Qt Style

Designer

We do not use designer, composer or other layout languages, just Qt in Python. So there is just one language to know: Python. Others may prefer to use additional tools, but they are not used in this app ( at least so far ).

QT Version

We us a library call qtpy which is a compatibility layere that lets the underlying Qt code be Qt5, or Qt6 or Pyside.....

Chat

The style of QT programming here seems to differ quite a bit from what I get from a Chat Bot. I assume this is modeled on most code that it has read. For example: Claude, using python and qt6, could you give me a qt6 widget as a window with 3 qpushbuttons alternating with 3 qlablewidgets layout these on 3 lines. Do not use loops, just basic straight line code.

Claud wrote a short app, part of which was this:

# --- Row 1 ---
self.button1 = QPushButton("Button 1")
self.label1  = QLabel("Label 1")
self.label1.setAlignment(Qt.AlignmentFlag.AlignVCenter | Qt.AlignmentFlag.AlignLeft)
self.button1.clicked.connect(self.on_button1_clicked)

row1 = QHBoxLayout()
row1.addWidget(self.button1)
row1.addWidget(self.label1)

# --- Row 2 ---
self.button2 = QPushButton("Button 2")
self.label2  = QLabel("Label 2")
self.label2.setAlignment(Qt.AlignmentFlag.AlignVCenter | Qt.AlignmentFlag.AlignLeft)
self.button2.clicked.connect(self.on_button2_clicked)

row2 = QHBoxLayout()
row2.addWidget(self.button2)
row2.addWidget(self.label2)

............ skip some code ......

# --- Main layout ---
main_layout = QVBoxLayout()
main_layout.addLayout(row1)
main_layout.addLayout(row2)
main_layout.addLayout(row3)

We would refactor the code to:

# ---- Main layout
main_layout = QVBoxLayout()
main_layout.setSpacing(12)
main_layout.setContentsMargins(20, 20, 20, 20)
self.setLayout(main_layout)

# --- Row 1 ---
row_layout = QHBoxLayout()
main_layout.addLayout(row_layout)

widget       = QPushButton("Button 1")
self.button1 = widget
widget.clicked.connect( self.on_button1_clicked )
row_layout.addWidget( widget )

widget        = QLabel("Label 1")
self.label1   = widget
widget.setAlignment(Qt.AlignmentFlag.AlignVCenter | Qt.AlignmentFlag.AlignLeft)
row_layout.addWidget( widget )

# --- Row 2 ---
row_layout = QHBoxLayout()
main_layout.addLayout(row_layout)

widget       = QPushButton("Button 2")
self.button2 = widget
widget.clicked.connect( self.on_button2_clicked )
row_layout.addWidget( widget )

widget        = QLabel("Label 2")
self.label2   = widget
widget.setAlignment(Qt.AlignmentFlag.AlignVCenter | Qt.AlignmentFlag.AlignLeft)
row_layout.addWidget( widget )

# --- Row 3 ---
row_layout = QHBoxLayout()
main_layout.addLayout(row_layout)

widget       = QPushButton("Button 3")
self.button1 = widget
widget.clicked.connect( self.on_button3_clicked )
row_layout.addWidget( widget )

widget        = QLabel("Label 3")
self.label3   = widget
widget.setAlignment(Qt.AlignmentFlag.AlignVCenter | Qt.AlignmentFlag.AlignLeft)
row_layout.addWidget( widget )

So how is this different:

• Larger elements are created first, layout before the widgets place in them.
• Layout are place in their parents as soon as they are created, and then widgets are place in the layouts as soon as the widgets are created.
• Generic local variables are used over instance variables. If you look at the code you will see that this makes code between the different rows more identical, making copy and paste work well. All widgets are locally named widget, and the active layout is usually called layout.
• In much code the assignment of widget to an instance variable as self.lable3 = widget is not even needed and in fact the assignment of buttons to instance variables is not needed in this example ( to see this you would need the full example, the code may be in the repo .... )

Other