QPlainTextEdit is RightToLeft but displays LeftToRight

Question

I made a view with QPlainTextEdit and set setLayoutDirection(QtCore.Qt.RightToLeft). The output of self.plaintxt.isRightToLeft()is 1 but in the plain text view, persian and english text are displayed from left. What is happen in my code?

Code:

import sys, re

from PyQt5 import QtCore
from PyQt5.QtWidgets import QApplication, QLabel, QLineEdit, QMainWindow, QPushButton, QFileSystemModel, QTreeView, \
    QFileDialog, QComboBox, QPlainTextEdit
from PyQt5.QtCore import pyqtSlot


class App(QMainWindow):

    def __init__(self):
        super(App, self).__init__()

        self.title = 'by PyQt5 and python 3.7'
        self.left = 10
        self.top = 10
        self.width = 1000
        self.height = 500

        self.initUI()

    def initUI(self):
        self.setWindowTitle(self.title)
        self.setGeometry(self.left, self.top, self.width, self.height)

        self.btn_browse = QPushButton('Browse', self)
        self.btn_browse.move(50, 20)
        self.btn_browse.clicked.connect(self.on_click)

        self.textbox = QLineEdit(self)
        self.textbox.move(170, 20)
        self.textbox.resize(280, 40)
        self.textbox.setAlignment(QtCore.Qt.AlignRight) # It is in right.

        self.page_view = QPlainTextEdit(self)
        self.page_view.move(20, 100)
        self.page_view.resize(800, 400)
        self.page_view.setLayoutDirection(QtCore.Qt.RightToLeft) # It is not in right.

        self.show()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = App()
    sys.exit(app.exec_())

I updated my question with adding code. – mng97 Apr 16 '19 at 10:02 — mng97, Apr 16 '19 at 10:02

ncica · Accepted Answer · 2019-04-16T14:04:14.837

4

QWidget.setLayoutDirection no longer affects the text layout direction (Qt.LeftToRight or Qt.RightToLeft) of QTextEdit, QLineEdit and widgets based on them.

To programmatically force the text direction , you can change the defaultTextOption of the QTextDocument associated with that widget with a new QTextOption of different textDirection property.

QTextDocument *QPlainTextEdit::document() const

Returns a pointer to the underlying document.

void QTextDocument::setDefaultTextOption(const QTextOption &option)

Sets the default text option to option.

self.page_view.document().setDefaultTextOption(QTextOption(Qt.AlignRight))

edited Apr 16 '19 at 14:04

answered Apr 16 '19 at 13:07

ncica

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Can you add a short description? – help-info.de Apr 16 '19 at 13:51
thanks, you know - code-only answers are considered low quality. – help-info.de Apr 16 '19 at 14:05
thanks for advice, I will be more detailed in the future :) @help-info.de – ncica Apr 16 '19 at 14:09
Are you sure that the correct approach to display RTL text is to use `Qt.AlightRight`? Alignment doesn't change the layout direction and will still cause BiDi text to be rendered incorrectly. Maybe you should use `Qt.RightToLeft` (https://doc.qt.io/qt-6/qt.html#LayoutDirection-enum)? – Guss Apr 06 '23 at 17:03

score 2 · Answer 2 · answered Jun 16 '19 at 08:45

Don't use QPlainText, as it uses internally QPlainTextDocumentLayout which does not fully support RTL (automatic alignment for example - like you are looking for). You can use QTextEdit, or use a different document layout class (like QTextDocumentLayout) in your QPlainText.

The reason for those Plain classes exist, is to be faster by removing features... which you need.

QPlainTextEdit is RightToLeft but displays LeftToRight

2 Answers2