C++
int acedUsrBrk();
File
acedads.h
Description
Checks whether the user has pressed [Esc] to interrupt execution of the current external function.
This function enables ARX applications that do long, complex operations to check for a user interrupt.
The interactive ARX library functions, such as acedEntSel() or those in the user input (acedGetXxx()) group, check for [Esc] before they return to the ARX application (returning a status of RTCAN if [Esc] was pressed). Because of this, ARX applications don't need to call acedUsrBrk() unless they perform a lot of computation between requests for user input. Your application should call this function at strategic locations, such as at the top of a long evaluation loop. Do not use this function as a substitute for checking the value returned by ARX library functions.
If an application ignores a user's cancellation request, it must call acedUsrBrk() to clear the request. Otherwise, the [Esc] will still be outstanding and will cancel the next call to an acedGetXxx() function or to the acedCommand(), acedCmd(), acedDragGen(), acedEntSel(), acedNEntSelP(), acedNEntSel(), or acedSSGet() functions.
If the user has pressed [Esc], acedUsrBrk() returns 1; otherwise, it returns 0.
Notes
acedUsrBrk() may also return a value of 1 if the system is experiencing low memory. This notification occurs when the available memory dips below 32MB per every 4GB RAM.
For example, if the system has 1GB available RAM, the function will return 1 when the available memory dips below 8MB.