unable to change cursor position after document change

django.Reinhard

Hi,

I'm working on an editor like codeeditor-example, which means QPlainTextEdit ...

I use similar code to highlight current line ...

On change, I check the file for unsupported characters, which I replace to supported characters. Then I save the file to disk and reload the (possibly patched) content back into editor.

That all works so far.

My issue is - that I can't restore cursor position after replacing content in editor.

When I use editor->document()->setPainText( ... ) then cursor is positioned after then end of file and I can't move it from there.
When I use editor->setPlainText( ... ) then the cursor is positioned before the first line, and I can't move it from there neither.

I use editor->textCursor().setPosition( ... ). I even tried to replace QTextCursor with a new one, but that did not work.

Changing cursor with mouseclick on a line works, but I can't set cursor programmatically.

What am I missing?

Gojir4

hi @django-Reinhard ,

You should "apply" the modification done to the cursor. When you are using editor->textCursor(), you receive a QTextCursor object by copy and not by reference, which means that the change are only applied locally but not applied to the QPlaintextEdit instance itself.

This should fix your issue:

QTextCursor tc = editor->textCursor();
tc.setPosition(...);
editor.setTextCursor(tc);