C / C++ / MFC

1-Mar-02 9:34

I'm little blurry about the purpose of PreTranslateMessage so can someone clear it up for me if i'm wrong.

This function allows you to basically emulate the message pump of an SDK program...?

while(GetMessage(&msg, NULL, 0, 0))
{
  TranslateMessage(&msg);
  DispatchMessage(&msg);
}

is basically:

CMyView::PreTranslateMessage(MSG* pMsg)
{
  //You can use this function to dispatch messages to the 
  //proper window or ignore them them altogather
  //Is the following possible
  if(pMsg->message == WM_PAINT)
  {
    if(pMsg->lParam == 1000) //User-defined message
      //Change the message struct attribs a little
    else
      //Ignore the message altogather
  }
}

Do I call DispatchMessage directly from with the PreTranslateMessage() or do I call the default CView::PreTranslateMessage()

Can I change the message a little before sending it off to WndProc...?

Basically in the above code i'm trying to accomplish the following:

1) WM_PAINT message received THEN
2) Check lParam for user-defined value
3) if lParam==VALUE THEN
Change DC to another DC
else
Prevent message from getting to WndProc.

I think WM_PAINT actually can't be stopped until BeginPaint is called, which will remove it from the queue.

I hope I was clear on the effect I am after and I hope even more that someone understands me and can offer suggestions or advice.

Thanx!

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

Re: PreTranslateMessage

Paul M Watt1-Mar-02 10:12

Paul M Watt

1-Mar-02 10:12

Your code segment would work, and yes you could change the message a little, not send it forward at all, or even change the message itself to something entirely different. The main issue is making sure that people who may want to use your class or control in the future understand the behavior.

I should also say, that it is not very wise to send your own WM_PAINT messages, if this is how you intend on getting the user defined value in the lParam. Maybe create your own user defined paint message.

HockeyDude wrote:
I think WM_PAINT actually can't be stopped until BeginPaint is called, which will remove it from the queue.

If you want to stop WM_PAINT message from being sent, you can simply call ValidateRect(hWnd, NULL). WM_PAINT messages are not really entered into the message queue, GetMessage or PeekMessage for that matter will send a WM_PAINT message directly to the target window only when there are no other posted messages left in the message queue.

If you call ValidateRect(hWnd, NULL) after you have performed the painting that you are interested in, then a WM_PAINT message will never be generated.

Re: PreTranslateMessage

alex.barylski1-Mar-02 10:36

1-Mar-02 10:36

Thanx again Kilo.

I've only re-designed the friggen thing about 6 times now...each time it gets better and better naturally.

I always get so far, only to realize it's not possible... Cry | :((

But I think of a better and possibly easier way of doing things. I'm really trying to keep the control packaged nicely, not so much in fear of anyone using my class, but just for the experience. It's easier for me to use also.

It's this one hurdle that is stopping me in my tracks time and time again, causing me to re-think and re-design.

The parent class I want to do all the drawing, but it already draws the control, so any overriden OnDraw will stomp on the control UI. I thought i'd fix this problem by creating a child window which would also provide clipping, whenever the child gets WM_PAINT it would re-direct it to the parent...and i'd use OnErase for the control appearance UI. The approach which I (think) finally decided on, which is IMO Smile | :)

is the best approach, is to just use another virtual function like CParent::OnDrawView() which will respond to the custom message WM_DRAWVIEW sent inside the child's ON_PAINT with the childs CDC* as well

This way drawing can still be done with a virtual function of the parent class. Only problem i'm having now Poke tongue | ;-P

Is how to map a custom message...?

And should I use WM_USER+1 or RegisterWindowsMessage()

Thanx again!

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

Re: PreTranslateMessage

alex.barylski1-Mar-02 10:45

1-Mar-02 10:45

ON_MESSAGE macro... Smile | :)

that was easy...

Thanx again!

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

Winsock API

jangel1-Mar-02 8:19

jangel

1-Mar-02 8:19

Hi, i'm trying to check if a port is open in a remote PC, i'm using Winsock API with non-blocking sockets. When i call connect(...) this function doesn´t give me a code if the remote port is open. How can i assure that the port i'm looking for is open??

Tnx

Re: Winsock API

Nish Nishant1-Mar-02 13:00

Are the STL classes thread-safe?

1-Mar-02 13:00

If you can connect to that port, the port is open.
If connect() fails, it might be that the port is not open, though it could also be a firewall...

Nish

It's seven o'clock
On the dot
I'm in my drop top
Cruisin' the streets - Oh yeah
I got a real pretty, pretty little thing that's waiting for me

Le centriste1-Mar-02 8:05

Le centriste

1-Mar-02 8:05

In particular the deque class. If I have multiple threads doing pop_front()s and front()s and others at the same time, will I be in trouble, or is the class thread-safe? Do I have to do my own synchronization code?

Tx

Michel

Michel

If I am wrong or said something stupid, I apologize in advance Wink | ;)

Re: Are the STL classes thread-safe?

Nemanja Trifunovic1-Mar-02 8:04

Nemanja Trifunovic

1-Mar-02 8:04

If you do pop_front()s and front()s from multiple threads on the same deque object at the same time, you'd better do some synchronization.

I vote pro drink Beer | [beer]

CListCtrl question

jafrazee1-Mar-02 7:56

jafrazee

1-Mar-02 7:56

first if this is in twice i am sorry

is there a way to programmatically select an item in a list control and highlight it.
(my view = report)

thank you.

Re: CListCtrl question

Shog⁹1-Mar-02 7:59

Shog⁹

1-Mar-02 7:59

// select item
ctrlList.SetItemState(nItem, LVIS_SELECTED, LVIS_SELECTED);
// set focus to item
ctrlList.SetItemState(nItem, LVIS_FOCUSED, LVIS_FOCUSED);
// select and set focus to item
ctrlList.SetItemState(nItem, LVIS_SELECTED | LVIS_FOCUSED, LVIS_SELECTED | LVIS_FOCUSED);

farewell goodnight last one out turn out the lights

Smashing Pumpkins, Tales of a Scorched Earth

Re: Icon Searcher v1.2 and over 30,000 icons download

Jon Hulatt1-Mar-02 7:07

Jon Hulatt

1-Mar-02 7:07

If you want to advertise, then pay, and support codeproject. Otherwise p!ss off.

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Re: Icon Searcher v1.2 and over 30,000 icons download

Nish Nishant1-Mar-02 7:28

Re: Icon Searcher v1.2 and over 30,000 icons download

1-Mar-02 7:28

Nish

It's seven o'clock
On the dot
I'm in my drop top
Cruisin' the streets - Oh yeah
I got a real pretty, pretty little thing that's waiting for me

alex.barylski1-Mar-02 8:30

MSFlexGrid control in Console Application

1-Mar-02 8:30

There has to be a more ethical way of free advertising. My friend...I think, you may have made worse for yerself. Notice the comments...if you wanna advertise...pay for it and support our favourite site.

If you can't afford to advertise or care not to...then maybe do it indirectly and still support CodeProject.

Post some code used in your app as examples that others can learn from and use themselves. Certainly this isn't ideal for commercial products cuz you loose your proprietorship and people could use that code for there own apps to compete against yours (I think most are pretty respectful though).

However If your an established commercial vendor you SHOULD have the money to pay for advertisments. If your a struggling small time business then, maybe post some cool code, and indirectly get people interested in your product.

I'm positive this would work better on the CP human psyche cuz well your wasting everyones time advertising here. Which is only gonna make people NOT want to buy your product. But if you shared some sweet code, people liked it...and then noticed it's a small portion of a much better larger product...you might get some bytes (pun intended).

IMFO... I finally used the damn acronym...Yippee!!!

Cheers!

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

Don Miguel1-Mar-02 6:29

Don Miguel

1-Mar-02 6:29

Very strange situation for me:

I developed a console application,
to implement an NT Service. The service interact with desktop, to make settings changes, thru succesive dialogs.

Because I need to display a table content, I use MSFlexGrid in one of the dialogs. The problem is that the dialog with this control isn't displayed.

I try to make all necessary aditions to may application, to support MFC (as I say, is a console app.) - and it work, I also call
"AfxEnableControlContainer();" (????? I thinked I need this), but the dialog with control is still not displayed. Trying some work in debugger, show me that "OnInitDialog()" is never reached.

Really, I could not figure the right way to make
my application support ActiveX controls.

Does anybody know something about this problem?

Thanks in advance.

Nish Nishant1-Mar-02 6:29

1-Mar-02 6:29

I am not really sure about this, but sometimes calling InitCommonControlsEx does help.

Nish

It's seven o'clock
On the dot
I'm in my drop top
Cruisin' the streets - Oh yeah
I got a real pretty, pretty little thing that's waiting for me

Bill Wilson1-Mar-02 8:46

Bill Wilson

1-Mar-02 8:46

If you are running a console app, you cannot use Windows. (kind of by definition) If you want dialogs (or any other window for that matter) you need a windows app.

You can probably turn your console app into a windows app with enough work, but its much easier with one of the MS frameworks.

Hope this helps,
Bill

Carlos Antollini1-Mar-02 9:12

Carlos Antollini

1-Mar-02 9:12

I agree with Will. (A console can not display a dialog)
But for show a dialog you must to set the type of service like SERVICE_INTERACTIVE_PROCESS....

For the first point, I remember that a guy published a article that displayed a dialog from a console application....

Best Regards....

Carlos Antollini.
Sonork ID 100.10529 cantollini

Don Miguel1-Mar-02 20:46

Don Miguel

1-Mar-02 20:46

Thanks,

Really my problem was with OLE initialization.
As I said, the service interact ok with desktop,
and all MFC / GUI stuff work well. The single problem
occur when I'm using MSFlexGrid (ActiveX) in one of
my dialogs.

I feel that is something related to OLE support and initialization,
but I don't know exactly how to do this,
in proper way.

Nish Nishant1-Mar-02 20:56

1-Mar-02 20:56

Did you try calling InitCommonControlsEx()?

Nish

It's seven o'clock
On the dot
I'm in my drop top
Cruisin' the streets - Oh yeah
I got a real pretty, pretty little thing that's waiting for me

Don Miguel1-Mar-02 20:55

Don Miguel

1-Mar-02 20:55

Yes, I tryed it.
It doesn't seems to help with ActiveX controls...

Thanks.

Carlos Antollini5-Mar-02 11:39

Carlos Antollini

5-Mar-02 11:39

Add AfxOleInit in your initInstance...;)

Best Regards

Carlos Antollini.
Sonork ID 100.10529 cantollini

5-Mar-02 12:15

Carlos Antollini wrote:
AfxOleInit

Many thanks!! This is the solution, and work excellent.
I just put it before the point I need it.
Great tip!

Regards.

Winsock question?

Vladimir Georgiev1-Mar-02 6:21

Vladimir Georgiev

1-Mar-02 6:21

The following is my code:

void CFilerecvDlg::OnStartServer()
{
m_button.EnableWindow(false);
CString s_name;
UINT port;
try {
g_sListen.Create(0);
g_sListen.GetSockName(s_name, port);
g_sListen.Bind(port);
g_sListen.Listen();
AfxBeginThread(ServerThreadProc, GetSafeHwnd());
}
catch(CException* e) {
e->Delete();
}
}

UINT ServerThreadProc(LPVOID pParam)
{
CSocket sConnect;
g_sListen.Accept(sConnect);
TRACE ("\nSocket connetced\n");
sConnect.Detach();
sConnect.Close();
return 0;
}

The run fails... A message is issued tellin something like "Thread 0x5425.. has exited with code -1. Memory leak detected!...". g_sListen is a global CSocket variable (in my serverdlg.cpp file). There are no warnings or errors at compile time...
Can anyone tell me where is my mistake???

"Needless redundancy is the hobgoblin of software engineering." - Peter Darnell

Re: Winsock question?

Nish Nishant1-Mar-02 6:26