Re: Tweak for interactive SVGs?

[<pl...@pi...>]

Ethan A Merritt wrote:
> On Sunday 21 December 2008, pl...@pi... wrote:
>> I have had another think about adding functionality to svg terminal.
>> Today I realised that in using my gnuplot output to study system
>> performance I am constantly needing to read x,y values off the graph.
>> This currently means zooming to a large magnification, placing the mouse
>> cursor and then scrolling with arrow keys and praying that it falls near
>> enought to the axis to read the minor ticks near the cursor.
>>
>> In short rather unsatisfactory and hacky.
>>
>> What I need is something like the wxt terminal cursor output.
>>
>> How feasible would it be to add an onhover or onclick event  and grab
>> the event x,y and display plot related x,y values?
> 
> It should be feasible.  I have been trying to drum up enthusiasm for this,
> and find a volunteer to code it.
> 
>> That sounds like it would be fraught with browser compatibility issues.
> 
> To some extent. But there are working example of cross-platform code that
> uses javascript to do mouse-tracking.  Here is one:
>    http://dunnbypaul.net/js_mouse/
> 
> As I see it, we need to put the following in place:
> 
>  - create a jscript/ECMScript/javascript/whatever mouse-tracker, which
>    can be loaded from either the user's own web site or from some 
>    central place like the gnuplot pages on SourceForge.  It should
>    read the current mouse coords, apply a transformation matrix (see next)
>    and print the transformed coordinates on the page, similar to the 
>    current interactive terminals.

Hi Ethan,

maybe I'm missing the point but can't the javascript be included in the
SVG xml? I don't see it as desirable solution to wait for a response
from sourceforge before my plot can fully render, nor that I need an
open internet connection to diplay a local file.

Externalising what could potentially be common and invariant code may be
an option but I would have thought the first aim should be a self
contained svg file.

regards, Peter.

> 
>  - have the svg driver emit code that refers to the script by its URL,
>    and initializes the coordinate system to correspond to the one in
>    the current plot by providing an appropriate transformation matrix.
> 
> There may be other ways to do it.  I am intrigued by the "canvas terminal
> driver" uploaded to SourceForge as patch   #2056054
> 
>