[FIXED] How to vertically center a single-line in a QTextEdit instance (PySide/PyQt)?

Issue

I have a line editor that inherits from QTextEdit, and I am using it to edit view items that show rich text. The second parameter for QTextEdit.setAlignment is `QtAligntment' and the docs say:

Valid alignments are Qt.AlignLeft, Qt.AlignRight, Qt.AlignJustify and Qt.AlignCenter (which centers horizontally).

That is, there is no native support for vertical alignment. Is there an indirect way to vertically center the text in QTextEdit?

Related link

Center the Text of QTextEdit horizontally and vertically : Unfortunately, the accepted answer uses QLineEdit which won't work for me.

A clue?

At the following I found a clue about how to do it in C++/Qt. I am almost able to follow it, but not quite, as it is for c++:

http://www.qtcentre.org/threads/26003-Vertical-centering-of-a-QTextEdit

I will hack at it on my own for a couple of days and try to answer it myself, but wanted to post this now in case someone has already cracked it already or done it in a different/better way.

Solution

For a single-line edit centred vertically, you just need to calculate a correct fixed height.

Using the example delegate from your previous question, it can be achieved like this:

class RichTextLineEdit(QtGui.QTextEdit):   
    def __init__(self, parent=None):
        ...    
        margin = 1
        self.document().setDocumentMargin(margin)
        fontMetrics = QtGui.QFontMetrics(self.font())
        height = fontMetrics.height() + (margin + self.frameWidth()) * 2
        self.setFixedHeight(height)

(NB: the reimplemented sizeHint and minimumSizeHint methods are probably redundant in the original example).

Answered By - ekhumoro