#include "ctlspriv.h"
#define DF_ACTUALLYDRAG 0x0001
#define DF_DEFERRED 0x0002
#define INITLINESPERSECOND 6
#define VERTCHANGENUMLINES 25
#define TIMERID 238
#define TIMERLEN 50
#define DX_INSERT 16
#define DY_INSERT 16
typedef struct {
HWND hwndDrag;
UINT uFlags;
} DRAGPROP, *PDRAGPROP;
UINT uDragListMsg = 0;
#ifndef WINNT
#pragma data_seg(DATASEG_READONLY)
#endif
const TCHAR szDragListMsgString[] = DRAGLISTMSGSTRING;
#ifndef WINNT
#pragma data_seg()
#endif
BOOL NEAR PASCAL PtInLBItem(HWND hLB, int nItem, POINT pt, int xInflate, int yInflate)
{
RECT rc;
if (nItem < 0)
nItem = (int)SendMessage(hLB, LB_GETCURSEL, 0, 0L);
if (SendMessage(hLB, LB_GETITEMRECT, nItem, (LPARAM)(LPRECT)&rc) == LB_ERR)
return(FALSE);
InflateRect(&rc, xInflate, yInflate);
return(PtInRect(&rc, pt));
}
/*
* DragListSubclassProc
* --------------------
*
* Window procedure for subclassed list boxes
*/
LRESULT CALLBACK DragListSubclassProc(HWND hLB, UINT uMsg, WPARAM wParam,
LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
PDRAGPROP pDragProp;
DRAGLISTINFO sNotify;
BOOL bDragging;
POINT pt;
pDragProp = (PDRAGPROP)dwRefData;
bDragging = pDragProp->hwndDrag == hLB;
switch (uMsg)
{
case WM_NCDESTROY:
if (bDragging)
SendMessage(hLB, WM_RBUTTONDOWN, 0, 0L); /* cancel drag */
RemoveWindowSubclass(hLB, DragListSubclassProc, 0);
if (pDragProp)
LocalFree((HLOCAL)pDragProp);
break;
case WM_LBUTTONDOWN:
{
int nItem;
if (bDragging) /* nested button-down */
SendMessage(hLB, WM_RBUTTONDOWN, 0, 0L); /* cancel drag */
SetFocus(hLB);
pt.x = GET_X_LPARAM(lParam);
pt.y = GET_Y_LPARAM(lParam);
ClientToScreen(hLB, &pt);
nItem = LBItemFromPt(hLB, pt, FALSE);
if (nItem >= 0)
{
SendMessage(hLB, LB_SETCURSEL, nItem, 0L);
if (GetWindowLong(hLB, GWL_STYLE) & LBS_NOTIFY)
SendMessage(GetParent(hLB), WM_COMMAND,
GET_WM_COMMAND_MPS(GetDlgCtrlID(hLB), hLB, LBN_SELCHANGE));
sNotify.uNotification = DL_BEGINDRAG;
goto QueryParent;
}
else
goto FakeDrag;
}
case WM_TIMER:
if (wParam != TIMERID)
break;
lParam = GetMessagePosClient(hLB, &pt);
// fall through
case WM_MOUSEMOVE:
if (bDragging)
{
HWND hwndParent;
LRESULT lResult;
/* We may be just simulating a drag, but not actually doing
* anything.
*/
if (!(pDragProp->uFlags&DF_ACTUALLYDRAG))
return(0L);
/* We don't want to do any dragging until the user has dragged
* outside of the current selection.
*/
if (pDragProp->uFlags & DF_DEFERRED)
{
pt.x = GET_X_LPARAM(lParam);
pt.y = GET_Y_LPARAM(lParam);
if (PtInLBItem(hLB, -1, pt, 0, 4))
return 0;
pDragProp->uFlags &= ~DF_DEFERRED;
}
sNotify.uNotification = DL_DRAGGING;
QueryParent:
hwndParent = GetParent(hLB);
sNotify.hWnd = hLB;
sNotify.ptCursor.x = GET_X_LPARAM(lParam);
sNotify.ptCursor.y = GET_Y_LPARAM(lParam);
ClientToScreen(hLB, &sNotify.ptCursor);
lResult = SendMessage(hwndParent, uDragListMsg, GetDlgCtrlID(hLB),
(LPARAM)(LPDRAGLISTINFO)&sNotify);
if (uMsg == WM_LBUTTONDOWN)
{
/* Some things may not be draggable
*/
if (lResult)
{
SetTimer(hLB, TIMERID, TIMERLEN, NULL);
pDragProp->uFlags = DF_DEFERRED | DF_ACTUALLYDRAG;
}
else
{
FakeDrag:
pDragProp->uFlags = 0;
}
/* Set capture and change mouse cursor
*/
pDragProp->hwndDrag = hLB;
SetCapture(hLB);
}
else
{
switch (lResult)
{
case DL_STOPCURSOR:
SetCursor(LoadCursor(NULL, MAKEINTRESOURCE(IDC_NO)));
break;
case DL_COPYCURSOR:
SetCursor(LoadCursor(HINST_THISDLL, MAKEINTRESOURCE(IDC_COPY)));
break;
case DL_MOVECURSOR:
SetCursor(LoadCursor(HINST_THISDLL, MAKEINTRESOURCE(IDC_MOVE)));
break;
default:
break;
}
}
/* Don't call the def proc, since it may try to change the
* selection or set timers or things like that.
