Google Earth COM

[Werner Bleckwendt]

I am trying to get Coordinates from Google Earth, but the result always is empty, i.e Google Earth loads, but that it's. Can somebody point me in the right direction?

$PROGID_EARTHLib_PointOnTerrainGE = "GoogleEarth.PointOnTerrainGE"

' Interface Name  : IPointOnTerrainGE
' Description     : IPointOnTerrainGE Interface
' Class Name      : PointOnTerrainGE
' ClassID         : $CLSID_EARTHLib_PointOnTerrainGE
' ProgID          : $PROGID_EARTHLib_PointOnTerrainGE
' Version ProgID  : $PROGID_EARTHLib_PointOnTerrainGE1
Interface IPointOnTerrainGE $IID_EARTHLib_IPointOnTerrainGE 
    Inherit IDispatch

    Property Get Latitude <1> () As Double
    Property Get Longitude <2> () As Double
    Property Get Altitude <3> () As Double
    Property Get ProjectedOntoGlobe <4> () As Long
    Property Get ZeroElevationExaggeration <5> () As Long
End Interface


local oGoogle AS Idispatch
local latitude, longitude as double
oGoogle = newCOM $PROGID_EARTHLib_PointOnTerrainGE
sleep 2000 'to make sure google earth has finished initialisation
object get oGoogle.latitude to latitude
object get oGoogle.longitude to longitude
		
? using$("Latitude: #.##### Longitude: #.#### ",latitude,longitude)

rgds Werner

[Michael Mattias]

Longitude and latitude of WHAT? (WHERE?)

Just in plain English, it looks like you are creating an instance of an object and asking it to find the latitude and longitude of "nothing"

There must be a missing piece to this puzzle.

[George Bleck]

I've not used Google maps but it appears $PROGID_EARTHLib_PointOnTerrainGE represents a pin point object representing an existing point on the map so the GET is returning the existing info LAT/LONG info.

[Werner Bleckwendt]

Google Earth displays the current longitude and latitude in status window at the bottom of a map, so my assumption was the values of these two variables are always current. The point on terrain has it's own ProgID and it's interface has just 5 properties. Unfortunately Google publishes the interface description only, but no example how to access the data (or I was too blind to find it).

rgds
Werner

[Michael Mattias]

I don't have Google Earth on this machine, but IIRC there was a "setup" screen to tell it where you are. (I did this once, when I was on vacation Spring 2008 so the memory may be a tad off here).

Maybe you have to go thru something like that... you are at "0,0" until you tell Google Earth where you are?

[Dominic Mitchell]

Google Earth COM API Documentation is here

http://earth.google.com/comapi/index.html

Think of the IPointOnTerrainGE interface as mapping a point on your computer screen to a
point on the earth. In the following code snippet, the constants and coclasses have different
names, because I am using the Type Library Viewer for Phoenix 3.0.

'-------------------------------------------------------------------------------

FUNCTION Form1_InitWindow _
  ( _
  BYVAL hWnd    AS DWORD, _ ' handle of main window
  BYVAL lParam  AS LONG _   ' address of command line
  ) AS LONG

  LOCAL oGoogle       AS GoogleEarthApplicationGE 
  LOCAL oTerrain      AS GoogleEarthPointOnTerrainGE   
  LOCAL x             AS DOUBLE
  LOCAL y             AS DOUBLE 
  LOCAL Latitude      AS DOUBLE
  LOCAL Longitude     AS DOUBLE
  LOCAL fInitialized  AS LONG

  oGoogle = newCOM $PROGID_GOOGLEEARTHAPPLICATIONGE1
  IF ISOBJECT(oGoogle) THEN

    DO
      OBJECT CALL oGoogle.IsInitialized TO fInitialized
      IF fInitialized THEN EXIT DO
    LOOP 
    
    MSGBOX "Google Earth initialized"

    x = 0
    y = 0
    OBJECT CALL oGoogle.GetPointOnTerrainFromScreenCoords(x, y) TO oTerrain
    IF ISOBJECT(oTerrain) THEN
      OBJECT GET oTerrain.Latitude TO Latitude
      OBJECT GET oTerrain.Longitude TO Longitude
      ? USING$("Latitude: #.##### Longitude: #.#### ",latitude,longitude)      
    END IF
  END IF

END FUNCTION

[Werner Bleckwendt]

Thanks Dominic, I will try it again.

Rgds
Werner

[Christopher Becker]

Progress?

Werner (or anyone).... is there any progress with this thread? I was hoping to see a code example. I'd like to use Google Earth COM API with PowerBasic. I have to admit I don't know where to start, but could really use a 'Hello-World' type example from which to learn and grow.

Has anyone successfully used the Google Earth COM API with PB ?

[Joe Caverly]

How to Control Google Earth with VB 6

http://www.xtremevbtalk.com/showthread.php?t=287038

I realize this is not a PB example, but it should give you some ideas.

Joe

[Christopher Becker]

compile-ready code example?

Werner (or anyone else),
Can you post some complete, compile-ready source code that invokes the example function already given? I'm clearly missing an #INCLUDE statement or something. I've re-registered the Google Earth COM API, but PBCC5 is not seeing it. Just a simple example would be great.
Thank you so much!

[Christopher Becker]

Okay, I have made some progress on my own, but I still need some help. Here is a stripped-down example that uses OBJECT CALL into Google Earth. All this program does is get the latitude and longitude of Google Earth's center and print it in a PB console. It works. What I need now is the ability to issue command/control statements from PB into Google Earth. I've studied the interface, and tried all combinations of OBJECT CALL and OBJECT LET, but nothing works. Can someone write a line of PBCC code that drives Google Earth (for example, a line that moves the Google Earth latitude/longitude window)?

I've attached the #INCLUDE file in case someone wants to test.

Michael Mattias, I need you now. You can insult my intelligence, that's okay, I just need the code to work.

#COMPILER PBCC 5
' also requires Google Earth 5.x to be installed
#INCLUDE "googleearth.inc"
FUNCTION PBMAIN() AS LONG
    DIM oGoogle AS IDISPATCH
    DIM oTerrain AS IDISPATCH
    DIM fInitialized  AS LONG
    DIM x AS DOUBLE
    DIM Latitude AS DOUBLE
    DIM Longitude AS DOUBLE
    oGoogle = NEWCOM $PROGID_EARTHLib_ApplicationGE1
    IF ISOBJECT(oGoogle) THEN
        WHILE fInitialized <> 1
            OBJECT CALL oGoogle.IsInitialized TO fInitialized
        WEND
        WHILE fInitialized = 1
            OBJECT CALL oGoogle.IsInitialized TO fInitialized
            OBJECT CALL oGoogle.GetPointOnTerrainFromScreenCoords(x, x) TO oTerrain
            OBJECT GET oTerrain.Latitude TO Latitude
            OBJECT GET oTerrain.Longitude TO Longitude
            PRINT Latitude, Longitude
            SLEEP 300
        WEND
    END IF
END FUNCTION

[Chris Holbrook]

On startup two identical splash screens are shown in different locations.

I can get Altitude out of the Terrain object.

SaveScreenShot needs a full path using Unicode. "Quality 0" is amusingly bad!

Still messing about.

******** added this link may be useful http://nuigroup.com/forums/viewthread/5646/