C / C++ / MFC Discussion Boards

Simon Steele11-Feb-03 11:10

11-Feb-03 11:10

Hi,

1. Surely somebody here has written a really efficient and fast function which will replace special characters in a string with their XML entity equivalents? Every programmer using C++ and XML must surely have had to write this by now? I've just knocked a quick one up here:

//typedef basic_string<TCHAR> tstring;
void XMLSafeString(tstring& str)
{
	int len = str.size();
	TCHAR * buffer = new TCHAR[len+1];
	_tcscpy(buffer, str.c_str());
	// make an attempt at reducing re-allocs...
	str.reserve(len + 20);
	str = _T("");

	for(int i = 0; i < len; i++)
	{
		switch(buffer[i])
		{
			case _T('"'):
				str += """;
				break;
			case _T('<'):
				str += "<";
				break;
			case _T('>'):
				str += ">";
				break;
			case _T('&'):
				str += "&";
				break;
			case _T('\''):
				str += "'";
				break;
			default:
				str += i;
		}
	}

	delete [] buffer;
}

but I'm sure there must be better ways. Also, I would like to see an efficient solution that doesn't modify the incoming string, but returns a tstring. The reason for this is:

2. I want to write out XML using the ofstream class. Unfortunately, I can't use the function I've got above without permanently modifying my input strings - which is a no-no. Therefore, I will have to copy every string into another object, and pass the xmlsafe-ised version of that string into the ofstream. This kind of reduces the simplicity of iostreams. Does anyone have anything clever like a modifier which enables XML character escaping?

Thanks in advance for any suggestions, code, etc...

Oh, and a quick disclaimer: I haven't tested the above code yet.

--
Simon Steele
Programmers Notepad - http://www.pnotepad.org/

Re: XML-safe strings, and iostreams

palbano11-Feb-03 11:13

palbano

11-Feb-03 11:13

Sounds like great work for regular expressions no?

"No matter where you go, there your are..." - Buckaoo Banzi

-pete

Re: XML-safe strings, and iostreams

Simon Steele11-Feb-03 11:42

Simon Steele

11-Feb-03 11:42

Possibly, but will this be faster than my brute force replacer? Also, it involves the inclusion of a regular expression library. I'm not against the idea, but it has drawbacks.

Also, would I have to use x different regexs where each x represents one transformation:

" -> "
' -> '
...

or is there a way I can do all of these with one regex?

Thanks for your help,

--
Simon Steele
Programmers Notepad - http://www.pnotepad.org/

Re: XML-safe strings, and iostreams

Simon Steele11-Feb-03 11:46

Simon Steele

11-Feb-03 11:46

Firstly, the above code contains a bug:

str += i;

should be:

str += buffer[i];

Also, I have found a simple way of using the above function with iostreams. It works like this:

struct FormatXML {
   tstring str_;
   explicit FormatXML(const tstring& str) : str_(str) { XMLSafeString(str_); }
   friend std::ostream& operator<<(std::ostream& s, const FormatXML& x)
   {
		s << x.str_;
		return s;
   }
};

This copies the input string, and performs the XML safety check on construction. The safe string is then passed into the stream. It would be used like this:

<br />
tstring str = _T("My string with \"Quotes\".");<br />
myostream << FormatXML(str);<br />

This isn't very efficient, however. Cry | :((

Therefore, I'm still on the lookout for cool code. Let me know!

--
Simon Steele
Programmers Notepad - http://www.pnotepad.org/

How to draw password bullets in an edit control on XP?

Brian Morearty11-Feb-03 10:30

Brian Morearty

11-Feb-03 10:30

Win32 question: anyone know what font and character used to draw the bullets in a password edit control in XP with Visual Styles turned on?

Background: for historical reasons related to resources and performance on Win16, as well as to reduce flicker when resizing, my Win32 app draws all controls on a window. For edit controls it only moves a REAL edit control into place when the user tries to move the focus there. When the focus moves out, the real edit control becomes invisible again (or is moved to wherever the focus moved, if that was another edit control).

