Typecasting Structs to One Another - C / C++ / MFC Discussion Boards

alex.barylski3-Dec-05 15:44

3-Dec-05 15:44

Basically whats happening here is I am trying to determine which checkboxes in an FTP program should be checked...

Based on the linux permissions of the file...

So, For example:

777 would require all the checkboxes RWX for Owner/Group/Other to be checked...

Whereas 400, would require ONLY the READ/Owner to be checked...

I have the permission bits, ie: 777 or 666 or 400...

Now i'm trying to use this number and programatically determine which of the corresponding checkboxes need to be checked...

I cannot use any FTP helper functions, etc...I must do this completely independant of any library...

The reason I asked if it's possible to localize a certain number inside another...is because...

400 in binary = 110010000 - 3 bits are SET, but ONLY one checkbox (READ/Owner is checked)

However, 666 in binary = 1010011010 - 5 bits are SET and all READ/WRITE for Owner, Group, Other are checked!!!

A trivial:
((666 & 400) == 400)

Doesn't work!!! I'm not sure why it doesn't work...but it doesn't work...atleast the last time I tried it it didn't work Smile | :)

Now does it make sense what I am trying to accomplish???

Any ideas???

It's frustrating being a genius and living the life of a moron!!!

Re: bitwise operations

kevincwong3-Dec-05 17:39

kevincwong

3-Dec-05 17:39

666 => 1010011010
400 => 0110010000

bitwise & => 0010010000
It probably will not match 400 ( 0110010000 ).

In Unix, those permission are in octet.
So, you may want to try

((0666 & 0400 ) == 0400 )

If I understand your problem correctly, I probably will try
different approach.

You probably have 9 checkbox for all permissions.
I probably will have a function to take the
permission & all 9 checkbox.

Inside the function.

if ( permission & 0400 )
ownerRead->SetCheck ( TRUE);
if ( permission & 0200 )
ownerWrite->SetCheck ( TRUE);
& etc.

Kevin

Re: bitwise operations

markkuk3-Dec-05 22:27

markkuk

3-Dec-05 22:27

You're missing the fact that the Unix numerical permissions are octal (base 8) numbers. This means 400 octal is 100000000 in binary and 666 octal is 101101101 in binary.

Re: bitwise operations

Jörgen Sigvardsson4-Dec-05 2:02

Jörgen Sigvardsson

4-Dec-05 2:02

Indeed. Each digit in an octal number, is represented by three bits in the binary number system. E.g: base 8: xyz => base 2: x₀x₁x₂y₀y₁y₂z₀z₁z₂

--
Pictures[^] from my Japan trip.

Re: bitwise operations

David Crow5-Dec-05 2:57

David Crow

5-Dec-05 2:57

markkuk wrote:
...and 666 octal is 101101101 in binary.

Correction. 666 in base 8 is 110110110 in base 2.

"Take only what you need and leave the land as you found it." - Native American Proverb

I need help with printing text from a view.

Mark F.3-Dec-05 12:15

Mark F.

3-Dec-05 12:15

I have an SDI app with several views (mostly CFormView), one of which is a CEditView class. From this class I need to add a "centered" heading with a larger font and set a decent margin to print only text.

I would like some help understanding how to use OnPreparePrinting, OnBeginPrinting, and OnEndPrinting functions that are already in my edit class. I know there are a few classes for printing but if I don't understand how it all works, they are of little value to me.

Another problem is that the book stores in my area have mostly .NET stuff and I'm using VC++ 6.0.

Thanks!

Mark

Re: I need help with printing text from a view.

Gary R. Wheeler4-Dec-05 2:48

Gary R. Wheeler

4-Dec-05 2:48

Printing in an MFC app is supposed to be just like drawing on the screen. The On...Printing functions are there to help you in the places that drawing during printing is different. The main difference is that, when printing, you probably want to keep track of pages. For example, if you're printing text, you wouldn't want to print the top half of a line on one page, and the bottom half on the next.

If your view class is derived from CEditView, you might look to see if CEditView has any printing support built-in.

Software Zen: delete this;

Typecasting Structs to One Another

Steve L.3-Dec-05 10:50

Steve L.

