actually, you contradict this:
To draw a polygon outlining the shape of the property over an aerial image (from Google Maps)
Ideally the end user should be able to click on an image in FileMaker, add the polygon, save, and go on to the next record
something like this might work:
Thanks Mike. To clarify, the image will be a screen shot of a Google Map image rather than a loaded live from Google Maps.
It's sounds like an option. I'll discuss it with my counterpart doing the web side of things.
Are you familiar with loading custom content into a web viewer and scraping the web viewer? The web guy can do the code for you to load, but you’ll still need to do a lot of work in FM to make it work.
Good luck! Would make a great solution to share on modularfilemaker.org if you get it working.
We'll need to coordinate but I've worked with loading custom data and scaling data. I need to study the specifics and see what I need to do to extract specifics.
Um, a couple questions:
What is the coordinate system expected to be for representing the polygon for these screen shots?
Or another way of putting it - if these are really screenshots does the record have metadata regarding the bounding box of the image for use in GIS systems?
If you don't have information to translate a screen's x,y pixel coordinates into the proper latitude,longitude GIS coordinates this isn't possible.
If that info is available its entirely possible via any of the methods Mike mentioned above. My preference is to draw on live maps in web viewers. That way the APIs handle all of the coordinate conversions on your behalf.
There is no need to have long/lat data. All we need to know are the size of the image, the shape of the polygon and the absolute position of the polygon relative to the edges of the image (x,y). This is for visual marking of properties on the image only, no coordination with or use of long/lat is required. Essentially we are creating a mostly transparent object over the primary image to mark the location and shape of the property.
Ah, OK. That helps figure things out.
This can be done with a variety of tools - one of which is the jsDraw2D link posted above.
It's not a trivial task to do what is being requested by the client. Even Todd said GoDraw doesn't lend itself to being bent that way. It's a bunch of moving parts to get it working end to end...
I'm sure there's a dev out there who could help you implement it, but I don't know of an off the shelf solution that includes both drawing polyshapes on top of images and retrieving the metadata of the drawn shape as some sort of text for storage in a record.
GoDraw does export out the overlay information in JSON into a text field called "document" in the demo file and Todd did think that it might be possible to provide a conversion for that text string to something that included (x,y) coordinates but it would take some digging in to find out...something my client might be willing to pay for. However, GoDraw is limited to ovals and rectangles and we really need a polygon tool with unlimited points that can be joined into a boundary area.
I'm not familiar in depth with GoDraw internals, but if my hunch is correct I think Polyshapes are possible. I'd need to talk with Todd to confirm.
As for the json translation, that is also feasible...just a matter of effort to code it.
Private message me if you'd like to discuss further...happy to investigate a bit.