Function onMSNH_HScroll

outdated/sys/wince/mhmap.c:788–846

on WM_HSCROLL */

/* on WM_HSCROLL */
void
onMSNH_HScroll(HWND hWnd, WPARAM wParam, LPARAM lParam)
{
    PNHMapWindow data;
    SCROLLINFO si;
    int xNewPos;
    int xDelta;

    /* get window data */
    data = (PNHMapWindow) GetWindowLong(hWnd, GWL_USERDATA);

    switch (LOWORD(wParam)) {
    /* User clicked shaft left of the scroll box. */
    case SB_PAGEUP:
        xNewPos = data->xPos - data->xPageSize;
        break;

    /* User clicked shaft right of the scroll box. */
    case SB_PAGEDOWN:
        xNewPos = data->xPos + data->xPageSize;
        break;

    /* User clicked the left arrow. */
    case SB_LINEUP:
        xNewPos = data->xPos - 1;
        break;

    /* User clicked the right arrow. */
    case SB_LINEDOWN:
        xNewPos = data->xPos + 1;
        break;

    /* User dragged the scroll box. */
    case SB_THUMBTRACK:
        xNewPos = HIWORD(wParam);
        break;

    default:
        xNewPos = data->xPos;
    }

    xNewPos = max(0, min(COLNO - data->xPageSize + 1, xNewPos));
    if (xNewPos == data->xPos)
        return;

    xDelta = xNewPos - data->xPos;
    data->xPos = xNewPos;

    ScrollWindowEx(hWnd, -data->xScrTile * xDelta, 0, (CONST RECT *) NULL,
                   (CONST RECT *) NULL, (HRGN) NULL, (LPRECT) NULL,
                   SW_INVALIDATE | SW_ERASE);

    if (!GetNHApp()->bHideScrollBars) {
        si.cbSize = sizeof(si);
        si.fMask = SIF_POS;
        si.nPos = data->xPos;
        SetScrollInfo(hWnd, SB_HORZ, &si, TRUE);
    }