Window transparant

[Sver]

' Set the Variables
   WS.EX.LAYERED = 524288 ' WS_EX_LAYERED Unrecognized Windows constant
   ColorRef = 0 ' ColorRef set to black
   bAlpha = 255 ' Degree of opacity (0 - 255)ignored in this instance
   LWA.COLORKEY = 1 ' LWA_COLORKEY Unrecognized Windows constant
   dwFLAGS = LWA.COLORKEY ' Action is colorRef is transparent color
   Nomainwin

   WindowWidth = 600
   WindowHeight = 400

   UpperLeftX = int((DisplayWidth-WindowWidth)/2)
   UpperLeftY = int((DisplayHeight-WindowHeight)/2)

   Graphicbox #main.gfb, 0,0,600,400

   Stylebits #main, 0, 0, WS.EX.LAYERED, 0
   Open "Transparent Window" for window as #main

   #main, "Trapclose EndDemo"
   hMain = hWnd(#main)

   Call SetLayeredWindowAttributes, hMain, ColorRef, bAlpha, dwFLAGS
       #main.gfb, "down ; fill black ; color red"
       #main.gfb, "size 2"
       #main.gfb, "setfocus"
       #main.gfb, "line 0 0 200 200"
       #main.gfb, "when leftButtonMove draw"
   wait

   Sub draw handle$, x, y
       #handle$, "set "; x; " "; y
   End Sub

   Sub EndDemo handle$
       Close #main
       End
   End Sub

   Sub SetLayeredWindowAttributes hWindow, ColorRef, bAlpha, dwFLAGS
   CallDLL #user32, "SetLayeredWindowAttributes", _
       hWindow as Ulong, _
       ColorRef as Long, _
       bAlpha as Long, _
       dwFLAGS as Long, _
       result as Long
   End Sub



[Rod]

It might be useful if you included a reference to where these snippets were sourced from. Folks could then explore a bit further.

[xxgeek]

That is an odd window.

There is no glass!
If you click inside the window, it goes behind what was behind it when you clicked.

So where, or on what, is the red line being drawn?

After increasing the size of the red line to 10 so it could be clicked, clicking the red line does not put the window behind.

Very interesting, never seen that before today.

[tsh73]

Interesting
For me Shift F5 produces

OS error 16r582
Class already exists error

But via Debug/Light debug it works.

I found mention in a help file, on "TroubleShooting" page:

Class already exists error

Every once in a while someone reports experiencing a Class already exists(OS Error 16r582) error. There is no fix for this at this time. Sometimes it is necessary to reboot to eliminate this condition.

I will reboot, just for a case, and report here how it ends...

Also
if you click (and hold) on that red line
you can continue to draw red dots on empty space
(taht actually native LB code
but to start it you should click somewhere on a window
where it will not be intercepted by Windows itself,
so borders (resize) anf window title (move) will not do.
Ans since everything else is transparent, that leaves red line as only starting point.
Drawn points could be used to start another drawing.
)

Also
minimizing/restoring, or resizing window, kills transparent effect - turns to be ordinary window with white graphicbox

!! adding a"flush" make effect stay after resize
(if you draw something taht is)

Sub draw handle$, x, y
#handle$, "set "; x; " "; y
' #handle$, "flush"
End Sub

!! (
trying to add "flash" before first WAIT make Ctrl F5 open debugger, like in a case of Alt F5
This is definitely weird
It looks like we are treading on thin ice, without understanding what's going on,
and it could suddenly break...

[tsh73]

It got away without reboot
Happens I had JustBASIC window opened
Then I close it program in LB started running on Shift F5
Then I run JB again, LB program started barking on Shift F5.

I pretty sure it should not interfere, but indeed it does.

[Rod]

While we can create transparent Windows, the idea is to have something opaque on them, thus creating a uniquely shaped (ie non rectangular) visible window. The subject is very well covered in the LBPE. Being able to click through the invisible part of the window is something I would expect to be able to do. Else you might be clicking in vain on a visible control.

'floating "gadget" code
   nomainwin
   WindowWidth = 120
   WindowHeight = 144

   'set window stylebits to layered and stay on top
   WS.EX.LAYERED = 524288
   style=WS.EX.LAYERED or _WS_EX_TOPMOST
   stylebits #1, 0, 0, style, 0

   'set graphicbox stylebits to no border
   stylebits #1.gb, 0, _WS_BORDER, 0, 0
   graphicbox #1.gb, 0,0,120,144

   'open popup window
   open "Clock" for window_popup as #1

   'get the window handle
   hMain = HWND(#1)

   'set the window to use red as transparent mask
   'red bits of your image won't bee seen
   'they will be transparent and allow "shaped" or
   'floating graphic windows
   calldll #user32, "SetLayeredWindowAttributes",_
   hMain As long,_         'window handle
   255 As long,_           '255 = Red color key (rgb color value)
   bAlpha As long,_        '0 = Completely transparent (0-255)
   1 As long,_             '1 = use color key for transparency / 2 = use bAlpha
   ret As long             'nonzero=success


