[Qt-interest] sketcher program

[Kishore]

Partially. Atleast the information of coordinates will be "duplicated". ie. 
the values will be stored in your database and also in the QGraphicsItem 
objects. It will be your responsibility to keep the data in sync.

On Saturday 07 May 2011 12:43:48 PM phil prentice wrote:
> Having now had a bit more of a read, I now realise that  I should use the
> QGraphicsView class. I think that I got side-tracked by the Model-View
> architecture. because I wanted to understand it a lot more.  However it
> looks like the QGraphicsView class will do most of what I need.  I still
> have one question.  It looks like that I will need to create a scene with
> loads of QT graphics items in it.  Suppose I have a database (e.g. a
> garden design) which has loads of other information in it (plant types,
> soil types etc) would this mean that you would end up with data
> duplication i.e. each item would hold duplicate data of element
> positioning as your main database.  Is that just something that you would
> except as part of the design?  I think the answer is probably yes, because
> as a result you get the extra functionality of the graphics items?  As a
> result though if your database is massive then there would be a lot of
> data duplication.  Anyway I will start writing the app using the
> QGraphicsView class.
> 
> Thanks again
> 
> On Friday 06 May 2011 20:03, phil prentice wrote:
> > Hi
> > 
> >   Recently I have been looking at an MFC example of a program that lets
> >   you
> > 
> > draw lines, circles, polylines etc in an MDI.  As a little exercise for
> > myself I have decided to try to perform the same functionality using Qt.
> > (I know its probably already been done, but I would like to go through
> > the exercise myself to try and learn!!)
> > I have some very basic questions about the model view architecture.
> > And I need to read a lot more.
> > I would eventually like to create a Model view (QStandardItem model or a
> > custom model), but to start with I thought that I might try and use the
> > item view conveniance classes.
> > 
> > I was thinking of using QListWidget.
> > I was thinking of deriving an element base class from QListWidgetItem and
> > then deriving line, circle etc from the element base(using a virtual draw
> > function for each element)
> > 
> > I would then use setItemDelegate for editing/displaying the elements.
> > 
> > Is this a stupid idea?
> > Would this be very inefficient?
> > 
> > I know that QListWidget is normally used to store text and icons, so if I
> > extend it like this its probably not the way to do things?
-- 
Cheers!
Kishore