On XP we have visual styles turned on (using a manifest). We call the Theme API functions in uxtheme.dll to simulate the drawing of controls. When visual styles are turned on, bullet points are drawn instead of asterisks. Unfortunately, the Theme API does not provide a "password state" for drawing an edit control. See the Parts and States table[^].

When focus moves out of a password edit control (one with the ES_PASSWORD style), we draw the edit control ourselves. Our old code was drawing asterisks and it looked fine. On XP we're trying to figure out what font and character the edit control uses to draw the password characters.

The documentation for the ES_PASSWORD style says this:

Microsoft® Windows® XP: If an edit control is from user32.dll, an asterisk is the default character for the ES_PASSWORD style. However, if an edit control is from comctl32.dll version 6, a black circle is the default character for the ES_PASSWORD style. Note that comctl32.dll version 6 is not redistributable but is included with Microsoft® Windows® XP or later. To use comctl32.dll version 6, specify it in a manifest. For more information on manifests, see Using Windows XP Visual Styles[^].

I tried sending EM_GETPASSWORDCHAR to the edit control. The result was -59 decimal, or 0xCF. In most fonts this is a capital I with an umlaut. I can't find any symbol font where this is a bullet point.

We've already tried a few bullet points in a few fonts, but can't seem to find one that's the right size and char width. When the user tabs out of the password field, it looks funny because the bullets shift.

- Brian Morearty Smile | :)

Re: How to draw password bullets in an edit control on XP?

MAAK12-Feb-03 0:02

MAAK

12-Feb-03 0:02

I do not know exactly how your code works, but as I understand you draw the edit control part by part as an image on th parent window DC when it is not focused.

Did you try to get the DC of the control directly and blitting it? By that you will just copy the edit's look just as the window draws it however it do it.

this is sample code may explain what i mean:

<br />
CClientDC dc(this); //client dc of the edit's parent window<br />
GetDlgItem(IDC_EDIT1)->HideCaret(); //caret should not be drawn<br />
CWindowDC tempDC(GetDlgItem(IDC_EDIT1));  //window dc make a snapshot of the whole edit<br />
//getting the rectangle of the edit<br />
CRect rct;<br />
GetDlgItem(IDC_EDIT1)->GetWindowRect(rct);<br />
ScreenToClient(rct); //convert to parent's coordinate<br />
<br />
//darw the edit control's image on the dc<br />
dc.BitBlt(rct.left, rct.top, rct.Width(), rct.Height(), &tempDC, 0, 0, SRCCOPY);<br />
GetDlgItem(IDC_EDIT1)->ShowCaret(); //re-show the caret<br />

Re: How to draw password bullets in an edit control on XP?

Brian Morearty12-Feb-03 5:47

Brian Morearty

12-Feb-03 5:47

Thanks for the suggestion, MAAK. Not bad. I'll keep it in mind if nothing better comes up, although I'd prefer to draw password edit controls the same way we draw all other edit controls--and without having to keep a bitmap for each one.

- Brian Morearty Smile | :)

Dynamic linkage

RalfPeter11-Feb-03 10:25

RalfPeter

11-Feb-03 10:25

I need to dynamically link my appln. Any one knows how to find out which .dll are needed? I have an MFC appln. I'm doing it the hard way, ie, taking the binary and running it on a computer w/o any .dll to see which .dll pops up on the error message window. Any short cuts? Thx,
Ralf.

ralf.riedel@usm.edu

Re: Dynamic linkage

Christian Graus11-Feb-03 11:13

Christian Graus

11-Feb-03 11:13

mfc42.dll and if you use the C libraray, msvcrt42.dll

Christian

No offense, but I don't really want to encourage the creation of another VB developer.
- Larry Antram 22 Oct 2002

C# will attract all comers, where VB is for IT Journalists and managers - Michael
P Butler 05-12-2002

