How do I delete a rectangle?

[jaberwacky]

I found a >function by Malkey that draws a rectangle onto the screen.  Works great.  I need to delete that rect.  Is that possible?  If so, how?  I searched all over and tried several things but no joy.  Any ideas, hints, and or tips will be greatly appreciated.

I modifed the func and so here it is just in case:

Func _WinAPI_DrawRect(const $l_zoom_level, const $x, const $y, Const $pen_style = $PS_SOLID)
  ; Author: Malkey
  ; http://www.autoitscript.com/forum/topic/135728-how-to-i-draw-one-rectangle-on-screen/?p=947819
 
  Local Static $zoom_width = $main_width - 4
 
  local const $zoom_by_two = Int($l_zoom_level / 2)
 
  local const $left = $x - $zoom_by_two
 
  local const $top = $y - $zoom_by_two
 
  local const $right = $left + $l_zoom_level
 
  local const $bottom = $top + $l_zoom_level
 
  local static $tRect = DllStructCreate($tagRECT)

  $tRect.Left   = $left
  $tRect.Top    = $top
  $tRect.Right  = $right
  $tRect.Bottom = $bottom

  local static $hDC = _WinAPI_GetWindowDC(0)

  local const $hPen = _WinAPI_CreatePen($pen_style, 2, 0xFF0000)
 
  DllCall($user32_dll, "int", "FrameRect", "handle", $hDC, "struct*", $tRect, "handle", $hPen) ; _WinAPI_FrameRect
EndFunc

Edited February 4, 2014 by jaberwacky

[JohnOne]

Probably need to use _WinAPI_DeleteObject() on _WinAPI_CreatePen()  and _WinAPI_ReleaseDC() on _WinAPI_GetWindowDC.

It is also possible you may have to redraw screen.

I runnable example would help.

[Danyfirex]

At the same thread there are many examples almost all with realese (DC) cleaning the Rect

saludos

[jaberwacky]

Probably need to use _WinAPI_DeleteObject() on _WinAPI_CreatePen()  and _WinAPI_ReleaseDC() on _WinAPI_GetWindowDC.

It is also possible you may have to redraw screen.

I runnable example would help.

Ok, I tried the release and delete stuff so I may have to refresh the screen.  Thanks I will look into that!

Here is a runnable example (the whole thing): [REDACTED]

Move the mouse around and click F4 to see a red rectangle.

The rects disappear when I bring focus to the window but I want them disappear at the end of a timer or maybe a hotkey I don't know yet.

Edited February 8, 2014 by jaberwacky

[jaberwacky]

Ok, what I'm thinking is that I will need to either screenshot the desktop or overlay a transparent gui over it and then use GDI+ to draw and erase the rectangles?

[jaberwacky]

Ok, so I found this example in the helpfile.

#include <WinAPI.au3>
#include <WindowsConstants.au3>

ShowCross(@DesktopWidth / 2, @DesktopHeight / 2, 20, 2, 0xFF, 3000)

Func ShowCross($start_x, $start_y, $length, $width, $color, $time)
    Local $hDC, $hPen, $obj_orig

    $hDC = _WinAPI_GetWindowDC(0) ; DC of entire screen (desktop)
    $hPen = _WinAPI_CreatePen($PS_SOLID, $width, $color)
    $obj_orig = _WinAPI_SelectObject($hDC, $hPen)

    _WinAPI_DrawLine($hDC, $start_x - $length, $start_y, $start_x - 5, $start_y) ; horizontal left
    _WinAPI_DrawLine($hDC, $start_x + $length, $start_y, $start_x + 5, $start_y) ; horizontal right
    _WinAPI_DrawLine($hDC, $start_x, $start_y - $length, $start_x, $start_y - 5) ; vertical up
    ;   _WinAPI_DrawLine($hDC, $start_x, $start_y + $length, $start_x, $start_y + 5) ; vertical down
    _WinAPI_MoveTo($hDC, $start_x, $start_y + $length)
    _WinAPI_LineTo($hDC, $start_x, $start_y + 5)

    Sleep(3000) ; show cross over screen for defined seconds

    ; refresh desktop (clear cross)
    _WinAPI_RedrawWindow(_WinAPI_GetDesktopWindow(), 0, 0, $RDW_UPDATENOW + $RDW_ERASENOW + $RDW_INVALIDATE + $RDW_ALLCHILDREN)
  
    Sleep(3000)
  
    ; clear resources
    _WinAPI_SelectObject($hDC, $obj_orig)
    _WinAPI_DeleteObject($hPen)
    _WinAPI_ReleaseDC(0, $hDC)
EndFunc   ;==>ShowCross

It seems as though _WinAPI_RedrawWindow does not erase the cross mark after all.  Have I misunderstood the purpose of _WinAPI_RedrawWindow?

