SDK Question Conflict with Terminal MFD Input Box

[JMW]

Hi All,

I have a little problem that can't solve myself.........

In an autopilot, I select a base to land at via

case OAPI_KEY_M:  // Base Box
                {
			HUD2 = 1;
			oapiSetHUDMode (HUD_DOCKING);
						
			oapiOpenInputBox("Enter Base Name", InputTarget, 0, 15, (void*)this) ;
                			  
					return true;
                }

bool InputTarget(void *id, char *bstr, void *user_data)

This "*bstr" is changed by "Base = bstr; " and printed to HUD in:

bool ShuttlePB::clbkDrawHUD (int mode, const HUDPAINTSPEC *hps, oapi::Sketchpad *skp)

Base = _strupr(Base);
		
		len = sprintf_s(buffer,"%s",Base);
		skp->SetTextColor(0x00ff00);
		skp->Text(0, 170, buffer,  len);

		len = sprintf_s(buffer,"Pad:%02.02d",padNum);
		skp->Text(46, 160, buffer,  len);
	
Base = _strlwr(Base);

But then, if I use Terminal MFD, as soon as the "Input" box is opened, the "Base" data inputted previously disappears and any imputed data is printed instead in HUD. (It does not interfere with the operation of the autopilot though)

How can I get the print of the string entered in my Input box to be protected?

 

[orb]

The `Base` is declared in your class as a pointer to char, right?

The pointer points to an internal character buffer of Orbiter's input box. It isn't a copy of the string. That buffer will change every time you use Orbiter's input box, in any place, any module.

Use `strcpy` or `strcpy_s` function to copy the string from the input box buffer to your own character buffer in the class, or convert it to std::string object (which will copy the character buffer contents).

 

[JMW]

Ok.
I've tried

bool InputTarget(void *id, char *bstr, void *user_data)
{.................
strcpy(Base,bstr);
.......................
return true;}

Is that in the right place? (Please excuse my elementary knowledge)
Scenario crashes on initializing Input Box ----

 

[orb]

bool InputTarget(void *id, char *bstr, void *user_data)
{.................
strcpy(Base,bstr);
.......................
return true;}

Is that in the right place?

If Base is:

char * Base;

and it wasn't given an address to a `char []` variable, then it's a wrong way to do it.



Untested example, but try making `Base` a string object:

#include <string>

// {...}

class YourClass : public ClassBeingExtended {
public:
// {...}
    std::string Base;
// {...}
}

bool InputTarget (void *id, char *bstr, void *user_data) {
// {...}
    ((YourClass *)user_data)->Base = bstr;
// {...}
    return true;
}

bool YourClass::clbkDrawHUD (int mode, const HUDPAINTSPEC *hps, oapi::Sketchpad *skp) {
// {...}
    skp->Text (0, 170, Base.c_str (), Base.size ());
// {...}
}

If you want in upper case, then copy contents of the `Base.c_str ()` to `buffer` first, convert the `buffer` to upper case, and use `buffer` instead of `Base.c_str ()` while calling the Text function.

 

[JMW]

Thank you Orb - it works perfectly!

While you're on, could you havea look athttp://www.orbiter-forum.com/showthread.php?t=27378.
I still haven't managed to get this working yet.
(Getting dragged out to shop right now, but will be back on later.)


---------- Post added at 04:04 PM ---------- Previous post was at 09:55 AM ----------

Hmm....
I was a little optimistic ref my abilities...

Trying to

copy contents of the `Base.c_str ()` to `buffer` first,

what term do I use to do this?
Is it straightforward after this, or will I need some different terms than before?

 

[orb]

Trying to

copy contents of the `Base.c_str ()` to `buffer` first,

what term do I use to do this?

strcpy (buffer, Base.c_str ());

or

strcpy_s (buffer, sizeof (buffer), Base.c_str ());

 

[JMW]

doesn't like my

_strupr

to convert to upper case anymore??????
gives

error C2440: '=' : cannot convert from 'char *' to 'char [256]'

 

[orb]

Try without assigning value returned from _strupr anywhere.

The _strupr conversion is done in place. The returned pointer value is the same as passed to the function.

 

[JMW]

That's it!

Thanks orb, you're a pal.:tiphat:

At the risk of being cheeky, could you give some "pointers" on this too please when you have a minute?

While you're on, could you havea look at http://www.orbiter-forum.com/showthread.php?t=27378.