ArcGIS Engine Developer Guide

BUILDING APPLICATIONS WITH C++ AND CONTROL WIDGETS
Loading map documents into the PageLayoutControl and MapControl
Individual data layers or preauthored ESRI map documents can be loaded into the
MapControl and PageLayoutControl. You can either load the sample map document
provided, or you can load your own map document. Later you will add an
ArcGIS command to the ToolbarControl, which will allow you to browse to a map
document.
1. Programmatically add data to the PageLayoutControl. To do so you will write a
new function, LoadData.
a. Place a forward declaration after the forward declaration for the
CloseAppCallback function at the top of MapViewer.h.
void CloseAppCallback(Widget w, XtPointer client_data,
XtPointer call_data);
void LoadData();
b. Now define LoadData in MapViewer.cpp after the definition for the
CloseAppCallback function.
void CloseAppCallback(Widget w, XtPointer client_data,
XtPointer call_data)
{
…
}
Data can also be loaded to the toolbar’s buddy
at runtime by using
esriControlCommands.ControlsOpenDocCommand,
a command that will be placed on the toolbar
later in this scenario.
void LoadData()
{
CComBSTR MX_DATAFILE;
MX_DATAFILE =
L"../data/arcgis_engine_developer_guide/gulf of st. lawrence.mxd";
VARIANT_BOOL bValidDoc;
g_ipPageLayoutControl->CheckMxFile(MX_DATAFILE, &bValidDoc);
if (bValidDoc)
g_ipPageLayoutControl->LoadMxFile(MX_DATAFILE);
}
c. Call LoadData from the main function after the widgets are placed in
FormSetup.
FormSetup(argc, argv, &app_context);
LoadData();
2. You want the same map to appear in the MapControl. When the document in
the PageLayoutControl changes, the contents of the MapControl must be
updated. To do that, you must listen for events in the PageLayoutControl by
writing a class that inherits from IPageLayoutControlEventsHelper. Open a new
text file called PageLayoutControlEvents.h. Place the following code into that
file, making sure to include the macro IUNKNOWN_METHOD_DEFS to
implement IUnknown:
#ifndef __PAGELAYOUTCONTROLEVENTS_H_
#define __PAGELAYOUTCONTROLEVENTS_H_
// ArcObjects Headers
Chapter 6 • Developer scenarios • 369