Android Tutorial OSMDroid - MapView for B4A tutorial

davelew1s said:

is 'Marker0' the reference you mean

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Sub Globals
   '   create a Map in your Globals
   Dim MyMarkers As Map
End Sub

Sub Activity_Create(FirstTime As Boolean)
   '   Initialize the Map in Create
   MyMarkers.Initialize
End Sub

Sub Mark_Click
   Dim b As Button
   b = Sender
   Dim value As String
   value = b.Text

   Select value
   Case "Start Drift"
   Dim Icon As BitmapDrawable
   Icon.Initialize(LoadBitmap(File.DirAssets, "marker_start_icon.png"))
   Case "End Drift"
   Dim Icon As BitmapDrawable
   Icon.Initialize(LoadBitmap(File.DirAssets, "marker_end_icon.png"))
   Case "Fish"
   Dim Icon As BitmapDrawable
   Icon.Initialize(LoadBitmap(File.DirAssets, "marker_fish1_icon.png"))
   End Select

   markersactive = True
   Dim name As String = Marker & markernumber
   
   '   create a new Marker, keep a reference to it using the Marker name as a key in the MyMarkers Map
   Dim NewMarker As Marker
   NewMarker.Initialize3 (name,"Text to gohere",MapView1.GetCenter,Icon)
   MyMarkers.Put(name, NewMarker)
   
   markernumber = markernumber + 1
   markers .Add (NewMarker)
   MarkersOverlay1.AddMarkers(markers)
   MapView1.Invalidate
   lastmark = (MapView1.GetCenter) 'Remember last mark so you can get the distance later
End Sub

Sub RemoveMarker(Name As String)
   Dim MarkerToRemove As Marker=MyMarkers.Get(Name)
   MarkersOverlay1.RemoveMarker(MarkerToRemove)
End Sub

davelew1s said:

Hi!
I've just discovered the beauty of the MyLocationOverlay and wondered if the following can be changed from true to false?

'FollowLocationAutoDisabled is generated if FollowLocation is enabled and the user drags the map. The drag causes FollowLocation to be automatically disabled.
This is the default behaviour of the native Android OSMDroid library - i couldn't decide whether to change that default behaviour so have left it as it is for now.'
Thanks Dave.

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warwound said:

Version 3.21 of OSMDroid supports the TilesOverlay

TilesOverlay is similar to the XYTileSource, you use it to add a new TileSource to your map.
A TilesOverlay however displays on top of the currently selected TileSource.
You use it to add a transparent tile layer to your map.

Take a look at this tile from the OpenSeaMap project:

It's a transparent tile created so that it can be displayed on top of another tile layer.
This is the type of tile you'll use a TilesOverlay to display.

Some example code:

B4X:

Sub Process_Globals
End Sub

Sub Globals
   Dim MapView1 As MapView
   Dim TilesOverlay1 As TilesOverlay
End Sub

Sub Activity_Create(FirstTime As Boolean)
   If File.ExternalWritable=False Then
      '   OSMDroid requires the use of external storage to cache tiles
      '   if no external storage is available then the MapView will display no tiles
      Log("WARNING NO EXTERNAL STORAGE AVAILABLE")
   End If
  
   MapView1.Initialize("")
   MapView1.SetMultiTouchEnabled(True)
   MapView1.SetZoomEnabled(True)
   MapView1.Zoom=9
   MapView1.SetCenter(53.024, 0.421)
   Activity.AddView(MapView1, 0, 0, 100%x, 100%y)
  
   '   open sea map tiles are available from zoom levels 11 to 19
   TilesOverlay1.Initialize("SeaMap", 11, 19, 256, ".png", "http://tiles.openseamap.org/seamark/")
  
   '   TilesOverlay1.LoadingBackgroundColor=Colors.LightGray
   '   TilesOverlay1.LoadingLineColor=Colors.DarkGray
  
   MapView1.AddOverlay(TilesOverlay1)
  
End Sub

Sub Activity_Resume
End Sub

Sub Activity_Pause (UserClosed As Boolean)
End Sub

Load the MapView, displaying the default Mapnik tiles and displays the OpenSeaMap tiles on top ofthe Mapnik tiles.

You'll need to pan to an area of sea to see the OpenSeaMap tiles.
(There is a windfarm that should be visible in the demo code).

And you can uncomment the LoadingBackgroundColor and LoadingLineColor lines to experiment with those properties and see how they work.

Note that OpenSeaMap tiles do not exist for many areas and at many zoom levels.
Where an OpenStreetMap tile is requested and it does not exist, the MapView will (internally) generate a 404 tile not found error.
If the LoadingBackgroundColor is set to Colors.TRANSPARENT then no background color is displayed while waiting for a tile to load and there is no problem.
If you set a LoadingBackgroundColor that color is displayed until the requested tile has been downloaded.
So where tiles do not exist and fail to download you will see the background color persist and block the underlying Mapnik tiles.

I have not yet tried offline tiles with a TilesOverlay but it should work - the TilesOverlay should fetch tiles from any tiles archive in the osmdroid folder and display them instead of downloading tiles from the internet.

Martin.

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javiers said:

Hi, the URL is as follows. I do not know if it is correct;

TilesOverlay2.Initialize ("SeaMap", 4, 7, 256, ".Png", "http://www.openportguide.org/tiles/actual/wind_vector/5/7/67/41/")

More information is at: http://www.openportguide.org/wiki_/Help:Weather_tiles

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javiers said:

Hello, is possible move a marker on the map?

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Immutable class describing a GeoPoint with a Title and a Description.

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