[jdev] Whiteboard.
Heiner Wolf
wolf at bluehands.de
Fri Jun 4 12:31:21 CDT 2004
Hi,
there are 3 additions.
Summary:
1. Add optional <subject/> and <body/> to the <path/> for
annotations (see TEXT).
2. Add optional shape-attribute for path with values like: 'rect',
'pointer' (see SHAPE HINT).
3. Add an optional uri-attribute for DOM-based positioning
(see ALTERNATE POSITIONING).
The ALTERNATE POSITIONING is only for positioning above an HTML DOM
window. So probably ony the first to apply for whiteboarding in general.
TEXT:
I added a text element. I know the arguments agains text:
- Text is difficult because of fonts and
- Assumed JEP-113 re-uses SVG and assumed JEP-113 is simple. Then
text in general is ruled out, because SVG-text is complex, which
the simplicity assumption.
However, as you wrote: typical karma settings make path based text
impossible. If we want simple text then we must deviate from SVG. Here
is what I have: I do not really need text as a graphical design
element, but as an annotation. So, text is rather an opaque rectangle
with text
inside. I am using:
<text x=1 y=2 w=30 h=40 stroke=#000000 stroke-width=5>Text</text>
The attributes describe the rectangle. The payload text has no styles
at all yet. While I am writing I just discover, that it might be nice
to merge the <text/>, which is basically a rectangle, with the path
element, so that any <path/> can have a payload Text. Maybe like
<message/> with <subject/> and <body/> sub-tags. I would not define
where the annotation is attached to the path. That's up to the
implementation.
It is not a content element, like SVG-text.
SHAPE HINT
I also implemented pointers, which are just paths with a fixed shape.
But for the implementation it was nice to know that it is a pointer.
The shape is fixed. It can not be changed accidentally. The hotspot
is always at the tip of the pointer (arrow).
I implemented a rectange to frame things. It is a path, but it is nice
for the implementation to 'know' that it is a rectangle. Moving a
point of the path will keep the rectangle shape by adjusting other
points. So, I propose a 'shape' hint for the <path/>
The shape-attribute also helps to position the annotation
appropriatly.
ALTERNATE POSITIONING
My whiteboard draws on the web page where people meet (Peter, if you
read this: yes, I am talking about the LLuna project).
For the whiteboard on the web page I added a positioning relative to
DOM elements of the underlying browser window. I use a uri-attribute
for the path. The uri-attribute overrides absolute coordinate based
positioning.
It looks like:
uri='dom:/BODY[1]/DIV[2]/IMG[1]#(225,98)'
This means the position is pixel (225,98) relative to the element
which is the 1st IMG in the 2nd DIV of the 1st BODY tag. There is
usually only one, but of course, I keep the index for consistency.
BTW: the URI refers to a pixel. Is a pixel a resource in the URI
sense?
Expressing the absolute URI including the URL of the document:
uri='http://www.jabber.org/#dom:/BODY[1]/DIV[2]/IMG[1]#(225,98)'
There is a frameset issue. Each frame has a complete DOM. The uri is
like:
uri='dom:/BODY[1]/FRAMESET[1]/FRAME[2]/BODY[1]/TABLE[1]/TR[2]/...
using one DOM as a start, the switching to another DOM, if a FRAME
comes in the way.
hw
--
Dr. Klaus H. Wolf
bluehands GmbH & Co.mmunication KG
http://www.bluehands.de/people/hw
+49 (0721) 16108 75
--
LLuna: Jabber enabled virtual presence on the web / http://www.lluna.de/
Galactic developments: Open source future history /
http://www.galactic-developments.com/
> -----Original Message-----
> From: Rodolfo Gonzalez Gonzalez
> [mailto:rodolfo at equinoxe.g-networks.net]
> Sent: Friday, June 04, 2004 6:10 PM
> To: Heiner Wolf
> Subject: RE: [jdev] Whiteboard.
>
>
> On Fri, 4 Jun 2004, Heiner Wolf wrote:
>
> > Hi,
>
> Hello Heiner,
>
> > I implemented the JEP-113 in LLuna (www.lluna.de). I needed
> a simple WB
> > protocol for Jabber and JEP-113 is as good as anything
> (simple) I would
> > dream up myself. So there was no point in re-inventing. I made some
> > (compatible) extensions and sent them to the author. I
> don't know what
> > he did with my comments.
>
>
> It sounds like a good choice. Is there anyway to share those
> extensions? I
> didn't know about LLuna, but it looks great.
>
> Thanks in advance.
> Rodolfo.
>
>
>
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