When using GtkBuilder to create constraints and guides,
the layout manager is already rooted when the guides get
created, and we were forgetting to create the guides
constraints in this case. Fix it by adding a call to
gtk_constraint_guide_update().
This was showing up in the new builder-based constraints
demo as the guide not having the expected effect.
This isn't strictly required for correctness, but
it makes the GtkBuilder codepath do the same that
the vfl codepath does: call gtk_layout_manager_layout_changed
only once, after all the constraints have been added.
Instead of playing games with mapping negative symbolic values to
positive ones, let's use the appropriate constants everywhere. This
allows us to use:
GTK_CONSTRAINT_STRENGTH_WEAK * 2
Or
GTK_CONSTRAINT_STRENGTH_STRONG + 1
In code using the public API.
We also store the strength values as integers, so we can compare them
properly, and only turn them into doubles when they are inserted into
the solver, just like every other variable.
Only constraint the opposite direction if we
actually have a for_size, and measure natural
size after removing the edit constraints. With
these changes, the test that compares constraint
layout to grid layout passes.
It makes more sense to treat the natural size
of both children and guides as stays, since
we want to meet these values as closely as we
can, under the circumstances.
Set up all constraints for minimum + natural
width + height when measuring, regardless
of the orientation we're measuring. Anything
else will lead to incorrect answers when
there are constraints that cut across
dimensions.
This commit moves GtkConstraintGuide into its own
source files to avoid gtkconstraintlayout.c turning
too messy, adds max size properties and implements
getters and setters.
We cannot use the given "for size" when querying our children, because
the constraint layout has no idea about the opposite size of its
children until the layout is complete.
Additionally, we should only suggest an opposite size for the layout if
we have one, instead of suggesting a weak zero size.
The size constraints are transient to measurement and allocation, so
they don't really need to be stored inside the GtkLayoutChild subclass
created by a GtkConstraintLayout.
The relations between left, right, width
and top, bottom, height are required for
internal consistency. It doesn't make sense
to ever drop these.
Changing the strength of these relations makes
my systems behave much more stable.
