desktop.cpp

Go to the documentation of this file.

/*
 * Copyright 2003, 2004, 2005 Martin Fuchs
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */


 //
 // Explorer clone
 //
 // desktop.cpp
 //
 // Martin Fuchs, 09.08.2003
 //


#include <precomp.h>

#include "../resource.h"

#include "../taskbar/desktopbar.h"
#include "../taskbar/taskbar.h" // for PM_GET_LAST_ACTIVE


static BOOL (WINAPI*SetShellWindow)(HWND);
static BOOL (WINAPI*SetShellWindowEx)(HWND, HWND);


#ifdef _USE_HDESK

Desktop::Desktop(HDESK hdesktop/*, HWINSTA hwinsta*/)
 :  _hdesktop(hdesktop)
//  _hwinsta(hwinsta)
{
}

Desktop::~Desktop()
{
    if (_hdesktop)
        CloseDesktop(_hdesktop);

//  if (_hwinsta)
//      CloseWindowStation(_hwinsta);

    if (_pThread.get()) {
        _pThread->Stop();
        _pThread.release();
    }
}

#endif


Desktops::Desktops()
 :  _current_desktop(0)
{
}

Desktops::~Desktops()
{
     // show all hidden windows
    for(iterator it_dsk=begin(); it_dsk!=end(); ++it_dsk)
        for(WindowSet::iterator it=it_dsk->_windows.begin(); it!=it_dsk->_windows.end(); ++it)
            ShowWindowAsync(*it, SW_SHOW);
}

void Desktops::init()
{
    resize(DESKTOP_COUNT);

#ifdef _USE_HDESK
    DesktopPtr& desktop = (*this)[0];

    desktop = DesktopPtr(new Desktop(OpenInputDesktop(0, FALSE, DESKTOP_SWITCHDESKTOP)));
#endif
}

#ifdef _USE_HDESK

void Desktops::SwitchToDesktop(int idx)
{
    if (_current_desktop == idx)
        return;

    DesktopPtr& desktop = (*this)[idx];

    DesktopThread* pThread = NULL;

    if (desktop.get()) {
        if (desktop->_hdesktop)
            if (!SwitchDesktop(desktop->_hdesktop))
                return;
    } else {
        FmtString desktop_name(TEXT("Desktop %d"), idx);

        SECURITY_ATTRIBUTES saAttr = {sizeof(SECURITY_ATTRIBUTES), 0, TRUE};
/*
        HWINSTA hwinsta = CreateWindowStation(TEXT("ExplorerWinStation"), 0, GENERIC_ALL, &saAttr);

        if (!SetProcessWindowStation(hwinsta))
            return;
*/
        HDESK hdesktop = CreateDesktop(desktop_name, NULL, NULL, 0, GENERIC_ALL, &saAttr);
        if (!hdesktop)
            return;

        desktop = DesktopPtr(new Desktop(hdesktop/*, hwinsta*/));

        pThread = new DesktopThread(*desktop);
    }

    _current_desktop = idx;

    if (pThread) {
        desktop->_pThread = DesktopThreadPtr(pThread);
        pThread->Start();
    }
}

int DesktopThread::Run()
{
    if (!SetThreadDesktop(_desktop._hdesktop))
        return -1;

    HDESK hDesk_old = OpenInputDesktop(0, FALSE, DESKTOP_SWITCHDESKTOP);

    if (!SwitchDesktop(_desktop._hdesktop))
        return -1;

    if (!_desktop._hwndDesktop)
        _desktop._hwndDesktop = DesktopWindow::Create();

    int ret = Window::MessageLoop();

    SwitchDesktop(hDesk_old);

    return ret;
}

#else // _USE_HDESK

static BOOL CALLBACK SwitchDesktopEnumFct(HWND hwnd, LPARAM lparam)
{
    WindowSet& windows = *(WindowSet*)lparam;

    if (hwnd!=g_Globals._hwndDesktopBar && hwnd!=g_Globals._hwndDesktop)
        if (IsWindowVisible(hwnd))
            windows.insert(hwnd);

    return TRUE;
}

void Desktops::SwitchToDesktop(int idx)
{
    if (_current_desktop == idx)
        return;

