[Phpmyadmin-devel] GIS visualization

[Tyron Madlener]

On Thu, Jun 2, 2011 at 6:05 PM, Tyron Madlener <tyronx at gmail.com> wrote:
> On Thu, Jun 2, 2011 at 4:21 PM, Madhura Jayaratne <madhura.cj at gmail.com> wrote:
>>
>>
>> On Thu, Jun 2, 2011 at 7:28 PM, Tyron Madlener <tyronx at gmail.com> wrote:
>>>
>>> On Thu, Jun 2, 2011 at 3:29 PM, Madhura Jayaratne <madhura.cj at gmail.com>
>>> wrote:
>>> >
>>> >
>>> > On Thu, Jun 2, 2011 at 6:16 PM, Tyron Madlener <tyronx at gmail.com> wrote:
>>> >>
>>> >> On Thu, Jun 2, 2011 at 2:35 PM, Madhura Jayaratne
>>> >> <madhura.cj at gmail.com>
>>> >> wrote:
>>> >> >
>>> >> >
>>> >> > On Thu, Jun 2, 2011 at 1:32 PM, Tyron Madlener <tyronx at gmail.com>
>>> >> > wrote:
>>> >> >>
>>> >> >> On Thu, Jun 2, 2011 at 4:27 AM, Madhura Jayaratne
>>> >> >> <madhura.cj at gmail.com>
>>> >> >> wrote:
>>> >> >> >
>>> >> >> >
>>> >> >> > On Thu, Jun 2, 2011 at 1:42 AM, Marc Delisle <marc at infomarc.info>
>>> >> >> > wrote:
>>> >> >> >>
>>> >> >> >> Madhura Jayaratne a écrit :
>>> >> >> >> (...)
>>> >> >> >> >      >     Hi Ammar,
>>> >> >> >> >      >
>>> >> >> >> >      >     I'm not sure what exactly your requirement is. But
>>> >> >> >> > pls
>>> >> >> >> > have a
>>> >> >> >> >     look
>>> >> >> >> >      >     at the visualization of data at [1] by clicking on
>>> >> >> >> > the
>>> >> >> >> > 'Visualize
>>> >> >> >> >      >     GIS data' link in the 'Query results operations'
>>> >> >> >> > section
>>> >> >> >> >     towards the
>>> >> >> >> >      >     bottom of the page. Try out zooming by double
>>> >> >> >> > clicking
>>> >> >> >> > and
>>> >> >> >> >     panning
>>> >> >> >> >      >     by dragging. I believe you are looking for something
>>> >> >> >> > like
>>> >> >> >> >     this for
>>> >> >> >> >      >     your zoom search feature.
>>> >> >> >> >
>>> >> >> >> >     Madhura,
>>> >> >> >> >
>>> >> >> >> >     I have issues operating panning and zooming. Here is the
>>> >> >> >> > scenario:
>>> >> >> >> >
>>> >> >> >> >     1. Browse world_cities and click Visualize GIS data
>>> >> >> >> >     2. Click-drag: pans OK
>>> >> >> >> >     3. Double-click: this is a zoom out, I guess
>>> >> >> >> >     4. Click-drag: no panning
>>> >> >> >> >     5. Click "zoom out": data points are enlarging, isn't this
>>> >> >> >> > a
>>> >> >> >> > zoom-in?
>>> >> >> >> >
>>> >> >> >> > Marc,
>>> >> >> >> >
>>> >> >> >> > This is a Firefox compatibility problem. Resolved and pushed to
>>> >> >> >> > the
>>> >> >> >> > repo. Demo will take some time to upgrade to the new version.
>>> >> >> >> > Meanwhile
>>> >> >> >> > if you have Chrome, you can still experience what it's suppose
>>> >> >> >> > to
>>> >> >> >> > do.
>>> >> >> >>
>>> >> >> >> Madhura,
>>> >> >> >> ok, panning and zooming are fine now.
>>> >> >> >>
>>> >> >> >> Is the saving feature ready? I tried to save in PNG and got a
>>> >> >> >> bunch
>>> >> >> >> of
>>> >> >> >> binary data on-screen.
>>> >> >> >>
>>> >> >> >> Saving in PDF generates
>>> >> >> >> Fatal error: Call to undefined method
>>> >> >> >> PMA_GIS_Visualization::toFileAsPdf() in
>>> >> >> >>
>>> >> >> >>
>>> >> >> >>
>>> >> >> >> /srv/http/pma.cihar.com/gsoc-madhura/libraries/gis_visualization.lib.php
>>> >> >> >> on line 161
>>> >> >> >>
>>> >> >> >> --
>>> >> >> >> Marc Delisle
>>> >> >> >> http://infomarc.info
>>> >> >> >>
>>> >> >> > Hi Marc,
>>> >> >> > In my previous mail to the group, I mentioned that this feature is
>>> >> >> > not
>>> >> >> > yet
>>> >> >> > ready. BTW, this is a feature which is to be delivered in the
>>> >> >> > second
>>> >> >> > half of
>>> >> >> > GSoC (after mid-term eval), according to the schedule. However I
>>> >> >> > started
>>> >> >> > working on it, since it is very much related to what I've done so
>>> >> >> > far. I
