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I chanced upon the DragDetect API the other day but so far I cannot make it work.
What it is supposed to do: msdn
What happens in my clumsy hands: the first few iterations of the while loop do just what I would expect. Then - GPF!
Here is my attempt in code. Any ideas on how to make this API work would be appreciated:
What it is supposed to do: msdn
What happens in my clumsy hands: the first few iterations of the while loop do just what I would expect. Then - GPF!
Here is my attempt in code. Any ideas on how to make this API work would be appreciated:
Code:
' to investigate DragDetect API
' Chris Holbrook 10 Dec 2008
#compile exe
#dim all
#include once "win32api.inc"
%pic_margin = 3
global GrDialogProc as long ' used in subclassing the grapic control to get mouse msgs
global GrOldProc as long ' used in subclassing the grapic control to get mouse msgs
global gMousePt as pointapi ' Mouse x and y
global gLbDOWN as long,gRBDOWN as long ' Left and right mouse button
'--------------------------------------------------------------------------------
function GrProc(byval hWnd as dword, byval wMsg as dword, byval wParam as dword, byval lParam as long) as long
static startpt, dragpt as pointAPI
select case wMsg
'
case %wm_mousemove
gMousePt.X = lo(word,lParam)
gMousePt.Y = hi(word,lParam) ' Current Mouse X and Y Position in the graphic window
if glbdown then
?"StartDrag"
startpt = gmousept
while dragdetect (hWnd, startpt)
sleep 2
getcursorpos ( dragpt) ' screen coordinates
screentoclient(hWnd, dragpt) ' window coordinates
? "DrawDrag", dragpt.x, dragpt.y
wend
?"EndDrag"
gmousept = dragpt
end if
exit function
'
case %wm_lbuttondown
gMousePt.X = lo(word,lParam)
gMousePt.Y = hi(word,lParam) ' Current Mouse X and Y Position in the graphic window
gLBDOWN = 1
exit function ' Left button pressed
case %wm_lbuttonup
glbdown = 0
exit function
'
end select
function = CallWindowProc(GrOldProc, hWnd, wMsg, wParam, lParam)
end function
'----------------------------------------------------------------------
'-----------------------------------------------------------------------------------
function pbmain () as long
local skey as string
local currentrect as rect
local hGW as dword
local clicked, X, Y as long
local lastpt as point
local hWin as dword
' Create and show a Graphic window on screen
graphic window "", 450, 130, 500, 500 to hWin
graphic attach hWin, 0, redraw
hGW = GetWindow(hWin, %GW_CHILD) ' Retrieve hWnd of graphic window
' Subclass the Graphic control
GrOldProc = SetWindowLong(hGW, %GWL_WNDPROC, codeptr(GrProc))
graphic set pos (0,0)
setrect currentrect, 0, 70, 250, 250
lastpt = gMousePt
graphic box (currentrect.nleft, currentrect.ntop)- (currentrect.nright, currentrect.nbottom),0,0,-2,0
graphic redraw
do
graphic clear -1, 0
graphic print "resize and drag a box on a GRAPHIC WINDOW"
graphic print "start with cursor in the graphic window(this one)"
graphic print "Use the mouse to size the box. Left button down to drag it"
graphic print "system drag rect is" + str$(getsystemmetrics(%SM_CXDRAG)) + " x" + _
str$(getsystemmetrics(%SM_CXDRAG))
graphic print "<Esc> to exit"
graphic box (currentrect.nleft, currentrect.ntop)- (currentrect.nright, currentrect.nbottom),0,0,-2,0
graphic redraw
if gLBdown then
offsetrect currentrect, gMousePt.X - lastpt.X , gMousePt.Y - lastpt.Y
else
currentrect.nright = gMousePt.X
currentrect.nbottom = gMousePt.Y
end if
skey = ""
graphic inkey$ to skey
if skey$ = $esc then exit loop
lastpt = gMousePt
sleep 50
loop
SetWindowLong(hGW, %GWL_WNDPROC, GrOldProc) ' remove subclassing
graphic window end
end function
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