B4i Library [class]GoogleMapsExtra

This class extends GoogleMaps library.
Currently it supports:
- AddCircle - Adds a circle at a give point.
- AddGroundOverlay - Adds an image at the given bounds.
- ZoomToPoints
- SetSelectedMarker
- SetMarkerRotation
- SetGroundAnchor - sets the marker anchor.
- AddPolygon


Example:

gextra.Initialize(gmap)
Dim ne, sw As LatLng
ne.Initialize(20, 20)
sw.Initialize(00, 00)
Dim bounds As Object = gextra.CreateBounds(ne, sw)
gextra.AddGroundOverlay(bounds, LoadBitmap(File.DirAssets, "up76.png"))

Note that the bundle in the special folder is not included. You need to download it from the tutorial.

Updates:

v2.15 - New AnimateCameraWithDuration method. Same as gmap.AnimateCamera with configurable duration.
v2.10 - Adds support for custom info windows (appear when the user clicks on a marker).

You need to add this event sub and create the custom panel or return Null:

'Return Null for the default marker layout
Sub gmap_MarkerInfoWindow (OMarker As Object) As Object
   Dim SelectedMarker As Marker = OMarker
   Dim p As Panel
   p.Initialize("")
   p.Color = Colors.Red
   p.SetLayoutAnimated(0, 1, 0, 0, 200, 200)
   Dim lbl As Label
   lbl.Initialize("")
   lbl.Text = SelectedMarker.Title
   p.AddView(lbl, 10, 10, 200, 200)
   Return p
End Sub

 

[RichardHirst]

Hello Erel

Works great, thank you.

One more question, is there any Transparency function..?



Found this :
http://stackoverflow.com/questions/...pha-of-a-groundoverlay-in-goolge-maps-ios-sdk

Could this be added to the gExtra file...?

Thanks

Richard

 

[Erel]

You can add the transparency to the image itself.

 

[RichardHirst]

Do you mean before you load the image (transparency applied external to the App) or after the image has been loaded...?

how would I set the transparency with IOS ide..?

Thanks

 

[Erel]

The image file itself can be semi-transparent.

 

[RichardHirst]

Can this be done in code. The external image does not have transparency set..

Had a look at the Bitmap properties but can not set how to set transparency.

Thanks

 

[Erel]

Currently no.

 

[RichardHirst]

Thanks for all you help Erel..

 

[Paul Leischow]

This Class is great for adding circles to a map.
Was wondering what is the best way to remove circles from the map??

 

[Erel]

Modify AddCircle sub and return the circle object.

Later you can remove this circle by calling:

circle.SetField("map", Null)

 

[Paul Leischow]

Ok, I have the Sub addCircle returning the NativeObject using... Return circle
Should I be putting this result in a List using Result.add(gextra.addCircle(blah,blah)) ??
And if so, I'm not understanding how to pull out the info I need so I can use circle.SetField

Should I maybe not be using the GoogleMapsExtra and making the circle native object global?
Quite confused
Thanks.

 

[Paul Leischow]

Well, not sure if this was the right way to do it but it seems to work
I returned circle as a NativeObject and stored it in a List called Marker.

Then later, I cycled through the List and put it into a new NativeObject...
Dim obj As NativeObject=Markers.Get(tmp)
That allowed me to do
obj.SetField("map",Null)

Was this the correct way?

 

[Erel]

Yes.

 

[vikingivesterled]

The GoogleMapsExtras library for b4a has a LatLngBoundsBuilder in it which in
https://www.b4x.com/android/forum/threads/gmaps-zoom.34926/#post-204557
is used to autozoom a Googlemap according to a set of markers.

Is there a plan for a similar feature for this b4i class,
or is there another way of auto zooming (incl. cameraposition) on a set of markers (= lat,long positions)
for a b4i GoogleMap.

 

[Erel]

New version was uploaded to the first post.

gextra.ZoomToPoints - Updates the camera position to show all the given points.

Dim l1, l2, l3, l4 As LatLng
l1.Initialize(10, 10)
l2.Initialize(10, 20)
l3.Initialize(20, 20)
l4.Initialize(20, 10)
gextra.ZoomToPoints(Array(l1, l2, l3, l4))

 

[vikingivesterled]

Excellent addition that, together with a polyline list, works well for displaying a route taken .

 

[Erel]

New version was uploaded with support for polygons.

 

[iCAB]

As I was looking for a solution to control and read back visibility for markers and shapes. I have noticed that the following code doesn't delete the object which in turn can be used to control visibility.

circle.SetField("map", Null)

So I thought I would share the code I am using, but I wasn't sure if this is the best way to to achieve the results I am looking for

Here is the code I am using to set the visibility

Public Sub SetMarkerVisiblity( Marker As Marker, blnVisible As Boolean )

    Dim m As NativeObject = Marker

    If blnVisible = True Then
        m.SetField("map", gm)
    Else
        m.SetField("map", Null)
    End If

End Sub

To check if Visible, I am using the code below, but I was hoping for a cleaner solution

Public Sub IsMarkerVisible( Marker As NativeObject ) As Boolean

    Dim blnVisible As Boolean = True
Try
    Dim bTemp As Object = Marker.GetField("map")

Catch
    blnVisible = False
End Try
    Return blnVisible

End Sub

The same can be applied for Polygons and Circles

 

[iCAB]

Hi All,
I am looking for the code to check if a marker is within the visible region. Basically code equivalent to the B4A code below

Public Sub UpdateProjection1()
   

#if B4A   
    Projection1 = GoogleMapsExtrasRef.GetProjection( GmapRef )   
    VisibleRegion1 = Projection1.GetVisibleRegion
   
#else

#end if                                                                               

End Sub


Sub Region_CheckContainsMarker(TLocalMarker As TMarker ) As Boolean
   
    Dim blnInRegion As Boolean

#if B4A
    blnInRegion  = VisibleRegion1.LatLngBounds.Contains(TLocalMarker.Marker.Position)
#else

#end if   
   
    Return blnInRegion
   
End Sub

Thank you

 

[Erel]

Add this code to the OBJC section:

- (BOOL)boundsContain:(GMSCoordinateBounds*) bounds :(B4ILatLng*) ll {
   return [bounds containsCoordinate:CLLocationCoordinate2DMake(ll.Latitude, ll.Longitude)];
}
- (NSObject*)coordinateBoundsFromProjection:(GMSProjection*) p {
   return [[GMSCoordinateBounds alloc]initWithRegion: [p visibleRegion]];
}

Add these subs to GoogleMapsExtra code:

Public Sub GetProjection As NativeObject
   Dim ngm As NativeObject = gm
   Return ngm.GetField("projection")
End Sub

Public Sub GetVisibleBounds As NativeObject
   Dim Bounds As NativeObject
   Bounds = no.RunMethod("coordinateBoundsFromProjection:", Array(GetProjection))
   Return Bounds
End Sub

Public Sub BoundsContain(Bounds As NativeObject, LatLng As LatLng) As Boolean
   Return no.RunMethod("boundsContain::", Array(Bounds, LatLng)).AsBoolean
End Sub

You can now call it with:

Dim ll As LatLng
ll.Initialize(42, 30)
Log(gextra.BoundsContain(gextra.GetVisibleBounds, ll))