C / C++ / MFC

2-Nov-02 13:40

Hello,
I am doing the following to shake a window (kinda like Yahoo! messenger's BUZZ friend).. Mine doesn't look as clean as theirs, any ideas on how I can do this better?

CRect pRect;
		pMain->GetWindowRect(pRect);
		int iH = pRect.Height();
		int iW = pRect.Width();

		pRect.InflateRect(-10,10);
		pMain->MoveWindow(pRect,TRUE);

		Sleep(10);

		pRect.InflateRect(10,-10);
		pMain->MoveWindow(pRect,TRUE);

		Sleep(10);

		pRect.InflateRect(20,20);
		pMain->MoveWindow(pRect,TRUE);

		Sleep(10);

		pRect.InflateRect(-20,-20);
		pMain->MoveWindow(pRect,TRUE);

		Sleep(10);

and so on and so on.....................................

Re: Shake a window..

ian mariano2-Nov-02 14:58

2-Nov-02 14:58

Try smaller increments instead of a 10 pixel jump:

#define MAX_INFLATE_ITERATIONS  20
#define MAX_BOUNCE_ITERATIONS 3
#define INFLATE_INCR  2
#define INFLATE_SLEEP 5

// ...

CRect  rc;
int i, j;

pMain->GetWindowRect(&rc);

for(j = 0; j < MAX_BOUNCE_ITERATIONS; j++
{
   for(i = 1; i <= MAX_INFLATE_ITERATIONS; i++)
   {
      rc.InflateRect(-INFLATE_INCR, INFLATE_INCR);
      pMain->MoveWindow(&rc, TRUE);
      Sleep(INFLATE_SLEEP);
   }

   for(i = MAX_INFLATE_ITERATIONS; i > 0; i++)
   {
      rc.InflateRect(INFLATE_INCR, -INFLATE_INCR);
      pMain->MoveWindow(&rc, TRUE);
      Sleep(INFLATE_SLEEP);
   }
}

Of course you won't be processing any windows messages at the time Wink | ;)

"The greatest danger to humanity is humanity without an open mind."
- Ian Mariano - http://www.ian-space.com/

Re: Shake a window..

ian mariano2-Nov-02 15:02

2-Nov-02 15:02

OOps, Shake, not expand, you could alter the top and left of the rect before moving the window, oh well, you get the point Wink | ;)

SHouldn't give advice when passing through paint fume filled lobbies...

"The greatest danger to humanity is humanity without an open mind."
- Ian Mariano - http://www.ian-space.com/

Re: Shake a window..

Anonymous2-Nov-02 15:08

Selecting a region into a DC?

2-Nov-02 15:08

imariano wrote:
SHouldn't give advice when passing through paint fume filled lobbies...

Big Grin | :-D

Too funny! Thanks for the reply, I'll give that a shot Smile | :)

Michael Dunn2-Nov-02 12:16

Michael Dunn

2-Nov-02 12:16

I was reading thru the GDI region docs a couple of days ago, and saw that you can select a HRGN into a DC. MSDN says "After a region is selected into a device context, the application can perform various operations on it" however AFAICT all the region APIs take a HRGN to operate on, instead of operating on whatever is currently in a DC.

So, riddle me this... what does selecting a region into a DC actually do?

--Mike--
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Re: Selecting a region into a DC?

Paul M Watt2-Nov-02 13:38

Paul M Watt

2-Nov-02 13:38

Michael Dunn wrote:
what does selecting a region into a DC actually do?

It is basically like calling SelectClipRgn. It makes the current clipping rgn for the DC the region that you select into the DC.

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

First-chance Exception in C++ Runtime

Roger Wright2-Nov-02 11:53

Roger Wright

2-Nov-02 11:53

What the heck does that mean? I've never seen this error before, but Explorer.exe is crashing and reporting it, then when VC++ tries to debug it, the whole system goes unstable. What is a "First-chance Exception"? I don't understand the reference.

