On Thursday 19 November 2009, 15:55:58 Mark Summerfield wrote: > On 2009-11-19, Mitchell Model wrote: > > I am just starting to do serious work with PyQt, having used many > > other GUI/widget toolkits over the years. The rich collection of demos > > and examples included in the installation -- apparently a large subset > > of the ones in the Qt installation -- is impressive and very helpful. > > I am surprised, however, by the absence of what to me is the canonical > > demonstration, and one that I often program as my first exercise in a > > new toolkit: a small drawing program. The program should offer a > > palette of shapes (including lines), with the ability to place, move, > > resize, delete, and duplicate a shape. Optional features like > > specifying the color or size of the border and the color of the fill > > are good too. Grouping, locking, anchoring lines to shapes, and Undo/ > > Redo/History would be even better. > > > > Surely a demo like this exists somewhere? Could someone point me to > > one? (I am aware of the Diagram Scene example. It has some of what I > > am looking for, but apparently no way to resize shapes using the > > standard maneuver of grabbing a handle or corner and dragging). > > With Qt you really have two different ways you can implement a drawing > program. One way is to create your own in-memory data structures and > create a QWidget subclass where you paint everything yourself. Another > way is to create a QGraphicsScene and populate it with QGraphicsItems. > Which is best rather depends on what you want to achieve, although I > think that using QGraphicsScene is easier. > > I present an example that does some of the things you're talking about > in my PyQt book (chapter 13's Page Designer---in particular > pagedesigner_ans.pyw). It uses QGraphicsScene and should be easy to > extend to do all the things you mention. The book's examples can be > downloaded from my web site.
and let me add, that even experienced with PyQt3 since a few years, Mark's book was tremendously helpful for me in grasping the new concepts of PyQt4. And to not forget to mention: in contrast to many (most) IT-books I read, Mark's book is a _real_ pleasure to read. Pete _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt
