C / C++ / MFC

15-Sep-09 6:23

Hi,

Am getting to grips with the g++ compiler...

I have my main cpp file containing the main function in

/home/alfred/Public/Test/

I have my header file in

/home/alfred/Public/Test/header/

I have my src file for the header in

/home/alfred/Public/Test/src/

I used the command

g++ -c -Wall -I/home/alfred/Public/Test/header/ myclass.cpp

to generate my myclass.o object file and then the archiver to create the library

ar rc mylib.a myclass.o

which was fine but now I am having problems compiling and linking the main.cpp file to get my exe. I am trying to use the command

g++ -L/home/alfred/Public/Test/src -I/home/alfred/Public/Test/header/ main.cpp -o a.out

but I am being returned the error

/tmp/ccmZLiDt.o: In function `main':
main.cpp Frown | :(

text+0x59): undefined reference to `myclass::myclass(int, std::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
collect2: ld returned 1 exit status

meaning that it cannot see the constructor for the class myclass. I thought the -L flag is to tell it where your library is which has the constructor definition? Ummm, am I getting confused with the -l flag?

Thanks for any information.

Smile | :)

Stuart Dootson15-Sep-09 7:06

Stuart Dootson

15-Sep-09 7:06

You still need to tell the linker which library to use. You can:

Add mylib.a to the list of inputs (note that a.out is the default output name from the linker):

g++ -L/home/alfred/Public/Test/src -I/home/alfred/Public/Test/header/ main.cpp -o a.out mylib.a

You can rename the library so it starts with 'lib' - e.g. libmylib.a and then use the -l option by removing the 'lib' prefix:
```
g++ -L/home/alfred/Public/Test/src -I/home/alfred/Public/Test/header/ -lmylib main.cpp -o a.out
```

The -L option tells the linker what directory to look in for library files. The -l option tells the linker which library files to use.

HTH!

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

minkowski15-Sep-09 22:47

15-Sep-09 22:47

Hey ya,

Many thanks for your tips, I tried both but unfortunately I got errors....

For the command line

g++ -L/home/alfred/Public/Test/src -I/home/alfred/Public/Test/header/ main.cpp -o a.out mylib.a

I got the error

g++: mylib.a: No such file or directory

and for the command line

g++ -L/home/alfred/Public/Test/src/   -I/home/alfred/Public/Test/header/ main.cpp -lmylib.a  -o a.out

I got

/usr/bin/ld: cannot find -lmylib.a
collect2: ld returned 1 exit status

even though I have libmylib.a (where the -l substitututes the lib part).

Ummm, any ideas? Seems it still can't "see" the mylib.a

Many thanks!

Stuart Dootson15-Sep-09 23:33

Stuart Dootson

15-Sep-09 23:33

minkowski wrote:
For the command line

g++ -L/home/alfred/Public/Test/src -I/home/alfred/Public/Test/header/ main.cpp -o a.out mylib.a

I got the error

g++: mylib.a: No such file or directory

Sorry - for that one, you need the path to the lib on the command-line, not just the name

minkowski wrote:
for the command line

g++ -L/home/alfred/Public/Test/src/ -I/home/alfred/Public/Test/header/ main.cpp -lmylib.a -o a.out

I got

/usr/bin/ld: cannot find -lmylib.a
collect2: ld returned 1 exit status

even though I have libmylib.a (where the -l substitututes the lib part).

Again - sorry, I forgot to say that you don't need the '.a' part either

HTH!

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

minkowski16-Sep-09 0:29

16-Sep-09 0:29

Hi ya,

Thanks for your reply. The folllowing worked....

g++ -L/home/mpotter/Public/Test/src/mylib.a -I/home/mpotter/Public/Test/header/ main.cpp -o a.out /home/mpotter/Public/Test/src/mylib.a

as opposed to

g++ -L/home/mpotter/Public/Test/src/ -I/home/mpotter/Public/Test/header/ main.cpp -o a.out mylib.a

which did not. also

g++ -I/home/mpotter/Public/Test/header/ main.cpp -o a.out /home/mpotter/Public/Test/src/mylib.a

works, so I am afraid I don't see the point of using the -L flag to give the location? you can just put the path on the end to your library and it will work fine.