    Desktop& old_desktop = (*this)[_current_desktop];
    WindowSet& windows = old_desktop._windows;
    Desktop& desktop = (*this)[idx];

    windows.clear();

     // collect window handles of all other desktops
    WindowSet other_wnds;
    for(const_iterator it1=begin(); it1!=end(); ++it1)
        for(WindowSet::const_iterator it2=it1->_windows.begin(); it2!=it1->_windows.end(); ++it2)
            other_wnds.insert(*it2);

     // save currently visible application windows
    EnumWindows(SwitchDesktopEnumFct, (LPARAM)&windows);

    old_desktop._hwndForeground = (HWND)SendMessage(g_Globals._hwndDesktopBar, PM_GET_LAST_ACTIVE, 0, 0);

     // hide all windows of the previous desktop
    for(WindowSet::iterator it=windows.begin(); it!=windows.end(); ++it)
        ShowWindowAsync(*it, SW_HIDE);

     // show all windows of the new desktop
    for(WindowSet::iterator it=desktop._windows.begin(); it!=desktop._windows.end(); ++it)
        ShowWindowAsync(*it, SW_SHOW);

    if (desktop._hwndForeground)
        SetForegroundWindow(desktop._hwndForeground);

     // remove the window handles of the other desktops from what we found on the previous desktop
    for(WindowSet::const_iterator it=other_wnds.begin(); it!=other_wnds.end(); ++it)
        windows.erase(*it);

     // We don't need to store the window handles of what's now visible the now current desktop.
    desktop._windows.clear();

    _current_desktop = idx;
}

#endif // _USE_HDESK


static BOOL CALLBACK MinimizeDesktopEnumFct(HWND hwnd, LPARAM lparam)
{
    list<MinimizeStruct>& minimized = *(list<MinimizeStruct>*)lparam;

    if (hwnd!=g_Globals._hwndDesktopBar && hwnd!=g_Globals._hwndDesktop)
        if (IsWindowVisible(hwnd) && !IsIconic(hwnd)) {
            RECT rect;

            if (GetWindowRect(hwnd,&rect))
                if (rect.right>0 && rect.bottom>0 &&
                    rect.right>rect.left && rect.bottom>rect.top) {
                minimized.push_back(MinimizeStruct(hwnd, GetWindowStyle(hwnd)));
                ShowWindowAsync(hwnd, SW_MINIMIZE);
            }
        }

    return TRUE;
}

void Desktops::ToggleMinimize()
{
    list<MinimizeStruct>& minimized = (*this)[_current_desktop]._minimized;

    if (minimized.empty()) {
        EnumWindows(MinimizeDesktopEnumFct, (LPARAM)&minimized);
    } else {
        for(list<MinimizeStruct>::const_reverse_iterator it=minimized.rbegin(); 
                                                            it!=minimized.rend(); ++it) {
            ShowWindowAsync(it->first, it->second&WS_MAXIMIZE? SW_MAXIMIZE: SW_RESTORE);
            Sleep(20);
        }

        minimized.clear();
    }
}


BOOL IsAnyDesktopRunning()
{
    HINSTANCE hUser32 = GetModuleHandle(TEXT("user32"));

    SetShellWindow = (BOOL(WINAPI*)(HWND)) GetProcAddress(hUser32, "SetShellWindow");
    SetShellWindowEx = (BOOL(WINAPI*)(HWND,HWND)) GetProcAddress(hUser32, "SetShellWindowEx");

    return GetShellWindow() != 0;
}


BackgroundWindow::BackgroundWindow(HWND hwnd)
 :  super(hwnd)
{
     // set background brush for the short moment of displaying the
     // background color while moving foreground windows
    SetClassLongPtr(hwnd, GCL_HBRBACKGROUND, COLOR_BACKGROUND+1);

