Highlighting search

[dvillalobos]

Hi all,

I want to know how can I highlight a text like Qt Creator does when is searching text.

Best regards.
David

[akonradwesolutions]

Take a look at [[Doc:QSyntaxHighlighter]]. If you display text using a [[Doc:QTextDocument]] or [[Doc:QTextEdit]] this might just be what you need.

[dvillalobos]

Hi Arnold,

Thanks for the reply, I use QTextDocument, what I do not know how to is show the yellow box when text is found. Qt Creator uses QSyntaxHighlighter?

[akonradwesolutions]

I cannot say what QtCreator actually uses, but if you display your text using a [[Doc:QTextEdit]] then my suggestion would be that you subclass [[Doc:QSyntaxHighlighter]] and reimplement the highLightBlock method. This method will be called automatically once it is attached to a [[Doc:QTextDocument]]. The idea is that the syntax highlighter knows your search term and can apply a [[Doc:QTextCharFormat]] to the appropriate substring:

@
void MySyntaxHighlighter::highLightBlock(const QString& text)
{
int index = text.indexOf(searchTerm);
if (index != -1) {
QTextCharFormat currentFormat = format(0);
currentFormat.setBackground(Qt::yellow);
setFormat(index, searchTerm.length(), currentFormat);
}
}
@

The code above is untested and shall only give you a basic idea. It is of course a bit oversimplified - it for example does not take into account that there might be more than one occurrence of the search term in a block of text.

Hope this helps.

[dvillalobos]

Yes, it helps.

Thanks.