I got the

g++ -L/home/mpotter/Public/Test/src/ -I/home/mpotter/Public/Test/header/ main.cpp -lmylib -o a.out

to work fine. This one with the -l flag makes sense as you use the -L to give the location and -l to give the library name. But the one with just the -L flag (the 1st case) does not make sense to me.... Can you pls explain?

Thanks !

Stuart Dootson16-Sep-09 0:37

Stuart Dootson

16-Sep-09 0:37

The -L option is only relevant if you use -l to specify the library name. The g++ documentation[^] says:

<blokquote>-Ldir
Add directory dir to the list of directories to be searched for -l.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

minkowski16-Sep-09 1:00

How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

16-Sep-09 1:00

hey ya

Thanks for that. I can see now why it didn't work for the initial -L case. I thought the -L and -l were independent but apparently not !

Smile | :)

Neil Urquhart15-Sep-09 4:31

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

15-Sep-09 4:31

Using MFC Dialog App with VC6

I need some help to force redraw of buttons?

I have a bitmap image displayed in my dialog using the picture control and have positioned over the top of it number of CButton's (ie the buttons overlap the image). I want to get the buttons to remain displayed when I change the bitmap image in the button selected function.

If I have an "OnSel" function for each button with code like this :

void CDesignEditDlg::OnButtonSel3() <br />
{<br />
	// TODO: Add your control notification handler code here<br />
	MessageBox("Button 3 Pressed", "Select", MB_OK) ;<br />
	<br />
}

When I run the app and press a button it is all fine, ie I get the button pressed message pops up and all the buttons are still shown.

Since I want to change the image displayed while the button is pressed I tried to modify my code to something like this.

void CDesignEditDlg::OnButtonSel2() <br />
{<br />
	// TODO: Add your control notification handler code here<br />
	// Set new image<br />
	m_ctrlPageImage.SetBitmap(cBmp[1]);<br />
<br />
	MessageBox("Button 2 Pressed", "Select", MB_OK) ;<br />
<br />
	// Put old image back<br />
	m_ctrlPageImage.SetBitmap(cBmp[0]);<br />
}

This works in that it changes the displayed image while the popup message is on screen but all the buttons other than the one I pressed have disappeared.

Is there a way to force MFC to redraw my buttons over the top of the image after I have changed it ??

Code-o-mat15-Sep-09 4:48

Code-o-mat

15-Sep-09 4:48

Try adding the WS_CLIPSIBLINGS[^] style to your picture control, maybe add WS_CLIPCHILDREN to the dialog itself. If all that doesn't help, try using RedrawWindow[^] on your buttons.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

Neil Urquhart15-Sep-09 6:02

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

15-Sep-09 6:02

Could'nt find WS_CLIPSIBLINGS as property to my Picture Control ! I tired setting WS_CLIPCHILDREN in the dialog, it had no effect.

RedrawWindow seems to be "half" working in that it is redrawing the buttons before my pop dialog displays. But after exiting the popup and reverting the image to the orignal bitmap the button redraw does not have any effect. ie After finishing the ButtonPressed func all the buttons have dissappeared again except the one I pressed.

Any more thoughts ?

