ArcGIS Engine Developer Guide

BUILDING APPLICATIONS WITH C++ AND CONTROL WIDGETS
Controlling label editing in the TOCControl
By default, the TOCControl allows users to automatically toggle the visibility of
layers and to change map and layer names as they appear in the table of contents.
You will add code to prevent users from editing a name and replacing it with an
empty string.
1. The TOCControl label editing events must be triggered. To do so, add the
following code to MapViewer.cpp in main after FormSetup.
FormSetup(argc, argv, &app_context);
g_ipTOCControl->put_LabelEdit(esriTOCControlManual);
2. You must listen for events in the TOCControl by writing a class that inherits
from ITOCControlEventsHelper, as you did for the PageLayoutControl earlier.
Start by creating TOCControlEvents.h, a new text file:
#ifndef __TOCCONTROLEVENTS_H_
#define __TOCCONTROLEVENTS_H_
#include
#include
class TOCControlEvents : public ITOCControlEventsHelper
{
public:
// IUnknown
IUNKNOWN_METHOD_DEFS
// ITOCControlEvents
void OnMouseDown(long button, long shift, long x, long y);
void OnMouseUp(long button, long shift, long x, long y);
void OnMouseMove (long button, long shift, long x, long y);
void OnDoubleClick (long button, long shift, long x, long y);
void OnKeyDown (long keyCode, long shift);
void OnKeyUp (long keyCode, long shift);
void OnBeginLabelEdit (long x, long y, VARIANT_BOOL* CanEdit);
void OnEndLabelEdit (long x, long y, BSTR newLabel, VARIANT_BOOL*
CanEdit);
};
#endif // __TOCCONTROLEVENTS_H_
3. Place the implementation for ITOCControlEventsHelper’s functions into
TOCControlEvents.cpp, another new file. Since they are void functions, they
can be left empty. However, you will implement OnEndLabelEdit. In that
function, tell the TOC to forbid the edit if the new label is an empty string.
#include "TOCControlEvents.h"
void TOCControlEvents::OnMouseDown(long button, long shift, long x, long y)
{
380 • ArcGIS Engine Developer Guide