//
// "$Id: fl_dnd_x.cpp 219 2002-10-28 11:12:57Z laza2000 $"
//
// Drag & Drop code for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2002 by Bill Spitzak and others.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 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
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
//
// Please report all bugs and problems to "fltk-bugs@fltk.org".
//

#include <efltk/Fl.h>
#include <efltk/Fl_Window.h>
#include <efltk/x.h>

extern Atom fl_XdndAware;
extern Atom fl_XdndSelection;
extern Atom fl_XdndEnter;
extern Atom fl_XdndTypeList;
extern Atom fl_XdndPosition;
extern Atom fl_XdndLeave;
extern Atom fl_XdndDrop;
extern Atom fl_XdndStatus;
extern Atom fl_XdndActionCopy;
extern Atom fl_XdndFinished;
extern Atom fl_textplain;
//extern Atom fl_XdndProxy;
extern Atom *fl_incoming_dnd_source_types;

extern bool fl_i_own_selection[2];

extern void fl_sendClientMessage(Window window, Atom message,
unsigned long d0,
unsigned long d1=0,
unsigned long d2=0,
unsigned long d3=0,
unsigned long d4=0);

// return version # of Xdnd this window supports.  Also change the
// window to the proxy if it uses a proxy:
static int dnd_aware(Window& window)
{
    Atom actual; int format; unsigned long count, remaining;
    unsigned char *data = 0;
    XGetWindowProperty(fl_display, window, fl_XdndAware,
        0, 4, False, XA_ATOM,
        &actual, &format,
        &count, &remaining, &data);
    if (actual == XA_ATOM && format==32 && count && data)
        return int(*(Atom*)data);
    return 0;
}


static bool drop_ok;
static bool moved;

static bool grabfunc(int event)
{
    if (event == FL_RELEASE) Fl::pushed(0);
    else if (event == FL_MOVE) moved = true;
    else if (!event && fl_xevent.type == ClientMessage
        && fl_xevent.xclient.message_type == fl_XdndStatus)
    {
        drop_ok = fl_xevent.xclient.data.l[1] != 0;
        if (drop_ok) fl_dnd_action = fl_xevent.xclient.data.l[3];
    }
    return false;
}


                                 // in Fl.cxx
extern bool (*fl_local_grab)(int);

// send an event to an fltk window belonging to this program:
static bool local_handle(int event, Fl_Window* window)
{
    fl_local_grab = 0;
    Fl::e_x = Fl::e_x_root-window->x();
    Fl::e_y = Fl::e_y_root-window->y();
    int ret = Fl::handle(event,window);
    fl_local_grab = grabfunc;
    return ret;
}


bool Fl::dnd()
{
    // Remember any user presets for the action and types:
    Atom* types;
    Atom action;
    Atom local_source_types[2] = {fl_textplain, 0};
    if (fl_dnd_source_types == fl_incoming_dnd_source_types)
    {
        types = local_source_types;
        action = fl_XdndActionCopy;
    }
    else
    {
        types = fl_dnd_source_types;
        action = fl_dnd_source_action;
    }

    Fl_Window* source_fl_window = Fl::first_window();
    Window source_window = fl_xid(source_fl_window);

    fl_local_grab = grabfunc;
    Window target_window = 0;
    Fl_Window* local_window = 0;
    int version = 4; int dest_x, dest_y;
    XSetSelectionOwner(fl_display, fl_XdndSelection, fl_message_window, fl_event_time);
    Fl_Cursor oldcursor = FL_CURSOR_DEFAULT;
    drop_ok = true;
    moved = true;

    while (Fl::pushed())
    {

        // figure out what window we are pointing at:
        Window new_window = 0; int new_version = 0;
        Fl_Window* new_local_window = 0;
        for (Window child = RootWindow(fl_display, fl_screen);;)
        {
            Window root; unsigned int junk3;
            XQueryPointer(fl_display, child, &root, &child,
                &e_x_root, &e_y_root, &dest_x, &dest_y, &junk3);
            if (!child)
            {
                if (!new_window && (new_version = dnd_aware(root))) new_window = root;
                break;
            }
            new_window = child;
            if ((new_local_window = fl_find(child))) break;
            if ((new_version = dnd_aware(new_window))) break;
        }

        if (new_window != target_window)
        {
            if (local_window)
            {
                fl_dnd_source_window = 0;
                local_handle(FL_DND_LEAVE, local_window);
            }
            else if (version)
            {
                fl_sendClientMessage(target_window, fl_XdndLeave, source_window);
            }
            version = new_version;
            target_window = new_window;
            local_window = new_local_window;
            if (local_window)
            {
                fl_dnd_source_window = source_window;
                fl_dnd_source_types = types;
                fl_dnd_type = fl_textplain;
                local_handle(FL_DND_ENTER, local_window);
            }
            else if (version)
            {
                fl_sendClientMessage(target_window, fl_XdndEnter, source_window,
                    version<<24,
                    types[0], types[1], types[1] ? types[2] : 0);
            }
        }
        if (local_window)
        {
            fl_dnd_source_window = source_window;
                                 // ?? is this needed?
            fl_dnd_source_types = types;
            fl_dnd_action = fl_XdndActionCopy;
            drop_ok = local_handle(FL_DND_DRAG, local_window);
        }
        else if (version)
        {
            if (moved)
                fl_sendClientMessage(target_window, fl_XdndPosition, source_window,
                    0, (e_x_root<<16)|e_y_root, fl_event_time,
                    fl_dnd_source_action);
        }
        else
        {
            // Windows that don't support DnD are reported as ok because
            // we are going to try the middle-mouse click on them:
            drop_ok = types[0]==fl_textplain;
        }        
		Fl_Cursor cursor = Fl_Cursor(drop_ok ? 21 : FL_CURSOR_NO);
        if (cursor != oldcursor)
        {
            oldcursor = cursor;
            source_fl_window->cursor(cursor);
        }
        moved = false;
        Fl::wait();
    }

    if (!drop_ok) ;
    else if (local_window)
    {
        fl_i_own_selection[0] = true;
        if (local_handle(FL_DND_RELEASE, local_window)) paste(*belowmouse(),false);
    }
    else if (version)
    {
        fl_sendClientMessage(target_window, fl_XdndDrop, source_window,
            0, fl_event_time);
    }
    else if (target_window)
    {
        // fake a drop by clicking the middle mouse button:
        XButtonEvent msg;
        msg.type = ButtonPress;
        msg.window = target_window;
        msg.root = RootWindow(fl_display, fl_screen);
        msg.subwindow = 0;
        msg.time = fl_event_time+1;
        msg.x = dest_x;
        msg.y = dest_y;
        msg.x_root = Fl::e_x_root;
        msg.y_root = Fl::e_y_root;
        msg.state = 0x0;
        msg.button = Button2;
        XSendEvent(fl_display, target_window, False, 0L, (XEvent*)&msg);
        msg.time++;
        msg.state = 0x200;
        msg.type = ButtonRelease;
        XSendEvent(fl_display, target_window, False, 0L, (XEvent*)&msg);
    }

    fl_local_grab = 0;
    if (oldcursor) source_fl_window->cursor(FL_CURSOR_DEFAULT);

    // reset the action and type:
    fl_dnd_source_types = fl_incoming_dnd_source_types;

    return drop_ok;
}


//
// End of "$Id: fl_dnd_x.cpp 219 2002-10-28 11:12:57Z laza2000 $".
//
