Re: /, source code questions - C / C++ / MFC Discussion Boards

Leslie Sanford26-Nov-08 9:00

26-Nov-08 9:00

I've written a custom GUI library for creating GUI's for my VST plugins. I would love to use MFC, but I've never gotten them to play together nicely (long story).

Anyway, the GUI library has come together well, but there are a few anomalies to work out. The one I'm dealing with right now is a problem with the cursor.

In VST, the host asks the plugin to create a child window representing the plugin's UI. It's the host's job to display the window. All of this works well, but what I've noticed is that if I move the cursor from outside my GUI window to inside the window, sometimes the cursor shape doesn't change. For example, it may get stuck with the resizing handle image.

I've noticed that this problem doesn't occur in a standalone app I made with my library. I've made sure when registering the GUI window class that I used the obligatory: ::LoadCursor(instance, IDC_ARROW).

There's way too much code for me to post anything here. So I'm just looking for some general clues.

EDIT: Strange. I changed the code to ::LoadCursor(NULL, IDC_ARROW), and it fixed the problem.

modified on Wednesday, November 26, 2008 3:09 PM

Re: Cursor not changing

CPallini26-Nov-08 9:30

CPallini

26-Nov-08 9:30

Leslie Sanford wrote:
EDIT: Strange. I changed the code to ::LoadCursor(NULL, IDC_ARROW), and it fixed the problem.

Not so strange if you have a look at documentation [^]:

To use one of the predefined cursors, the application must set the hInstance parameter to NULL

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Re: Cursor not changing

Leslie Sanford26-Nov-08 10:06

Leslie Sanford

26-Nov-08 10:06

CPallini wrote:
Not so strange if you have a look at documentation

Yup. I should have checked out the documenation. Having worked with the Windows API this long, I should have realized that simply taking a function at face value and passing it what it appears to want is not always the correct thing to do.

Sorry if that sounds like whining. It's just that these special cases, these gotchas, add up over time to a point of making an API hard to use.

Re: Cursor not changing

CPallini26-Nov-08 10:17

CPallini

26-Nov-08 10:17

Reading the documentation is the best way to avoid headaches, when dealing with Windows API. Big Grin | :-D

<tag>/, source code questions</tag>

ForNow26-Nov-08 6:26

ForNow

26-Nov-08 6:26

Hi,

seems like i just got aome people angry at me by not posting code the right way in the message

Just read up on the tag/pretag so......

My question is do I have to put a start tag / end tag on every line of code that

I post ?????? in addtion when I tag my code do I have to check the ignore HTML box or

not

thankx and sorry

Re: /, source code questions

Maximilien26-Nov-08 6:52

Maximilien

26-Nov-08 6:52

put your code between pre tags.

/// some coed

Re: /, source code questions

jeron126-Nov-08 7:16

jeron1

26-Nov-08 7:16

Maximilien wrote:
/// some coed

Got something else on your mind? Big Grin | :-D

Re: /, source code questions

CPallini26-Nov-08 7:13

CPallini

26-Nov-08 7:13

You should use the code block button or, manually, the <pre> tags, this way:

<code><pre></code>
// code snippet here
<code></pre></code>

Re: /, source code questions

led mike26-Nov-08 7:21

led mike

26-Nov-08 7:21

ForNow wrote:
seems like i just got aome people angry

Angry? We may have had some fun with you but I didn't see anyone getting angry. Did I miss something?

led mike

Re: /, source code questions

CPallini26-Nov-08 7:46

CPallini

26-Nov-08 7:46

led mike wrote:

Angry? We may have had some fun with you but I didn't see anyone getting angry. Did I miss something?

YES

hook for Outlook Express 6

Dr. Kelwin26-Nov-08 5:33

Dr. Kelwin

26-Nov-08 5:33

Hi all!
I implement 2 hooks: for MS Outlook 2003 and for Outlook Express. MS Outlook 2003 interception was implemented on IMAPIAdviseSink. But I have some problems with Outlook Express 6. After research I find library msoe.dll which used by OE 6 and export some MAPI functions (MAPILogon, MAPISendMail, MAPIReadMail etc). I inject custom hook into msoe.dll on MAPILogon, MAPILogoff, MAPISendMail, MAPIReadMail, but I cannot received any notification about call its by OE6. How are other ways for hook send/receive messages from Outlook Express 6? Thanks. Smile | :)

Child window and tab stop

BadJerry26-Nov-08 5:08

BadJerry

26-Nov-08 5:08

Hi I am trying to create a MFC control made out of two edits and a pseudo-tab control... they are all children controls of a CWnd. I want to make sure that when the controls gets the focus through a tab, one of the 2 edit controls gets the focus and if another tab is pressed, that the focus goes to the next control in the parent dialog.
I am aware of WS_TABSTOP ( I use it to create the CWnd) but that des not seem to do the trick... any tips?

Thanks in advance

Re: Child window and tab stop

Code-o-mat26-Nov-08 8:34

Code-o-mat

26-Nov-08 8:34

Do you mean that your control is a CWnd which hosts 2 edits and that tab and is a child window of another window? If so, make your "host" CWnd WS_CONTROLPARENT and also make it WS_TABSTOP. Hope that helps, good luck.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <

Is MFC DLL reentrant?

rp_suman26-Nov-08 3:56

rp_suman

26-Nov-08 3:56

Is the MFC DLL created with option "Regular DLL using shared MFC DLL" is reentrant / thread-safe?

If not, how to create reentrant DLL using VC 2005?

Thanks in advance!!
Suman

--
"Programming is an art that fights back!"

Re: Is MFC DLL reentrant?

Mark Salsbery26-Nov-08 5:04

Mark Salsbery

26-Nov-08 5:04

You have the source code.

