[ocemp-devel] Update process and dirty flag

[Bertrand C. <ber...@gm...>]

Hi all,

There is something I don't understand in the update process.
When a widget need to be modified (its rendering), it is marked as dirty.
This way, its parent is also marked as dirty. That mean that the container
will redraw everything: its background and all its children.
Instead of this process, when a widget is marked as dirty, its parent don't
need to be marked as dirty and we can override the update method into the
Container module and do the things like that:

    def update (self, *args):
        DirtyChild = False
        ChildrenRects = []
        for child in self._children:
            if child.dirty == True:
                child.update()
                self._image.blit(child.image,child.image.get_rect())
                ChildrenRects.append(child.image.get_rect())
                DirtyChild = True

        if DirtyChild:
            self._oldrect = self._rect
            rect = ChildrenRects[0]

            for r in ChildrenRects:
                if r.left < rect.left:
                    rect.left = r.left
                if r.top < rect.top:
                    rect.top = r.top
                if r.right > rect.right:
                    rect.right = r.right
                if r.bottom > rect.bottom:
                    rect.bottom = r.bottom
            self._rect = rect
      BaseWidget.update(self)

This way, only modified widget included into the container are modified,
which is faster.

What do you thing of this solution, and what do I have missed ?

Sincerely
Bertrand