Re: [pygame] BUG: LayeredUpdate 'layer' vs '_layer'

[DR0ID <dr0id@xxxxxxxxxx>]

Am 19.03.2014 07:29, schrieb Jeffrey Kleykamp:
> Hi all,
>
> In pygame.sprite.LayeredUpdate.add documentation it says
>
> "If the sprite(s) have an attribute layer then that is used for the layer.
> If **kwargs contains 'layer' then the sprite(s) will be added to that
> argument (overriding the sprite layer attribute). If neither is passed then
> the sprite(s) will be added to the default layer."
>
> This implies it relies on sprite.layer. But by looking at the source I saw
> if you want to affect which layer your sprite will get added to, you have
> to set sprite._layer before calling add(). So the documentation and the
> code doesn't match.
>
> Not so much a bug; more of a clarification.
>
> Sincerely,
> Jeffrey


Hi

In my version of sprites.py it looks like the code beneath (it might be 
outdated). The sprite._layer is an internal variable that should not be 
used directly (sprite._layer is read only).

If you want to change a layer of a sprite use 'change_layer(self, 
sprite, new_layer)'. So 'layer' will be handled correctly from the kwargs.

LayeredUpdates:

    def add_internal(self, sprite, layer=None):
        """Do not use this method directly.

        It is used by the group to add a sprite internally.

        """
        self.spritedict[sprite] = Rect(0, 0, 0, 0) # add a old rect

        if layer is None:
            try:
                layer = sprite._layer
            except AttributeError:
                layer = sprite._layer = self._default_layer
        elif hasattr(sprite, '_layer'):
            sprite._layer = layer

        sprites = self._spritelist # speedup
        sprites_layers = self._spritelayers
        sprites_layers[sprite] = layer
        ....


Hope that helps

~DR0ID