Example of a Clipboard Viewer - Win32 Programmer's Reference

Win32 Programmer's Reference

Home Index About

Custom Search

Example of a Clipboard Viewer

The following example shows a simple clipboard viewer application.

HINSTANCE hinst;

UINT uFormat = (UINT)(-1);

BOOL fAuto = TRUE;

LRESULT APIENTRY MainWndProc(hwnd, uMsg, wParam, lParam)

HWND hwnd;

UINT uMsg;

WPARAM wParam;

LPARAM lParam;

{

static HWND hwndNextViewer;

HDC hdc;

HDC hdcMem;

PAINTSTRUCT ps;

LPPAINTSTRUCT lpps;

RECT rc;

LPRECT lprc;

HGLOBAL hglb;

LPSTR lpstr;

HBITMAP hbm;

HENHMETAFILE hemf;

HWND hwndOwner;

switch (uMsg)

{

case WM_PAINT:

hdc = BeginPaint(hwnd, &ps);

// Branch depending on the clipboard format.

switch (uFormat)

{

case CF_OWNERDISPLAY:

hwndOwner = GetClipboardOwner();

hglb = GlobalAlloc(GMEM_DDESHARE,

sizeof(PAINTSTRUCT));

lpps = GlobalLock(hglb);

memcpy(lpps, &ps, sizeof(PAINTSTRUCT));

GlobalUnlock(hglb);

SendMessage(hwndOwner, WM_PAINTCLIPBOARD,

(WPARAM) hwnd, (LPARAM) hglb);

GlobalFree(hglb);

break;

case CF_BITMAP:

hdcMem = CreateCompatibleDC(hdc);

if (hdcMem != NULL)

{

if (OpenClipboard(hwnd))

{

hbm = (HBITMAP)

GetClipboardData(uFormat);

SelectObject(hdcMem, hbm);

GetClientRect(hwnd, &rc);

BitBlt(hdc, 0, 0, rc.right, rc.bottom,

hdcMem, 0, 0, SRCCOPY);

CloseClipboard();

}

DeleteDC(hdcMem);

}

break;

case CF_TEXT:

if (OpenClipboard(hwnd))

{

hglb = GetClipboardData(uFormat);

lpstr = GlobalLock(hglb);

GetClientRect(hwnd, &rc);

DrawText(hdc, lpstr, -1, &rc, DT_LEFT);

GlobalUnlock(hglb);

CloseClipboard();

}

break;

case CF_ENHMETAFILE:

if (OpenClipboard(hwnd))

{

hemf = GetClipboardData(uFormat);

GetClientRect(hwnd, &rc);

PlayEnhMetaFile(hdc, hemf, &rc);

CloseClipboard();

}

break;

case 0:

GetClientRect(hwnd, &rc);

DrawText(hdc, "The clipboard is empty.", -1,

&rc, DT_CENTER | DT_SINGLELINE |

DT_VCENTER);

break;

default:

GetClientRect(hwnd, &rc);

DrawText(hdc, "Unable to display format.", -1,

&rc, DT_CENTER | DT_SINGLELINE |

DT_VCENTER);

}

EndPaint(hwnd, &ps);

break;

case WM_SIZE:

if (uFormat == CF_OWNERDISPLAY)

{

hwndOwner = GetClipboardOwner();

hglb = GlobalAlloc(GMEM_DDESHARE, sizeof(RECT));

lprc = GlobalLock(hglb);

GetClientRect(hwnd, lprc);

GlobalUnlock(hglb);

SendMessage(hwndOwner, WM_SIZECLIPBOARD,

(WPARAM) hwnd, (LPARAM) hglb);

GlobalFree(hglb);

}

break;

case WM_CREATE:

// Add the window to the clipboard viewer chain.

hwndNextViewer = SetClipboardViewer(hwnd);

break;

case WM_CHANGECBCHAIN:

// If the next window is closing, repair the chain.

if ((HWND) wParam == hwndNextViewer)

hwndNextViewer = (HWND) lParam;

// Otherwise, pass the message to the next link.

else if (hwndNextViewer != NULL)

SendMessage(hwndNextViewer, uMsg, wParam, lParam);

break;

case WM_DESTROY:

ChangeClipboardChain(hwnd, hwndNextViewer);

PostQuitMessage(0);

break;

case WM_DRAWCLIPBOARD: // clipboard contents changed.