    _display_version = RegGetDWORDValue(HKEY_CURRENT_USER, TEXT("Control Panel\\Desktop"), TEXT("PaintDesktopVersion"), 1);
}

LRESULT BackgroundWindow::WndProc(UINT nmsg, WPARAM wparam, LPARAM lparam)
{
    switch(nmsg) {
      case WM_ERASEBKGND:
        DrawDesktopBkgnd((HDC)wparam);
        return TRUE;

      case WM_MBUTTONDBLCLK:
        /* Imagelist icons are missing if MainFrame::Create() is called directly from here!
        explorer_show_frame(SW_SHOWNORMAL); */
        PostMessage(g_Globals._hwndDesktop, nmsg, wparam, lparam);
        break;

      case PM_DISPLAY_VERSION:
        if (lparam || wparam) {
            DWORD or_mask = wparam;
            DWORD reset_mask = LOWORD(lparam);
            DWORD xor_mask = HIWORD(lparam);
            _display_version = ((_display_version&~reset_mask) | or_mask) ^ xor_mask;
            RegSetDWORDValue(HKEY_CURRENT_USER, TEXT("Control Panel\\Desktop"), TEXT("PaintDesktopVersion"), _display_version);
            InvalidateRect(_hwnd, NULL, TRUE);
        }
        return _display_version;

      default:
        return super::WndProc(nmsg, wparam, lparam);
    }

    return 0;
}

void BackgroundWindow::DrawDesktopBkgnd(HDC hdc)
{
    PaintDesktop(hdc);

/* special solid background
    HBRUSH bkgndBrush = CreateSolidBrush(RGB(0,32,160));    // dark blue
    FillRect(hdc, &rect, bkgndBrush);
    DeleteBrush(bkgndBrush);
*/
}


DesktopWindow::DesktopWindow(HWND hwnd)
 :  super(hwnd)
{
    _pShellView = NULL;
}

DesktopWindow::~DesktopWindow()
{
    if (_pShellView)
        _pShellView->Release();
}


HWND DesktopWindow::Create()
{
    static IconWindowClass wcDesktop(TEXT("Progman"), IDI_REACTOS, CS_DBLCLKS);
    /* (disabled because of small ugly temporary artefacts when hiding start menu)
    wcDesktop.hbrBackground = (HBRUSH)(COLOR_BACKGROUND+1); */

    int width = GetSystemMetrics(SM_CXSCREEN);
    int height = GetSystemMetrics(SM_CYSCREEN);

    HWND hwndDesktop = Window::Create(WINDOW_CREATOR(DesktopWindow),
                    WS_EX_TOOLWINDOW, wcDesktop, TEXT("Program Manager"), WS_POPUP|WS_VISIBLE,  //|WS_CLIPCHILDREN for SDI frames
                    0, 0, width, height, 0);

     // work around to display desktop bar in Wine
    ShowWindow(GET_WINDOW(DesktopWindow, hwndDesktop)->_desktopBar, SW_SHOW);

     // work around for Windows NT, Win 98, ...
     // Without this the desktop has mysteriously only a size of 800x600 pixels.
    MoveWindow(hwndDesktop, 0, 0, width, height, TRUE);

    return hwndDesktop;
}


LRESULT DesktopWindow::Init(LPCREATESTRUCT pcs)
{
    if (super::Init(pcs))
        return 1;

    HRESULT hr = GetDesktopFolder()->CreateViewObject(_hwnd, IID_IShellView, (void**)&_pShellView);
/* also possible:
    SFV_CREATE sfv_create;

    sfv_create.cbSize = sizeof(SFV_CREATE);
    sfv_create.pshf = GetDesktopFolder();
    sfv_create.psvOuter = NULL;
    sfv_create.psfvcb = NULL;

