AutoHotkey Community

; Script Function:
;    Wraps the windows API message WM_NCHITTEST, that allows to know which part of a window is
;   at specified coordinates.
;
; ******************************************************************************
;
;   IsOverTitleBar (i.e. MinButton or MaxButton or CloseButton or HelpButton or TitleBarCaption or TitleBarIcon)
;   IsOverMinButton
;   IsOverMaxButton
;   IsOverCloseButton
;   IsOverHelpButton
;   IsOverTitleBarCaption
;   IsOverTitleBarIcon
;   IsOverTitleSysMenu (same as IsOverTitleBarIcon)
;   IsOverClientArea
;   IsOverBorder (resizable or not)
;   IsOverResizableBorder (at top, bottom, left, right or corners)
;   IsOverNonResizableBorder (no difference between top, bottom, left, right and corners)
;   IsOverResizableLeftBorder
;   IsOverResizableRightBorder
;   IsOverResizableTopBorder
;   IsOverResizableBottomBorder
;   IsOverResizableTopLeftBorder
;   IsOverResizableBottomLeftBorder
;   IsOverResizableTopRightBorder
;   IsOverResizableBottomRightBorder
;
; ******************************************************************************
;
; From winuser.h & MSDN:
; WM_NCHITTEST = 0x84
; The return value is one of the following values, indicating the position of the cursor hot spot.
; #define HTERROR             (-2)         On the screen background or on a dividing line between windows (same as HTNOWHERE, except that the DefWindowProc function produces a system beep to indicate an error).
; #define HTTRANSPARENT       (-1)         In a window currently covered by another window in the same thread (the message will be sent to underlying windows in the same thread until one of them returns a code that is not HTTRANSPARENT).
; #define HTNOWHERE           0            On the screen background or on a dividing line between windows.
; #define HTCLIENT            1            In a client area.
; #define HTCAPTION           2            In a title bar.
; #define HTSYSMENU           3            In a window menu or in a Close button in a child window.
; #define HTGROWBOX           4            In a size box (same as HTSIZE).
; #define HTSIZE              HTGROWBOX
; #define HTMENU              5            In a menu (works for basic menus like notepad, not for menu **bars like in MS Word)
; #define HTHSCROLL           6            In a horizontal scroll bar.
; #define HTVSCROLL           7            In the vertical scroll bar.
; #define HTMINBUTTON         8            In a Minimize button.
; #define HTMAXBUTTON         9            In a Maximize button.
; #define HTLEFT              10         In the left border of a resizable window (the user can click the mouse to resize the window horizontally).
; #define HTRIGHT             11         In the right border of a resizable window (the user can click the mouse to resize the window horizontally).
; #define HTTOP               12         In the upper-horizontal border of a window.
; #define HTTOPLEFT           13         In the upper-left corner of a window border.
; #define HTTOPRIGHT          14         In the upper-right corner of a window border.
; #define HTBOTTOM            15         In the lower-horizontal border of a resizable window (the user can click the mouse to resize the window vertically).
; #define HTBOTTOMLEFT        16         In the lower-left corner of a border of a resizable window (the user can click the mouse to resize the window diagonally).
; #define HTBOTTOMRIGHT       17         In the lower-right corner of a border of a resizable window (the user can click the mouse to resize the window diagonally).
; #define HTBORDER            18         In the border of a window that does not have a sizing border.
; #define HTCLOSE             20         In a Close button.
; #define HTHELP              21         In a Help button.
;
; ******************************************************************************

IsOverClientArea(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 1)
}
; ------------------------------------------------------------------------------

IsOverTitleBar(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   if ErrorLevel in 2,3,8,9,20,21
      return true
   else
      return false
}
; ------------------------------------------------------------------------------

IsOverTitleBarCaption(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 2)
}
; ------------------------------------------------------------------------------

IsOverTitleBarIcon(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 3)
}
; ------------------------------------------------------------------------------

IsOverSysMenu(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 3)
}
; ------------------------------------------------------------------------------

IsOverMinButton(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 8)
}
; ------------------------------------------------------------------------------

IsOverMaxButton(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 9)
}
; ------------------------------------------------------------------------------

IsOverCloseButton(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 20)
}
; ------------------------------------------------------------------------------

IsOverHelpButton(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 21)
}
; ------------------------------------------------------------------------------

IsOverBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel >= 10 && ErrorLevel <= 18)
}
; ------------------------------------------------------------------------------

IsOverResizableBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel >= 10 && ErrorLevel <= 17)
}
; ------------------------------------------------------------------------------

IsOverNonResizableBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 18)
}
; ------------------------------------------------------------------------------

IsOverResizableLeftBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 10)
}
; ------------------------------------------------------------------------------

IsOverResizableRightBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 11)
}
; ------------------------------------------------------------------------------

IsOverResizableTopBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 12)
}
; ------------------------------------------------------------------------------

IsOverResizableBottomBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 15)
}
; ------------------------------------------------------------------------------

IsOverResizableTopLeftBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 13)
}
; ------------------------------------------------------------------------------

IsOverResizableBottomLeftBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 17)
}
; ------------------------------------------------------------------------------

IsOverResizableTopRightBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 14)
}
; ------------------------------------------------------------------------------

IsOverResizableBottomRightBorder(x, y, hWnd)
{
   SendMessage, 0x84,, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   return (ErrorLevel == 17)
}

(Y << 16) | X

(x & 0xFFFF) | (y & 0xFFFF) << 16

(X & 0xFFFF) | (Y & 0xFFFF) << 16

;HT_4294967294 := "ERROR"
;HT_4294967295 := "TRANSPARENT"
HT_0  := "NOWHERE"
HT_1  := "CLIENT"
HT_2  := "CAPTION"
HT_3  := "SYSMENU"
HT_4  := "SIZE"
HT_5  := "MENU"
HT_6  := "HSCROLL"
HT_7  := "VSCROLL"
HT_8  := "MINBUTTON"
HT_9  := "MAXBUTTON"
HT_10 := "LEFT"
HT_11 := "RIGHT"
HT_12 := "TOP"
HT_13 := "TOPLEFT"
HT_14 := "TOPRIGHT"
HT_15 := "BOTTOM"
HT_16 := "BOTTOMLEFT"
HT_17 := "BOTTOMRIGHT"
HT_18 := "BORDER"
HT_19 := "OBJECT"
HT_20 := "CLOSE"
HT_21 := "HELP"

NCHITTEST(x, y, hWnd)
{
   SendMessage, 0x84, 0, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   Return   ErrorLevel >= 0 ? HT_%ErrorLevel% : ErrorLevel = -1 ? "TRANSPARENT" : "ERROR"
}

CoordMode, Mouse, Screen
MouseGetPos, x, y, hWnd
MsgBox, % NCHITTEST(x, y, hWnd)

WM_NCHITTEST()
{
   CoordMode, Mouse, Screen
   MouseGetPos, x, y, z
   SendMessage, 0x84, 0, (x&0xFFFF)|(y&0xFFFF)<<16,, ahk_id %z%
   RegExMatch("ERROR TRANSPARENT NOWHERE CLIENT CAPTION SYSMENU SIZE MENU HSCROLL VSCROLL MINBUTTON MAXBUTTON LEFT RIGHT TOP TOPLEFT TOPRIGHT BOTTOM BOTTOMLEFT BOTTOMRIGHT BORDER OBJECT CLOSE HELP", "(?:\w+\s+){" . ErrorLevel+2&0xFFFFFFFF . "}(?<AREA>\w+\b)", HT)
   Return   HTAREA
}

MsgBox, % NCHITTEST()

_CompactPoint( x, y )
{
    x := (x<0) ? 0x10000+x : x  ; 0x10000 is UShort_max_value+1
    y := (y<0) ? 0x10000+y : y
    return x | (y<<16)
}

(x & 0xFFFF) | (y & 0xFFFF) << 16

_CompactPoint( x, y )
{
    x := (x<0) ? 0x10000+x : x  ; 0x10000 is UShort_max_value+1
    y := (y<0) ? 0x10000+y : y
    return x | (y<<16)
}

x<<48>>48

(x & 0xFFFF) | (y & 0xFFFF) << 16

;HT_4294967294 := "ERROR"
;HT_4294967295 := "TRANSPARENT"
HT_0  := "NOWHERE"
HT_1  := "CLIENT"
HT_2  := "CAPTION"
HT_3  := "SYSMENU"
HT_4  := "SIZE"
HT_5  := "MENU"
HT_6  := "HSCROLL"
HT_7  := "VSCROLL"
HT_8  := "MINBUTTON"
HT_9  := "MAXBUTTON"
HT_10 := "LEFT"
HT_11 := "RIGHT"
HT_12 := "TOP"
HT_13 := "TOPLEFT"
HT_14 := "TOPRIGHT"
HT_15 := "BOTTOM"
HT_16 := "BOTTOMLEFT"
HT_17 := "BOTTOMRIGHT"
HT_18 := "BORDER"
HT_19 := "OBJECT"
HT_20 := "CLOSE"
HT_21 := "HELP"

NCHITTEST(x, y, hWnd)
{
   SendMessage, 0x84, 0, (x & 0xFFFF) | (y & 0xFFFF) << 16,, ahk_id %hWnd%
   Return   ErrorLevel >= 0 ? HT_%ErrorLevel% : ErrorLevel = -1 ? "TRANSPARENT" : "ERROR"
}

CoordMode, Mouse, Screen
MouseGetPos, x, y,, hWnd,2
MsgBox, % NCHITTEST(x, y, hWnd)