C / C++ / MFC

Re: How to set the text of a CEdit to include a newline?

19-Oct-05 9:10

atom wrote:
m_MyEdit.SetWindowText( _T("Three \n Different \n Lines");

Use:

_MyEdit.SetWindowText( _T("Three\r\nDifferent\r\nLines");

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

Ghasrfakhri19-Oct-05 9:15

Ghasrfakhri

19-Oct-05 9:15

Hi You most Set Multi line & Want Return Properties of your Edit control

Iman Ghasrfakhri

Re: How to set the text of a CEdit to include a newline?

David Crow19-Oct-05 10:06

Preventing the resizing of a window

19-Oct-05 10:06

Ghasrfakhri wrote:
You most Set...Want Return Properties of your Edit control

Not required.

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

Dilpo19-Oct-05 7:13

Dilpo

19-Oct-05 7:13

First post, I usually can find what im looking for by searching but this seems to have eluded me.
I want to create a window that cannot be resized and its getting frustrating.
I have made up a solution that will work, but it looks messy.
What it does is use the CS_HREDRAW and CS_VREDRAW window styles to tell the window to redraw everytime its addjusted. Then in the case for recieving that message I calculate the difference between the top and bottom, and left and right sides. If they are not the size i want then it resets them to that size and redraws the window. As you can imagine when somenoe trys to resize the window it blinks rediculously untill they stop. Is there some other way of acchiving this? I still want the end user to be able to move it about the screen, just keeping the same size.

Re: Preventing the resizing of a window

Maximilien19-Oct-05 7:34

Maximilien

19-Oct-05 7:34

remove the WS_THICKFRAME style from your CWnd derived frame window ( I assume that is what you have )
or handle the WM_GETMINMAXINFO message to prevent the resizing of the window.

search for WS_THICKFRAME in msdn, there's an article there about that.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: Preventing the resizing of a window

Dilpo19-Oct-05 7:36

Dilpo

19-Oct-05 7:36

thanks
I was using WS_OVERLAPPEDWINDOW wich inclused WS_THICKFRAME
I must have read over that 100 times and it just didnt click
hate it when that happens

Transparent temporaries..?

Bob Stanneveld19-Oct-05 7:07

19-Oct-05 7:07

Hello,

I have the following problem. I want to create a temporary object that is transparent to the caller of the function which creates the temporary. We all know that a temporary object is created on the stack for objects returned by value from a function.

I wan't to use this property of the temporary to create a locking / unlocking mechanism for an object. See the following code for details

// this class will be used by the user of the API
// In the actual code it will be a template parameter.
class CArbitraryClass
{
public:
    void DoFoo() {}
};

// this is the wrapper that the user uses to store CArbitraryClass objects
class CWrapperClass
{
public:
    // will return a temporary object which the user doesn't know or sees
    CInvisibleTemporary operator->() 
    {
	return CInvisibleTemporary::CInvisibleTemporary();
    }
};

// this object is the 'invisible' temporary. It should pass on the 
// stored object (CArbitraryClass). The user should not have to 
// call any extra functions for it.
class CInvisibleTemporary
{
public:
    CArbitraryClass& operator->() { return m_ArbitraryObject; }

private:
    CArbitraryClass m_ArbitraryObject;
};

So the code should look like the following statements:

CWrapperClass Wrapper;<br />
Wrapper->DoFoo();

But it looks like:

CWrapperClass Wrapper;<br />
Wrapper.operator ->().operator ->().DoFoo();

Am I trying to do something impossible?

Behind every great black man...
... is the police. - Conspiracy brother

Blog[^]

BadKarma19-Oct-05 9:08

BadKarma

19-Oct-05 9:08

Hi, Bob,

its normal that you should write

CWrapperClass Wrapper;<br />
Wrapper.operator ->().operator ->().DoFoo();

because after each function .operator ->() call you have returned a other object
temporary, pointer or reference. From this object you can call again some functions and so on.

The first call (Wrapper.operator ->()) returns the temp object 'TempX' (CInvisibleTemporary)
You have now a object from which you can call some functions like TempX.operator ->() which returns a reference to the encapsulted object (CArbitraryClass m_ArbitraryObject) and now you can call the finale funtion DoFoo();

If you want to encapsulate the function call list, you will have to return the correct object immediatly. But then you could lose the transparancy you need.

