  | - qjpeg4.dll
  | - qsvg4.dll
  ...

The Qt4 DLLs and imageformats formats directory need to be there for image processing support. I can't figure out how to embed them inside the executable, so you need to distribute this whole directory.

Target machines must have the Microsoft Visual C++ Redistributable installed, available from http://www.microsoft.com/en-us/download/confirmation.aspx?id=29