[haiku-bugs] Re: [Haiku] #7447: *LayoutBuilder::DefaultInsets()
- From: "yourpalal" <trac@xxxxxxxxxxxx>
- Date: Sat, 04 Jun 2011 16:32:33 -0000
#7447: *LayoutBuilder::DefaultInsets()
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Reporter: jonas.kirilla | Owner: yourpalal
Type: enhancement | Status: assigned
Priority: normal | Milestone: R1
Component: Kits/Interface Kit | Version: R1/Development
Resolution: | Keywords:
Blocked By: | Blocking:
Has a Patch: 0 | Platform: All
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Comment (by yourpalal):
Firstly, sorry to perform ticket-necromancy, but I'd like to tackle this
now :)
Replying to [comment:5 bonefish]:
> Replying to [comment:4 jonas.kirilla]:
> > Yes, some shorthand for BControlLook-based insets. (But I'm not sure
if the item spacing BControlLook provides applies to insets.)
>
> Maybe a set of constants for different inset situations could be defined
and `BControlLook` could provide the respective inset values. Maybe that
even depends on the kind of frame around the inset area.
This is the idea I would like to go with, much like the current
B_USE_DEFAULT_SPACING.
For the record, the reason that constant has such a name, is that it can
be passed to a spacing function or an inset function, and is equivalent to
using be_control_look->DefaultItemSpacing(). I put the 'USE' in the name
to distinguish the fact that it is a symbolic constant (-2 or something),
not the actual spacing. The [https://dev.haiku-
os.org/browser/haiku/trunk/src/kits/interface/ControlLook.cpp#L54
BControlLook::ComposeItemSpacing()] method will be extended (and renamed
to ComposeSpacing()) to support the new constants.
> > There are some uses of
(BTwoDimensionalLayout::)SetInsets(B_USE_DEFAULT_SPACING,
B_USE_DEFAULT_SPACING, B_USE_DEFAULT_SPACING, B_USE_DEFAULT_SPACING) which
could perhaps be helped by a single-argument version - SetInsets(float
side) - or a no-argument version.
B_USE_DEFAULT_SPACING should probably be renamed, maybe to
B_USE_ITEM_SPACING.
> Yep, a single argument version of SetInsets() can certainly be added for
convenience to both BTwoDimensionalLayout and the builders and also a
version with two arguments (horizontal/vertical). I'm not in favor of a
no-argument version, as it is not clear what inset values it would set.
This is the other portion of the strategy I would like to use. 3 versions
of SetInsets(): 4 arguments, 2 arguments, 1 argument.
> > Perhaps a BInsets class, grouping a quad of floats, sort of BRect-
like, defaulting to non-zero values?
>
> Introducing a BInsets class is possible (since the layout management API
was inspired by Java's I considered it back then), but not for this
purpose. We should introduce such class only, if we decide that it is
passed around and used enough to improve convenience. I didn't add it,
because it turned out that there were really only the `{Set,Get}Insets()`
methods where it would have been used.
>
> > (Or one could make the layout classes default to non-zero insets. I
don't know what makes the most sense.)
>
> Indeed. :-) The default constructor should initialize the object to 0
insets. Global constants or getters (e.g. in BControlLook) could be added
to provide insets for different situations. That's also what should be
analyzed first: What are the situations and how do we want to provide the
insets? Whether a BInsets class is introduced can be decided when that is
clearer.
I think that for now, the insets will need to remain defaulted to 0. This
is assumed all over the place in our repo, and is actually a pretty sane
default. Here's what I'm thinking for different spacing constants:
* B_USE_ITEM_SPACING
* B_USE_HALF_ITEM_SPACING (this is a common use case I have seen in our
tree)
* B_USE_WINDOW_INSETS (INSETS because this shouldn't be used from spacing
between items)
* B_USE_SMALL_SPACING
* B_USE_BIG_SPACING
I don't know how we would choose values the SMALL/BIG spacing, but it
could be nice to offer a bit of consistency to developers. For now, they
could be some multiple of be_control_look->DefaultItemSpacing(). The
values these constants map to will all be available from BControlLook as
well.
As for a BInsets class, I don't think this is required. I don't really see
it being very useful, and if some developer really wants to use something
like that, it would be trivial to write a template method that called
SetInsets() on some object with the values from a BRect.
Anyway, if nobody objects, I'll implement this in a day or two.
--
Ticket URL: <http://dev.haiku-os.org/ticket/7447#comment:6>
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