AnimateWindow function Advanced GDI routines

Unit

acGraphics

Declaration

function AnimateWindow(

hWnd: HWND;     // handle to window

dwTime: DWORD;  // duration of animation

dwFlags: DWORD  // animation type

): BOOL;

Description
The AnimateWindow function enables you to produce special effects when showing or hiding windows. There are three types of animation: roll, slide, and alpha-blended fade.

Parameters

hwnd

Handle to the window to animate. The calling thread must own this window.

dwTime

Specifies how long it takes to play the animation, in milliseconds. Typically, an animation takes 200 milliseconds to play.

dwFlags

Specifies the type of animation. This parameter can be one or more of the following values.

Value   Description

AW_SLIDE

Uses slide animation. By default, roll animation is used. This flag is ignored when used with AW_CENTER.

AW_ACTIVATE

Activates the window. Do not use this value with AW_HIDE.

AW_BLEND

Uses a fade effect. This flag can be used only if hwnd is a top-level window. This effect works on Win2000 or later.

AW_HIDE

Hides the window. By default, the window is shown.

AW_CENTER

Makes the window appear to collapse inward if AW_HIDE is used or expand outward if the AW_HIDE is not used.

AW_HOR_POSITIVE

Animates the window from left to right. This flag can be used with roll or slide animation. It is ignored when used with AW_CENTER or AW_BLEND.

AW_HOR_NEGATIVE

Animates the window from right to left. This flag can be used with roll or slide animation. It is ignored when used with AW_CENTER or AW_BLEND.

AW_VER_POSITIVE

Animates the window from top to bottom. This flag can be used with roll or slide animation. It is ignored when used with AW_CENTER or AW_BLEND.

AW_VER_NEGATIVE

Animates the window from bottom to top. This flag can be used with roll or slide animation. It is ignored when used with AW_CENTER or AW_BLEND.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. The function will fail in the following situations:

·

The window uses the window region.

·

The window is already visible and you are trying to show the window.

·

The window is already hidden and you are trying to hide the window.

To get extended error information, call the GetLastError function.

Remarks

You can combine AW_HOR_POSITIVE or AW_HOR_NEGATIVE with AW_VER_POSITIVE or AW_VER_NEGATIVE to animate a window diagonally.

The window procedures for the window and its child windows may need to handle any WM_PRINT or WM_PRINTCLIENT messages. Dialog boxes, controls, and common controls already handle WM_PRINTCLIENT. The default window procedure already handles WM_PRINT.

Requirements

Windows NT/2000: Requires Windows 2000 or later.

Windows 95/98: Requires Windows 98 or later.

If you call this function on Win95, or on Win98 with AW_BLEND parameter — nothing happends.

Example

procedure TForm1.FormShow(Sender: TObject);

var

I: Integer;

begin

AnimateWindow(Handle, 300, AW_HOR_POSITIVE + AW_VER_POSITIVE + AW_SLIDE + AW_ACTIVATE);

end;

See also

acAnimateWindow function and acWin2kEffects component.