It'd probably be fairly easy to make a bot that'd post random stupid VB questions, and nobody would probably ever notice - benjymous - 21-Jan-2003

Re: Dynamic linkage

Chris Richardson11-Feb-03 11:24

Chris Richardson

11-Feb-03 11:24

You can use Depends. If you have VC6 installed, you'll find it in a Tools submenu of your Microsoft Visual Studio menu. If you don't have VC6, you can find Depends on the following site:

http://www.dependencywalker.com/[^]

Chris Richardson

C/C++ Include Finder[^]

Dialogbox doesn't appear when Treelist control added

nitingonsalves11-Feb-03 9:11

nitingonsalves

11-Feb-03 9:11

Hi I am working in the Visual .NET environment and am using the Resource View to add a Treelist control to my dialog box. The dialog box itself comes up when a button is pressed on another dialog window. However I have found that certain controls when added to any dialog box in my project prevent the dialog box from coming up. One of thse that prevents the dialog box from coming up is the Treelist control. However this does not happen with the picture control.
Would anyone have an idea why this is happening?
Thanks
Regards
Nitin

Re: Dialogbox doesn't appear when Treelist control added

Michael Dunn11-Feb-03 9:29

Michael Dunn

11-Feb-03 9:29

Call InitCommonControls() before creating the dialog.

--Mike--
The Internet is a place where absolutely nothing happens.
-- Strong Bad

1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
Sonork-100.19012 Acid_Helm

Re: Dialogbox doesn't appear when Treelist control added

nitingonsalves11-Feb-03 10:35

nitingonsalves

11-Feb-03 10:35

Thanks for the suggestion. However it gave me some link errors explained below.

I initially added the InitCommonControls() function right before this line
DialogBox(hInst, (LPCTSTR)IDD_SPECDIRBOX, hDlg, (DLGPROC)SpecifyDirectory);

I got this linker error
error LNK2019: unresolved external symbol __imp__InitCommonControls@4 referenced in function "long __stdcall AddRecord(struct HWND__ *,unsigned int,unsigned int,long)" (?AddRecord@@YGJPAUHWND__@@IIJ@Z)

I then tried replacing that function because Microsoft says it is obsolete and has been replaced by
bool InitCommonControlsEx(LPINITCOMMONCONTROLSEX lpInitCtrls);

So now instead of just InitCommonControlsEx(); I have
INITCOMMONCONTROLSEX iccex; // INITCOMMONCONTROLSEX structure
iccex.dwSize = sizeof (INITCOMMONCONTROLSEX);
iccex.dwICC = ICC_TREEVIEW_CLASSES;
InitCommonControlsEx (&iccex);

which is exactly the same as a MS example.

I got the same error
error LNK2019: unresolved external symbol __imp__InitCommonControlsEx@4 referenced in function "long __stdcall AddRecord(struct HWND__ *,unsigned int,unsigned int,long)" (?AddRecord@@YGJPAUHWND__@@IIJ@Z)

Any suggestions as to what to do next?

Thanks
Nitin

Re: Dialogbox doesn't appear when Treelist control added

nitingonsalves11-Feb-03 10:46

nitingonsalves

11-Feb-03 10:46

Hi
I just solved the problem by adding the COMCTL32.LIB to my library includes.

Thanks
Nitin

Taskbar HELP! - MFC/C++

mister trunks11-Feb-03 8:54

mister trunks

11-Feb-03 8:54

ok i have a question...

I am working on a project right now whos base class is CFormView... When i create dialog boxes from the main application they do not minimize into the taskbar - instead they minimize to the bottom of the screen just above the taskbar area... Is there anyway to make these dialog boxes minimize into the taskbar - for example - AOL INSTANT MESSENGER - each chat conversation box that opens up minimizes into the taskbar and eventually they start stacking up on each other....

is there a setting i have to change in the dialog boxes properties? perhaps change the owner of the window???

HELP!