3-Dec-05 10:50

I've got two structs that I want to be able to typecast to one another, so I have something like this:

struct S1
{
	S1( const S2 &s2 ) { a = s2.b }
	float a;
};

struct S2
{
	S2( const S1 &s1 ) { b = s1.a }
	float b;
};

But each struct needs to know about the other, so I can't get this to compile. Is there a way to tell each class the other exists or some other way to get around this?

- Steve

Re: Typecasting Structs to One Another

James Brown3-Dec-05 12:21

James Brown

3-Dec-05 12:21

use a "forward declaration" of S2 prior to defining S1:

struct S2;

struct S1
{
//
};

struct S2
{
//
};

http://www.catch22.net

Using CFormView in SDI app

RoyceF3-Dec-05 7:09

RoyceF

3-Dec-05 7:09

Hi,

I have a CFormView-based SDI project in which I need to programmatically create & update an array of buttons in a view window. It seems that a CFormView would be the best class to use for this window, but I can't seem to create the window. What type of parent should the window have? I need to create it in the app's main CFormView window. Can that be done? Can anyone point me to a sample project?

Thanks,
Royce

Re: Using CFormView in SDI app

Jörgen Sigvardsson3-Dec-05 10:10

Jörgen Sigvardsson

3-Dec-05 10:10

A CFormView is basically a modeless dialog. It's nothing special really. What window fails to create? The buttons, or the CFormView?

--
Pictures[^] from my Japan trip.

Re: Using CFormView in SDI app

RoyceF3-Dec-05 12:36

RoyceF

3-Dec-05 12:36

The CFromView fails to create a window when the class ctor is called.

Re: Using CFormView in SDI app

Jörgen Sigvardsson3-Dec-05 14:20

Jörgen Sigvardsson

3-Dec-05 14:20

You cannot create child controls in the constructor, because the window is not created yet. You see, the CFormView object is nothing but a wrapper around a HWND (window handle). You will have much better luck if you create the child controls in OnInitialUpdate() (that is a virtual method which you can override, and is found in the classwizard).

All MFC window/control* classes are only wrappers around window handles, they are not windows themselves. They merely present a C++-friendly interface (some may disagree with this) to the messaging protocols which the window supports.

--
Pictures[^] from my Japan trip.

-- modified at 8:56 Sunday 4th December, 2005

Re: Using CFormView in SDI app

Gary R. Wheeler4-Dec-05 2:53

Gary R. Wheeler

4-Dec-05 2:53

Jörgen Sigvardsson wrote:
They merely present a C++-friendly interface (some may disagree with this)

Aw, don't spoil his fun, Jörgen Big Grin | :-D

Software Zen: delete this;

Re: Using CFormView in SDI app

RoyceF4-Dec-05 6:24

RoyceF

4-Dec-05 6:24

Yes, I understand all that. It is the creation of the CFormview window that I am having trouble with. How and when do I create it? Must it be a child of a CFrameWnd? Can it be a child of another CFormView?

How to list the connected USB devices or COM port

BaySeagull3-Dec-05 1:34

BaySeagull

3-Dec-05 1:34

Hi, everyone! Big Grin | :-D

My current project is an application to control the 3-axis table for the optical microscope. The each stepping motor can be controlled by the serial communication port using the ASCII text format.

Now, I would like to know which COM port is connected or not.
Is there any method to list the connected USB or COM port?

BaySeagull

How to generate a bmp file

Ming Luo3-Dec-05 0:10

Ming Luo

3-Dec-05 0:10

Hi all:
I am writing a program which is a opengl like library. Finally I need to generate a bmp file to display the result. Does anybody know how to make a bmp file from c++ please???
Thanks a lot

Asura

Re: How to generate a bmp file

BaySeagull3-Dec-05 1:16

BaySeagull

3-Dec-05 1:16

Well, I guess a lot of examples you can get through the internet.

Anyway, the followings are my humble example.

