PyQt5 - Make all QScrollArea scrollable

[Patitotective]

I'm have an horizontal QScrollArea and i want that even if you're not hovering the scrollbar, just being hover the QScrollArea you could scroll.

[eyllanesc]

@Patitotective A possible solution is to use an eventFilter to send the QLabel's wheel event to the horizontal QScrollBar:

import sys

from PyQt5.QtWidgets import (
    QApplication,
    QLabel,
    QDialog,
    QVBoxLayout,
    QGridLayout,
    QScrollArea,
)

from PyQt5.QtCore import QCoreApplication, QEvent, Qt


class ScrolLabel(QScrollArea):
    # constructor
    def __init__(self, *args, **kwargs):
        QScrollArea.__init__(self, *args, **kwargs)

        self.label = QLabel()
        self.label.setContentsMargins(0, 10, 0, self.horizontalScrollBar().height())

        self.setWidgetResizable(True)

        self.setWidget(self.label)
        self.setHorizontalScrollBarPolicy(Qt.ScrollBarAsNeeded)
        self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)

        self.label.installEventFilter(self)

    def setText(self, text):
        self.label.setText(text)
        self.setFixedHeight(self.sizeHint().height())

    def eventFilter(self, obj, event):
        if self.label is obj and event.type() == QEvent.Wheel:
            QCoreApplication.sendEvent(self.horizontalScrollBar(), event)
        return super().eventFilter(obj, event)


class MainWindow(QDialog):
    def __init__(self):
        super().__init__()

        self.layout = QGridLayout(self)

        scrollable = ScrolLabel()
        scrollable.setText(
            r"sO+Yu_b>P*vG1F3W@X\hU/J]o=HaE4M2&9f6m\"j0r<z:e!DlL}q^8[R7y'5~t#k)w(gN-A|B{V,pC.Z$I?K;cSxTdQ`i%n"
        )
        self.layout.addWidget(scrollable)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    mainwindow = MainWindow()
    mainwindow.show()
    sys.exit(app.exec_())

[SGaist]

Hi,

Are you using the mouse wheel ?

[Patitotective]

@SGaist If you mean i use the mouse wheel to scroll, yes i do.
Look this video, i try to scroll in the label but it doesn't work.
https://youtu.be/zA1OObSaggA

[eyllanesc]

@Patitotective please provide a minimal and verifiable example

[Patitotective]

@eyllanesc

import sys

from PyQt5.QtWidgets import (
    QApplication, QLabel, QDialog,   
    QVBoxLayout, QWidget, QGridLayout, 
    QMainWindow, QScrollArea, qApp) 

from PyQt5.QtCore import Qt

class ScrolLabel(QScrollArea):

    # constructor
    def __init__(self, *args, **kwargs):
        QScrollArea.__init__(self, *args, **kwargs)

        self.setWidgetResizable(True)

        content = QWidget(self)
        self.setWidget(content)

        lay = QVBoxLayout(content)

        self.setHorizontalScrollBarPolicy(Qt.ScrollBarAsNeeded)
        self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)

        self.label = QLabel(content)

        self.label.setAlignment(Qt.AlignLeft | Qt.AlignTop)

        lay.addWidget(self.label)

    def setText(self, text):
        self.label.setText(text)

class MainWindow(QDialog):
    def __init__(self):
        super().__init__()

        self.layout = QGridLayout(self)

        scrollable = ScrolLabel()
        scrollable.setText(r"sO+Yu_b>P*vG1F3W@X\hU/J]o=HaE4M2&9f6m\"j0r<z:e!DlL}q^8[R7y'5~t#k)w(gN-A|B{V,pC.Z$I?K;cSxTdQ`i%n")

        scrollable.setFixedHeight(60)

        self.layout.addWidget(scrollable)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    mainwindow = MainWindow()
    mainwindow.show()
    sys.exit(app.exec_())

[eyllanesc]

@Patitotective A possible solution is to use an eventFilter to send the QLabel's wheel event to the horizontal QScrollBar:

import sys

from PyQt5.QtWidgets import (
    QApplication,
    QLabel,
    QDialog,
    QVBoxLayout,
    QGridLayout,
    QScrollArea,
)

from PyQt5.QtCore import QCoreApplication, QEvent, Qt


class ScrolLabel(QScrollArea):
    # constructor
    def __init__(self, *args, **kwargs):
        QScrollArea.__init__(self, *args, **kwargs)

        self.label = QLabel()
        self.label.setContentsMargins(0, 10, 0, self.horizontalScrollBar().height())

        self.setWidgetResizable(True)

        self.setWidget(self.label)
        self.setHorizontalScrollBarPolicy(Qt.ScrollBarAsNeeded)
        self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)

        self.label.installEventFilter(self)

    def setText(self, text):
        self.label.setText(text)
        self.setFixedHeight(self.sizeHint().height())

    def eventFilter(self, obj, event):
        if self.label is obj and event.type() == QEvent.Wheel:
            QCoreApplication.sendEvent(self.horizontalScrollBar(), event)
        return super().eventFilter(obj, event)


class MainWindow(QDialog):
    def __init__(self):
        super().__init__()

        self.layout = QGridLayout(self)

        scrollable = ScrolLabel()
        scrollable.setText(
            r"sO+Yu_b>P*vG1F3W@X\hU/J]o=HaE4M2&9f6m\"j0r<z:e!DlL}q^8[R7y'5~t#k)w(gN-A|B{V,pC.Z$I?K;cSxTdQ`i%n"
        )
        self.layout.addWidget(scrollable)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    mainwindow = MainWindow()
    mainwindow.show()
    sys.exit(app.exec_())

[Patitotective]

@eyllanesc Thanks, it worked.