How to create a valid and "usable" QTextFrameFormat

Nixxer

Hi!

I was experimenting with the options for formatting text and frames, but i can't make a valid QTextFrameFormat...

I have tried to make this function:

void MainWindow::setDoc()
{
    QTextDocument doc(this);
    QTextFrame frame1(&doc);
    QTextCursor cursor1 = frame1.firstCursorPosition();
    QTextFrameFormat format1;

    cursor1.insertText("Some text.\nOther text.");

    format1.setBorderStyle(QTextFrameFormat::BorderStyle_Solid);
    format1.setBorder(0.5);
    format1.setPosition(QTextFrameFormat::InFlow);

    qDebug() << format1.isValid();

    if(format1.isValid())
    {
        frame1.setFrameFormat(format1);
    }
}

When i call this function, the program crashes, reporting this error "ASSERT failure in QVector<T>::operator[]: "index out of range", file ....\include/QtCore/../../src/corelib/tools/qvector.h, line 401".

I have also tried with the function isValid() to verify the validity of the format, but it returns true...
So, am i missing some important options? Or am i applying the method in the wrong way?

Thanks in advance for the help!

mrjj

@Nixxer said:

QTextFrameFormat

Hi never used it so no expert, but I was wondering if you looked at
https://doc.qt.io/archives/4.6/richtext-orderform.html

as it uses a QTextTableFormat for its order element.

Nixxer

@mrjj
Well, thanks for the reply, but i took a look at the page, but i see that QTextTableFormat is for a table, so i don't think it's the right tool for my intent...

Moreover, i see this code:

  TextFrameFormat topFrameFormat = topFrame->frameFormat();
 topFrameFormat.setPadding(16);
 topFrame->setFrameFormat(topFrameFormat);

It reminds me my code, but maybe i'm missing something...

mrjj

@Nixxer
hi
well it also uses a QTextFrameFormat..
I agree that your code looks very alike. except maybe how to get the cursor.

Did you try to single step it and see what line it crashes on?

Nixxer

@mrjj
I have tried to put a breakpoint in every line of the function, it works until the last line, the one that applies the QTextFramwFormat to the QTextFrame...

I have also tried to get the current format (prior my changes) with format1 = frame1.frameFormat(), to make sure to start with a "sensible" format, but it didn't work anyway...

mrjj

@Nixxer
hmm so it dont like format1.
Only thing that spring to mind is the cursor thing. but firstCursorPosition should be fine too?

If we look at sample code:

QTextEdit *editor = new QTextEdit;
QTextCursor cursor(editor->textCursor());
cursor.movePosition(QTextCursor::Start);
QTextFrame *topFrame = cursor.currentFrame();
QTextFrameFormat topFrameFormat = topFrame->frameFormat();
topFrameFormat.setPadding(16);
topFrame->setFrameFormat(topFrameFormat);
...
QTextCharFormat boldFormat;
boldFormat.setFontWeight(QFont::Bold);
cursor.insertText("A company", boldFormat);

It looks like yours alot.

mrjj

One difference:

QTextFrameFormat topFrameFormat = topFrame->frameFormat();

where your code just declare a new one.
QTextFrameFormat format1;

So I wonder if its need more "setup"

Nixxer

@mrjj
One thing that differs is that i declare all my variables in the stack, while the example declares them in the heap, but i hope that all that works in the heap should work also in the stack and vice-versa...

My intention was to make a QTextDocument, put in this a QTextFrame, put a text in it with a QTextCursor, create a QTextFrameFormat to be applied to the QTextFrame...

mrjj

minimal sample that works for me

QTextEdit *editor = new QTextEdit;
QTextCursor cursor(editor->textCursor());
cursor.movePosition(QTextCursor::Start);
QTextFrame *topFrame = cursor.currentFrame();
QTextFrameFormat topFrameFormat = topFrame->frameFormat();
topFrameFormat.setPadding(16);
topFrame->setFrameFormat(topFrameFormat);
cursor.insertBlock();
cursor.insertText("321 City Street");

mrjj

@Nixxer
Well it crashes before you run out of scope so I doubt it is related to the stack :)

mrjj

@Nixxer said:
One thing I wondered:
The sample does not new / create a QTextDocument as far as I can see.
I wonder if it is needed to do , or I simply don't understand what you want to do :)

Nixxer

@mrjj
I'll try this snippet, maybe I'll learn something...

I begin with the QTextDocument because I'd like to make a program to make documents, like a list of properties of a client, so I thought that I could make a QTextDocument in which inserting one after one these properties with different frames and their ...

Maybe I took the problem by the wrong way...

Btw, I was thinking to make this program as a exercise to begin to "mess" with Qt...

SGaist

Hi,

In that case, I'd recommend the excellent "C++ GUI Programming with Qt 4 (2nd Edition)" from Mark Summerfield and Jasmin Blanchette. Although it's Qt 4, it still relevant for Qt 5 and there's a good chapter about QTextDocument

mrjj

@Nixxer
Like a database with clients and their properties ?
Depending on your coding skills, construction a RTF doc on the fly is maybe a somewhat hardcore start :)

Nixxer

@SGaist
Thanks for the suggestion! If I can learn something for Qt 5, I'll gladly read this book...

Nixxer

@mrjj
It's right, but I prefer to learn starting from "real" problems (I'm an self-taught "programmer")...

mrjj

@Nixxer
Well thats really understandable. More fun when it's real.
I can only second SGaist book suggestion.
I found it free on
http://www.bogotobogo.com/cplusplus/files/c-gui-programming-with-qt-4-2ndedition.pdf
(takes a moment to load)

Good luck