Py Con 2016

PySide For Beginners

What We'll learn

• Qt Framework brief history
• PySide Introduction
• PySide Fundamentals
• Some Code Example

Qt Framework

Key Features

• Cross platform application framework Using C++ 
• Executable on various operating systems with little or none code change.
• native speed and capabilities

Supported Platforms :

• Windows/ Linux / OSX
• Embedded Windows / Linux
• iOS / Android Windows Phone 

Qt Framework

Main Cores  

• QtCore : Core Functionality ( database, network , data structures, thread management  , etc. )  
• QtGUI : Interface Widgets

Some Extentions :

• Qt Creator IDE 
• QtQuick : QML for rapid UI Creation + Javascript Logic + CPP Native calls

Personal favourite :support for a subset of CSS

Qt Framework

Architechture  

• Transparent, Platform Independent UI
  Qt used to draw the UI from scratch in its early releases. In later versions, it uses call to native APIs
  You'll never draw a button. you ask OS to draw it for you!
• Signal And Slots : Implementing the Observable Pattern

Qt Framework

Free, somehow!

• Qt Framework is licensed unde LGPL. 
• Free to use for non commertial usage
• paid for commertial usage ( and it's not cheap! ) 

Long History

• Started at 1990
• Tooltech : rise
• Nokia : Official Symbian SDK 
• Sold to Digia after nokia (finally!) switched to Windows Phone OS  

PySide

PySide is the Python Qt bindings project, providing access the complete Qt 4.8 framework as well as to generator tools for rapidly generating bindings for any C++ libraries.

PyQt : Almost 100% similar to PySide

• PySide : LGPL , PyQt : GLP
• Doccumentation and Support : PySide is more reliable

PySide

Why you might choose PySide/PyQt over Pure Qt 

• Qt Worked hard on making core functionalities easy to use :
• Entire Qt-Specific IDE, Custom data types ( QVector, QList, .. ) ,integrated Database,
•  but...

PySide

But... 

• In one word : Python has almost all of it out of the box, and much easier 

PySide FUNdementals

The Code we will use : 

• https://github.com/Kianenigma
• each step is available on a separate commit
• clone the code, or view it online on github

HEllo wor... pyside!

• Create a minimal application window
• Set window title : 

Hello PySide!  

'Classing' it up

• Basically, every visual element in qt is a widget.
• Create a class that inherits from QWidget, write your own custom widget!
• Widgets can nest any other object that inherits from QWidget,
• a push button is also a widget, Nest it!
• Ref : PySide Widget Manual

classic stuff

• Some basic thing that basically every Gui framework has ( boring :| )
• Menu Bar 
• Tooltip
• Toolbar
• But,
• QWidget is just a blank surface, Menu Bars and.. are applicable to QMainWindow 
• Reference 1, Reference 2

ow beautiful qt!

• Basic Layout in Qt, PySide
• Absolute Positioning :
• Move, Set Geometry,
• Layouts :
  Grid , Box
• Lock window size, center it,..
• And Lovely CSS ! 
• Reference , Reference2 

there is a special place in hell for you if you use absolute geometry

trust the signals you get

• Any Widget can emit signals
• Any Widget can register itself as a slot, waiting for that signal
  Actually, anything inheriting from QtCore.QObject can emit and send, which is more general than QWidget!
• Binding a signal and slot : .connect()
  after calling app.exec_()
• Override internal slots
   

Signals, signals everywhere

• Passing parameter to a slot with lambda
• Emitting a custom events 
• Emitters might not be UI Elements,
  Network Event,
  Native Events,
  Time Intervals, etc...