How to make a text scrooling - Text ticker

Question

Hi All,
I have  written this piece of code.

HWND hTaskBar = FindWindow(TEXT(

"HHTaskBar"),NULL);

RECT rect;

 

 

//Retrieve the client area coordinates...

GetWindowRect(hWnd,&rect);

 

HDC hWndDC = GetWindowDC(hWnd);

 

HDC hMemDc = CreateCompatibleDC(hWndDC);

HBITMAP hBitMap = CreateCompatibleBitmap(hWndDC,rect.right,rect.bottom - rect.top);

 

HBITMAP hOldBitmap = (HBITMAP)SelectObject(hMemDc,hBitMap);

PatBlt(hMemDc,rect.left,rect.top,rect.right,rect.bottom,WHITENESS);

 

DrawText(hMemDc,TEXT(

"Phone Incoming Call"),19,&rect,DT_RIGHT|DT_SINGLELINE);

 

BitBlt(hWndDC,rect.left,rect.top,rect.right,rect.bottom,hMemDc,0,0,SRCCOPY);

 

 

 

DeleteObject(SelectObject(hMemDc,hOldBitmap));

DeleteDC(hMemDc);

ReleaseDC(hWnd,hWndDC);

The above code will display a bitmap on the title bar of the homescreen with the text "Phone Incoming Call"
How do i make it scrolling from right to left like a text ticker...Give me any code ...


Thanks,
Chakri

Answer 1

To create a scrolling "text ticker" you must set up a timer that will fire your paint routine. Every time you paint, the code must shift the text RECT left coordinate by subtracting a fixed value (say 4). The code must also consider the full string width in pixels (you can use DT_CALCRECT on the DrawText call) so that it paints a second string to the right whenever the first starts displaying its right edge, so you get the following effect:

Incoming phone call...   Incom ing phone call...

Bold is visible.

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João Paulo Figueira (Device Application Development MVP)

Answer 2

Hello João Paulo Figueira ,

I am begineer to windows programming. I am working on text ticker application on win CE platform. Can you post some sample code for scrolling text like a ticker without flickering. Thank you.

Regards
Kalyani

Answer 3

 

case WM_CREATE:

SetTimer(hWnd,ID_TICK1,150,NULL);

 

break;

case

break;

case

 

WM_PAINT:

{

hdc = BeginPaint(hWnd, &ps);

 

// TODO: Add any drawing code here...

 

//Move the window to the upper of the client area..

 

HWND hTaskBar = FindWindow(TEXT(

"HHTaskBar"),NULL);

RECT rect;

 

 

//Retrieve the client area coordinates...

GetWindowRect(hWnd,&rect);

 

HDC hWndDC = GetWindowDC(hWnd);

 

HDC hMemDc = CreateCompatibleDC(hWndDC);

HBITMAP hBitMap = CreateCompatibleBitmap(hWndDC,rect.right,rect.bottom - rect.top);

 

HBITMAP hOldBitmap = (HBITMAP)SelectObject(hMemDc,hBitMap);

PatBlt(hMemDc,rect.left,rect.top,rect.right,rect.bottom,WHITENESS);

SetBkMode( hMemDc , TRANSPARENT );

 

 

rect.left = GetTickerPosition(hdc);

 

DrawText(hMemDc,szText,-1,&rect,DT_LEFT);

 

BitBlt(hWndDC,rect.left,rect.top,rect.right,rect.bottom,hMemDc,0,0,SRCCOPY);

 

 

 

DeleteObject(SelectObject(hMemDc,hOldBitmap));

DeleteDC(hMemDc);

ReleaseDC(hWnd,hWndDC);

 

EndPaint(hWnd, &ps);

}

 

break;

 

case WM_TIMER:

{

 

if(wParam == ID_TICK1)

{

RECT rect;

 

//Retrieve the client area coordinates...

GetClientRect(hWnd,&rect);

InvalidateRect(hWnd,&rect,TRUE);

}

}

 

break;

int

 

GetTickerPosition(HDC hdc)

{

iPos = iPos - 3;

 

SIZE size;

GetTextExtentExPoint(hdc,szText,_tcslen(szText),NULL,NULL,NULL,&size);

 

if(iPos < -62)

iPos = GetSystemMetrics(SM_CXSCREEN) - size.cx;

 

return iPos;

 

}

Answer 4

You can find an implementation of a text ticker here .

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João Paulo Figueira (Device Application Development MVP)