-kevin

Show macro code expanded in Visual Studio

Aaron Schaefer11-Feb-03 8:21

Aaron Schaefer

11-Feb-03 8:21

Hi All,

I've put some macros together, and I would like to see what my code looks like after the macros have been handled by the preprocessor. I remember that there is a way to do this in Visual Studio, but I can't rememebr exaclty how.

Anyone know?

Thanks

Re: Show macro code expanded in Visual Studio

Michael Dunn11-Feb-03 8:28

Michael Dunn

11-Feb-03 8:28

You can use the /E switch (preprocess to stdout) or /P switch (preprocess to a file). Run cl /? for a full list of switches.

--Mike--
The Internet is a place where absolutely nothing happens.
-- Strong Bad

1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
Sonork-100.19012 Acid_Helm

round off problem

wong190711-Feb-03 8:14

wong1907

11-Feb-03 8:14

Hello,

How to round a number into nearest integer in C++?
Is there any function to do that?

THX!!!
Smile | :)

Re: round off problem

Rickard Andersson²⁰11-Feb-03 8:27

Rickard Andersson²⁰

11-Feb-03 8:27

double a_bouble_val = 23,34;
int an_integer = (int)a_double_val;

This small code will assign an_integer to 23.

double a_bouble_val = 23,7;
int an_integer = (int)a_double_val;

This, will assign an_integer to 24.

Did I understand you?

Rickard Andersson@Suza Computing
C# and C++ programmer from SWEDEN!
UIN: 50302279
E-Mail: nikado@pc.nu
Speciality: I love C#, ASP.NET and C++!

Re: round off problem

PJ Arends11-Feb-03 8:35

PJ Arends

11-Feb-03 8:35

Rickard Andersson wrote:
double a_bouble_val = 23,7;int an_integer = (int)a_double_val;

This, will assign an_integer to 24.

Actually, this will evaluate to 23. Casting a double to an int will always round to the whole number given (down for positive numbers, up for negative)

CPUA 0x5041

Sonork 100.11743 Chicken Little

"So it can now be written in stone as a testament to humanities achievments "PJ did Pi at CP"." Colin Davies

Within you lies the power for good - Use it!

Re: round off problem

PJ Arends11-Feb-03 8:31

PJ Arends

11-Feb-03 8:31

You can use floor(), ceil(), or just cast to an integer.

This code rounds a value to the nearest integer.

int rounded = (int)(doubleval + 0.5);

Re: round off problem

C^hris L^osinger11-Feb-03 9:36

C^hris L^osinger

11-Feb-03 9:36

it rounds up, to the nearest integer.

this goes both ways.

int i = (d > 0 ? (int)(d + 0.5) : (int)(d - 0.5));

-c

WWT2D?

Fractals

Re: round off problem

David Chamberlain11-Feb-03 9:00

David Chamberlain

11-Feb-03 9:00

It's a little more complicated if you are going to be dealing with both positive and negative numbers, as the floor() function moves the decimal number toward zero and the ceil() function moves the decimal number away from zero. The value of floor(-23.7) is -23, where rounded you probably would want -24. Adding 0.5 to the value before casting to an int works only for positive values, and not for negatives. There, you would have to subtract.

floor(-23.7 - 0.5) = floor(-24.2) = 24<br />
floor( 23.7 + 0.5) = floor( 24.2) = 24

Dave

"You can say that again." -- Dept. of Redundancy Dept.

I subclassed a CStatic...

User 988511-Feb-03 8:04

User 9885

11-Feb-03 8:04

... and added the SS_OWNERDRAW style, but I never get a call to DrawItem.
Why? Confused | :confused:

My article on a reference-counted smart pointer that supports polymorphic objects and raw pointers

modified 29-Aug-18 21:01pm.

Re: I subclassed a CStatic...

palbano11-Feb-03 8:17

palbano

11-Feb-03 8:17

show yur code where you subclass it.

"No matter where you go, there your are..." - Buckaoo Banzi

-pete

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.