    HRESULT hr = SHCreateShellFolderView(&sfv_create, &_pShellView);
*/
    HWND hWndView = 0;

    if (SUCCEEDED(hr)) {
        FOLDERSETTINGS fs;

        fs.ViewMode = FVM_ICON;
        fs.fFlags = FWF_DESKTOP|FWF_NOCLIENTEDGE|FWF_NOSCROLL|FWF_BESTFITWINDOW|FWF_SNAPTOGRID; //|FWF_AUTOARRANGE;

        ClientRect rect(_hwnd);

        hr = _pShellView->CreateViewWindow(NULL, &fs, this, &rect, &hWndView);


        if (SUCCEEDED(hr)) {
            g_Globals._hwndShellView = hWndView;

             // subclass shellview window
            new DesktopShellView(hWndView, _pShellView);

            _pShellView->UIActivate(SVUIA_ACTIVATE_FOCUS);

        /*
            IShellView2* pShellView2;

            hr = _pShellView->QueryInterface(IID_IShellView2, (void**)&pShellView2);

            SV2CVW2_PARAMS params;
            params.cbSize = sizeof(SV2CVW2_PARAMS);
            params.psvPrev = _pShellView;
            params.pfs = &fs;
            params.psbOwner = this;
            params.prcView = &rect;
            params.pvid = params.pvid;//@@

            hr = pShellView2->CreateViewWindow2(&params);
            params.pvid;
        */

        /*
            IFolderView* pFolderView;

            hr = _pShellView->QueryInterface(IID_IFolderView, (void**)&pFolderView);

            if (SUCCEEDED(hr)) {
                hr = pFolderView->GetAutoArrange();
                hr = pFolderView->SetCurrentViewMode(FVM_DETAILS);
            }
        */
        }
    }

    if (hWndView && SetShellWindowEx)
        SetShellWindowEx(_hwnd, hWndView);
    else if (SetShellWindow)
        SetShellWindow(_hwnd);

     // create the explorer bar
    _desktopBar = DesktopBar::Create();
    g_Globals._hwndDesktopBar = _desktopBar;

    return 0;
}


LRESULT DesktopWindow::WndProc(UINT nmsg, WPARAM wparam, LPARAM lparam)
{
    switch(nmsg) {
      case WM_LBUTTONDBLCLK:
      case WM_RBUTTONDBLCLK:
      case WM_MBUTTONDBLCLK:
        explorer_show_frame(SW_SHOWNORMAL);
        break;

      case WM_DISPLAYCHANGE:
        MoveWindow(_hwnd, 0, 0, LOWORD(lparam), HIWORD(lparam), TRUE);
        MoveWindow(g_Globals._hwndShellView, 0, 0, LOWORD(lparam), HIWORD(lparam), TRUE);
        MoveWindow(_desktopBar, 0, HIWORD(lparam) - DESKTOPBARBAR_HEIGHT, LOWORD(lparam), DESKTOPBARBAR_HEIGHT, TRUE);
        break;

      case WM_GETISHELLBROWSER:
        return (LRESULT)static_cast<IShellBrowser*>(this);

      case WM_DESTROY:


        if (SetShellWindow)
            SetShellWindow(0);
        break;

      case WM_CLOSE:
        ShowExitWindowsDialog(_hwnd);
        break;

      case WM_SYSCOMMAND:
        if (wparam == SC_TASKLIST) {
            if (_desktopBar)
                SendMessage(_desktopBar, nmsg, wparam, lparam);
        }
        goto def;

      case WM_SYSCOLORCHANGE:
        // redraw background window - it's done by system
        //InvalidateRect(g_Globals._hwndShellView, NULL, TRUE);