Maybe this could be done by using templates. I will check this out!!

codito ergo sum

Bob Stanneveld19-Oct-05 10:11

19-Oct-05 10:11

BadKarma wrote:
its normal that you should write
CWrapperClass Wrapper;<br />
Wrapper.operator ->().operator ->().DoFoo();

I know that I should write this and I want to avoid this obfuscation by introducing the invisible temporary.

My current solution is that the user has to create the temporary himself by calling a function from the wrapper class. This is OK, but if the user doesn't destroy the object, the cache I use it for, might get polluted.

I'll let you know if I find a solution. Thanks for your time, really appreciate it! Big Grin | :-D

Behind every great black man...
... is the police. - Conspiracy brother

Blog[^]

BadKarma19-Oct-05 20:55

BadKarma

19-Oct-05 20:55

You can decrease the level of complexity by changing the -> operator in the CInvisibleTemporary class
from
CArbitraryClass& operator->() { return m_ArbitraryObject; }
to
CArbitraryClass* operator->() { return &m_ArbitraryObject; }

the code for calling is now
Wrapper.operator ->()->DoFoo();

in stead of
Wrapper.operator ->().operator ->().DoFoo();

codito ergo sum

Bob Stanneveld20-Oct-05 0:56

20-Oct-05 0:56

Thank you!

The following change did the trick:

BadKarma wrote:
CArbitraryClass& operator->() { return m_ArbitraryObject; }
to
CArbitraryClass* operator->() { return &m_ArbitraryObject; }

The compiler now automatically calls the second operator->() and everything looks like you have no temporary object! I tested this syntax on VS2005 and I don't know if it works on previous versions of visual studio. I'll try it as soon when I get my hands on one of those versions.

I first tried it with implicit casting, but this didn't work. I now have the solution thanks to you. Big Grin | :-D

Behind every great black man...
... is the police. - Conspiracy brother

Blog[^]

how to use a class to be a utility class of another class?

BadKarma19-Oct-05 23:00

BadKarma

19-Oct-05 23:00

Hi, bob

If you mean invisible (like hide the class/object from the user) instead of transparent (don't care for the object class type), I may have a solution that works like you intended.

class CArbitraryClass
{
public:
void DoFoo() {}
};

class CInvisibleTemporary
{
public:
CInvisibleTemporary(void (CArbitraryClass::*pFunction)()) 
{
// TODO: implement locking
(m_ArbitraryObject.*pFunction)();
}

private:
CArbitraryClass m_ArbitraryObject;
};

class CWrapperClass
{
public:
void Call(void (CArbitraryClass::*p)()) 
{ 
CInvisibleTemporary::CInvisibleTemporary(p);
}
};

The way you need to call it is like this:

CWrapperClass Wrapper;
Wrapper.Call(CArbitraryClass::DoFoo);

The function Call does create a temporary object of the type CInvisibleTemporary. To this object the function that needs to be called is given via its constructor.
The 'invisible' temporary object doens't exist anymore after the 'Call', which frees the locked resoruces.

I hope that this may be a solution or at least sets you on route to one Smile | :)

codito ergo sum

knightz10119-Oct-05 6:29

knightz101

19-Oct-05 6:29

how can you use a class to be a utility class of another class?? need help!! im quite stuck with this one

Re: how to use a class to be a utility class of another class?

Maximilien19-Oct-05 6:50

Maximilien

19-Oct-05 6:50

in many different ways ...

class MyClass
{
  class MyUtilityClass
  {
   // some members...
  };

  MyUtilityClass myUtilityClass;
};

class MyUtilityClass
{
  // some members
};
class MyClass
{
  MyUtilityClass myUtilityClass; // or MyUtilityClass* pMyUtilityClass;
};

or something else ..

maybe if you give us a hint at what you want to achieve, we would be in better position to give you a better answer.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: how to use a class to be a utility class of another class?

Bob Stanneveld19-Oct-05 8:12

Looking for scheduling control (Outlook2003 like)

19-Oct-05 8:12

Hello,

If the class has a default constructor, the following approach works:

CSomeClassUtil
{
public:
    static void DoFoo(); // also other utility methods
    // more methods

private:
    static CSomeClass m_Class;
};

This will not work if the class you want to use has a constructor with parameters. The following modifications will have to be made:

CSomeClassUtil
{
public: 
    static void Initialize(/* parameters */)
    {  m_pClass = new CSomeClass( /* parameters */ ); }

    static void DoFoo();

private:
    static CSomeClass* m_pClass; 
};

With this method you have to do some initialization checking to protect yourself from using uninitialized pointers and initializing the same pointer more than once resulting in memory leaks.