<br />
<br />
BITMAPFILEHEADER bfh;<br />
BITMAPINFOHEADER bih;<br />
char* pBuffer; // please provide the bitmap.<br />
<br />
<br />
			bfh.bfType = ((WORD) ('M' << 8) | 'B');; <br />
			bfh.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + lBuffer; <br />
			bfh.bfReserved1 = 0; <br />
			bfh.bfReserved2 = 0; <br />
			bfh.bfOffBits = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER); <br />
<br />
			bih.biSize = sizeof(BITMAPINFOHEADER);<br />
			bih.biWidth = pvih->bmiHeader.biWidth;<br />
			bih.biHeight = pvih->bmiHeader.biHeight;<br />
			bih.biPlanes = pvih->bmiHeader.biPlanes;<br />
			bih.biBitCount = pvih->bmiHeader.biBitCount;<br />
			bih.biCompression = BI_RGB;<br />
			bih.biSizeImage = 0; <br />
			bih.biXPelsPerMeter = 0;<br />
			bih.biYPelsPerMeter = 0;<br />
			bih.biClrUsed = 0;<br />
			bih.biClrImportant = 0;<br />
<br />
			CFileDialog dlg(FALSE, _T("bmp"), NULL,<br />
				OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,<br />
				"BMP (*.bmp)|*.bmp|All Files (*.*)|*.*||");<br />
				<br />
			if(dlg.DoModal()==IDOK)<br />
			{<br />
				CFile file(dlg.GetPathName(), CFile::modeCreate|CFile::modeWrite);<br />
				file.Write(&bfh, sizeof(BITMAPFILEHEADER));<br />
				file.Write(&bih, sizeof(BITMAPINFOHEADER));<br />
				file.Write(pBuffer, lBuffer);<br />
				file.Close();<br />
			}	<br />

BaySeagull

Saving a Bitmap from Window Enviornment

Jeeva Mary Varghese2-Dec-05 22:15

Jeeva Mary Varghese

2-Dec-05 22:15

Hai,
Please tell me that how to save a picture from client enviornment(CFormView) as Bitmap.

regards,
Jeeva

BN_DOUBLECLICKED

LeeeNN2-Dec-05 20:02

LeeeNN

2-Dec-05 20:02

Hi, suprise! BN_DOUBLECLICKED wouldn't work! I want a button when single click do one thing, and when double clicked do another thing. but it never hit OnButtonDoubleclicked().
I search on Web, some one said, should change the button style to BS_NOTIFY, then I did check this style on property page. It made no difference.

Any one can help?

Thank you in advance. Confused | :confused:

Re: BN_DOUBLECLICKED

Branislav2-Dec-05 23:31

Branislav

2-Dec-05 23:31

http://www.codeproject.com/buttonctrl/doubleclick.asp[^]

Re: BN_DOUBLECLICKED

LeeeNN3-Dec-05 6:34

LeeeNN

3-Dec-05 6:34

Yes I went there before. I don't like the way to check double click. and I tried to check Notify option in property page, OnDoulbleClick() still could not be called. I still think there should be a better to do it. otherwise Wizzard should remove DoubleClicked notification from CButton.
MSDN says BS_USERBUTTON can get BN_DOUBLECLICKED notification. how to create BS_USERBUTTON?
Roll eyes | :rolleyes:

Re: BN_DOUBLECLICKED

Branislav4-Dec-05 20:51

Branislav

4-Dec-05 20:51

Did you select Notify in Puch Button Properties - Styles dialog box?

Re: BN_DOUBLECLICKED

Owner drawn4-Dec-05 22:23

Owner drawn

4-Dec-05 22:23

Try to subclass the button and handle the double click

<marquee direction="up" height="30" scrolldelay="1" step="1" scrollamount="1" hspace="0" vspace="0">
--Owner Drawn
--Nothing special
--Defeat is temporary but surrender is permanent
--Never say quits
--Jesus is Lord

LNK2001 error

QuickDeveloper2-Dec-05 18:20

QuickDeveloper

2-Dec-05 18:20

I am converting an appln to unicode.

I use the code as follows

HtmlHelp(pWnd->GetSafeHwnd(), strHelpPath+="::/Popuptext.txt",
HH_DISPLAY_TEXT_POPUP, (DWORD)&popup);

but it throws up the following error

ExportDlg.obj : error LNK2001: unresolved external symbol _HtmlHelpW@16
ImportDlg.obj : error LNK2001: unresolved external symbol _HtmlHelpW@16
ReleaseUMinSize/ImportExport.dll : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

when i include HtmlHelp.lib it says

LINK : warning LNK4098: defaultlib "LIBCMT" conflicts with use of other libs; use /NODEFAULTLIB:library

i have the htmlhelp.lib in current directory

what do i need to remove this error??

thanx in advance

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