        // forward message to common controls
        SendMessage(g_Globals._hwndShellView, WM_SYSCOLORCHANGE, 0, 0);
        SendMessage(_desktopBar, WM_SYSCOLORCHANGE, 0, 0);
        break;

      case WM_SETTINGCHANGE:
        SendMessage(g_Globals._hwndShellView, nmsg, wparam, lparam);
        break;

      default: def:
        return super::WndProc(nmsg, wparam, lparam);
    }

    return 0;
}


HRESULT DesktopWindow::OnDefaultCommand(LPIDA pida)
{
#ifndef ROSSHELL    // in shell-only-mode fall through and let shell32 handle the command
    if (MainFrameBase::OpenShellFolders(pida, 0))
        return S_OK;
#endif

    return E_NOTIMPL;
}


DesktopShellView::DesktopShellView(HWND hwnd, IShellView* pShellView)
 :  super(hwnd),
    _pShellView(pShellView)
{
    _hwndListView = GetNextWindow(hwnd, GW_CHILD);

     // work around for Windows NT, Win 98, ...
     // Without this the desktop has mysteriously only a size of 800x600 pixels.
    ClientRect rect(hwnd);
    MoveWindow(_hwndListView, 0, 0, rect.right, rect.bottom, TRUE);

     // subclass background window
    new BackgroundWindow(_hwndListView);

    _icon_algo = 0; // default icon arrangement

    InitDragDrop();
}


DesktopShellView::~DesktopShellView()
{
    if (FAILED(RevokeDragDrop(_hwnd)))
        assert(0);
}


bool DesktopShellView::InitDragDrop()
{
    CONTEXT("DesktopShellView::InitDragDrop()");

    DesktopDropTarget * pDropTarget = new DesktopDropTarget(_hwnd);

    if (!pDropTarget)
        return false;

    pDropTarget->AddRef();

    if (FAILED(RegisterDragDrop(_hwnd, pDropTarget))) {
        pDropTarget->Release();
        return false;
    }

    FORMATETC ftetc;

    ftetc.dwAspect = DVASPECT_CONTENT;
    ftetc.lindex = -1;
    ftetc.tymed = TYMED_HGLOBAL;
    ftetc.cfFormat = CF_HDROP;

    pDropTarget->AddSuportedFormat(ftetc);
    pDropTarget->Release();

    return true;
}

LRESULT DesktopShellView::WndProc(UINT nmsg, WPARAM wparam, LPARAM lparam)
{
    switch(nmsg) {
      case WM_CONTEXTMENU:
        if (!DoContextMenu(GET_X_LPARAM(lparam), GET_Y_LPARAM(lparam)))
            DoDesktopContextMenu(GET_X_LPARAM(lparam), GET_Y_LPARAM(lparam));
        break;

      case PM_SET_ICON_ALGORITHM:
        _icon_algo = wparam;
        PositionIcons();
        break;

      case PM_GET_ICON_ALGORITHM:
        return _icon_algo;

      case PM_DISPLAY_VERSION:
        return SendMessage(_hwndListView, nmsg, wparam, lparam);

      default:
        return super::WndProc(nmsg, wparam, lparam);
    }

    return 0;
}

int DesktopShellView::Command(int id, int code)
{
    return super::Command(id, code);
}

int DesktopShellView::Notify(int id, NMHDR* pnmh)
{
    return super::Notify(id, pnmh);
}

bool DesktopShellView::DoContextMenu(int x, int y)
{
    IDataObject* selection;

    HRESULT hr = _pShellView->GetItemObject(SVGIO_SELECTION, IID_IDataObject, (void**)&selection);
    if (FAILED(hr))
        return false;

    PIDList pidList;

    hr = pidList.GetData(selection);
    if (FAILED(hr)) {
        selection->Release();
        //CHECKERROR(hr);
        return false;
    }

    LPIDA pida = pidList;
    if (!pida->cidl) {
        selection->Release();
        return false;
    }

    LPCITEMIDLIST parent_pidl = (LPCITEMIDLIST) ((LPBYTE)pida+pida->aoffset[0]);

