What I'd like to achieve:
A visual indication to draw attention to newly added items in a QListView. I had in mind having the background color 'throb' once (fading from a color to the background).
The setup
I have a model/view using QListView displaying QStandardItems. Qt version 4.7
What I've tried:
I've created a new class derived from QStyledItemDelegate. I have my own paint method to render the item. That part works. I created a QTimeLine object and set it up to create events to redraw the items.
I can't figure out how to trigger redraws of the QListView item.
In the item delegate constructor:
timeLine = new QTimeLine( 3000, this );
timeLine->setFrameRange( 100, 0 );
connect( timeL开发者_StackOverflow中文版ine, SIGNAL( frameChanged( int ) ), this, SLOT( update() ) );
timeLine->start();
I tried connecting to the sizehintChanged event but this does not work
void myDelegate::update()
{
const QModelIndex index;
emit QStyledItemDelegate::sizeHintChanged( index );
}
Any suggestions? Can this be done with style sheets?
The standard practice to include animations into code is to use state machines. Animations in Qt cannot be achieved using QtStylesheets. Either use QML or use QStyledItemDelegate and a state machine.
/*CustomItemDelegate*/
int state;
enum states{
animating,
normal
}
void setstate(int state){
this->state = state;
/*Start animation depending on state ,by starting a QTimer and calling
repaint when the timer expires,also change animation variables like opacity ,
angle etc etc*/
}
void paint(QPainter *painter, const QStyleOptionViewItem &option,
const QModelIndex &index) const{
switch(state){
case animating:
break;
case normal;
break;
}
}
....
/*CustomListView*/
slots:
void dataChanged ( const QModelIndex & topLeft, const QModelIndex & bottomRight ){
( (CustomItemDelegate)itemDelegate(topleft) )->setState(animating);
}
....
/*Mainwindow*/
connect(model,SIGNAL(datachanged(QModelIndex,QModelindex)),view,SLOTS(QModelindex,QModelindex));
精彩评论