My code is now like this in the button selection.

void CDesignEditDlg::ButtonPressed(int btn)<br />
{<br />
	m_ctrlPageImage.SetBitmap(cBmp[1]);<br />
<br />
	CButton* pImage ;<br />
	int b ;<br />
	for(b = 0 ; cButPos[b].id > 0 ; b++) {<br />
		// Move the button<br />
		pImage = (CButton*)GetDlgItem(cButPos[b].id);<br />
		pImage->RedrawWindow() ;<br />
	}<br />
<br />
	CColourFaderDlg dlg;<br />
	int nResponse = dlg.DoModal();<br />
	if (nResponse == IDOK)<br />
	{<br />
		// TODO: Place code here to handle when the dialog is<br />
		//  dismissed with OK<br />
	}<br />
	else if (nResponse == IDCANCEL)<br />
	{<br />
		// TODO: Place code here to handle when the dialog is<br />
		//  dismissed with Cancel<br />
	}<br />
<br />
	for(b = 0 ; cButPos[b].id > 0 ; b++) {<br />
		// Move the button<br />
		pImage = (CButton*)GetDlgItem(cButPos[b].id);<br />
		pImage->RedrawWindow() ;  // Seems to have no effect<br />
	}<br />
<br />
	m_ctrlPageImage.SetBitmap(cBmp[1]);<br />
}

Neil Urquhart15-Sep-09 6:09

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

15-Sep-09 6:09

Ignore pervious message, I goofed !!

I had the redraw of the buttons before changing the bitmap instead of after.

Code-o-mat15-Sep-09 6:13

Code-o-mat

15-Sep-09 6:13

Use ModifyStyle[^] to add the WS_CLIPSIBLINGS style (piccontrol.ModifyStyle(0, WS_CLIPSIBLINGS);). If that still doesn't work, do the redrawing of the windows after you call SetBitmap on your picture control, not before it. Btw if i were you i would go another way with this, having overlapped controls on a dialog is imho nothing but trouble.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog [modified]

Moak15-Sep-09 14:09

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

15-Sep-09 14:09

Neil Urquhart wrote:
I have a bitmap image displayed in my dialog using the picture control and have positioned over the top of it number of CButton's (ie the buttons overlap the image). I want to get the buttons to remain displayed when I change the bitmap image in the button selected function.

Hi! I suggest to make the buttons child controls of the image. They have to be child controls, because overlapping siblings are poorly supported by Windows (see KB79981). Yes the MSDN article is one of the worst I have ever read and left me also confused the first time I read it. Even if you would manage to make overlapping controls work somehow else (e.g. by using transparency), you will sooner or later see redraw artefacts such as parts not been redrawn correctly.

Create your buttons as child controls from the start or use SetParent() in CDesignEditDlg::OnInitDialog().

Let me know if this works for you. Smile | :)

/M

[Edit: Fixed name of message handler and added some swearing]

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modified on Tuesday, September 15, 2009 8:32 PM

Neil Urquhart15-Sep-09 20:04

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

15-Sep-09 20:04

I tried using SetParent on all the buttons as below but now I don't see any buttons anywhere ! Did I miss something ? Do I need to set some extra things ?