    LPCITEMIDLIST* apidl = (LPCITEMIDLIST*) alloca(pida->cidl*sizeof(LPCITEMIDLIST));

    for(int i=pida->cidl; i>0; --i)
        apidl[i-1] = (LPCITEMIDLIST) ((LPBYTE)pida+pida->aoffset[i]);

    hr = ShellFolderContextMenu(ShellFolder(parent_pidl), _hwnd, pida->cidl, apidl, x, y, _cm_ifs);

    selection->Release();

    if (SUCCEEDED(hr))
        refresh();
    else
        CHECKERROR(hr);

    return true;
}

HRESULT DesktopShellView::DoDesktopContextMenu(int x, int y)
{
    IContextMenu* pcm;

    HRESULT hr = DesktopFolder()->GetUIObjectOf(_hwnd, 0, NULL, IID_IContextMenu, NULL, (LPVOID*)&pcm);

    if (SUCCEEDED(hr)) {
        pcm = _cm_ifs.query_interfaces(pcm);

        HMENU hmenu = CreatePopupMenu();

        if (hmenu) {
            hr = pcm->QueryContextMenu(hmenu, 0, FCIDM_SHVIEWFIRST, FCIDM_SHVIEWLAST-1, CMF_NORMAL|CMF_EXPLORE);

            if (SUCCEEDED(hr)) {
                AppendMenu(hmenu, MF_SEPARATOR, 0, NULL);
                AppendMenu(hmenu, 0, FCIDM_SHVIEWLAST-1, ResString(IDS_ABOUT_EXPLORER));

                UINT idCmd = TrackPopupMenu(hmenu, TPM_LEFTALIGN|TPM_RETURNCMD|TPM_RIGHTBUTTON, x, y, 0, _hwnd, NULL);

                _cm_ifs.reset();

                if (idCmd == FCIDM_SHVIEWLAST-1) {
                    explorer_about(_hwnd);
                } else if (idCmd) {
                  CMINVOKECOMMANDINFO cmi;

                  cmi.cbSize = sizeof(CMINVOKECOMMANDINFO);
                  cmi.fMask = 0;
                  cmi.hwnd = _hwnd;
                  cmi.lpVerb = (LPCSTR)(INT_PTR)(idCmd - FCIDM_SHVIEWFIRST);
                  cmi.lpParameters = NULL;
                  cmi.lpDirectory = NULL;
                  cmi.nShow = SW_SHOWNORMAL;
                  cmi.dwHotKey = 0;
                  cmi.hIcon = 0;

                  hr = pcm->InvokeCommand(&cmi);
                }
            } else
                _cm_ifs.reset();
            DestroyMenu(hmenu);
        }

        pcm->Release();
    }

    return hr;
}


#define ARRANGE_BORDER_DOWN  8
#define ARRANGE_BORDER_HV    9
#define ARRANGE_ROUNDABOUT  10

static const POINTS s_align_start[] = {
    {0, 0}, // left/top
    {0, 0},
    {1, 0}, // right/top
    {1, 0},
    {0, 1}, // left/bottom
    {0, 1},
    {1, 1}, // right/bottom
    {1, 1},

    {0, 0}, // left/top
    {0, 0},
    {0, 0}
};

static const POINTS s_align_dir1[] = {
    { 0, +1},   // down
    {+1,  0},   // right
    {-1,  0},   // left
    { 0, +1},   // down
    { 0, -1},   // up
    {+1,  0},   // right
    {-1,  0},   // left
    { 0, -1},   // up

    { 0, +1},   // down
    {+1,  0},   // right
    {+1,  0}    // right
};

static const POINTS s_align_dir2[] = {
    {+1,  0},   // right
    { 0, +1},   // down
    { 0, +1},   // down
    {-1,  0},   // left
    {+1,  0},   // right
    { 0, -1},   // up
    { 0, -1},   // up
    {-1,  0},   // left

    {+1,  0},   // right
    { 0, +1},   // down
    { 0, +1}    // down
};

typedef pair<int,int> IconPos;
typedef map<IconPos, int> IconMap;

void DesktopShellView::PositionIcons(int dir)
{
    DWORD spacing = ListView_GetItemSpacing(_hwndListView, FALSE);

