1. Desktop Window Manager
Mindaugas Butkus
IV kursas, PS2 grupė

2. Features Glass window frames; 3-D window transition animation;
Windows Flip and Windows Flip3D;
Live taskbar thumbnails;
High resolution support.

3. How to use it #include <Dwmapi.h> Link with Dwmapi.lib
DLL: Dwmapi.dll

4. Retrieving the Colorization Information
HRESULT WINAPI DwmGetColorizationColor( _Out_ DWORD *pcrColorization, _Out_ BOOL *pfOpaqueBlend );
pcrColorization [out]
A pointer to a value that, when this function returns successfully, receives the current color used for glass composition. The color format of the value is 0xAARRGGBB.
pfOpaqueBlend [out]
A pointer to a value that, when this functions returns successfully, indicates whether the color is an opaque blend. TRUE if the color is an opaque blend; otherwise, FALSE.

5. Retrieving the Colorization Information
... case WM_DWMCOLORIZATIONCOLORCHANGED: { g_currColor = (DWORD)wParam; g_opacityblend = (BOOL)lParam; } break; ...

6. Controlling Non-Client Region Rendering
HRESULT WINAPI DwmGetWindowAttribute( HWND hwnd, DWORD dwAttribute, _Out_ PVOID pvAttribute, DWORD cbAtribute);
hwnd – the handle to the window from which the attribute data is retrieved.
dwAttribute – the attribute to retrieve, specified as a DWMWINDOWATTRIBUTE value.
pvAttribute[out] – a pointer to a value that, when this function returns successfully, received the current value of the attribute. The type depends on the dwAttribute parameter.
cbAttribute – the size of the DWMWINDOWATTRIBUTE value being retrieved. Depends on pvAttribute.

7. DWMWINDOWATTRIBUTE enum
typedef enum _DWMWINDOWATTRIBUTE { DWMWA_NCRENDERING_ENABLED = 1, DWMWA_NCRENDERING_POLICY, DWMWA_TRANSITIONS_FORCEDISABLED, DWMWA_ALLOW_NCPAINT, DWMWA_CAPTION_BUTTON_BOUNDS, DWMWA_NONCLIENT_RTL_LAYOUT, DWMWA_FORCE_ICONIC_REPRESENTATION, DWMWA_FLIP3D_POLICY, DWMWA_EXTENDED_FRAME_BOUNDS, DWMWA_HAS_ICONIC_BITMAP, DWMWA_DISALLOW_PEEK, DWMWA_EXCLUDED_FROM_PEEK, DWMWA_CLOAK, DWMWA_CLOAKED, DWMWA_FREEZE_REPRESENTATION, DWMWA_LAST } DWMWINDOWATTRIBUTE;

8. DwmGetWindowAttribute example
HRESULT IsNCRenderingEnabled(HWND hwnd, BOOL enabled) { HRESULT hr = S_OK; hr = DwmGetWindowAttribute(hwnd, DWMWA_NCRENDERING_ENABLED, &enabled, sizeof(BOOL)); if (SUCCEEDED(hr)) { // Use the retrieved information } return hr; }

9. Controlling Non-Client Region Rendering
HRESULT WINAPI DwmSetWindowAttribute( HWND hwnd, DWORD dwAttribute, _In_ LPCVOID pvAttribute, DWORD cbAttribute);
hwnd – the handle to the window that will receive the attribute.
dwAttribute – a single DWMWINDOWATTRIBUTE flag to apply to the window.
pvAttribute[in] – a pointer to the value of the attribute specified in the dwAttribute parameter.
cbAttribute – the size, in bytes, of the value type pointed to by the pvAttribute parameter.

