problem of opacity for textLabel

[Stephano]

Hello!

I ve an text Label with palette backgrounColor(default set the palette of parent)

I would like have a Label with not Color Font(tital opacity)




thanks

[zlatko]

Hm..can you give us extended explain?
Are you mean set foreground color for label?
As i know you can set opacity only for widget not for fonts
Also tell what version of Qt you use

[Stephano]

hello

yes ,sure ,i mean foregroundColor of widget.
but the pb is palettebackgrouncolor:
So,opacity is for "font "not for widget(String)
then I would like have a widget label with total opacity of Font (or backgrpoundcolor).

Thanks

[jpn]

Huh... I might be misunderstanding the half of what you are trying to say, but...

QColor color(Qt::yellow);
color.setAlpha(150); // set alpha level for text color (0-255)
QPalette pal = label->palette();
if (label->textFormat() == Qt::RichText)
	pal.setColor(QPalette::Text, color); // if using rich text
else
	pal.setColor(label.foregroundRole(), color); // otherwise if not using rich text
label->setPalette(pal);

QColor color(Qt::yellow);
color.setAlpha(150); // set alpha level for text color (0-255)
QPalette pal = label->palette();
if (label->textFormat() == Qt::RichText)
	pal.setColor(QPalette::Text, color); // if using rich text
else
	pal.setColor(label.foregroundRole(), color); // otherwise if not using rich text
label->setPalette(pal);

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[Stephano]

Hello!

Thanks very match for your response.
Qt3 has not the method setAlpha:this is a problem!
So,
my code is:
void SAG_Text::SAG_text_afficher()
{
QRgb rgb,rgb1;
this->setGeometry(*text_rectangle);

rgb1=text_state.Text_IDLE.Font_Color;
QColor color1=QColor(rgb1,0xffffffff);
this->setPaletteForegroundColor(color1);
//this->setPaletteForegroundColor(*text_color_contents) ;

this->setFont(*text_font);
this->setText(*text_contents);
if(opacity==TRUE)
{
rgb=text_state.Text_IDLE.Background_Color;
QColor color=QColor(rgb,0xffffffff);
this->setPaletteBackgroundColor(color);

}
else
{
QPainter *p=new QPainter();
p->setBackgroundMode( Qt::TransparentMode );
this->drawFrame(p); }
this->show();
}

But ,no result!

[Stephano]

i would like have a text transparentTransparence of cadre of text,not of contents)the user of my application can choose between 2 choice:

• transparent
• opaque

So , qt 4 can resolve the pb with Qcolor.setAlpha(..);
But ,i have many pb of installation of Qt4.

then ,how can i ,for exemple ,use Qpainter (paintEvent...) to define a transparence.
If there are other solutions or explications, help me ,please!
My regards!

[Stephano]

i would like have a text transparent :
Transparence of cadre of text,not of contents)
the user of my application can choose between 2 choice:
transparent
opaque

So , qt 4 can resolve the pb with Qcolor.setAlpha(..);
But ,i have many pb of installation of Qt4.

then ,how can i ,for exemple ,use Qpainter (paintEvent...) to define a transparence.
If there are other solutions or explications, help me ,please!
My regards!

[wysota]

Please, do not start multiple threads on the same subject! This is fourth or fifth thread you start about the same thing. Please use a single thread which is opened for discussion!

[Stephano]

hello!

i wouls like draw a Qlabel.
i need choose between :
tansparence or no!

the pb is qthas not setAlpha!
so, how can i use Qpainter for exemple ,to have a backgroundColor of text transparent
.It s urgency!

Thanks!!!!

[jacek]

Please, don't start multiple threads on the same problem or else...

[Stephano]

Sorry Mr.jacek ,
but it s very urgent!
Can u help me?

[wysota]

What about jpn's answer?

[jacek]

but it s very urgent!

There are no urgent matters --- this is a community forum. People answer questions in their free time.

Can u help me?

What exactly do you want to achieve? What is under the label?

One of the QQ articles suggests three solutions:

We need a different approach if we want the parent widget's background to shine through. [...] In Qt 3, there are several ways to simulate this feature:

• You can use QPainter::redirect() and then call the parent widget's paintEvent() to have the parent draw itself onto the widget's background directly.
• You can set a transparency mask (QWidget::setMask()). The parent widget is aware of the child widget's mask and will paint all areas not covered by the mask.
• If the parent doesn't paint anything underneath the child widget other than its background, you can fill the child widget's background by inheriting the parent widget's brush and applying a suitable offset by calling QWidget::setBackgroundOrigin().

[Stephano]

thanks!very match

[Stephano]

i would like a tewt Label
witch contents only the string
So the cadre of label must be transparent
Because the text will be draw in the bitmap(no backgroun color)
thanks

[jacek]

Because the text will be draw in the bitmap(no backgroun color)

Is that bitmap the background of your window or is it displayed by some widget (for example a QLabel)?

You might try to reimplement the paintEvent() for your widget and draw that text there.

[Stephano]

i would like draw only the String of Qlabel
So ,how i implemente
paintEvent()
please?
can u give me an exemple!

[wysota]

Have you tried simply using QWidget::backgroundOrigin property? If you assign both your label and its parent the same bitmap as a background, it should be possible to blend them together.

[Stephano]

thanks
but,
to set the color of parent dont resolve the problem.
i neded a realy transparent label in my application

[wysota]

What for? Maybe you could explain what do you intend to do with it.