layout management in PySide2

-
Qt has Layout System. PySdie2 is wrapper of Qt5 for python. so that PySide2 supports Qt Layout System.

in this page, I will what is the layout system and why we should learn it. and I will introduce them shortly.

layout system is a simple and easy way to arrange child widgets automatically. Qt provide a few layout classes that layouts automatically position and resize width and height of widgets when the children are changed.

they are in charge of below tasks.


  • Positioning of child widgets
  • Sensible default sizes for windows
  • Sensible minimum sizes for windows
  • Resize handling
  • Automatic updates when contents change:
    • Font size, text or other contents of child widgets
    • Hiding or showing a child widget
    • Removal of child widgets

typically, there are 4 types of layout management classes.

QHBoxLayout
QVBoxLayout
GRidLayout
QFormLayout

they inherit QLayout class. if you need more complex layout, you can nest them inside each other.

I mainly focused what layout management is in this page.
after this, I will introduce how to use them one by one with example code.


Comments

Post a Comment

Popular posts from this blog

making menubar and menu on QML

-
Image
Qt Quick Control module has ApplicationWindow object that has menubar, toolbar, footer and contents areas. in this page, I will introduce how to make menubar. first of all, we need application engine in python. so you can learn the way how to make the application object in python from  how to use Qt Quick Controls in PySdie2 we need simple window like below. import QtQuick 2.13 import QtQuick.Controls 2.13 ApplicationWindow { visible: true width: 720 height: 480 title: "simple window" } WindowApplication is invisible by default. so, we should set the visibility to true. and the properties that I used above are derived from QML Item object. ApplicationWindow has its own properties like below. activeFocusControl : Control background : Item contentData : list contentItem : Item font : font footer : Item header : Item locale : Locale menuBar : Item palette : palette we will focus on only menubar property of them in this pa
Read more

let's start QML programming with PySide2

-
Image
What is QML? QML is UI programming language. it is some like the structure of JSON format. QML is supported by QtQML module. In other words, it is based in Qt framework. QtQuick module includes QtQML module. and QtQuick includes visual components, model-view support, animation framework and other many components to build UI. What is strength of QML? QML is derived from Qt. using QML means using Qt. Qt is cross-platform framework. so, once you are familiar with Qt, you can make desktop, mobile(andorid and ios) and embedded GUI application with only Qt knowledge. and you can choose what you use for back-end with c++ and python. when learning new programming, it would be best way to print "Hello World". so, I will show you how to print "Hello World" with QML and Python. first of all, you should make .qml file. I made View.qml file for example. and then, just type like below code. //View.qml import QtQuick 2.0 Rectangle { width: 200 height
Read more

QSizePolicy Fixed example in pyside2

-
Image
when you set the size policy property of widget to QSizePolicy::Fixed,  the size of widget is fixed. even if the space of layout is changed, the size of widget is fixed. layout management of Qt manages the position and the size of nested widgets. but if any of widgets has fixed size policy, the widget is not handled by layout management. widget has setFixedSize() function. if you use this function, the maximum size and minimum size of widget is set to that value. let's check this behavior from example code. from PySide2 import QtWidgets app = QtWidgets . QApplication([]) window = QtWidgets . QWidget() layout = QtWidgets . QHBoxLayout() fixedSizedButton = QtWidgets . QPushButton( "Fixed Widget" ) print (fixedSizedButton . sizePolicy()) fixedSizedButton . setSizePolicy(QtWidgets . QSizePolicy . Fixed, QtWidgets . QSizePolicy . Fixed) layout . addWidget(fixedSizedButton) window . setLayout(layout) window . show() app . exec_() I created window widg
Read more