10. DwmSetWindowAttribute example
HRESULT DisableNCRendering(HWND hwnd) { HRESULT hr = S_OK; DWMNCRENDERINGPOLICY ncrp = DWMNCRP_DISABLED; // Disable non-client area rendering on the window hr = DwmSetWindowAttribute(hwnd, DWMWA_NCRENDERING_POLICY, &ncrp, sizeof(ncrp)); if (SUCCEEDED(hr)) { // Do work here } return hr; }

11. DwmSetWindowAttribute example
ENABLED non-client area rendering
Disabled non-client area rendering

12. Adding Blur to a Specific Region of the Client Area
HRESULT WINAPI DwmEnableBlurBehindWindow( HWND hWnd, _In_ const DWM_BLURBEHIND *pBlurBehind);
hWnd – The handle to the window on which the blur behind data is applied.
pBlurBehind – A pointer to a DWM_BLURBEHIND structure that provides blur behind data.

13. DWM_BLURBEHIND struct
typedef struct _DWM_BLURBEHIND { DWORD dwFlags; BOOL fEnable; HRGN hRgnBlur; BOOL fTransitionOnMaximized; } DWM_BLURBEHIND, *PDWM_BLURBEHIND;
dwFlags – A bitwise combination of DWM Blur Behind constant values (DWM_BB_ENABLE, DWM_BB_BLURREGION, DWM_BB_TRANSITIONONMAXIMIZED) that indicates which of the members of this structure have been set.
fEnable – TRUE to register the window handle to DWM blur behind; FALSE to unregister the window handle from DWM blur behind.
hRgnBlur – The region within the client area where the blur behind will be applied. A NULL value will apply the blur behind the entire client area.
fTransitionOnMaximized – TRUE if the window's colorization should transition to match the maximized windows; otherwise, FALSE.

14. DwmEnableBlurBehindWindow example
HRESULT EnableBlurBehind(HWND hwnd) { HRESULT hr = S_OK; // Create and populate the Blur Behind structure DWM_BLURBEHIND bb = {0}; // Enable Blur Behind and apply to the entire client area bb.dwFlags = DWM_BB_ENABLE; bb.fEnable = true; bb.hRgnBlur = NULL; // Apply Blur Behind hr = DwmEnableBlurBehindWindow(hwnd, &bb); if (SUCCEEDED(hr)) { // } return hr; }

15. DwmEnableBlurBehindWindow example

16. Extending the Window Frame into the Client Area
HRESULT WINAPI DwmExtendFrameIntoClientArea( HWND hWnd, _In_ const MARGINS *pMarInset);
hWnd – The handle to the window in which the frame will be extended into the client area.
pMarInset – A pointer to a MARGINS structure that describes the margins to use when extending the frame into the client area.
typedef struct _MARGINS { int cxLeftWidth; int cxRightWidth; int cyTopHeight; int cyBottomHeight; } MARGINS, *PMARGINS;

17. ExtendIntoClientBottom example
HRESULT ExtendIntoClientBottom(HWND hwnd) { HRESULT hr = S_OK; // Set the margins, extending the bottom margin MARGINS margins = {0,0,0,25}; // Extend the frame on the bottom of the client area hr = DwmExtendFrameIntoClientArea(hwnd,&margins); if (SUCCEEDED(hr)) { // } return hr; }

18. ExtendIntoClientBottom example

19. “Sheet of glass” effect
HRESULT ExtendIntoClientAll(HWND hwnd) { HRESULT hr = S_OK; // Negative margins have special meaning to DwmExtendFrameIntoClientArea // Negative margins create the "sheet of glass" effect, where the client // area is rendered as a solid surface without a window border MARGINS margins = {-1}; // Extend the frame across the whole window hr = DwmExtendFrameIntoClientArea(hwnd,&margins); if (SUCCEEDED(hr)) { // } return hr; }

20. “Sheet of glass” effect

21. Live taskbar thumbnails

22. Live taskbar thumbnails
HRESULT WINAPI DwmRegisterThumbnail( HWND hwndDestination, HWND hwndSource, _Out_ PHTHUMBNAIL phThumbnailId);
hwndDestination – The handle to the window that will use the DWM thumbnail. Setting the destination window handle to anything other than a top-level window type will result in a return value of E_INVALIDARG.
hwndSource – The handle to the window to use as the thumbnail source. Setting the source window handle to anything other than a top-level window type will result in a return value of E_INVALIDARG.
phThumbnailId – A pointer to a handle that, when this function returns successfully, represents the registration of the DWM thumbnail.

