Slide Show Wallpapers (at Windows Desktop - New)

Let say there is a galactica-wallpaper.jpg at My Documents folder. We can change desktop background image using SystemParametersInfoW function of User32. (tested on Windows 11 Pro 22H2).

Module TestMe {
	module changeWallPaper (strImagePath$){
		declare SystemParametersInfo lib "User32.SystemParametersInfoW" {Long action, Long Param, &pvParam$, Long fWinIni}
		const SPI_SETDESKWALLPAPER = 20&
		const SPIF_SENDWININICHANGE = &H2
		const SPIF_UPDATEINIFILE = &H1
		Call void SystemParametersInfo(SPI_SETDESKWALLPAPER, 0&, &strImagePath$, SPIF_UPDATEINIFILE Or SPIF_SENDWININICHANGE)
	}
	// 0x5 for Documents Folder - see: help path$()
	changeWallPaper path$(0x5)+"galactica-wallpaper.jpg"
}
TestMe

Now what if we have some jpg files at My Documents and we wish to cbange desktop background every half minute ?

This is the slide show. We get file names and put them to menu, without showing menu. We just read the menu items one by one.

Module TestMe {
	module changeWallPaper (strImagePath$){
		declare SystemParametersInfo lib "User32.SystemParametersInfoW" {Long action, Long Param, &pvParam$, Long fWinIni}
		const SPI_SETDESKWALLPAPER = 20&
		const SPIF_SENDWININICHANGE = &H2
		const SPIF_UPDATEINIFILE = &H1
		Call void SystemParametersInfo(SPI_SETDESKWALLPAPER, 0&, &strImagePath$, SPIF_UPDATEINIFILE Or SPIF_SENDWININICHANGE)
	}
	// 0x5 for My Documents Folder - see: help path$()
	Title "SlideShow", 0
	Try {
		Repeat
			dir path$(0x5)
			menu
			files + "jpg"
			dir user
			if menuitems>0 then
				for i=1 to menuitems
					try {
						changeWallPaper path$(0x5)+menu$(i)+".jpg"
					}
					wait 30000
				next
			end if
		Until menuitems=0
	}
	Title "M2000", 1
}
TestMe

And the best of all (using 0% processor for most time):

Module TestMe {
	module changeWallPaper (strImagePath$){
		declare SystemParametersInfo lib "User32.SystemParametersInfoW" {Long action, Long Param, &pvParam$, Long fWinIni}
		const SPI_SETDESKWALLPAPER = 20&
		const SPIF_SENDWININICHANGE = &H2
		const SPIF_UPDATEINIFILE = &H1
		Call void SystemParametersInfo(SPI_SETDESKWALLPAPER, 0&, &strImagePath$, SPIF_UPDATEINIFILE Or SPIF_SENDWININICHANGE)
	}
	// 0x5 for My Documents Folder - see: help path$()
	flush
	Title "SlideShow", 0
	Try {
		every 30000 {
			if empty  then
				dir path$(0x5)
				menu
				files + "jpg"
				dir user			
				if menuitems>0 then
					for i=1 to menuitems
						try {
							data path$(0x5)+menu$(i)+".jpg"
						}
					next
				end if
			end if
			if not empty then changeWallPaper
		}
	}
	Title "M2000", 1
}
TestMe

And final, using a mutex to run only once and without using a window at taskbar (running like a service).  When the first (which create the mutex) exit delete the mutex. (We have to clode by task manager, or automatic close at shutdown of windows.

Module TestMe {
	Declare m Mutex
	boolean pass
	try {
		method m, "CREATE", "Global\SLIDE10101001"
		pass=true
	}
	if pass else exit
	module changeWallPaper (strImagePath$){
		declare SystemParametersInfo lib "User32.SystemParametersInfoW" {Long action, Long Param, &pvParam$, Long fWinIni}
		const SPI_SETDESKWALLPAPER = 20&
		const SPIF_SENDWININICHANGE = &H2
		const SPIF_UPDATEINIFILE = &H1
		Call void SystemParametersInfo(SPI_SETDESKWALLPAPER, 0&, &strImagePath$, SPIF_UPDATEINIFILE Or SPIF_SENDWININICHANGE)
	}
	// 0x5 for My Documents Folder - see: help path$()
	flush
	Title "", 0
	Try {
		every 30000 {
			if empty  then
				dir path$(0x5)
				menu
				files + "jpg"
				dir user			
				if menuitems>0 then
					for i=1 to menuitems
						try {
							data path$(0x5)+menu$(i)+".jpg"
						}
					next
				end if
			end if
			if not empty then changeWallPaper
		}
	}
	Title "M2000", 1
}
TestMe: End