"When in danger, fear, or doubt, run in circles, scream and shout!" - Lorelei and Lapis Lazuli Long

Re: First-chance Exception in C++ Runtime

Ravi Bhavnani2-Nov-02 14:09

Ravi Bhavnani

2-Nov-02 14:09

From what I recall, first chance exceptions are "expected" failures within the Windows API (eg: at the network and file system layers). Here's[^] a link that may (not) shed more light on the subject.

/ravi

Let's put "civil" back in "civilization"
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ravib@ravib.com

Re: First-chance Exception in C++ Runtime

Roger Wright2-Nov-02 18:29

Roger Wright

2-Nov-02 18:29

Thanks, Ravi! That does shed some light on it, and adds it to a list of clues I've been accumulating until a pattern appears. The first chance exception refers to an error state available to the debugger; for a few weeks now my server has had stability problems, and when attempting to shut down the system, has reported that certain processes could not be shut down as they were being debugged. This occurs when the debugger is not running, and this episode appears to be related. Thanks for the tip! Big Grin | :-D

"When in danger, fear, or doubt, run in circles, scream and shout!" - Lorelei and Lapis Lazuli Long

Calendar Control Problem

Anonymous2-Nov-02 11:00

Reading binary files with c stdio fread

2-Nov-02 11:00

When I UpdateData(TRUE) to set the value in my Calendar Control to its corresponding CTime object it arbitrarily adds a fixed number of days to the selected date. Example:
If the the user selected November 5, 2002 the date that would be stored in the CTime object would November 12, 2002. Likewise if they choose December 8, 2002 the date that would be stored would be December 20, 2002.
Fairly annoying. Any ideas?

Anonymous2-Nov-02 10:18

Re: Reading binary files with c stdio fread

2-Nov-02 10:18

I thought the following would read in blocks of 15 floats from a binary file but after a bunch of correct reads all the output numbers are giberish, numbers like 1E-20 type stuff..

I have to use stdio routines like fread, I have written the same code with fstreams and it works fine. I am missing some stdio quirk or something.. It seems to get hosed when the _cnt variable in the FILE structure becomes < then the size of 15 floats (60).. I believe it has to do with the buffering of the file, which is the system 4096 size.

float CPDATA[15];
do{
fread((char*)CPDATA,sizeof(float)*15, 1, thO->fd);
//outfile read info to a file
outfile<<ftell(tho->fd)<<" ";
for(int i=0;i<15;i++)
outfile<

Anders Molin3-Nov-02 2:48

Anders Molin

3-Nov-02 2:48

Anonymous wrote:
fread((char*)CPDATA,sizeof(float)*15, 1, thO->fd);

Just an idea, try with fread((unsigned char*)CPDATA,sizeof(float)*15, 1, thO->fd); instead...

- Anders

Money talks, but all mine ever says is "Goodbye!"

Serialization Progress

Ted Christiansen2-Nov-02 9:42

Ted Christiansen

2-Nov-02 9:42

Hello,

I need to display the progress during a file open (serialization) process. I have looked for some examples of how to do this and havent found any. Has anyone worked on this? The easiest approach might be to use the file size and the number of bytes read?

Ted

Re: Serialization Progress

ian mariano2-Nov-02 9:51

2-Nov-02 9:51

That's the easiest approach:

//  assumes m_wndProgress is your window and this is MFC
m_wndProgress.SetRange32(0, nFileSize);  // nFileSize is total size
m_wndProgress.SetPos(0);  // to reset

while(/*  more data to read */)
{
  //  read in some data
  m_wndProgress.SetStep(nReadSize);  // nReadSize is how much you read in
  m_wndProgress.StepIt();
}

Here's a cool way to add the progress bar to the status bar: Showing progress bar in a status bar pane[^]