   'move window with api call
   clockx=DisplayWidth-130
   clocky=10
   calldll #user32, "MoveWindow",_
   hMain as ulong, _       'window handle
   clockx as long,_        'x location of window
   clocky as long,_        'y location of window
   120 as long,_           'desired width of window
   144 as long,_           'desired height of window
   1 as boolean,_          'repaint flag,0=false,1=true
   ret as long             'nonzero=success
   if ret=0 then [quit]

   ' start event tracking
   #1 "trapclose [quit]"
   #1.gb "when leftButtonUp [quit]"
   #1.gb "when leftButtonMove [movewindow]"

   'these are simple drawn graphics, you can do photorealist bmp images to
   'draw clock face
   #1.gb "down ; fill red ; home ; backcolor darkgray ; circlefilled 48 ;color white ; circle 49"
   for angle = 0 to 330 step 30
       #1.gb "up ; home ; north ; turn "; angle
       #1.gb "go 40 ; down ; go 5"
   next angle
   #1.gb "flush"


   timer 1000, [display]
   wait

   [display]
   time$ = time$()
   hours = val(time$)
   if hours > 12 then hours = hours - 12
   minutes = val(mid$(time$, 4, 2))
   seconds = val(right$(time$, 2))

   ' center the cursor and turtle draw the clock
   #1.gb "up ; home ; down ; north"

   ' erase each hand if its position has changed
   if oldHours <> hours then #1.gb "size 2 ; color darkgray ; turn "; oldHours * 30 + int(oldMinutes/2) ; " ; go 19 ; home ; color black ; north" : oldHours = hours
   if oldMinutes <> minutes then #1.gb "size 2 ; color darkgray ; turn "; oldMinutes * 6 ; " ; go 38 ; home ; color black ; north" : oldMinutes = minutes
   if oldSeconds <> seconds then #1.gb "size 1 ; color darkgray ; turn "; oldSeconds * 6 ; " ; go 38 ; home ; color black ; north" : oldSeconds = seconds

   ' redraw all three hands, second hand first
   #1.gb "size 1 ; turn "; seconds * 6 ; " ; go 38"
   #1.gb "size 2 ; home ; north ; turn "; hours * 30 + int(minutes/2); " ; go 19"
   #1.gb "home ; north ; turn "; minutes * 6 ; " ; go 38"
   #1.gb "delsegment seg"
   #1.gb "flush seg"
   wait

   [movewindow]
   'this is called when we place the window and whenever it is dragged
   CallDLL #user32, "ReleaseCapture",r As void
   CallDLL #user32, "SendMessageA",hMain As ULong,_WM_NCLBUTTONDOWN As ULong,_HTCAPTION As Long,0 As Long,r As Long
   wait


   [quit]
   timer 0
   close #1
   end


[Sver]

Nov 26, 2023 7:17:56 GMT -5 Rod said:

It might be useful if you included a reference to where these snippets were sourced from. Folks could then explore a bit further.

I really don't know.  I saved things in the past, from different sources into my database. 
I know, that this last snippet don't work perfect, but people can use parts of it or change it.

Nice clock !


When people want normal window transparant:


nomainwin

   graphicbox #main.1 ,0 ,0 ,800 ,600
   open "Test" for window as #main
   #main "trapclose [quit]"

   hwnd1 = hwnd(#main)

   call MakeWindowTransparent hwnd1, 150   'between 0 - 255
   wait

   [quit] close #main:end


   sub MakeWindowTransparent hwnd, transparency
   calldll #user32, "GetWindowLongA", hwnd as ulong, -20 as long,_
   r as long
   x = r or 524288
   calldll #user32, "SetWindowLongA", hwnd as ulong, -20 as long,_
   x as long, r as long
   calldll #user32, "SetLayeredWindowAttributes", hwnd as ulong,_
   0 as long, transparency as long, 2 as long, r as long
   end sub

[Sver]

Rod,

You made a cool example with drawing a clock.

With BMP pictures they only have to chance the background with the color 255 0 0 (red)
and it looks like a window-sprite with a red color which isn't visible on the desktop or not on=top window.

Of course some width and height are different.


The whole window or windows can move/locate with

nomainwin
open "Hi" for window as #1
#1 "trapclose [quit]"
h=hwnd(#1)
x=10
y=50
width=500
height=100

calldll #user32, "SetWindowPos",_
h as ulong,_              'window handle
_HWND_TOP as ulong,_      'position flag
x as long,_               'new left x coord
y as long,_               'new top y coord
width as long,_           'new window width
height as long,_          'new window height
_SWP_SHOWWINDOW as long,_ 'SetWindowPos show flag
re as boolean

CallDLL #kernel32, "Sleep", 2000 As long, ret As void

x=100
y=50
width=500
height=100

calldll #user32, "SetWindowPos",_
h as ulong,_              'window handle
_HWND_TOP as ulong,_      'position flag
x as long,_               'new left x coord
y as long,_               'new top y coord
width as long,_           'new window width
height as long,_          'new window height
_SWP_SHOWWINDOW as long,_ 'SetWindowPos show flag
re as boolean

wait

[quit]close#1:end