Font size for QwtPlot title?

[HappyCoder]

Hi,

i'm testing this code with the "friedberg" example and latest Qwt version:

in plot.cpp after line 70 add a qDebug() line

setTitle( "Temperature of Friedberg/Germany" );
    qDebug() << title().font();   // NEW

setTitle( "Temperature of Friedberg/Germany" );
    qDebug() << title().font();   // NEW

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The output is:

QFont( "MS Shell Dlg 2,8.25,-1,5,50,0,0,0,0,0" )

But the font size of the plot title is never 8.25.

Here
https://msdn.microsoft.com/de-de/lib...(v=vs.85).aspx
you can find, that "MS Shell Dlg 2 simply uses the Tahoma font regardless of language.".

I rebuild the title in Word Pad and the font size must be 14.

Fontsize.jpg

What's is going wrong here? Why is the size wrong of the returned font by title().font() ? Guess it is a bug.

Thx

[KT_HG]

What do you want?
for changing your title font, color, ..... you can use QwtText like this:

QFont font14;
    font14.setPointSize(14);
    QwtText title;
    title.setText("Your Title");
    title.setFont(font14);

QFont font14;
    font14.setPointSize(14);
    QwtText title;
    title.setText("Your Title");
    title.setFont(font14);

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[HappyCoder]

What do you want?

I wrote it: Why is the size wrong of the returned font by title().font() ?

[Uwe]

Maybe because Qt uses the "closest matching installed font" only ( see the QFont docs ) ?

Uwe

[fallerd]

I wrote it: Why is the size wrong of the returned font by title().font() ?

I had this same question, and could not make sense of Uwe's answer here. The cause is that there are two different QFonts that apply to the title - one from the QwtText returned from QwtPlot::title() and a different one from the QwtTextLabel returned from QwtPlot::titleLabel().

As HappyCoder demonstrated, plot->title().font() returns:

QFont( "MS Shell Dlg 2,8.25,-1,5,50,0,0,0,0,0" )

Which you can verify is incorrect/not-in-use by assigning this back to the title by plot->title().setFont(), which results in the font visibly shrinking.

So, instead, plot->titleLabel()->font() gives you the actual initial/default font in the correct size, which returns:

QFont( "MS Shell Dlg 2,14,-1,5,75,0,0,0,0,0" )

For reference, I found this comment/thread that led me to this answer: https://www.qtcentre.org/threads/673...5432#post35432