Android Tutorial (old) Google Maps Android v2 tutorial

warwound said:

GoogleMapsExtras has been updated to version 1.35

The new Snapshot method takes a snapshot of the current map.
The event SnapshotReady is raised when the snapshot has been created, the snapshot passed to your event handling Sub as a Bitmap.

B4X:

Sub Process_Globals
   '   i'll use a Process_Global to enable me to pass the snapshot Bitmap from this Activity to the SnapshotViewer Activity
   Dim LastSnapshot As Bitmap
End Sub

Sub Globals
  Dim MapFragment1 As MapFragment
  Dim GoogleMap1 As GoogleMap
   Dim GoogleMapsExtras1 As GoogleMapsExtras
  Dim MapPanel As Panel
End Sub

Sub Activity_Create(FirstTime As Boolean)
   Activity.LoadLayout("Main")
  If MapFragment1.IsGooglePlayServicesAvailable = False Then
  ToastMessageShow("Google Play services not available.", True)
  Else
  MapFragment1.Initialize("MapFragment1", MapPanel)
  End If
End Sub

Sub GoogleMapsExtras1_SnapshotReady(Bitmap1 As Bitmap)
   Log("GoogleMapsExtras1_SnapshotReady")
   LastSnapshot=Bitmap1
   StartActivity(SnapshotViewer)
End Sub

Sub MapFragment1_LongClick (Point As LatLng)
   '   a long click on the map will add a new Marker
   GoogleMap1.AddMarker(Point.Latitude, Point.Longitude, "("&Point.Latitude&", "&Point.Longitude&")")
End Sub

Sub MapFragment1_Ready
  Log("MapFragment1_Ready")
  GoogleMap1 = MapFragment1.GetMap
  If GoogleMap1.IsInitialized = False Then
  ToastMessageShow("Error initializing map.", True)
  Else
     GoogleMap1.AddMarker(52.75619, 0.3980, "Home Sweet Home")
   
  Dim CameraPosition1 As CameraPosition
  CameraPosition1.Initialize(52.75619, 0.3980, 6)
  GoogleMap1.AnimateCamera(CameraPosition1)
  End If
End Sub

Sub SnapshotButton_Click
   Log("SnapshotButton_Click")
   GoogleMapsExtras1.Snapshot(GoogleMap1, "GoogleMapsExtras1")
End Sub

This is the Main Activity, it shows a basic map with a single Marker.
A long click on the map adds a new Marker.

A click on the 'Take snapshot' button calls the new Snapshot method.
When the 'SnapshotReady' event is raised, the snapshot (a Bitmap) is saved as a ProcessGlobal and a new Actvitiy started.
The new Activity contains just an ImageView and displays the snapshot Bitmap centered in the ImageView.

IMPORTANT: In order to use the new Snapshot method you must ensure that your b4a additional libraries folder contains the latest version of google-play-services.jar.
Run the Android SDK Manager utility and check whether or not you have the latest version, i have tested with version 10 of the Google Play servcies library.

Your attention is drawn to the notes from the GoogleMap API reference:



Martin.

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Erel said:

Have you checked the logs in the IDE? There should be a more complete error message.

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warwound said:

The way that Erel created the b4a GoogleMaps library did not expose the MarkerOptions object and this is the object you'd need to use to create a Marker that is initially not visible.

So i've now partly wrapped the MarkerOptions object and added a new method to GoogleMapsExtras AddMarker(MarkerOptions1 As MarkerOptions) As Marker.

Have a look at this example code:

B4X:

Sub Process_Globals

End Sub

Sub Globals
    Dim MapFragment1 As MapFragment
    Dim GoogleMap1 As GoogleMap
   Dim GoogleMapsExtras1 As GoogleMapsExtras
    Dim MapPanel As Panel
End Sub

Sub Activity_Create(FirstTime As Boolean)
   Activity.LoadLayout("Main")
    If MapFragment1.IsGooglePlayServicesAvailable = False Then
        ToastMessageShow("Google Play services not available.", True)
    Else
        MapFragment1.Initialize("MapFragment1", MapPanel)
    End If
End Sub

Sub MapFragment1_Ready
    Log("MapFragment1_Ready")
    GoogleMap1 = MapFragment1.GetMap
    If GoogleMap1.IsInitialized = False Then
        ToastMessageShow("Error initializing map.", True)
    Else
      '   use the new MarkerOptions method to create and add a Marker to the map
     
      Dim MarkerOptions1 As MarkerOptions
      MarkerOptions1.Initialize
     
      MarkerOptions1.Position2(52.75619, 0.3980).Snippet("Home is where the heart is").Title("Home Sweet Home").Visible(True)
      Dim Marker1 As Marker=GoogleMapsExtras1.AddMarker(GoogleMap1, MarkerOptions1)
     
        Dim CameraPosition1 As CameraPosition
        CameraPosition1.Initialize(52.75619, 0.3980, 6)
        GoogleMap1.AnimateCamera(CameraPosition1)
    End If
End Sub

MarkerOptions
Methods:

• Anchor (U As Float, V As Float) As MarkerOptions
• Draggable (Draggable As Boolean) As MarkerOptions
• Initialize
• IsInitialized As Boolean
• Position (LatLng1 As LatLng) As MarkerOptions
• Position2 (Latitude As Double, Longitude As Double) As MarkerOptions
• Snippet (Snippet As String) As MarkerOptions
• Title (Title As String) As MarkerOptions
• Visible (Visible As Boolean) As MarkerOptions

I've not fully wrapped the MarkerOptions object, there are various other methods that can also be wrapped, take a look: https://developers.google.com/maps/...m/google/android/gms/maps/model/MarkerOptions.

Code and beta library files attached - i'll complete the MarkerOptions object hopefully tomorrow and get it uploaded to the GoogleMapsExtras thread.

When the device orientation changes you have no way to tell the activity not to destroy all of it's objects and variables - that's the way android works.

You could keep references as process global objects - not sure about a sticky service but i guess that's another way to keep a reference to objects you create but don't want destroyed when the orientation changes.

Note that you should not keep a reference to a Marker - a Marker is an Activity object and should be destroyed when the activity is destroyed.
Don't try to keep a process global reference to a Marker - there's no point, you can't add a Marker to the map, BUT you can keep a process global reference to a MarkerOptions object.

So create a MarkerOptions object for each of your many markers, and keep each MarkerOptions object as a process global (or try and use a service), then on orientation change you can re-create new Markers from the (already created) MarkerOptions objects.

Martin.

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Erel said:

Are you running it on Android 3+ ?

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abceasyas123 said:

Yeah

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warwound said:

@ValDog Looks like you have checked both OSMDroid and GoogleMaps libraries in the IDE.
They both contain a Marker object and that's confusing the compiler.

Uncheck OSMDroid and try again.

Martin.

Click to expand...

warwound said:

@abceasyas123

I'm not sure what to suggest next.
I am pretty sure that you cannot use an emulator to run an app that contains a GoogleMap, so make sure you always use a real device (a real device running android 3 or later).

What device are you getting these errors with?
And what android version is that device running?

@ValDog

Yes that is all possible with GoogleMaps and GoogleMapsExtras.

GoogleMaps has the AddMarker and AddPolyline methods.

GoogleMapsExtras has an AddMarker method which exposes more of the available MarkerOptions, and an AddPolygon method if you need to create Polygons.
GoogleMapsExtras also has an AddCircle method if you need to create Circles.

You might not even require GoogleMapsExtras if basic Marker and Polyline objects are all that you require.

Martin.

Click to expand...