[ptx] artifacts when scrolling

[Rob Park]

On 5/30/05, douglas wilkins <dgswilkins at yahoo.co.uk> wrote:
> > http://artography.ath.cx/hugin-xul-images.png
> 
> I like the look of this, but isn't it a little too long vertically? There
> doesn't seem to be enough space at the bottom for the preview image.

Yeah, it is a bit long. I had planned on making the preview image
smaller to fit (about the size as seen in autopano-sift) eg, a small
thumbnail.

> > http://artography.ath.cx/hugin-xul-lens.png
> >
> > At this point I have no idea how hard it would be to code in the
> > actual functionality, but I'm having fun with this, it's so easy to
> > write and it looks good (yes, I'm a superficial bastard) ;)
> 
> If you take a look at the mozilla site for XUL you'll find the following
> statement:
> "The intention is to build cross-platform applications like browsers and mail
> clients from a set of tools designed for that purpose. The intention is not to
> implement a generic cross-platform application framework. That's been done, and
> is a great deal of work. We intend to provide a subset of cross-platform
> functionality suitable for building network applications like browsers,
> leveraging the cross-platform functionality already built into Gecko, Mozilla's
> HTML layout engine."

Heh, missed that.

> hugin doesn't fit into any of these categories.

Well sure, but that's a poor reason to reject a toolkit... I mean,
using code for something that the author hadn't anticipated is a sign
of good, successfull code.

> Also using XUL would imply using the xpfe component to do layout rendering, but

xpfe?

> work that we need the framework to do, on the control point tab for instance, I
> doubt can be done by xpfe.

I think the control point tab would not be that hard. XUL has a widget
called, IIRC, "stackbox", which allows you to basically lay widgets
overtop of each other in an arbitrary way. So you just display the
image, and then display control point widgets on top of it. You can
embed SVG into XUL, so it'd be fairly straightforward to create little
colored circles to represent the control points like hugin does now,
without need for bitmapped images.

The difficulty that I'm actually having with XUL at this point is threefold:

1. xul is missing the spinbox widget (eg, the text entry field with
the "up" and "down" buttons on the right side, so we lose out on that.

2. in Gtk, there are two kinds of dropdown boxes: the kind you can
edit the value of like a text box, and the kind you can't. XUL allows
you to control whether the dropdown box is editable or not, but either
way the widget looks like Gtk's editable dropdown, it's impossible to
create the Gtk "non-editable" dropdown box widget (well, you can
create a widget that behaves the same way but it looks different).
That breaks consistency in a bad way for me.

3. XUL's grids (table layout widgets) don't support making a widget
span multiple rows/columns, so eg for something like the
hugin-test.png screenshot, it's impossible to make the "best fit"
button be in the middle of two lines, and it's also impossible to make
the "projection" drop down be the width of the two widgets combined,
meaning that the dropdown list will stretch the textbox to be wider
than necessary.

So the end result is that it's impossible to be compliant with *any*
HIG (GNOME's or Apple's) using XUL.

XUL was very appealing to me at first just for the way it's simple
XML, and the way you can actually style it with CSS, it's very slick
and it's very easy to code up an elaborate interface quickly.
Unfortunately it has a couple fatal flaws that make it unsuitable for
hugin...

Back to the drawing board, I guess. What I really need is some kind of
XUL/XRC thing, but for just straight Gtk. Preferrably more like XUL
than XRC ;)

-- 
Urban Artography
http://artography.ath.cx