wxWidgets/samples/dnd/dnd.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        dnd.cpp
// Purpose:     Drag and drop sample
// Author:      Vadim Zeitlin
// Modified by:
// Created:     04/01/98
// RCS-ID:
// Copyright:
// Licence:   	wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#include "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#ifndef WX_PRECOMP
#include "wx/wx.h"
#endif

#include  "wx/intl.h"
#include  "wx/log.h"

#include  "wx/dnd.h"

// ----------------------------------------------------------------------------
// Derive 2 simple classes which just put in the listbox the strings (text or
// file names) we drop on them
// ----------------------------------------------------------------------------
class DnDText : public wxTextDropTarget
{
public:
  DnDText(wxListBox *pOwner) { m_pOwner = pOwner; }

  virtual bool OnDropText(long x, long y, const char *psz);

private:
  wxListBox *m_pOwner;
};

class DnDFile : public wxFileDropTarget
{
public:
  DnDFile(wxListBox *pOwner) { m_pOwner = pOwner; }

  virtual bool OnDropFiles(long x, long y,
                           size_t nFiles, const char * const aszFiles[]);

private:
  wxListBox *m_pOwner;
};

// ----------------------------------------------------------------------------
// Define a new application type
// ----------------------------------------------------------------------------
class DnDApp : public wxApp
{ 
public:
  bool OnInit();
};

IMPLEMENT_APP(DnDApp);

// ----------------------------------------------------------------------------
// Define a new frame type
// ----------------------------------------------------------------------------
class DnDFrame : public wxFrame
{ 
public:
  DnDFrame(wxFrame *frame, char *title, int x, int y, int w, int h);
 ~DnDFrame();

  void OnPaint(wxPaintEvent& event);
  void OnQuit (wxCommandEvent& event);
  void OnAbout(wxCommandEvent& event);
  void OnDrag (wxCommandEvent& event);
  void OnHelp (wxCommandEvent& event);
  void OnLogClear(wxCommandEvent& event);

  void OnMouseBtnDown(wxMouseEvent& event);

  bool OnClose();
  
  DECLARE_EVENT_TABLE()

private:
  wxListBox  *m_ctrlFile,
             *m_ctrlText;
  wxTextCtrl *m_ctrlLog;

  wxLog *m_pLog, *m_pLogPrev;

  wxString m_strText;
};

// ----------------------------------------------------------------------------
// IDs for the menu commands
// ----------------------------------------------------------------------------
enum
{
  Menu_Quit = 1,
  Menu_Drag,
  Menu_About = 101,
  Menu_Help,
  Menu_Clear,
};

BEGIN_EVENT_TABLE(DnDFrame, wxFrame)
  EVT_MENU(Menu_Quit,  DnDFrame::OnQuit)
  EVT_MENU(Menu_About, DnDFrame::OnAbout)
  EVT_MENU(Menu_Drag,  DnDFrame::OnDrag)
  EVT_MENU(Menu_Help,  DnDFrame::OnHelp)
  EVT_MENU(Menu_Clear, DnDFrame::OnLogClear)

  EVT_LEFT_DOWN(OnMouseBtnDown)
  EVT_RIGHT_DOWN(OnMouseBtnDown)
  EVT_MIDDLE_DOWN(OnMouseBtnDown)
END_EVENT_TABLE()

// `Main program' equivalent, creating windows and returning main app frame
bool DnDApp::OnInit(void)
{
  // create the main frame window
  DnDFrame *frame = new DnDFrame(NULL, "Drag & Drop wxWindows App", 
                                 50, 50, 450, 340);

  // activate it
  frame->Show(TRUE);

  SetTopWindow(frame);

  return TRUE;
}

DnDFrame::DnDFrame(wxFrame *frame, char *title, int x, int y, int w, int h)
        : wxFrame(frame, -1, title, wxPoint(x, y), wxSize(w, h)),
          m_strText("wxWindows drag & drop works :-)")

{
  // frame icon and status bar
  SetIcon(wxIcon("mondrian"));
  const int widths[] = { -1 };
  CreateStatusBar();

  // construct menu
  wxMenu *file_menu = new wxMenu;
  file_menu->Append(Menu_Drag, "&Test drag...");
  file_menu->AppendSeparator();
  file_menu->Append(Menu_Quit, "E&xit");

  wxMenu *log_menu = new wxMenu;
  log_menu->Append(Menu_Clear, "Clear");

  wxMenu *help_menu = new wxMenu;
  help_menu->Append(Menu_Help, "&Help...");
  help_menu->AppendSeparator();
  help_menu->Append(Menu_About, "&About");

  wxMenuBar *menu_bar = new wxMenuBar;
  menu_bar->Append(file_menu, "&File");
  menu_bar->Append(log_menu,  "&Log");
  menu_bar->Append(help_menu, "&Help");

  SetMenuBar(menu_bar);
  
  // make a panel with 3 subwindows
  wxPoint pos(0, 0);
  wxSize  size(400, 200);

  wxString strFile("Drop files here!"), strText("Drop text on me");

  m_ctrlFile  = new wxListBox(this, -1, pos, size, 1, &strFile, wxLB_HSCROLL);
  m_ctrlText  = new wxListBox(this, -1, pos, size, 1, &strText, wxLB_HSCROLL);
  m_ctrlLog   = new wxTextCtrl(this, -1, "", pos, size, 
                               wxTE_MULTILINE | wxTE_READONLY | 
                               wxSUNKEN_BORDER| wxHSCROLL);