23. Live taskbar thumbnails
HRESULT WINAPI DwmUpdateThumbnailProperties( HTHUMBNAIL hThumbnailId, _In_ const DWM_THUMBNAIL_PROPERTIES *ptnProperties);
hThumbnailId – The handle to the DWM thumbnail to be updated. Null or invalid thumbnails, as well as thumbnails owned by other processes will result in a return value of E_INVALIDARG.
ptnProperties – A pointer to a DWM_THUMBNAIL_PROPERTIES structure that contains the new thumbnail properties.

24. DWM_THUMBNAIL_PROPERTIES struct
typedef struct _DWM_THUMBNAIL_PROPERTIES { DWORD dwFlags; RECT rcDestination; RECT rcSource; BYTE opacity; BOOL fVisible; BOOL fSourceClientAreaOnly; } DWM_THUMBNAIL_PROPERTIES, *PDWM_THUMBNAIL_PROPERTIES;
dwFlags – A bitwise combination of DWM thumbnail constant values (DWM_TNP_RECTDESTINATION, DWM_TNP_RECTSOURCE, DWM_TNP_OPACITY, DWM_TNP_VISIBLE, DWM_TNP_SOURCECLIENTAREAONLY) that indicates which members of this structure are set.

25. DWM_THUMBNAIL_PROPERTIES struct
rcDestination – The area in the destination window where the thumbnail will be rendered.
rcSource – The region of the source window to use as the thumbnail. By default, the entire window is used as the thumbnail.
opacity – The opacity with which to render the thumbnail. 0 is fully transparent while 255 is fully opaque. The default value is 255.
fVisible – TRUE to make the thumbnail visible; otherwise, FALSE. The default is FALSE.
fSourceClientAreaOnly – TRUE to use only the thumbnail source's client area; otherwise, FALSE. The default is FALSE.

26. Live taskbar thumbnails
HRESULT WINAPI DwmQueryThumbnailSourceSize( HTHUMBNAIL hThumbnail, _Out_ PSIZE pSize);
hThumbnail – A handle to the thumbnail to retrieve the source window size from.
pSize – A pointer to a SIZE structure that, when this function returns successfully, receives the size of the source thumbnail.

27. Live taskbar thumbnails
HRESULT WINAPI DwmUnregisterThumbnail( HTHUMBNAIL hThumbnailId);
hThumbnailId – The handle to the thumbnail relationship to be removed. Null or non-existent handles will result in a return value of E_INVALIDARG.

28. Live taskbar thumbnails example
HRESULT hr = S_OK; HTHUMBNAIL thumbnail = NULL; // Register the thumbnail hr = DwmRegisterThumbnail(hwnd, FindWindow(_T("Progman"), NULL), &thumbnail); if (SUCCEEDED(hr)) { // Specify the destination rectangle size RECT dest = {0,50,100,150}; // Set the thumbnail properties for use DWM_THUMBNAIL_PROPERTIES dskThumbProps; dskThumbProps.dwFlags = DWM_TNP_SOURCECLIENTAREAONLY | DWM_TNP_VISIBLE | DWM_TNP_OPACITY | DWM_TNP_RECTDESTINATION; dskThumbProps.fSourceClientAreaOnly = FALSE; dskThumbProps.fVisible = TRUE; dskThumbProps.opacity = (255 * 70)/100; dskThumbProps.rcDestination = dest; // Display the thumbnail hr = DwmUpdateThumbnailProperties(thumbnail,&dskThumbProps); if (SUCCEEDED(hr)) { // } } return hr;

29. DWM usage examples

30. DWM usage examples

31. Sources