[BrewManNH]

It will erase the cross, if the cross is drawn over the desktop. If you're running it from SciTE, more than likely it's being drawn over the SciTE window, and the line is clearing the wrong window. Change the _WinAPI_RedrawWindow line to the line below if running it from SciTE.

_WinAPI_RedrawWindow(WinGetHandle("[class:SciTEWindow]"), 0, 0, $RDW_INVALIDATE + $RDW_ALLCHILDREN)

[jaberwacky]

Oh wow!  So I'm guessing there is no way to make it go away no matter where it is or what it's over?

[JohnOne]

If BrewManNH suggestion works within scite, then you might have to write a function to enumerate all windows which have been drawn on.

Or simply all visible windows, and redraw them all.

[jaberwacky]

Alritey, so there's no one shot set of functions which manage this then?  I can't just say to draw a rectangle on the screen and then simply call a function which basically says, "Hey, you know that rectangle you just drew?  Yeah, that one. Erase it, bud."

Ok, just occurred to me, I could make a func which remembers the pixel colors of the area where the lines of the rectangle will reside.  Draw the rectangle, and then call a function which will color those rectangle pixels back to the original colors.  Good idea?

[BrewManNH]

That would work if every pixel were the same color, otherwise you'll end up with another rectangle in a different color.

[jaberwacky]

I was thinking of storing them in an array and then color each pixel individually.

[jaberwacky]

If BrewManNH suggestion works within scite, then you might have to write a function to enumerate all windows which have been drawn on.

Or simply all visible windows, and redraw them all.

I tried this and it works well.  Thank you.

Func _WinAPI_DrawRect(Const $l_zoom_level, Const $x, Const $y)
  Local Const $zoom_by_two = Int($l_zoom_level / 2)

  Local Const $left = $x - $zoom_by_two

  Local Const $top = $y - $zoom_by_two

  _WinAPI_DrawLine($hDC, $x - $zoom_by_two, $y + $zoom_by_two, $x - $zoom_by_two, $y - $zoom_by_two) ; left
  _WinAPI_DrawLine($hDC, $x + $zoom_by_two, $y - $zoom_by_two, $x - $zoom_by_two, $y - $zoom_by_two) ; top
  _WinAPI_DrawLine($hDC, $x + $zoom_by_two, $y + $zoom_by_two, $x + $zoom_by_two, $y - $zoom_by_two) ; right
  _WinAPI_DrawLine($hDC, $x - $zoom_by_two, $y + $zoom_by_two, $x + $zoom_by_two, $y + $zoom_by_two) ; bottom

  Sleep(1000)

  Local Const $window_list = WinList()

  For $i = 1 To $window_list[0][0]
    _WinAPI_RedrawWindow($window_list[$i][1], 0, 0, $RDW_INVALIDATE + $RDW_ALLCHILDREN)
  Next
EndFunc

[techbard]

jaberwacky! your solution works for me!

Thanks~

[jaberwacky]

I should mention that I may have gotten that from user Malkey.  I forgot.

[Malkey]

From Au3Info, and running on Win 7, the desktop handle is

ControlGetHandle("[Class:WorkerW]", "", "SysListView321")

So on Win 7, this appears to work.

#include <WinAPI.au3>
#include <WindowsConstants.au3>

_WinAPI_DrawRect(20, 20, @DesktopWidth / 2, @DesktopHeight / 2, 0x0000FF)
Sleep(2000)

_WinAPI_RedrawWindow(ControlGetHandle("[Class:WorkerW]", "", "SysListView321"), 0, 0, $RDW_INVALIDATE + $RDW_ALLCHILDREN)

Sleep(3000)


Func _WinAPI_DrawRect($start_x, $start_y, $iWidth, $iHeight, $iColor)
    Local $hDC = _WinAPI_GetWindowDC(0) ; DC of entire screen (desktop)
    Local $tRect = DllStructCreate($tagRECT)
    DllStructSetData($tRect, 1, $start_x)
    DllStructSetData($tRect, 2, $start_y)
    DllStructSetData($tRect, 3, $iWidth)
    DllStructSetData($tRect, 4, $iHeight)
    Local $hBrush = _WinAPI_CreateSolidBrush($iColor)

    _WinAPI_FrameRect($hDC, DllStructGetPtr($tRect), $hBrush)

    ; clear resources
    _WinAPI_DeleteObject($hBrush)
    _WinAPI_ReleaseDC(0, $hDC)
EndFunc   ;==>_WinAPI_DrawRect