  // redirect log messages to the text window (don't forget to delete it!)
  m_pLog = new wxLogTextCtrl(m_ctrlLog);
  m_pLogPrev = wxLog::SetActiveTarget(m_pLog);

  // associate drop targets with 2 text controls
  m_ctrlFile->SetDropTarget(new DnDFile(m_ctrlFile));
  m_ctrlText->SetDropTarget(new DnDText(m_ctrlText));

  wxLayoutConstraints *c;

  // Top-left listbox
  c = new wxLayoutConstraints;
  c->left.SameAs		(this, wxLeft);
  c->top.SameAs			(this, wxTop);
  c->right.PercentOf(this, wxRight, 50);
  c->height.PercentOf(this, wxHeight, 40);
  m_ctrlFile->SetConstraints(c);

  // Top-right listbox
  c = new wxLayoutConstraints;
  c->left.SameAs    (m_ctrlFile, wxRight);
  c->top.SameAs     (this, wxTop);
  c->right.SameAs   (this, wxRight);
  c->height.PercentOf(this, wxHeight, 40);
  m_ctrlText->SetConstraints(c);

  // Lower text control
  c = new wxLayoutConstraints;
  c->left.SameAs    (this, wxLeft);
  c->right.SameAs   (this, wxRight);
  c->height.PercentOf(this, wxHeight, 40);
  c->top.SameAs(m_ctrlText, wxBottom);

  m_ctrlLog->SetConstraints(c);

  SetAutoLayout(TRUE);
}

void DnDFrame::OnQuit(wxCommandEvent& /* event */)
{
  Close(TRUE);
}

void DnDFrame::OnDrag(wxCommandEvent& /* event */)
{
  wxString strText = wxGetTextFromUser
  (
    "After you enter text in this dialog, press any mouse\n"
    "button in the bottom (empty) part of the frame and \n"
    "drag it anywhere - you will be in fact dragging the\n"
    "text object containing this text",
    "Please enter some text", m_strText, this
  );

  m_strText = strText;
}

void DnDFrame::OnAbout(wxCommandEvent& /* event */)
{
  wxMessageDialog dialog(this, 
                         "Drag-&-Drop Demo\n"
                         "Please see \"Help|Help...\" for details\n"
                         "Copyright (c) 1998 Vadim Zeitlin",
                         "About wxDnD");

  dialog.ShowModal();
}

void DnDFrame::OnHelp(wxCommandEvent& /* event */)
{
  wxMessageDialog dialog(this, 
"This small program demonstrates drag & drop support in wxWindows. "
"The program window consists of 3 parts: the bottom pane is for "
"debug messages, so that you can see what's going on inside. "
"The top part is split into 2 listboxes, the left one accepts "
"files and the right one accepts text."
"\n\n"
"To test wxDropTarget: open wordpad (write.exe), select some text in "
"it and drag it to the right listbox (you'll notice the usual visual "
"feedback, i.e. the cursor will change). Also, try dragging some "
"files (you can select several at once) from Windows Explorer (or "
"File Manager) to the left pane. Hold down Ctrl/Shift keys when "
"you drop text (doesn't work with files) and see what changes. "
"\n\n"
"To test wxDropSource: just press any mouse button on the empty zone of "
"the window and drag it to wordpad or any other droptarget accepting "
"text (and of course you can just drag it to the right pane). Due to "
"a lot of trace messages, the cursor might take some time to change, "
"don't release the mouse button until it does. You can change the "
"string being dragged in in \"File|Test drag...\" dialog."
"\n\n"
"Please send all questions/bug reports/suggestions &c to "
"Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>",
                        "wxDnD Help");

  dialog.ShowModal();
}

void DnDFrame::OnLogClear(wxCommandEvent& event)
{
  m_ctrlLog->Clear();
}

bool DnDFrame::OnClose() 
{ 
  return TRUE; 
}

void DnDFrame::OnMouseBtnDown(wxMouseEvent& event)
{
  if ( !m_strText.IsEmpty() ) {
    // start drag operation
    wxTextDataObject data(m_strText);
    wxDropSource dragSource(data);
    const char *pc;

    switch ( dragSource.DoDragDrop(TRUE) ) {
      case wxDropSource::Error:   pc = "Error!";    break;
      case wxDropSource::None:    pc = "Nothing";   break;
      case wxDropSource::Copy:    pc = "Copied";    break;
      case wxDropSource::Move:    pc = "Moved";     break;
      case wxDropSource::Cancel:  pc = "Cancelled"; break;
      default:                    pc = "Huh?";      break;
    }

    SetStatusText(wxString("Drag result: ") + pc);
  }
}

DnDFrame::~DnDFrame()
{
  if ( m_pLog != NULL ) {
    if ( wxLog::SetActiveTarget(m_pLogPrev) == m_pLog )
      delete m_pLog;
  }
}

// ----------------------------------------------------------------------------
// Notifications called by the base class
// ----------------------------------------------------------------------------
bool DnDText::OnDropText(long, long, const char *psz)
{
  m_pOwner->Append(psz);

  return TRUE;
}

bool DnDFile::OnDropFiles(long, long, size_t nFiles, 
                          const char * const aszFiles[])
{
  wxString str;
  str.Printf("%d files dropped", nFiles);
  m_pOwner->Append(str);
  for ( size_t n = 0; n < nFiles; n++ ) {
    m_pOwner->Append(aszFiles[n]);
  }

  return TRUE;
}