"The greatest danger to humanity is humanity without an open mind."
- Ian Mariano

http://www.ian-space.com/

Philosophical question

C^hris L^osinger2-Nov-02 9:21

2-Nov-02 9:21

if you have a file, foo.cpp, which contains the implementations of some (C-style, not classes) functions used elsewhere in the app, and a header file, foo.h, which defines those functions, would you #include "foo.h" inside foo.cpp ?

assume there's nothing in foo.h that foo.cpp needs: no constants, struct definitions, etc. foo.h simply provides an external definition of the functions in foo.cpp.

strictly, i think it's unnecessary, because the functions aren't really dependent on the external definitions - that association doesn't happen until the linker gets involved and it needs to match what callers of foo's functions think those functions are to the functions that the linker has available.

on the other hand, it seems logically 'right' to associate them somehow.

opinions?

-c

“losinger is a colorizing text edit control”
-- googlism

let me answer my own question...

C^hris L^osinger2-Nov-02 9:46

2-Nov-02 9:46

if foo.h defines those functions as 'extern "C"', you actually have to #include the header with the functions, or else the compiler will define them as C++ functions, and you'll get linker errors.

carry on, my wayward sons.

-c

“losinger is a colorizing text edit control”
-- googlism

ian mariano2-Nov-02 9:42

2-Nov-02 9:42

You don't have to even #include an .h (in C or C++) if you define the prototypes of any functions used in your implementation file Big Grin | :-D

I, personally, include the header for readability. And besides, you can write the functions in any order since all their prototypes are defined ahead of time.

Of course, if you want "C" linkage you have to define them as extern "C".

"The greatest danger to humanity is humanity without an open mind."
- Ian Mariano

http://www.ian-space.com/

ColinDavies2-Nov-02 9:43

ColinDavies

2-Nov-02 9:43

Why then would foo.h exist at all ?
Shouldnt foo.cpp be foo.c to distinguish itself ?
IMHO if you use .cpp as an extension you should hold the relevant .h header as per normal usage.
But if it's C you should name it as such as well.
Sure it won't make any differences to compiling but it becomes easier to have conventions to follow.

Regardz
Colin J Davies

Sonork ID 100.9197:Colin

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Gary R. Wheeler3-Nov-02 4:29

Gary R. Wheeler

3-Nov-02 4:29

Include foo.h in foo.c so that the compiler validates how you've declared the functions (foo.h) with how you've defined them (foo.c). Since the other parts of your software that use the functions in foo.cpp use the function prototypes in foo.h, this helps ensure that the callers and the callee agree on the type and order of parameters.

The only time I omit a header file for each source file is when there is a single header (ex: library.h) for multiple source files (library_part1.cpp, library_part2.cpp, etc.).

Software Zen: delete this;

C^hris L^osinger2-Nov-02 9:49

2-Nov-02 9:49

foo.h exists so that the rest of the app can get at the functions in foo.cpp.

and, only the functions it exports are C, foo.cpp may use C++ internally.

-c

“losinger is a colorizing text edit control”
-- googlism

C^hris L^osinger3-Nov-02 5:33

3-Nov-02 5:33

Gary R. Wheeler wrote:
so that the compiler validates how you've declared the functions (foo.h) with how you've defined them

but it doesn't do this. it doesn't care if MyFunc is defined differently than the implementation. try it.

-c

“losinger is a colorizing text edit control”
-- googlism

markkuk2-Nov-02 12:49

markkuk

2-Nov-02 12:49

Including foo.h would make sure there aren't any conflicts between declarations and actual functions. Of course the linker will eventually catch any typos in either file.

C^hris L^osinger2-Nov-02 13:34

2-Nov-02 13:34

markkuk wrote:
Including foo.h would make sure there aren't any conflicts between declarations and actual functions.

actually, it wouldn't. because you can overload functions in C++, the compiler will ignore any differences. and that's the basis of the problem - the compiler really doesn't care. the only reason to include foo.h would be for my own benefit (ignoring the extern "C" linkage stuff)

-c

“losinger is a colorizing text edit control”
-- googlism

Anonymous4-Nov-02 4:17