Using custom Q_PROPERTY with Stylesheet

[hubbobubbo]

Hi

I have added a custom Q_PROPERTY like this:

Q_PROPERTY( bool isTalking READ isTalking WRITE setIsTalking )

bool _isTalking;

public:
MyClass(QWidget *parent );
~MyClass();

bool isTalking() const {return _isTalking;}
void setIsTalking(bool newIsTalking){_isTalking = newIsTalking;}

Then from my style sheet file I want to change the background color of a QTreeWidgetItem based on this Q_PROPERTY like this:

QTreeWidget#activeCalls::item:isTalking{
background: green;
}

However this has no effect. Using a normal property on the QTreeWidget like this works though:
QTreeWidget#activeCalls::item:selected{
background: grey;
}

So the Widget is named correctly but I do not think the item is updated based on the value of my cusomt Q_PROPERTY. How can I make sure the Widget is updated when my property changes so the correct stylesheet is applied dynamically.

[Lykurg]

QTreeWidget#activeCalls::item:selected{
background: grey;
}

You can not access all properties like that. It's only a bunch of properties you can use that way (called pseudo states). You can try to use something like that:

QTreeWidget#activeCalls[isTalking="true"]

QTreeWidget#activeCalls[isTalking="true"]

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[SABROG]

You must know, what Style Sheets added to QWidget only once and if you change QMetaProperty value later this do not change style with other rule.

[hubbobubbo]

Hi

I tried like this (changed to int to make it even simpler)

QTreeWidget#activeCalls::item[isTalking="0"]{
background: green;
}

QTreeWidget#activeCalls::item[isTalking="1"]{
background: yellow;
}

in the code I simple call setIsTalking(0) or setIsTalking(1)

Still no action at all though.

[Lykurg]

SABROG gave you the answer: you have to reaply the style sheet every time you change this property. So your approach doesn't seem to be the best. Without knowing exactely what you are doing, I would recomend you to use a custom item delegate where you can paint different backgrounds depending on the items "property". Or if you add widgets, use the widgets paint methode.

[hubbobubbo]

Ok thanks I will give up on that approach.

[SABROG]

Still no action at all though.

It's standard behaviour. Trolls don't want change this. I created bugreport about one year ago and he's been rejected.

[mrandreas]

I used this approach:

Q_PROPERTY( bool isTalking 
READ isTalking 
WRITE setIsTalking 
DESGNABLE true
SCRIPTABLE true)
 
bool _isTalking;
QFileSystemWatcher* _watch
 
public:
MyClass(QWidget *parent ) :
QWidget(parent)
{
  this->setObjectName("MyClass");
  _watch->addPath("xxxx.css");
  connect(_watch, SIGNAL(fileChanged(QString),
    this,SLOT(loadStyleSheet(QString)));
 
}
~MyClass();
 
bool isTalking() const 
{return _isTalking;}
void setIsTalking(bool newIsTalking)
{_isTalking = newIsTalking;}
 
public slots:
 void loadStyleSheet(const QString& css)
{
  QFile cssfile(css);
 
  if(cssfile.open(QIODevice::ReadOnly 
| IODevice::Text))
  {
    QTextStream in(&cssFile);
    QString cssssss(in.readAll());
    this->setStyleSheet(csssss);
  }
 
}

Q_PROPERTY( bool isTalking 
READ isTalking 
WRITE setIsTalking 
DESGNABLE true
SCRIPTABLE true)

bool _isTalking;
QFileSystemWatcher* _watch

public:
MyClass(QWidget *parent ) :
QWidget(parent)
{
  this->setObjectName("MyClass");
  _watch->addPath("xxxx.css");
  connect(_watch, SIGNAL(fileChanged(QString),
    this,SLOT(loadStyleSheet(QString)));
  
}
~MyClass();

bool isTalking() const 
{return _isTalking;}
void setIsTalking(bool newIsTalking)
{_isTalking = newIsTalking;}

public slots:
 void loadStyleSheet(const QString& css)
{
  QFile cssfile(css);

  if(cssfile.open(QIODevice::ReadOnly 
| IODevice::Text))
  {
    QTextStream in(&cssFile);
    QString cssssss(in.readAll());
    this->setStyleSheet(csssss);
  }

}

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In the css:

MyClass{qproperty-isTalking: true;}

MyClass{qproperty-isTalking: true;}

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However - changing properties from css file should not be used for all purposes (at least >5 pr second). it will be slooow.