Find QRegExp in the text

Ruzik

Hellow, i need find some RegExp construction in the QPlainTextEdit, i try do it
@ QTextCursor curs;
curs.setPosition(-1);
if (plainTextEdit->document()->find(QRegExp("{. }"))!=curs)
listWidget->addItem("empty stylesheet {it's empty!}");@
I want if there are { } in the text that program add item in the listWidget.
I think that i wrong chek position in the if(), can you say me how can chek this position right way
Advance many thanks for your help!

Franzk

try
@if (!plainTextEdit->document()->find(QRegExp("{. }")).isNull()))
listWidget->addItem(...);@

Ruzik

Dont work:(

Franzk

Might the cursor then be at the document end?

goetz

Curly brackets have a special meaning in regular expressions. You need to escape them like this:

@
QRegExp re("\{. \}");
@

Ruzik

I find my mistake
@ if (!plainTextEdit->document()->find(QRegExp("\{ *\}")).isNull())
listWidget->addItem("empty stylesheet {it's empty!}");@
And code work, but it is not work with sign of new string(\n), how can i modif my QRegExp to my code work, i try

@
QRegExp("\{[ \Z]\}"))
QRegExp("\{[ \Z]\}"))
@

And instead Z i try use A
All does not work

[EDIT: wrap your code!, Volker]

Ruzik

I also try QRegExp(”\{[ \n]*\}”))

soroush

AFAIK you can apply a regular expression in a single text block only. That is you cannot use \n notation with your regexp. I remember that in my homework I had to break my expression to two expressions to do that. I didn't found a way to use a regexp with two paragraphs in QPlainTextEdit....

you can use "this tool":http://sourceforge.net/projects/regexer to test regular expressions in Qt.

Ruzik

But there are operators \A and \Z - start and end of string in the QRegExp, so in QRegExp must work with it

goetz

[quote author="Ruzik" date="1307644633"]I also try

@
QRegExp(”\{[ \n]*\}”))[/quote]
@

[EDIT: code formatting! Volker]

soroush

QRegExp works with \n and so on but in QPlainTextEdit it's applied on a text block. not whole contents of QPlainTextEdit. you probably need to break your expression or use that on the QPlainTextEdit::toPlainText() to find begin and end indexes.

goetz

The search pattern is only applied for a text block. The pattern can not cross a text block boundary! See method static bool findInBlock() around line 1290 in qtextdocument.cpp of the Qt sources.

dcortesi

The answers above explain a problem I came to ask about, so thank you. However, in the general case of a user-entered pattern I do not see any way of getting around this bad restriction.

Suppose the pattern (example from QRegExp documentation) is .*, this cannot succeed when the document is:

@
some text or bold
text other etc.
@

You could examine the user's pattern and change it into:

@
.$
^.
@

But that would fail for the case of on one line and also would fail for the case of a target spanning three or more lines. In short I see no work-around for the general case of patterns matching across multiple lines. Comment?