Hover handler inclusion

[elemoine]

People want a mechanism where an action is triggered as the mouse goes over the map and pause - to send requests to some search service for example. See this: <http://openlayers.org/pipermail/users/2007-December/004254.html>.

The attached patch introduces the hover handler for that.

Patch includes the hover handler, an example and tests.

Credits: this hover handler was Tim's idea.

[elemoine]

Ignore patch-1252-r5674-A0.diff, which was a patch for #1252

[tschaub]

Nice work Eric. This is really cool. Two minor tweaks (for IE) in the example: removing trailing commas from lines 60 and 102 (hover-handler.html).

This will be great to have in the library. Please commit with the above changes.

(The other issue I was just reminded of is the poor destroy coverage we have on controls/handlers. We really need to go through the controls and make sure they destroy their handlers on destroy - and that those handlers deactivate themselves on destroy to remove event listeners. I added a ticket for this previously.)

[elemoine]

Replying to tschaub:

Nice work Eric. This is really cool. Two minor tweaks (for IE) in the example: removing trailing commas from lines 60 and 102 (hover-handler.html).

Thanks for catching this. I'll append an updated patch.

This will be great to have in the library. Please commit with the above changes.

Will do tomorrow, after I give it some extra testing on other browsers.

(The other issue I was just reminded of is the poor destroy coverage we have on controls/handlers. We really need to go through the controls and make sure they destroy their handlers on destroy - and that those handlers deactivate themselves on destroy to remove event listeners. I added a ticket for this previously.)

If the handlers call their parent's destroy method they should be ok. See < http://trac.openlayers.org/browser/trunk/openlayers/lib/OpenLayers/Handler.js#L251>.

[elemoine]

Tim's comments taken into account

[elemoine]

change passesTolerance() ND comment

[tschaub]

Replying to elemoine:

Replying to tschaub:

(The other issue I was just reminded of is the poor destroy coverage we have on controls/handlers. We really need to go through the controls and make sure they destroy their handlers on destroy - and that those handlers deactivate themselves on destroy to remove event listeners. I added a ticket for this previously.)

If the handlers call their parent's destroy method they should be ok. See < http://trac.openlayers.org/browser/trunk/openlayers/lib/OpenLayers/Handler.js#L251>.

Yeah, it's more a problem the other way (controls not destroying their handlers). For example, go to  http://openlayers.org, open firebug, and enter

c = map.controls[0];
map.destroy();

Then enjoy exploring things like

c.dragPan.handler.map.layerContainerDiv // etc.

[elemoine]

new patch with two callbacks: "pause" and "move"

[elemoine]

I attached a new patch. With this patch, a new callback is available: "move". This callback is called on mousemoves when the mouse actually moves (i.e. does not pause). This callback is necessary for the user to be able to abort an Ajax request sent when the mouse paused. This callback can be used for other things like closing a popup. I also renamed the "hover" callback, it's now named "pause".

Tim, does the patch still look ok?

Tests pass on FF.

[crschmidt]

Eric:

Quick comment -- can we call 'stopPropag' 'stopMove' instead? In the future, we may want to have seperate events for the different things that we're stopping propogation on possibly? I really don't like 'stopPropoag', in either case -- if we think we'll always want to stop as a group, then stopPropogation seems more right to me.

[elemoine]

Replying to crschmidt:

Eric: Quick comment -- can we call 'stopPropag' 'stopMove' instead? In the future, we may want to have seperate events for the different things that we're stopping propogation on possibly? I really don't like 'stopPropoag', in either case -- if we think we'll always want to stop as a group, then stopPropogation seems more right to me.

Thanks for the review Chris. I agree to rename 'stopPropag' 'stopMove'. Will update the patch...

[elemoine]

update to B0 patch, stopPropag renamed stopMove, add initialize() method

[elemoine]

I tested the hover-handler.html example on FF2/Linux, IE6, IE7, Opera9/Windows, Safari3/Windows. It works in all. Unit tests pass on FF2, IE6 and IE7; not run on Opera9 and Safari3.

[crschmidt]

Still looks fine -- please continue to feel free to commit :)

[elemoine]

(In [5746]) Add hover handler. With this handler user-defined actions can be triggered as the mouse moves over the map and pauses. An example of use is send WMS/GetFeatureInfo requests. r=crschmidt,tschaub (closes #1255)