[RESOLVED] Custom Control

Hi,
I'm trying to make a custom control to make a message balloon appear when a Cedit is focused. I know there are some classes on the internet but i'd really like to make one by myself. The problem i got is when i call the function Create(), there is no error, but nothing appear and onPaint is never called. If i use the resource editor, it works... Note that my main dialog is a dialog with a bitmap painted on it and have the shape of the bitmap.

myCtrl.cpp

Code:

---

// BalloonMessage.cpp : implementation file
//

#include "stdafx.h"
#include "TransparentDialog.h"
#include "BalloonMessage.h"

#define BALLONMESSAGE_CLASSNAME    _T("MFCBalloonMessage")

// CBalloonMessage

IMPLEMENT_DYNAMIC(CBalloonMessage, CWnd)

CBalloonMessage::CBalloonMessage()
{
        RegisterWindowClass();
}

CBalloonMessage::~CBalloonMessage()
{
}


BEGIN_MESSAGE_MAP(CBalloonMessage, CWnd)
        ON_WM_PAINT()
END_MESSAGE_MAP()



// CBalloonMessage message handlers



void CBalloonMessage::OnPaint()
{
        CPaintDC dc(this); // device context for painting
        // TODO: Add your message handler code here
        // Do not call CWnd::OnPaint() for painting messages
        dc.TextOut(0,0,"test");
}

BOOL CBalloonMessage::RegisterWindowClass(void)
{
        WNDCLASS wndcls;
    HINSTANCE hInst = AfxGetInstanceHandle();

        if (!(::GetClassInfo(hInst, BALLONMESSAGE_CLASSNAME, &wndcls)))
    {
        // otherwise we need to register a new class
        wndcls.style            = CS_DBLCLKS | CS_HREDRAW | CS_VREDRAW;
        wndcls.lpfnWndProc      = ::DefWindowProc;
        wndcls.cbClsExtra      = wndcls.cbWndExtra = 0;
        wndcls.hInstance        = hInst;
        wndcls.hIcon            = NULL;
        wndcls.hCursor          = AfxGetApp()->LoadStandardCursor(IDC_ARROW);
        wndcls.hbrBackground    = (HBRUSH) (COLOR_3DFACE + 1);
        wndcls.lpszMenuName    = NULL;
        wndcls.lpszClassName    = BALLONMESSAGE_CLASSNAME;

        if (!AfxRegisterClass(&wndcls))
        {
            AfxThrowResourceException();
            return FALSE;
        }
    }

    return TRUE;
}

BOOL CBalloonMessage::Create(LPCTSTR lpszClassName, LPCTSTR lpszWindowName, DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT nID, CCreateContext* pContext)
{
        // TODO: Add your specialized code here and/or call the base class

        return CWnd::Create(BALLONMESSAGE_CLASSNAME, lpszWindowName, dwStyle, rect, pParentWnd, nID, pContext);
}

void CBalloonMessage::PreSubclassWindow()
{
        // TODO: Add your specialized code here and/or call the base class

        CWnd::PreSubclassWindow();
}

void CBalloonMessage::PostNcDestroy()
{
        // TODO: Add your specialized code here and/or call the base class

        CWnd::PostNcDestroy();
}

---

myCtrl.h

Code:

---

#pragma once


// CBalloonMessage

class CBalloonMessage : public CWnd
{
        DECLARE_DYNAMIC(CBalloonMessage)

public:
        CBalloonMessage();
        virtual ~CBalloonMessage();

protected:
        DECLARE_MESSAGE_MAP()
public:
        afx_msg void OnPaint();
public:
        BOOL RegisterWindowClass(void);
public:
        virtual BOOL Create(LPCTSTR lpszClassName, LPCTSTR lpszWindowName, DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT nID, CCreateContext* pContext = NULL);
protected:
        virtual void PreSubclassWindow();
        virtual void PostNcDestroy();
};

---

the way i change the shape of my dialog :

Code:

---


CDialog::OnSize(nType, cx, cy);
        // Load the image
        m_hBitmap = (HBITMAP)LoadImage(GetModuleHandle(NULL), "palace.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
        if (m_hBitmap == NULL)
        {
                MessageBox("Error loading bitmap");
                return;
        }
        //Get information about the bitmap..
        GetObject(m_hBitmap, sizeof(m_Bitmap), &m_Bitmap);        // Get info about the bitmap
        // Put the bitmap into a memory device context
        CPaintDC dc(this);
        //get a memory dc object
        CDC dcMem;
        //create a compatible dc
        dcMem.CreateCompatibleDC(&dc);        // Select the bitmap into the in-memory DC
        //Select the bitmap into the dc
        CBitmap* pOldBitmap = dcMem.SelectObject(CBitmap::FromHandle(m_hBitmap));
        //Create a couple of region objects.
        CRgn crRgn, crRgnTmp;
        //create an empty region
        crRgn.CreateRectRgn(0, 0, 0, 0);
        //Create a region from a bitmap with transparency colour of Purple
        COLORREF crTransparent = TRANSPARENTCOLOR;       
        int iX = 0;
        int iY = 0;
        for (iY = 0; iY < m_Bitmap.bmHeight; iY++)
        {
                do
                {
                        //skip over transparent pixels at start of lines.
                        while (iX <= m_Bitmap.bmWidth && dcMem.GetPixel(iX, iY) == crTransparent)
                                iX++;
                        //remember this pixel
                        int iLeftX = iX;
                        //now find first non transparent pixel
                        while (iX <= m_Bitmap.bmWidth && dcMem.GetPixel(iX, iY) != crTransparent)
                                ++iX;
                        //create a temp region on this info
                        crRgnTmp.CreateRectRgn(iLeftX, iY, iX, iY+1);
                        //combine into main region.
                        crRgn.CombineRgn(&crRgn, &crRgnTmp, RGN_OR);
                        //delete the temp region for next pass (otherwise you'll get an ASSERT)
                        crRgnTmp.DeleteObject();
                }while(iX < m_Bitmap.bmWidth);
                iX = 0;
        }
        //Centre it on current desktop
        SetWindowRgn(crRgn, TRUE);
        iX = (GetSystemMetrics(SM_CXSCREEN)) / 2 - (m_Bitmap.bmWidth / 2);
        iY = (GetSystemMetrics(SM_CYSCREEN)) / 2 - (m_Bitmap.bmHeight / 2);
        SetWindowPos(&wndTopMost, iX, iY, m_Bitmap.bmWidth, m_Bitmap.bmHeight, NULL);

        // Free resources.
        dcMem.SelectObject(pOldBitmap);        // Put the original bitmap back (prevents memory leaks)
        dcMem.DeleteDC();
        crRgn.DeleteObject();

---

Following the call to create try calling the ShowWindow(SW_SHOW) function for your custom control.

Check to see is the WS_VISIBLE attribute is set in the style parameter.

i tried in my onInitDialog() of my main dialog:

Code:

---

CBalloonMessage bm;
        bm.Create(NULL, "", WS_VISIBLE, CRect(100,100,200,200), this, 45612);
        bm.ShowWindow(SW_SHOW);

---

Still not working :(

If you are looking for Balloon Tool tips, windows already has them for you. Look at this link.

That's great but i'd really like to find the problem with my class.
I tried the code in the linkand no balloon tip appear. :(:(:(

A Tracking Tooltip sounds like what you're asking for.

in my output window in debug i have this message:

Warning: calling DestroyWindow in CWnd::~CWnd; OnDestroy or PostNcDestroy in derived class will not be called.

maybe it has something to do with my problem?

Nah that is not the problem. Could you attach your source here so we can try.

here's a project that i use to test my controll.
Note that for the moment the only this it should do is print some texe to the screen.
Thanks in advance

The problem with code is nothing but the fact that you created a local 'CBalloonMessage' object which would get destroyed when control went out of scope. So simply create an object in the heap by using new operator on 'CBalloonMessage' object.

Thanks a lot!!!
You saved me from going crazy :P

And also thank for your fast answer

Are there any tool tip example projects out there? I would like to add tool tips to buttons on some of my projects.



TIA.

Oh Yeah one good example is CButtonST in Code Project as far as know.