Implementing Layers in 0324 Beta

[PjotrC]

Attached is a patch (based at 0324, following the 0001-Automatic-Daily-Track) implementing handling layers in Route Manager as signalled initially in Forums - Post 622989">-IRJDSUNE9932123321222xxeww-the-IRJDSUNE9932123321222xxeww-original-IRJDSUNE9932123321222xxeww-thread-IRJDSUNE9932123321222xxeww-.

Routes, tracks and waypoints can be aggregated into layers.
A layer is imported interactively via Import new Layer button or automatically on start of OpenCPN.
Automatic import occurs from /layers subdirectory under /data in the OCPN installation structure.
Any .gpx file in /layers becomes a separate layer.
Any subdirectory under /layers (e.g. /layers/windfarms) results in all of its .gpx contents (all the way down) to form a separate layer.

Objects in layers cannot be modified. They can be deleted only as the whole layer.
Objects in layers are not saved to navobj.xml and cannot be exported.

On the layers tab here are buttons for

- showing or hiding a layer on chart (initially: shown)
- showing or hiding the layer contents in other RM tabs (initially: hidden)
- showing or hiding on chart the layer's (incl. routes and tracks) waypoints names (initially: as specified in .gpx file)

For beginner's usage, it is recommended to use manual Load/Delete of layers sparingly. These are primarily layer development tools, and once you are happy with the GPX files, put them into /layers and just leave there.

During layer import the GUIDs (if present) in the GPX files are ignored. The rationale for this is that layers data is treated as _templates_ of Nav Objects, so they are never identified with any other _concrete_ object. This means that you can import the same layer many times over itself, and still have all these copies present. This has both upsides and downsides. I feel the GUID handling policy in OCPN should be reviewed, but for now you get reasonable behaviour and lots of possibilities.

Attached is a series of screenshots with preloaded layers sequentially hidden by single clicks on the visibility icon.

Enjoy,

Piotr

[sinbad7]

PjotrC..

Is this layers facility also available for us Windows Vista users?
If so,how do you use the patch file?

Tore

[PjotrC]

Tore,

It should work on all the platforms, including Vista.
If you are not building from source, you need to wait, until it will be included in the current (beta) release.

Piotr

[PjotrC]

With the feature now available for testing in 0412, just some comments to the user manual ...

In this simple model, layer objects are templates:

- unmodifiable
- undeletable individually
- not identified with any other, layer or regular, similar as they may be

Some of the consequences:

- you cannot extend a layer route nor track
- you cannot split a layer route nor track
- you cannot reverse a layer route

but

- you can activate and use a layer route unmodified
- you can extend a regular route into a layer route
- you can create an editable "copy" of a route (or other object), importing it twice - once as a layer, then as regular GPX
- to add a regular object to a given layer (e.g. "myLayer", for next restart), just export it into the /layers/myLayer directory

What I still can't figure out (implementation, not a user problem):

- how to avoid writing deleted layer objects into navobj.changes.xml? Should not be needed at all, since layers are always reconstructed fresh from source, not saved as current state...

[HamishB]

Hi,

any chance of getting this documented in the help html?

any chance of it looking in ~/.opencpn/layers/ as well as /usr/local/share/opencpn/layers/ on UNIXs? the program may be installed to /usr/share/opencpn/ and the user not have write access to anything other than their own home directory. (same is true for a work-issued locked down MS Windows laptop)

same goes for looking for UserIcons in ~/.opencpn/icons/


thanks,
Hamish

ps- wrt UserIcons, if any of these symbols look useful let me know & I'll generate some 24x24 bitmaps of them: (GPLv2, vectorized source)
IconSymbols - GRASS-Wiki

[cagney]

Originally Posted by HamishB

Hi,

any chance of getting this documented in the help html?

any chance of it looking in ~/.opencpn/layers/ as well as /usr/local/share/opencpn/layers/ on UNIXs? the program may be installed to /usr/share/opencpn/ and the user not have write access to anything other than their own home directory. (same is true for a work-issued locked down MS Windows laptop)

same goes for looking for UserIcons in ~/.opencpn/icons/


thanks,
Hamish

ps- wrt UserIcons, if any of these symbols look useful let me know & I'll generate some 24x24 bitmaps of them: (GPLv2, vectorized source)
IconSymbols - GRASS-Wiki

Hamish

In the last beta both "UserIcons" and "layers" have been moved to ~/.opencpn. Layers are documented in the wiki, which will become the 2.5 documentation. Reviews and suggestions regarding the wiki are always welcome. The documentation that comes with the betas are still the old 2.3.1 documentation, while he wiki tries to keep up to date with the beta releases.

Thomas

[HamishB]

Originally Posted by cagney

In the last beta both "UserIcons" and "layers" have been moved to ~/.opencpn.

great. y'all are one step ahead of me, as usual.

Layers are documented in the wiki,

ok

which will become the 2.5 documentation. Reviews and suggestions regarding the wiki are always welcome. The documentation that comes with the betas are still the old 2.3.1 documentation, while he wiki tries to keep up to date with the beta releases.

erm, how exactly would one access the help when at sea with no internet connection? will the 'final product' be fed back into the 2.5.x distributibles?

should a cron job mirror all wiki pages as html into a zip file, which could be installed on the local system?


thanks,
Hamish

[cagney]

Hamish

erm, how exactly would one access the help when at sea with no internet connection? will the 'final product' be fed back into the 2.5.x distributibles?

More or less - yes.
I suppose all this could be automated, as a snapshot of the wiki is always available at OpenCPN User Manual This link is available on the download page called "Live Snapshot". This "snapshot" can be used to update the documentation in the beta packages.
For an experienced user, using a beta release for actual navigation, I would recommend exactly this, or at least having the latest snapshot available on board.

When Dave is ready for a 2.5 release he will take a "snapshot", trim down the size of the picture directory (I thinK you did that last time?), ++, and include it in the release.

Thomas

[bdbcat]

Thomas....

Oh I will, will I?...

I had forgotten about how we do the last minute doc update.
Thanks for reminding me.....

Dave

[cagney]

Originally Posted by bdbcat

Thomas....

Oh I will, will I?...

I had forgotten about how we do the last minute doc update.
Thanks for reminding me.....

Dave

Dave

The documentation is more or less ready to go. I would appreciate some critical eyes, checking mainly for accuracy, but other things as well, ...it's a wiki!
I can take the snapshot and trim the picture sizes, and make it available for you. Anything else....?

Thomas

[bdbcat]

Thomas....

Thanks. I guess I could be ready for the doc files whenever you think the editing is complete, or at least good enough.

email to me directly, please, and I'll get them pushed.

Thanks again
Dave