Maintain the bounding box of drawables (i.e., the bounds of their
actual rendered content) separately from their logical boundary (as
shown in the UI).
The bounding box is calculated through the new
GimpDrawable::get_bounding_box() virtual function, which has a
corresponding gimp_drawable_get_bounding_box() function; the
default implementation simply returns the drawable's logical
boundary. The bounding box is specified in drawable coordinates,
i.e., it's not affected by the drawable's offset.
The bounding box is recalculated through
gimp_drawable_update_bounding_box(), which should be called
whenever a change may affect the bounding box (for example, when
setting a new buffer, as done implicitly by GimpDrawable's
::set_buffer() implementation, or when a drawable filter's
properties change, as will be done by GimpDrawableFilter in a
following commit). When the bounding box changes, the affected
regions of the drawable are updated, and the
GimpDrawable::bounding-box-changed signal is emitted.
When gimp_drawable_update() is called with negative width/height
values, the entire drawable's bounding box is updated, rather than
only its logical boundary.
Likewise, GimpDrawableStack and GimpLayerStack are adapted to use
the bounding box, instead of the logical bounds, when updating the
drawable's area.
which is just a #define to g_assert for now, but can now easily be
turned into something that does some nicer debugging using our new
stack trace infrastructure. This commit also reverts all constructed()
functions to use assert again.
Add an "active" property to GimpFilter, which replaces its
"visible" property. The new property assumes the lower-level role
"visible" had -- controlling whether the filter has any effect as
part of its parent filter-stack.
Add a "visible" property to GimpItem, separate from the "active"
property, which assumes the higher-level role "visible" had --
controlling whether the item is considered "visible", as per the
GUI. By default, the item's "visible" property is bound to the
filter's "active" property, so that changes in visibility directly
affect the filter's "activeness"; this binding can be controlled
using the new gimp_item_bind_visible_to_active() function.
This distinction is currently necessary for floating selections.
Floating selection layers must not be active in their parent stack,
regardless of their visibility, in particular, so that their mode
node doesn't hide the entire backdrop when their composite mode
excludes the backdrop (i.e., when it's dst-atop or src-in).
Instead, their visibility should affect the activeness of the
floating-selection filter of the drawable they're attached to.
This is handled by the next commit.
When a layer is removed from a layer stack, and its backdrop needs
invalidating, emit the UPDATE signals for the backdrop only after
the layer has been removed from the container.
A subclass of GimpDrawableStack, for layer stacks. Invalidates the
layers' backdrop as/when necessary, according to the value of their
excludes_backdrop property.
Make gimp_drawable_stack_update() protected, instead of private, so
that we can use it in GimpLayerStack.
Ell