BOOL CDesignEditDlg::OnInitDialog() <br />
{<br />
	CDialog::OnInitDialog();<br />
<br />
	<br />
	// TODO: Add extra initialization here<br />
	CWnd* pImage ;<br />
	WINDOWPLACEMENT wpImage ;<br />
	CRect rect;<br />
	CPoint imgPos ;<br />
<br />
	// Get the current top left position of the window<br />
	pImage = GetDlgItem(IDC_PAGEIMAGE) ;<br />
	pImage->GetWindowPlacement(&wpImage);<br />
	imgPos.x = wpImage.rcNormalPosition.left ;<br />
	imgPos.y = wpImage.rcNormalPosition.top ;<br />
<br />
	//pImage->ModifyStyle(0, WS_CLIPSIBLINGS);<br />
<br />
	int b ;<br />
	for(b = 0 ; cButPos[b].id > 0 ; b++) {<br />
		// Move the button<br />
		pImage = GetDlgItem(cButPos[b].id);<br />
		pImage->GetWindowRect(rect);<br />
		pImage->MoveWindow(imgPos.x + cButPos[b].x, imgPos.y + cButPos[b].y, rect.Width(), rect.Height(), TRUE);<br />
<br />
		// Make each CButton a child to CDesignEditDlg<br />
		pImage->SetParent(this) ;<br />
	}<br />
<br />
	<br />
	// Load the page images<br />
	cBmp[0].LoadBitmap(IDB_IMAGE0);	// This is the unselect version<br />
	cBmp[1].LoadBitmap(IDB_IMAGE1);<br />
/*	cBmp[2].LoadBitmap(IDB_IMAGE2);<br />
	cBmp[3].LoadBitmap(IDB_IMAGE3);<br />
	cBmp[4].LoadBitmap(IDB_IMAGE4);<br />
	cBmp[5].LoadBitmap(IDB_IMAGE5);<br />
	cBmp[6].LoadBitmap(IDB_IMAGE6);<br />
	cBmp[7].LoadBitmap(IDB_IMAGE7);<br />
	cBmp[8].LoadBitmap(IDB_IMAGE8);<br />
	cBmp[9].LoadBitmap(IDB_IMAGE9);<br />
	cBmp[10].LoadBitmap(IDB_IMAGE10);<br />
	cBmp[11].LoadBitmap(IDB_IMAGE11);<br />
	cBmp[12].LoadBitmap(IDB_IMAGE12);<br />
	cBmp[13].LoadBitmap(IDB_IMAGE13);<br />
	cBmp[14].LoadBitmap(IDB_IMAGE14);<br />
	cBmp[15].LoadBitmap(IDB_IMAGE15);<br />
	cBmp[16].LoadBitmap(IDB_IMAGE16);<br />
	cBmp[17].LoadBitmap(IDB_IMAGE17);<br />
	cBmp[18].LoadBitmap(IDB_IMAGE18);*/<br />
	<br />
	return TRUE;  // return TRUE unless you set the focus to a control<br />
	              // EXCEPTION: OCX Property Pages should return FALSE<br />
}

Neil Urquhart15-Sep-09 20:57

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

15-Sep-09 20:57

Ah ha !

Got it sussed. I should have used SetParent on the picture control and all its overlaping buttons to make them all children of the CDialog. I had to set the WS_CLIPCHILDREN/WS_CLIPSIBLINGS for the dialog/picture control to make it work. Without setting these properties the buttons don't display.

My code now looks like this with no "button redraw's" in the buttons select function.

BOOL CDesignEditDlg::OnInitDialog() 
{
	CDialog::OnInitDialog();

	
	// TODO: Add extra initialization here
	CWnd* pImage ;
	WINDOWPLACEMENT wpImage ;
	CRect rect;
	CPoint imgPos ;

	// Set CDesignEditDlg WS_CLIPCHILDREN
	ModifyStyle(0, WS_CLIPCHILDREN) ;

	// Get the current top left position of the picture control window
	pImage = GetDlgItem(IDC_PAGEIMAGE) ;
	pImage->GetWindowPlacement(&wpImage);
	imgPos.x = wpImage.rcNormalPosition.left ;
	imgPos.y = wpImage.rcNormalPosition.top ;

	// Set picture control WS_CLIPSIBLINGS
	pImage->ModifyStyle(0, WS_CLIPSIBLINGS);

	// Make picture control child to CDesignEditDlg
	pImage->SetParent(this) ;

	CWnd* pButton ;
	int b ;
	for(b = 0 ; cButPos[b].id > 0 ; b++) {
		// Move the button
		pButton = GetDlgItem(cButPos[b].id);
		pButton->GetWindowRect(rect);
		pButton->MoveWindow(imgPos.x + cButPos[b].x - (rect.Width()/2), imgPos.y + cButPos[b].y, rect.Width(), rect.Height(), TRUE);