*/
return(0L);
}
break;
case WM_RBUTTONDOWN:
case WM_LBUTTONUP:
/* if we are capturing mouse - release it and check for acceptable place
* where mouse is now to decide drop or not
*/
if (bDragging)
{
HWND hwndParent;
pDragProp->hwndDrag = NULL;
KillTimer(hLB, TIMERID);
ReleaseCapture();
SetCursor(LoadCursor(NULL, IDC_ARROW));
hwndParent = GetParent(hLB);
sNotify.uNotification = uMsg==WM_LBUTTONUP ? DL_DROPPED : DL_CANCELDRAG;
sNotify.hWnd = hLB;
sNotify.ptCursor.x = GET_X_LPARAM(lParam);
sNotify.ptCursor.y = GET_Y_LPARAM(lParam);
ClientToScreen(hLB, &sNotify.ptCursor);
SendMessage(hwndParent, uDragListMsg, GetDlgCtrlID(hLB),
(LPARAM)(LPDRAGLISTINFO)&sNotify);
/* We need to make sure to return 0 in case this is from a
* keyboard message.
*/
return(0L);
}
break;
case WM_GETDLGCODE:
if (bDragging)
{
return (DefSubclassProc(hLB, uMsg, wParam, lParam) |
DLGC_WANTMESSAGE);
}
break;
case WM_KEYDOWN:
if (wParam == VK_ESCAPE)
{
SendMessage(hLB, WM_RBUTTONDOWN, 0, 0L);
}
// fall through
case WM_CHAR:
case WM_KEYUP:
/* We don't want the listbox processing this if we are dragging.
*/
if (bDragging)
return(0L);
break;
default:
break;
}
return(DefSubclassProc(hLB, uMsg, wParam, lParam));
}
BOOL WINAPI MakeDragList(HWND hLB)
{
PDRAGPROP pDragProp;
if (!uDragListMsg)
uDragListMsg = RegisterWindowMessage(szDragListMsgString);
/* Check that we have not already subclassed this window.
*/
if (GetWindowSubclass(hLB, DragListSubclassProc, 0, NULL))
return(TRUE);
pDragProp = (PDRAGPROP)LocalAlloc(LPTR, sizeof(DRAGPROP));
if (!pDragProp)
return(FALSE);
if (!SetWindowSubclass(hLB, DragListSubclassProc, 0, (DWORD_PTR)pDragProp))
{
LocalFree((HLOCAL)pDragProp);
return(FALSE);
}
return(TRUE);
}
int WINAPI LBItemFromPt(HWND hLB, POINT pt, BOOL bAutoScroll)
{
static LONG dwLastScroll = 0;
RECT rc;
DWORD dwNow;
int nItem;
WORD wScrollDelay, wActualDelay;
ScreenToClient(hLB, &pt);
GetClientRect(hLB, &rc);
nItem = (int)SendMessage(hLB, LB_GETTOPINDEX, 0, 0L);
/* Is the point in the LB client area?
*/
if (PtInRect(&rc, pt))
{
/* Check each visible item in turn.
*/
for ( ; ; ++nItem)
{
if (SendMessage(hLB, LB_GETITEMRECT, nItem, (LPARAM)(LPRECT)&rc)
== LB_ERR)
break;
if (PtInRect(&rc, pt))
return(nItem);
}
}
else
{
/* If we want autoscroll and the point is directly above or below the
* LB, determine the direction and if it is time to scroll yet.
*/
if (bAutoScroll && (UINT)pt.x<(UINT)rc.right)
{
if (pt.y <= 0)
{
--nItem;
}
else
{
++nItem;
pt.y = rc.bottom - pt.y;
}
wScrollDelay = (WORD)(1000 /
(INITLINESPERSECOND - pt.y/VERTCHANGENUMLINES));
dwNow = GetTickCount();
wActualDelay = (WORD)(dwNow - dwLastScroll);
if (wActualDelay > wScrollDelay)
{
/* This will the actual number of scrolls per second to be
* much closer to the required number.
*/
if (wActualDelay > wScrollDelay * 2)
dwLastScroll = dwNow;
else
dwLastScroll += wScrollDelay;
SendMessage(hLB, LB_SETTOPINDEX, nItem, 0L);
}
}
}
return(-1);
}
void WINAPI DrawInsert(HWND hwndParent, HWND hLB, int nItem)
{
static POINT ptLastInsert;
static int nLastInsert = -1;
RECT rc;
/* Erase the old mark if necessary
*/
if (nLastInsert>=0 && nItem!=nLastInsert)
{
rc.left = ptLastInsert.x;
rc.top = ptLastInsert.y;
rc.right = rc.left + DX_INSERT;
rc.bottom = rc.top + DY_INSERT;
/* Need to update immediately in case the insert rects overlap.
*/
InvalidateRect(hwndParent, &rc, TRUE);
UpdateWindow(hwndParent);
nLastInsert = -1;
}
/* Draw a new mark if necessary
*/
if (nItem!=nLastInsert && nItem>=0)
{
HICON hInsert = NULL;
if (!hInsert)
hInsert = LoadIcon(HINST_THISDLL, MAKEINTRESOURCE(IDI_INSERT));
if (hInsert)
{
HDC hDC;
GetWindowRect(hLB, &rc);
ScreenToClient(hLB, (LPPOINT)&rc);
ptLastInsert.x = rc.left - DX_INSERT;
SendMessage(hLB, LB_GETITEMRECT, nItem, (LPARAM)(LPRECT)&rc);
ptLastInsert.y = rc.top - DY_INSERT/2;
nLastInsert = nItem;
ClientToScreen(hLB, &ptLastInsert);
ScreenToClient(hwndParent, &ptLastInsert);
hDC = GetDC(hwndParent);
DrawIcon(hDC, ptLastInsert.x, ptLastInsert.y, hInsert);
ReleaseDC(hwndParent, hDC);
}
}
}