>>> >> >> > should be able to get it ready (for all 3 formats, SVG, PNG and
>>> >> >> > PDF)
>>> >> >> > by
>>> >> >> > the
>>> >> >> > end of this week.
>>> >> >>
>>> >> >> Just in case I'm allowed to use Highcharts, could you make your
>>> >> >> conversion code generic enough so I could use it too? :)
>>> >> >> And just for your information, the current SVG converter of
>>> >> >> highcharts
>>> >> >> uses following post variables to a php file that calls a java tool
>>> >> >> (source is available btw):
>>> >> >>
>>> >> >>  * $tempName string The desired filename without extension
>>> >> >>  * $type string The MIME type for export.
>>> >> >>  * $width int The pixel width of the exported raster image. The
>>> >> >> height
>>> >> >> is calculated.
>>> >> >>  * $svg string The SVG source code to convert.
>>> >> >>
>>> >> > Hi Tyron,
>>> >> > For my work I am not doing any conversions as such. I am generating
>>> >> > SVGs
>>> >> > and
>>> >> > PNG separately in their basic forms. It's not that I generate it in
>>> >> > one
>>> >> > form
>>> >> > and converting it to the other.
>>> >> > --
>>> >>
>>> >> Does that mean you use jQuery SVG to generate the SVG and build/use
>>> >> another rendering library that generates the PNG/PDF? Why not just
>>> >> build a converter? That seems like a more reusable solution.
>>> >>
>>> > I use GD extension to generate PNGs and will be using TCPDF (which is
>>> > already included in PMA) to generate PDFs. Since both GD and TCPDF
>>> > support
>>> > rendering basic shapes, I find this approach needs only
>>> > few additional lines
>>> > of code, which would not have been the case if I am to build
>>> > a converter.
>>>
>> In total I did not have to add more that 100 LOC to get all 7 geometric
>> types to PNG.
>>
>>>
>>> A disadvantage is that you will have duplicate code. Also if we would
>>> have a converter we could include some cool features such as exporting
>>> the SVG with its currently selected zoom level and pan - which might
>>> turn out really useful for big amounts of data.
>>
>> Well, I agree that this will be useful.
>> About code duplication, I tried my best with a good class hierarchy to
>> ensure that code duplication is minimized as much as possible.
>>>
>>> And it will turn out really useful when I'm allowed use Highcharts for
>>> the status page. There the conversion code will be ~100% reusable.
>>>
>>> So how about we build one together? :)
>>
>> Great idea!!! But I doubt whether I will have enough time for this, since my
>> GSoC project is 'OpenGIS support for PMA' and not 'OpenGIS visualization
>> support for PMA' :) There is lot more I promised to deliver that is related
>> to OpenGIS.
>>>
>
> After some serious digging I found canvg
> (http://code.google.com/p/canvg/) which would let us convert svg into
> a canvas (in javascript). And canvas elements are basically already
> bitmaps so we can export them directly as png.
> The procedure sounds a bit odd but therefore even saves us any
> server-side conversion.
>
> Here's some examples what it can convert:
> http://canvg.googlecode.com/svn/trunk/examples/index.htm
> It's supposed to work for IE7-8 aswell but in my tests it couldn't
> convert my highcharts generated svg code. In Chrome it worked though.
>
> I'll keep researching on this ;-)

Hehe and here is the solution for jQuery SVG when using canvg:
http://stackoverflow.com/questions/4827764/convert-jquery-svg-to-image/4836882#4836882

Though at some point I would use Downloadify
(https://github.com/dcneiner/Downloadify) to eliminate any server
interaction and use the supplied php snippet only as fallback when
flash is not available.

>
>>> There should be some lib for it anyway. Might even turn out to be
>>> easier than the code to generate a PNG.
>>>
>>
>> --
>> Thanks and Regards,
>> Madhura Jayaratne
>>
>>
>>
>