		// Make each CButton a child to CDesignEditDlg
		pButton->SetParent(this) ;
	}

	
	// Load the page images
	cBmp[0].LoadBitmap(IDB_IMAGE0);	// This is the unselect version
	cBmp[1].LoadBitmap(IDB_IMAGE1);
/*	cBmp[2].LoadBitmap(IDB_IMAGE2);
	cBmp[3].LoadBitmap(IDB_IMAGE3);
	cBmp[4].LoadBitmap(IDB_IMAGE4);
	cBmp[5].LoadBitmap(IDB_IMAGE5);
	cBmp[6].LoadBitmap(IDB_IMAGE6);
	cBmp[7].LoadBitmap(IDB_IMAGE7);
	cBmp[8].LoadBitmap(IDB_IMAGE8);
	cBmp[9].LoadBitmap(IDB_IMAGE9);
	cBmp[10].LoadBitmap(IDB_IMAGE10);
	cBmp[11].LoadBitmap(IDB_IMAGE11);
	cBmp[12].LoadBitmap(IDB_IMAGE12);
	cBmp[13].LoadBitmap(IDB_IMAGE13);
	cBmp[14].LoadBitmap(IDB_IMAGE14);
	cBmp[15].LoadBitmap(IDB_IMAGE15);
	cBmp[16].LoadBitmap(IDB_IMAGE16);
	cBmp[17].LoadBitmap(IDB_IMAGE17);
	cBmp[18].LoadBitmap(IDB_IMAGE18);*/
	
	return TRUE;  // return TRUE unless you set the focus to a control
	              // EXCEPTION: OCX Property Pages should return FALSE
}



void CDesignEditDlg::ButtonPressed(int btn)
{
	// Set the selected button Image
	m_ctrlPageImage.SetBitmap(cBmp[1]);

/*	CButton* pImage ;
	int b ;
	for(b = 0 ; cButPos[b].id > 0 ; b++) {
		// Move the button
		pImage = (CButton*)GetDlgItem(cButPos[b].id);
		pImage->RedrawWindow() ;
	}*/

	CColourFaderDlg dlg;
	dlg.iFaderLineNo = btn ;
	int nResponse = dlg.DoModal();
	if (nResponse == IDOK)
	{
		// TODO: Place code here to handle when the dialog is
		//  dismissed with OK
	}
	else if (nResponse == IDCANCEL)
	{
		// TODO: Place code here to handle when the dialog is
		//  dismissed with Cancel
	}

	// Replace the original image
	m_ctrlPageImage.SetBitmap(cBmp[0]);

/*	for(b = 0 ; cButPos[b].id > 0 ; b++) {
		// Move the button
		pImage = (CButton*)GetDlgItem(cButPos[b].id);
		pImage->RedrawWindow() ;
	}*/

}


void CDesignEditDlg::OnButtonSel1() 
{
	// TODO: Add your control notification handler code here
	TRACE("Button 1\n") ;
	ButtonPressed(1) ;

}

Moak15-Sep-09 23:21

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

15-Sep-09 23:21

Neil Urquhart wrote:
// Make each CButton a child to CDesignEditDlg
pButton->SetParent(this) ;

No, as I said make the buttons child controls of the image. In your code this would probably be pButton->SetParent(pImage) and you do not necessarily need WS_CLIPCHILDREN/WS_CLIPSIBLINGS in this case.

Here a visualisation of how the client-parent hierachy should look like:

dialog
  |_____image
  |       |_____button1 over image
  |       |_____button2 over image
  |       |_____button3 over image, etc
  |_____ other controls

Overlapping controls must not be siblings, hope this makes it more clear.

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Neil Urquhart16-Sep-09 2:53

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

16-Sep-09 2:53

I am afraid this doose not seem to work in that the buttons are displayed but when I click on the overlapped buttons nothing happens. I think the picture control is taking the input and not passing it onto the buttons.

My version that makes the picture control and buttons children of the dialog does work. Requires the WS_CLIPCHILDREN & WS_CLIPSIBLINGS properties also.

