[maplab-users] Query question

[William A. Bronsema, C.E.T.]

Matt, Richard,

I have traced through the code and have found the problem.  It appears 
that only the zoom tool uses the MIN_RECT, not the query tool. 
Therefore when a query is performed, it is always a rectangle query (in 
ROSA mode).

If I perform a query on the "Parks" (polygon) layer using a single click 
I get results because the tiny rectangle "hits" the polygon therefore 
returning results.  If I perform a single click query on the "popplace" 
(point layer) it is likely that I will not get results because the click 
would have to be on the exact location of the point (tolerance is not 
used).  Make sense?

I'm not sure why re-projected would behave differently (lucky hit on the 
point?).

Anyway, I will file a bug about the MIN_RECT parameter not being used on 
the query tool.

Regards,
Bill

Post,Richard [NCR] wrote:
> Hi Matt,
> 
> I have not found a solution (I changed my query icon to represent a
> rectangular query!).  That is an interesting observation about projected
> verses non-projected data.  My application uses projected data as well
> (LCC).  Anyone have any more suggestions we might try?
> 
> Richard Post  
> 
> -----Original Message-----
> From: Matt Doggett [mailto:mdoggett@coas.oregonstate.edu] 
> Sent: November 21, 2003 6:58 PM
> To: mdoggett@coas.oregonstate.edu; bronsema@dmsolutions.ca;
> 'Post,Richard [NCR]'
> Cc: Maplab-users@dmsolutions.ca
> Subject: RE: [maplab-users] Query question
> 
> 
> Allow me to shed a little more light on this problem.
> 
> - I have a map file which outputs a map in "latlong" projection (ie.
> Unprojected geographic). With this map, a single click WILL return query
> results.
> - An identical application (same map file, data, ...everything) but
> outputs a PROJECTED map, using "aea" in my case, does NOT work. Ie. You
> have to click-and-drag in order for the query results to return
> anything.
> 
> So, perhaps someone could explain why my Maplab application behaves
> differently for projected/unprojected maps?
> 
> Matt
> 
> 
>>-----Original Message-----
>>From: maplab-users-admin@lists.maptools.org [mailto:maplab-users- 
>>admin@lists.maptools.org] On Behalf Of Matt Doggett
>>Sent: Friday, November 21, 2003 3:31 PM
>>To: bronsema@dmsolutions.ca; 'Post,Richard [NCR]'
>>Cc: Maplab-users@dmsolutions.ca
>>Subject: RE: [maplab-users] Query question
>>
>>I noticed that I have this exact same behavior. Changing the MIN_RECT 
>>appears to have no effect.  I was wondering if you discovered any 
>>solution to this problem? Would be nice to have working queries without
> 
> 
>>having to drag the mouse all the time.  Having to click-n-drag inside a
> 
> 
>>polygon to select that polygon seems kind of silly.
>>
>>Matt
>>
>>
>>>-----Original Message-----
>>>From: maplab-users-admin@lists.maptools.org [mailto:maplab-users- 
>>>admin@lists.maptools.org] On Behalf Of William A. Bronsema, C.E.T.
>>>Sent: Friday, October 17, 2003 4:36 AM
>>>To: Post,Richard [NCR]
>>>Cc: Maplab-users@dmsolutions.ca
>>>Subject: Re: [maplab-users] Query question
>>>
>>>Hi Richard,
>>>
>>>I'm not sure if this will help or not, but FYI -
>>>
>>>There is a constant defined in the globprefs.php file for your 
>>>gmapFactory application that should look something like this ( In my 
>>>version it is on line 65):
>>>
>>>define( "MIN_RECT", 5 );
>>>
>>>This constant controls the difference between a "point click" and 
>>>"rectangle select".  Essentially all interactions with the map are 
>>>"rectangle selects".  This constant tells the application the
> 
> threshold
> 
>>>at which the user was intending to perform a "point click" (i.e. a
> 
> tiny
> 
>>>rectangle) instead of a "rectangle select".
>>>
>>>In the case of querying, if the value is too small then more often
> 
> than
> 
>>>not a tiny rectangle query will be performed instead of a point query 
>>>which can lead to confusing results.
>>>
>>>HTH.
>>>
>>>Regards,
>>>Bill
>>>
>>>
>>>--
>>>
>>>William A. Bronsema, C.E.T.
>>>Applications Developer
>>>
>>>DM Solutions Group Inc.
>>>http://www.dmsolutions.ca ____________________________________
>>>
>>>Post,Richard [NCR] wrote:
>>>
>>>>Hello,
>>>>
>>>>I have a small problem with my gmapfactory application.  The
>>
>>application
>>
>>>>uses the query function to select points from a shape file.  The
>>
>>problem
>>
>>>>is that the query only works when you drag a box over the points
> 
> (ie.
> 
>>>>Doing a rectangular query).  When you simply click on the point
>>
>>nothing
>>
>>>>is selected (ie. The layer does not return any results).  I have
>>
>>already
>>
>>>>tried changing the TOLERANCE and TOLERANCEUNITS in the map file,
>>
>>which
>>
>>>>does not seem to have any effect.
>>>>
>>>>Any suggestions would be welcome.
>>>>
>>>>Thanks,
>>>>
>>>>Richard Post
>>>>Environment Canada
>>>>
>>>
>>>
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>>>Maplab-users mailing list
>>>Maplab-users@lists.maptools.org 
>>>http://lists.maptools.org/mailman/listinfo/maplab-users
>>
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-- 

William A. Bronsema, C.E.T.
Applications Developer,
DM Solutions Group Inc.

http://www.dmsolutions.ca
email: bronsema@dmsolutions.ca
Phone: (613) 565-5056 ext.25
Fax :  (613) 565-0925
____________________________________