    RECT work_area;
    SystemParametersInfo(SPI_GETWORKAREA, 0, &work_area, 0);

    /* disable default allignment */
    SetWindowStyle(_hwndListView, GetWindowStyle(_hwndListView)&~LVS_ALIGNMASK);//|LVS_ALIGNTOP|LVS_AUTOARRANGE);

    const POINTS& dir1 = s_align_dir1[_icon_algo];
    const POINTS& dir2 = s_align_dir2[_icon_algo];
    const POINTS& start_pos = s_align_start[_icon_algo];

    int dir_x1 = dir1.x;
    int dir_y1 = dir1.y;
    int dir_x2 = dir2.x;
    int dir_y2 = dir2.y;

    int cx = LOWORD(spacing);
    int cy = HIWORD(spacing);

    int dx1 = dir_x1 * cx;
    int dy1 = dir_y1 * cy;
    int dx2 = dir_x2 * cx;
    int dy2 = dir_y2 * cy;

    int xoffset = (cx-32)/2;
    int yoffset = 4/*(cy-32)/2*/;

    int start_x = start_pos.x * (work_area.right - cx) + xoffset;
    int start_y = start_pos.y * (work_area.bottom - cy) + yoffset;

    int x = start_x;
    int y = start_y;

    int all = ListView_GetItemCount(_hwndListView);
    int i1, i2;

    if (dir > 0) {
        i1 = 0;
        i2 = all;
    } else {
        i1 = all-1;
        i2 = -1;
    }

    IconMap pos_idx;
    int cnt = 0;
    int xhv = start_x;
    int yhv = start_y;

    for(int idx=i1; idx!=i2; idx+=dir) {
        pos_idx[IconPos(y, x)] = idx;

        if (_icon_algo == ARRANGE_BORDER_DOWN) {
            if (++cnt & 1)
                x = work_area.right - x - cx + 2*xoffset;
            else {
                y += dy1;

                if (y + cy - 2 * yoffset > work_area.bottom) {
                    y = start_y;
                    start_x += dx2;
                    x = start_x;
                }
            }

            continue;
        }
        else if (_icon_algo == ARRANGE_BORDER_HV) {
            if (++cnt & 1)
                x = work_area.right - x - cx + 2*xoffset;
            else if (cnt & 2) {
                yhv += cy;
                y = yhv;
                x = start_x;

                if (y + cy - 2 * yoffset > work_area.bottom) {
                    start_x += cx;
                    xhv = start_x;
                    x = xhv;
                    start_y += cy;
                    yhv = start_y;
                    y = yhv;
                }
            } else {
                xhv += cx;
                x = xhv;
                y = start_y;

                if (x + cx - 2 * xoffset > work_area.right) {
                    start_x += cx;
                    xhv = start_x;
                    x = xhv;
                    start_y += cy;
                    yhv = start_y;
                    y = yhv;
                }
            }

            continue;
        }
        else if (_icon_algo == ARRANGE_ROUNDABOUT) {


        }

        x += dx1;
        y += dy1;

        if (x<0 || x+cx-2*xoffset>work_area.right) {
            x = start_x;
            y += dy2;
        } else if (y<0 || y+cy-2*yoffset>work_area.bottom) {
            y = start_y;
            x += dx2;
        }
    }

     // use a little trick to get the icons where we want them to be...

    //for(IconMap::const_iterator it=pos_idx.end(); --it!=pos_idx.begin(); ) {
    //  const IconPos& pos = it->first;

    //  ListView_SetItemPosition32(_hwndListView, it->second, pos.second, pos.first);
    //}

    for(IconMap::const_iterator it=pos_idx.begin(); it!=pos_idx.end(); ++it) {
        const IconPos& pos = it->first;

        ListView_SetItemPosition32(_hwndListView, it->second, pos.second, pos.first);
    }
}


void DesktopShellView::refresh()
{
}