This is the code that does not work :

BOOL CDesignEditDlg::OnInitDialog() 
{
	CDialog::OnInitDialog();

	
	// TODO: Add extra initialization here
	CWnd* pImage ;
	WINDOWPLACEMENT wpImage ;
	CRect rect;
	CPoint imgPos ;

	// Set CDesignEditDlg WS_CLIPCHILDREN
	//ModifyStyle(0, WS_CLIPCHILDREN) ;

	// Get the current top left position of the picture control window
	pImage = GetDlgItem(IDC_PAGEIMAGE) ;
	pImage->GetWindowPlacement(&wpImage);
	imgPos.x = wpImage.rcNormalPosition.left ;
	imgPos.y = wpImage.rcNormalPosition.top ;

	// Set picture control WS_CLIPSIBLINGS
	//pImage->ModifyStyle(0, WS_CLIPSIBLINGS);

	// Make picture control child to CDesignEditDlg
	pImage->SetParent(this) ;

	CWnd* pButton ;
	int b ;
	for(b = 0 ; cButPos[b].id > 0 ; b++) {
		// Move the button
		pButton = GetDlgItem(cButPos[b].id);
		pButton->GetWindowRect(rect);
		pButton->MoveWindow(imgPos.x + cButPos[b].x - (rect.Width()/2), imgPos.y + cButPos[b].y, rect.Width(), rect.Height(), TRUE);

		// Make each CButton a child to CDesignEditDlg
		//pButton->SetParent(this) ;
		pButton->SetParent(pImage) ;
	}

This version of the code does work though!!

BOOL CDesignEditDlg::OnInitDialog() 
{
	CDialog::OnInitDialog();

	
	// TODO: Add extra initialization here
	CWnd* pImage ;
	WINDOWPLACEMENT wpImage ;
	CRect rect;
	CPoint imgPos ;

	// Set CDesignEditDlg WS_CLIPCHILDREN
	ModifyStyle(0, WS_CLIPCHILDREN) ;

	// Get the current top left position of the picture control window
	pImage = GetDlgItem(IDC_PAGEIMAGE) ;
	pImage->GetWindowPlacement(&wpImage);
	imgPos.x = wpImage.rcNormalPosition.left ;
	imgPos.y = wpImage.rcNormalPosition.top ;

	// Set picture control WS_CLIPSIBLINGS
	pImage->ModifyStyle(0, WS_CLIPSIBLINGS);

	// Make picture control child to CDesignEditDlg
	pImage->SetParent(this) ;

	CWnd* pButton ;
	int b ;
	for(b = 0 ; cButPos[b].id > 0 ; b++) {
		// Move the button
		pButton = GetDlgItem(cButPos[b].id);
		pButton->GetWindowRect(rect);
		pButton->MoveWindow(imgPos.x + cButPos[b].x - (rect.Width()/2), imgPos.y + cButPos[b].y, rect.Width(), rect.Height(), TRUE);

		// Make each CButton a child to CDesignEditDlg
		pButton->SetParent(this) ;
		//pButton->SetParent(pImage) ;
	}

Moak16-Sep-09 3:19

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

16-Sep-09 3:19

Neil, are you sure the second example works reliable? I wonder because, it does nothing regarding client-parent hierachy, SetParent(this) in a dialog just sets the existing parent again.

If you want the dialog to receive notifications from the buttons use SetOwner(this) additional to SetParent(pImage). Alternatively, let the image control handle the button clicks.

Cheers
/M

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Neil Urquhart16-Sep-09 3:56

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

16-Sep-09 3:56

Second example is definatley the one that works !!

I tried again making buttons SetParent(pImage) and SetOwner(this) and still the buttons don't respond to clicks.

Moak16-Sep-09 4:21

Re: How can I force the redraw of buttons which overlay a picture bitmap in a Dialog

16-Sep-09 4:21

Please try the following: Show your dialog, take another window (e.g. Windows Explorer) and move it over your dialog a couple of times. Does the redrawing work as it should, image and buttons are visible?

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Neil Urquhart16-Sep-09 4:41