QwtText background padding

Hi again,

I'm using QwtText in order to show a message on a QwtPlot.
I would like my QwtText to have some padding

I'm trying to do it in a dirty way, i'm adding some space so that the rectangle grow bigger.
See here : https://www.dropbox.com/s/7tojqexfon0b1ag/QwtTextEx.png
Problem I have with this approach is that the text is not centered no matter how I add the space

I also tried to subclass QwtText but I can't use the private field used in the draw() method, I would just increase the QRect size
or maybe I can write code directly in QwtText, but I'm not sure i'm allowed to do that and not good when Qwt has update..

if you have an idea thanks :)



Current code :

Quote:

---

void WorkoutPlot::setDisplayMessage(QString text, bool workoutPausedMsg) {

/// DISPLAY MSG
QFont fontBig;
fontBig.setPointSize(16);

int lengthText = text.length();
QString emptySpace = " ";
QString emptyLine;
for (int i=0; i<lengthText + 8; i++) {
emptyLine+= emptySpace;
}

QString msg = emptyLine + "\n";
msg += " " + text + " " + "\n";
msg += emptyLine;
displayMsgTxt = QwtText( msg );


displayMsgTxt.setFont(fontBig);
displayMsgTxt.setRenderFlags( Qt::AlignHCenter | Qt::AlignHCenter );
displayMsgTxt.setColor(Qt::white);
if (workoutPausedMsg)
displayMsgTxt.setBackgroundBrush(QBrush(QColor(1, 1, 1, 128), Qt::SolidPattern));

displayMessageLabel = new QwtPlotTextLabel();
displayMessageLabel->setText( displayMsgTxt );
displayMessageLabel->attach( this );

---

Quote:

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Originally Posted by Maximus2

I would like my QwtText to have some padding

---

You could try to do some formatting using the rich text syntax or simply overload QwtPlotTextLabel::textRect():

Code:

---

QRectF YourTextLabel::textRect( 
    const QRectF &rect, const QSizeF &textSize ) const
{
   QRectF rect = QwtPlotTextLabel::textRect( rect, textSize );
   rerturn rect.adjusted( ... );
}

---

Uwe

Thanks Uwe,
Finally I decided to go with a QLabel on top of the canvas and customize it with stylesheet
See you!

But be aware, that this label is not seen by QwtPlotRenderer and willl be missing, if you want to create something like a PDF document.

Uwe

Quote:

---

Originally Posted by Uwe

You could try to do some formatting using the rich text syntax or simply overload QwtPlotTextLabel::textRect():

Code:

---

QRectF YourTextLabel::textRect( 
    const QRectF &rect, const QSizeF &textSize ) const
{
   QRectF rect = QwtPlotTextLabel::textRect( rect, textSize );
   rerturn rect.adjusted( ... );
}

---

Uwe

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QwtPlotTextLabel::textRect is not static .. and you don't have the text to be able to create a temporary one ?
Or did I misunderstand ?

YourTextLabel is derived from QwtTextLabel and the method above is an overloading method ( calling the overloaded one from the base class ).

Uwe

Quote:

---

Originally Posted by Uwe

YourTextLabel is derived from QwtTextLabel and the method above is an overloading method ( calling the overloaded one from the base class ).

Uwe

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Oh, the original question (and what I was trying to do myself) was add padding to a QwtText not a QwtTextLabel.
In my case because I reimplementing QwtPlotPicker::trackerText()

Then you have to overload QwtPicker::trackerRect() - the idea is the same.
The target rectangle in a parameter of the draw operation, not an attribute of the text object.

Uwe

Hey Uwe, replying to this old thread since this is the exact thing I'm struggling with now.

I tried overriding trackerRect in my QwtPlotPicker subclass with

Code:

---

QRect ConcentrationMap::ConcentrationPicker::trackerRect(const QFont &font) const
{
    return QwtPlotPicker::trackerRect(font).adjusted(-5, -5, 5, 5);
}

---

but the result is

Attachment 12982

In my case, I'd like a margin around the text, not just to the right/bottom. Do you know if this is possible somehow?

but

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Added after 1 21 minutes:

I tried working around this with a custom text engine derived from QwtRichTextEngine which overrides textMargins, e.g. setTextEngine(QwtText::OtherFormat, new TextEngine()) and then m_text.setText(..., QwtText::OtherFormat) on my text, but despite this the textMargins() of my custom engine is never called :/

Overloading QwtPlotPicker::trackerRect - like you did - should be good enough.

I checked your code in the spectrogram example and it works like expected - also with rich text content.
So there has to be something in your code, what makes a difference.

Uwe