If this solution is not what you are looking for, could you explain your goal more clear?

Behind every great black man...
... is the police. - Conspiracy brother

Blog[^]

TheDen19-Oct-05 5:32

TheDen

19-Oct-05 5:32

Good day
For my application that deals with the scheduling routine i need some control
like we have in Outlook 2003 in Calendar menu:
The yellow one, with the horizontal line that shows the hour periods,
and the rectangles put on it with some text.
Have anybody done this, or know where i can find - please reply
Otherwise i have to design it from scratch Frown | :(

Great thanks,
Denis

P.S. reply to theden@yandex.ru

Re: Looking for scheduling control (Outlook2003 like)

S Douglas20-Oct-05 0:13

S Douglas

20-Oct-05 0:13

TheDen wrote:
The yellow one, with the horizontal line that shows the hour periods,
and the rectangles put on it with some text.

There are a few of those floating around Codeproject.

Here is one that I found with a quick search DayView - An Outlook Like Appointment View[^]

DEBUGGING : Removing the needles from the haystack.

How to determine hard drives?

wasife19-Oct-05 4:28

wasife

19-Oct-05 4:28

Can anybody tell how can i fine the number of hard drives and the drive letters associated with each drive in VC++? Also the size of each drive...

Re: How to determine hard drives?

David Crow19-Oct-05 4:40

Re: How to determine hard drives?

19-Oct-05 4:40

wasife wrote:
Can anybody tell how can i fine the number of hard drives...

Use the Win32_DiskDrive WMI class.

wasife wrote:
...the drive letters associated with each drive...

Use GetLogicalDrives().

wasife wrote:
Also the size of each drive...

Use GetDiskFreeSpaceEx().

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

Anehl19-Oct-05 4:44

Anehl

19-Oct-05 4:44

You can use _getdrives() and others directories routines

Example of msdn

/* GETDRIVE.C illustrates drive functions including:
* _getdrive _chdrive _getdcwd
*/

#include <stdio.h>
#include <conio.h>
#include <direct.h>
#include <stdlib.h>
#include <ctype.h>

void main( void )
{
int ch, drive, curdrive;
static char path[_MAX_PATH];

/* Save current drive. */
curdrive = _getdrive();

printf( "Available drives are: \n" );

/* If we can switch to the drive, it exists. */
for( drive = 1; drive <= 26; drive++ )
if( !_chdrive( drive ) )
printf( "%c: ", drive + 'A' - 1 );

while( 1 )
{
printf( "\nType drive letter to check or ESC to quit: " );
ch = _getch();
if( ch == 27 )
break;
if( isalpha( ch ) )
_putch( ch );
if( _getdcwd( toupper( ch ) - 'A' + 1, path, _MAX_PATH ) != NULL )
printf( "\nCurrent directory on that drive is %s\n", path );
}

/* Restore original drive.*/
_chdrive( curdrive );
printf( "\n" );
}

Output
Available drives are:
A: B: C: L: M: O: U: V:
Type drive letter to check or ESC to quit: c
Current directory on that drive is C:\CODE

Type drive letter to check or ESC to quit: m
Current directory on that drive is M:\

Type drive letter to check or ESC to quit:

Soundcard VU Meter

69 Bay19-Oct-05 2:24

69 Bay

19-Oct-05 2:24

Hi yet again

I have an application that has a bar graph to indicate the recording volume of my soundcard. This makes use of the control of MIXERCONTROL_CONTROLTYPE_PEAKMETER to draw the meter (I am using CPeakMeter class written by Langis Pitre). I have just found, however, that my target machine's soundcard (Sound Blaster Live! 24-bit) doesnt have this control! AAAAAARRRRRGGGGGHHHHH!
Is there a way round this?
I have taken a look at "Multimedia PeakMeter Control By Ernest Laurentin", but can't work out how to link this into the microphone level from my sound card.

Any help will be greatly appreciated - I apologise for asking, but I am relatively new to VC++.

Mike

api subversion

Anehl19-Oct-05 1:45

Anehl

19-Oct-05 1:45

I develop a c++ programme and I need to call some functions of subversion, but I don't succeed in using the api, somebody would have examples to help me

Re: api subversion

David Crow19-Oct-05 3:15