I don't recall seeing anything thread safe in the MFC code.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Is MFC DLL reentrant?

rp_suman28-Nov-08 18:36

rp_suman

28-Nov-08 18:36

Hi Mark,

It seems, reentrancy is wholly depend on the code.
Here are some rules for code to be reentrant:
Reentrancy[^]

And the code is as follows, the dll function will give the content of given file name:

<br />
void extern "C" __declspec(dllexport) getFileContent(LPCTSTR strFile, LPCTSTR& lpStrOut)<br />
{	<br />
	CFile pFile;<br />
	pFile.Open(strFile, CFile::modeRead);<br />
	int iLen = pFile.GetLength();<br />
	char *ch = new char[iLen+1];<br />
	pFile.Seek(0, CFile::begin);<br />
	pFile.Read(&ch[0], iLen);			<br />
	ch[iLen] = '\0';<br />
	lpStrOut = ch;<br />
	pFile.Close();<br />
}<br />

The function is reading file content into character array and returns pointer to the content.
As it does not use any static variable, but allocating and returning "new" character array, is it reentrant?

With Thanks & Regards,
Suman

--
"Programming is an art that fights back!"

Re: Is MFC DLL reentrant?

Mark Salsbery28-Nov-08 19:05

Mark Salsbery

28-Nov-08 19:05

As long as all the calls made in the function are reentrant then you're OK.

Additionally, "new" is thread safe.

On a side note, "ch" should be of type TCHAR*, not a char*, since you're using
generic text mappings (the 'T' in LPCTSTR).

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Transparent Window

Aabid26-Nov-08 2:54

Aabid

26-Nov-08 2:54

Hello All,

i am working in VS 6 using VC++ Win32 ::

I made a window using CreateWindowEx API and WNDCLASSEX Structure
with Background Brush as (HOLLOW_BRUSH) and Style as WS_EX_TRANSPARENT...
These 2 things made my window transparent....But the problem is when i maximize other window over my created window, its Background color changes to maximized window, that should not happen .......i always want my window background as desktop.....

Any suggesstion is heartly appreciated

Re: Transparent Window

Ahmed Charfeddine26-Nov-08 3:23

Ahmed Charfeddine

26-Nov-08 3:23

This a "repainting" pbm : there is sort of an asynchrnous notification that needs be handled and but it is not.
WM_ACTIVATE issue ? I do'nt have sufficient facts to reason and tell you.
Good luck.

Re: Transparent Window

Code-o-mat26-Nov-08 4:15

Code-o-mat

26-Nov-08 4:15

You want to make your window a sort of "hole" on the screen that lets you see the desktop all the time? I doubt there's a sane way of doing that, you could try hooking into explorer's process and somehow make the desktop window's part that your window is over being drawn onto your window but i don't much recommend it.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <

Re: Transparent Window

My2Cents30-Nov-08 12:51

My2Cents

30-Nov-08 12:51

Try SetLayeredWindowAttributes

Drag n Drop not working with desktop icon on Win7.

Shashi.Shinde26-Nov-08 2:28

Shashi.Shinde

26-Nov-08 2:28

Hello,

We have an application icon on desktop. If I drag and drop any file / folder to the MyApp desktop icon. Then it works fine on Windows XP and Vista. But, the same process is not working with Windows Ultimate 7. Also it is not getting focus while holding any file / folder on the MyApp desktop icon.

Other functionalities are working fine on all platforms; like doubleclick, rightclick->open file, etc.

Also Win7 can move file / folder using drag and drop functionality.

So request you to suggest me why this is happening and is there any way to overcome this issue?

Thank you.

With regards,

Shashikant

Re: Drag n Drop not working with desktop icon on Win7.

Ahmed Charfeddine26-Nov-08 3:27

Ahmed Charfeddine

26-Nov-08 3:27

Windows Ultimate 7 ?? OMG | :OMG:

¿Quién sabe? alphablending 2 bitmaps

Chesnokov Yuriy26-Nov-08 2:04

Chesnokov Yuriy

26-Nov-08 2:04

There 2 32bpp bitmaps with some images:

bitmap1
bitmap2

and graphics object g1 created from bitmap1

I set individualy alpha values in bitmap2 using LockBits:

C++

Gdiplus::BitmapData bitmapData;
Gdiplus::Status s = pBitmap->LockBits(&Gdiplus::Rect(0, 0, pBitmap->GetWidth(), pBitmap->GetHeight()),
                                      Gdiplus::ImageLockModeWrite | Gdiplus::ImageLockModeRead,
                                      PixelFormat32bppRGB, &bitmapData);
if (s == Gdiplus::Ok) {
        unsigned int* pPixels = (unsigned int *)bitmapData.Scan0;
        for (unsigned int i = 0; i < bitmapData.Height; i++) {
                for (unsigned int j = 0; j < bitmapData.Width; j++) {
                        if (mask(i, j) > 0)
                                pPixels[j] &= 0xFFFFFFFF;
                        else
                                pPixels[j] = 0x00FFFFFF;
                }
                pPixels += bitmapData.Stride / 4;
        }
        pBitmap->UnlockBits(&bitmapData);
}

And then draw it on bitmap1 using g1. But the alpha blending does not happen?

chesnokov

Re: ¿Quién sabe? alphablending 2 bitmaps

Christian Graus26-Nov-08 8:09

Christian Graus

26-Nov-08 8:09

I don't see where you're doing any alpha blending. Alpha blending would mean blending the values of two bitmaps. What are you trying to do ?

Also, have you stepped through the code to see if mask(i,j) is ever > 0 ?

I assume that mask is a method, calling a method for every pixel will really slow your code down.

Christian Graus

Driven to the arms of OSX by Vista.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.