On Friday, October 30, 2009, Dave Thomas <
[hidden email]> wrote:
>
> Hi Everyone,
Hi
>
> Hi have what I though would be a simple task but its proving to be a little more frustrating than I anticipated.
>
> What I need to do is get the coordinates for pan events so that I know the coordinates of when the drag started and when it ended. The logical way to do this as far as I thought was to listen for the mousedown (or movestart) and mouseup (or moveend) events and get the coordinates from there. Its not behaving the way I anticipated though. I've tried a whole bunch of different ideas - four of which I'll list here. Surely one of these is close. I think the first two are the closest.
>
> I'd very much appreciate any input that may help.
>
> Many Thanks
> Dave
>
>
>
> Method 1. Not all Events are recevied and of the ones that are I can't get the coordinates from all of them.
>
> click: yes
> mousemove: yes
> mouseup: yes
> mousedown: no
> movestart: yes - but coordinates recevied are NAN
> moveend: yes - but coordinates received are NAN
>
>
> var options =
> {
> ... other settings....
>
> eventListeners: {
> "movestart": doEvent
> }
> };
>
> function doEvent(event) {
> var obj = this.events.getMousePosition(event)
getMousePosition works with browser events only.
> alert(obj);
> }
>
>
> Method 2. Same results as Method 1
>
>
> map.events.register("mousemove", map, function(e) {
> var position = this.events.getMousePosition(e);
> alert(position);
> });
>
>
>
>
> Method 3. Clicks are called but not mousedowns.
>
>
> OpenLayers.Control.Click = OpenLayers.Class(OpenLayers.Control, {
> defaultHandlerOptions: {
> 'single': true,
> 'double': false,
> 'pixelTolerance': 0,
> 'stopSingle': false,
> 'stopDouble': false
> },
>
> initialize: function(options) {
> this.handlerOptions = OpenLayers.Util.extend(
> {}, this.defaultHandlerOptions
> );
> OpenLayers.Control.prototype.initialize.apply(
> this, arguments
> );
> this.handler = new OpenLayers.Handler.Click(
> this, {
> 'click': this.doClick,
> 'down': this.doDown,
> 'mousedown': this.doMouseDown
> }, this.handlerOptions
> );
> },
>
> doClick: function(e) {
> alert('click');
> },
> doDown: function(e) {
> alert('down');
> },
> doMouseDown: function(e) {
> alert('mouseDown');
> }
> });
>
>
> Method 4. Callbacks are only received if Navigation is deactivated.
>
>
> OpenLayers.Control.Drag = OpenLayers.Class(OpenLayers.Control, {
> defaultHandlerOptions: {
> stopDown: false
> },
>
> initialize: function(options) {
> this.handlerOptions = OpenLayers.Util.extend(
> {}, this.defaultHandlerOptions
> );
> OpenLayers.Control.prototype.initialize.apply(
> this, arguments
> );
> this.handler = new OpenLayers.Handler.Drag(
> this, {
> 'down': this.doDown,
> 'up': this.doUp,
> 'move': this.doMove,
> 'done': this.doDone
> }, this.handlerOptions
> );
> },
>
> doDown: function(e) {
> alert('down');
> },
> doUp: function(e) {
> alert('up')
> },
> doMove: function(e) {
> alert('move');
> },
> doDone: function(e) {
> alert('done');
> }
> });
implementing a specific control based on a Drag handler is what I'd go
with. You can look at the DragPan control to know how to use the Drag
handler - I tend to think that you could rely on the "move" and "done"
callbacks only. Now regarding the conflict with the Navigation
control: have you tried making sure your control is activated *before*
the Navigation control?
Cheers,
--
Eric Lemoine
Camptocamp France SAS
Savoie Technolac, BP 352
73377 Le Bourget du Lac, Cedex
Tel : 00 33 4 79 44 44 96
Mail :
[hidden email]
http://www.camptocamp.com_______________________________________________
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