IDatumShiftProgress Interface

The IDatumShiftProgress interface must be implemented by the user in order to receive regular updates on the progress of the DataSource.GetValidDatumShifts method.  The object that implements this interface must be passed to the DatumShiftPreferencesEx.AdviseOnProgress method in order to hook up the progress updates.  

Methods

Example

[VB6]

' Class Module DatumShiftProgress:

Implements IDatumShiftProgress

Private Sub IDatumShiftProgress_ProgressUpdate(ByVal index As Long, ByVal totalCount As Long, ByVal pData As Long)

    MsgBox ("Progress update: " + CStr(index) + " of " + CStr(totalCount) + ", pdata = " + CStr(pData))

End Sub

Sub DatumShiftPreferencesEx_AdviseOnProgress(data As DataSource)

    Dim source As ICoordSys

    Dim target As ICoordSys

    Set source = data.GetGeodeticCoordSys("BMG", "WGS84")

    Set target = data.GetProjectedCoordSys("BMG", "GA-27W")

    Dim shiftPrefs As New DatumShiftPreferencesEx

    shiftPrefs.area = data.GetEnvelope("BMG", "STANDARD_ENVELOPE")

    shiftPrefs.BitFlags = dsbBursaWolfe Or dsbMolodensky

    Dim progger As New DatumShiftProgress

    shiftPrefs.AdviseOnProgress progger, 0

    Dim shiftSets As DatumShiftInfoSetCollection

    If Not data.GetValidDatumShifts(source, target, shiftPrefs, shiftSets) Then

        MsgBox ("GetValidDatumShifts failed")

    End If

End Sub

[Delphi 7]

// Unit2.pas:

unit Unit2;

interface

uses

  GeoCalcCOM_TLB, Dialogs, SysUtils;

type

  TDatumShiftProgress = class(TInterfacedObject, IDatumShiftProgress)

public

  function ProgressUpdate(index: Integer; totalCount: Integer; pData: integer): HResult; stdcall;

end;

implementation

function TDatumShiftProgress.ProgressUpdate(index: Integer; totalCount: Integer; pData: integer): HResult; stdcall;

var

  msg : string;

begin

  msg := 'Progress Update: ' + IntToStr(index) + ' of ' + IntToStr(totalCount) + ', pData = ' + IntToStr(pData);

  ShowMessage(msg);

end;

end.

// In another unit:

procedure DatumShiftPreferencesEx_AdviseOnProgress(data : DataSource);

var

  ct : CoordTransform;

  shiftPrefs : DatumShiftPreferencesEx;

  shiftSets : DatumShiftInfoSetCollection;

  progger : TDatumShiftProgress;

begin

  ct := CoCoordTransform.Create;

  ct.SourceCoordSys := data.GetProjectedCoordSys('BMG', 'TX-27NC');

  ct.TargetCoordSys := data.GetGeodeticCoordSys('BMG', 'WGS84_coordinate_system');

  shiftPrefs := CoDatumShiftPreferencesEx.Create;

  shiftPrefs.OnlyGoThruIntermediate := false;

  shiftPrefs.BitFlags := dsbNadcon or dsbMolodensky or dsBursaWolfe;

  progger := TDatumShiftProgress.Create;

  shiftPrefs.AdviseOnProgress(progger, 0);

  shiftSets := CoDatumShiftInfoSetCollection.Create;

  if  not data.GetValidDatumShifts(ct.SourceCoordSys, ct.TargetCoordSys, shiftPrefs, shiftSets) then

  begin

    ShowMessage('GetValidDatumShifts failed');

  end;

end;