Update QListWidget item

[Zaher]

Hi,

I want to create a list of items where each item has an icon and label, but the icon could change depends on condition. I used QListWidget with CustomeItem. For updating the item, firstly I delete it then create a new one and insert it at the same index. I am wondering if there a widget like QListWidget but I can update the item without deleting.

[SGaist]

Hi and welcome to devnet,

Why are you deleting your CustomItem ? If you make it properly updatable you can avoid that.

[Zaher]

Thanks @SGaist for the reply, but is there a documentation page of example I can read to know how to use it.

[SGaist]

On how to use what ?

Did you already took a look at:

• Model/View Programming
• Item views examples
• Model View Tutorial

?

[Zaher]

I am wonder if the model works on a diffrent thread or not?

[Gojir4]

@Zaher No, models are working on the GUI main thread. See https://stackoverflow.com/questions/9485339/design-pattern-qt-model-view-and-multiple-threads.

But this does not avoid to handle heavy process in different thread and then update the model using signal and slots.

[Zaher]

@Gojir4 Thanks.

[Zaher]

Do you have any example for edit item by code in Python using PyQt?

[SGaist]

What do you mean by edit ?

[Zaher]

I issue is I want to change the icon in QListItem on condition this the code of widget of the item
In this code, I am reading from pass tuple "file" and depends on the condition I am choosing the icon

import os
from PyQt5 import QtGui, QtCore
from PyQt5.QtWidgets import QWidget, QLabel, QHBoxLayout, QPushButton

class CustomQWidget(QWidget):
    def __init__(self, file, parent=None):
        super(CustomQWidget, self).__init__(parent)
        self.file = file
        if self.file["l_file"]:
            pathname = os.path.join(parent.parent.main_script_path, "icons/correct.png")
        else:
            pathname = os.path.join(parent.parent.main_script_path, "icons/wrong.png")
        pixmap = QtGui.QPixmap(pathname)
        button = QPushButton()
        button.setStyleSheet("padding: 0px;")
        button.setFixedSize(16, 16)
        self.icon_size=button.size()

        # resize pixmap
        pixmap = pixmap.scaled(button.size(), QtCore.Qt.KeepAspectRatioByExpanding, QtCore.Qt.SmoothTransformation)

        # crop pixmap - the following assumes the image aspect is always wider than the button.  if that's not the case
        # you'll need to compare your image/button aspects and crop vertically/horizontally as necessary
        self.cropOffsetX = (pixmap.width() - button.size().width()) / 2
        pixmap = pixmap.copy(self.cropOffsetX, 0, button.size().width(), button.size().height())

        button.setIcon(QtGui.QIcon(pixmap))
        button.setIconSize(button.size())
        button.setFlat(True)
        label = QLabel(file["n_file"])
        layout = QHBoxLayout()
        layout.addWidget(button, 0)
        layout.addWidget(label, 0)
        layout.setContentsMargins(0, 0, 0, 0)
        self.setLayout(layout)

So, what I understand I could QStyledItemDelegate to rerender the item when I want to change the Icon I found a close question but I couldn't finger out how to connect it to the icon and how to make it render on a certain single.
Please, help I am desperate here, and thanks in advance.

[SGaist]

Something is not clear, do you want to use a delegate or have cell widgets ?