ArcGIS Engine Developer Guide

BUILDING APPLICATIONS WITH C++ AND CONTROL WIDGETS
Drawing an overview rectangle on the MapControl
You will now use the MapControl as an overview window and draw the current
extent of the focus map within the PageLayoutControl on its display. As you
navigate around the data within the data frame of the PageLayoutControl, you
will see the MapControl overview window update.
Navigating around the focus map using the map
navigation tools will change the extent of the
focus map in the PageLayoutControl and cause
the MapControl to update. Navigating around
the page layout with the page layout navigation
tools will change the extent of the page layout
(not the extent of the focus map in the
PageLayoutControl), so the MapControl will
not update.
1. First add IFillSymbol and IEnvelope interface pointers to the top of
MapViewer.cpp.
IToolbarMenuPtr g_ipPopupMenu;
IFillSymbolPtr g_ipFillSymbol;
IEnvelopePtr g_ipCurrentExtent;
int main(int argc, char* argv[])
2. You will use a new function to create the rectangle used on the MapControl to
highlight the current PageLayoutControl extent.
a. First place the forward declaration in MapViewer.h.
void AddPopupItems();
HRESULT CreateOverviewSymbol();
b. Place the implementation of that function at the end of MapViewer.cpp.
void AddPopupItems()
{
…
}
HRESULT CreateOverviewSymbol()
{
// IRgbColor interface
IRgbColorPtr ipColor(CLSID_RgbColor);
ipColor->put_Red(255);
ipColor->put_Green(0);
ipColor->put_Blue(0);
Alternatively, symbols can be retrieved from style
galleries. When working with style galleries and
the C++ API, ServerStyleGallery should be used
as it is across platforms.
// ILine symbol interface
ILineSymbolPtr ipOutline(CLSID_SimpleLineSymbol);
ipOutline->put_Width(2);
ipOutline->put_Color(ipColor);
// IFillSymbol properties
g_ipFillSymbol.CreateInstance(CLSID_SimpleFillSymbol);
g_ipFillSymbol->put_Outline(ipOutline);
((ISimpleFillSymbolPtr) g_ipFillSymbol)->put_Style(esriSFSHollow);
return S_OK;
}
c. Create the symbol in the main function of MapViewer.cpp before the
TOCControl label editing code.
CreateOverviewSymbol();
g_ipTOCControl->put_LabelEdit(esriTOCControlManual);
Chapter 6 • Developer scenarios • 383