// Update the window by using Auto clipboard format.

SetAutoView(hwnd);

// Pass the message to the next window in clipboard

// viewer chain.

SendMessage(hwndNextViewer, uMsg, wParam, lParam);

break;

case WM_INITMENUPOPUP:

if (!HIWORD(lParam))

InitMenu(hwnd, (HMENU) wParam);

break;

case WM_COMMAND:

switch (LOWORD(wParam))

{

case IDM_EXIT:

DestroyWindow(hwnd);

break;

case IDM_AUTO:

SetAutoView(hwnd);

break;

default:

fAuto = FALSE;

uFormat = LOWORD(wParam);

InvalidateRect(hwnd, NULL, TRUE);

}

break;

default:

return DefWindowProc(hwnd, uMsg, wParam, lParam);

}

return (LRESULT) NULL;

}

oid WINAPI SetAutoView(HWND hwnd)

{

static UINT auPriorityList[] = {

CF_OWNERDISPLAY,

CF_TEXT,

CF_ENHMETAFILE,

CF_BITMAP

};

uFormat = GetPriorityClipboardFormat(auPriorityList, 4);

fAuto = TRUE;

InvalidateRect(hwnd, NULL, TRUE);

UpdateWindow(hwnd);

}

oid WINAPI InitMenu(HWND hwnd, HMENU hmenu)

{

UINT uFormat;

char szFormatName[80];

LPCSTR lpFormatName;

UINT fuFlags;

UINT idMenuItem;

// If a menu is not the display menu, no initialization is necessary.

if (GetMenuItemID(hmenu, 0) != IDM_AUTO)

return;

// Delete all menu items except the first.

while (GetMenuItemCount(hmenu) > 1)

DeleteMenu(hmenu, 1, MF_BYPOSITION);

// Check or uncheck the Auto menu item.

fuFlags = fAuto ? MF_BYCOMMAND | MF_CHECKED :

MF_BYCOMMAND | MF_UNCHECKED;

CheckMenuItem(hmenu, IDM_AUTO, fuFlags);

// If there are no clipboard formats, return.

if (CountClipboardFormats() == 0)

return;

// Open the clipboard.

if (!OpenClipboard(hwnd))

return;

// Add a separator and then a menu item for each format.

AppendMenu(hmenu, MF_SEPARATOR, 0, NULL);

uFormat = EnumClipboardFormats(0);

while (uFormat)

{

// Call an application-defined function to get the name

// of the clipboard format.

lpFormatName = GetPredefinedClipboardFormatName(uFormat);

// For registered formats, get the registered name.

if (lpFormatName == NULL)

{

if (GetClipboardFormatName(uFormat, szFormatName,

sizeof(szFormatName)))

lpFormatName = szFormatName;

else

lpFormatName = "(unknown)";

}

// Add a menu item for the format. For displayable

// formats, use the format ID for the menu ID.

if (IsDisplayableFormat(uFormat))

{

fuFlags = MF_STRING;

idMenuItem = uFormat;

}

else

{

fuFlags = MF_STRING | MF_GRAYED;

idMenuItem = 0;

}

AppendMenu(hmenu, fuFlags, idMenuItem, lpFormatName);

uFormat = EnumClipboardFormats(uFormat);

}

CloseClipboard();

}

BOOL WINAPI IsDisplayableFormat(UINT uFormat)

{

switch (uFormat)

{

case CF_OWNERDISPLAY:

case CF_TEXT:

case CF_ENHMETAFILE:

case CF_BITMAP:

return TRUE;

}

return FALSE;

}

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network