//========================================================================
// GLFW 3.1 X11 - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2010 Camilla Berglund <elmindreda@elmindreda.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================

#include "internal.h"

#include <sys/select.h>

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

// Action for EWMH client messages
#define _NET_WM_STATE_REMOVE        0
#define _NET_WM_STATE_ADD           1
#define _NET_WM_STATE_TOGGLE        2

// Additional mouse button names for XButtonEvent
#define Button6            6
#define Button7            7

typedef struct
{
    unsigned long flags;
    unsigned long functions;
    unsigned long decorations;
    long input_mode;
    unsigned long status;
} MotifWmHints;

#define MWM_HINTS_DECORATIONS (1L << 1)


// Returns whether the event is a selection event
//
static Bool isFrameExtentsEvent(Display* display, XEvent* event, XPointer pointer)
{
    _GLFWwindow* window = (_GLFWwindow*) pointer;
    return event->type == PropertyNotify &&
           event->xproperty.state == PropertyNewValue &&
           event->xproperty.window == window->x11.handle &&
           event->xproperty.atom == _glfw.x11.NET_FRAME_EXTENTS;
}

// Translates an X event modifier state mask
//
static int translateState(int state)
{
    int mods = 0;

    if (state & ShiftMask)
        mods |= GLFW_MOD_SHIFT;
    if (state & ControlMask)
        mods |= GLFW_MOD_CONTROL;
    if (state & Mod1Mask)
        mods |= GLFW_MOD_ALT;
    if (state & Mod4Mask)
        mods |= GLFW_MOD_SUPER;

    return mods;
}

// Translates an X Window key to internal coding
//
static int translateKey(int keycode)
{
    // Use the pre-filled LUT (see updateKeyCodeLUT() in x11_init.c)
    if (keycode < 0 || keycode > 255)
        return GLFW_KEY_UNKNOWN;

    return _glfw.x11.keyCodeLUT[keycode];
}

// Translates an X Window event to Unicode
//
static int translateChar(XKeyEvent* event)
{
    KeySym keysym;

    // Get X11 keysym
    XLookupString(event, NULL, 0, &keysym, NULL);

    // Convert to Unicode (see x11_unicode.c)
    return (int) _glfwKeySym2Unicode(keysym);
}

// Splits and translates a text/uri-list into separate file paths
//
static char** parseUriList(char* text, int* count)
{
    const char* prefix = "file://";
    char** names = NULL;
    char* line;

    *count = 0;

    while ((line = strtok(text, "\r\n")))
    {
        text = NULL;

        if (*line == '#')
            continue;

        if (strncmp(line, prefix, strlen(prefix)) == 0)
            line += strlen(prefix);

        (*count)++;

        char* name = calloc(strlen(line) + 1, 1);
        names = realloc(names, *count * sizeof(char*));
        names[*count - 1] = name;

        while (*line)
        {
            if (line[0] == '%' && line[1] && line[2])
            {
                const char digits[3] = { line[1], line[2], '\0' };
                *name = strtol(digits, NULL, 16);
                line += 2;
            }
            else
                *name = *line;

            name++;
            line++;
        }
    }

    return names;
}

// Create the X11 window (and its colormap)
//
static GLboolean createWindow(_GLFWwindow* window,
                              const _GLFWwndconfig* wndconfig)
{
    unsigned long wamask;
    XSetWindowAttributes wa;
    XVisualInfo* visual = _GLFW_X11_CONTEXT_VISUAL;

    // Every window needs a colormap
    // Create one based on the visual used by the current context
    // TODO: Decouple this from context creation

    window->x11.colormap = XCreateColormap(_glfw.x11.display,
                                           _glfw.x11.root,
                                           visual->visual,
                                           AllocNone);

    // Create the actual window
    {
        wamask = CWBorderPixel | CWColormap | CWEventMask;

        wa.colormap = window->x11.colormap;
        wa.border_pixel = 0;
        wa.event_mask = StructureNotifyMask | KeyPressMask | KeyReleaseMask |
                        PointerMotionMask | ButtonPressMask | ButtonReleaseMask |
                        ExposureMask | FocusChangeMask | VisibilityChangeMask |
                        EnterWindowMask | LeaveWindowMask | PropertyChangeMask;

        _glfwGrabXErrorHandler();

        window->x11.handle = XCreateWindow(_glfw.x11.display,
                                           _glfw.x11.root,
                                           0, 0,
                                           wndconfig->width, wndconfig->height,
                                           0,              // Border width
                                           visual->depth,  // Color depth
                                           InputOutput,
                                           visual->visual,
                                           wamask,
                                           &wa);

        _glfwReleaseXErrorHandler();

        if (!window->x11.handle)
        {
            _glfwInputXError(GLFW_PLATFORM_ERROR,
                             "X11: Failed to create window");
            return GL_FALSE;
        }

        if (!wndconfig->decorated)
        {
            MotifWmHints hints;
            hints.flags = MWM_HINTS_DECORATIONS;
            hints.decorations = 0;

            XChangeProperty(_glfw.x11.display, window->x11.handle,
                            _glfw.x11.MOTIF_WM_HINTS,
                            _glfw.x11.MOTIF_WM_HINTS, 32,
                            PropModeReplace,
                            (unsigned char*) &hints,
                            sizeof(MotifWmHints) / sizeof(long));
        }

        XSaveContext(_glfw.x11.display,
                     window->x11.handle,
                     _glfw.x11.context,
                     (XPointer) window);
    }

    if (window->monitor && !_glfw.x11.hasEWMH)
    {
        // This is the butcher's way of removing window decorations
        // Setting the override-redirect attribute on a window makes the window
        // manager ignore the window completely (ICCCM, section 4)
        // The good thing is that this makes undecorated fullscreen windows
        // easy to do; the bad thing is that we have to do everything manually
        // and some things (like iconify/restore) won't work at all, as those
        // are tasks usually performed by the window manager

        XSetWindowAttributes attributes;
        attributes.override_redirect = True;
        XChangeWindowAttributes(_glfw.x11.display,
                                window->x11.handle,
                                CWOverrideRedirect,
                                &attributes);

        window->x11.overrideRedirect = GL_TRUE;
    }

    // Declare the WM protocols supported by GLFW
    {
        int count = 0;
        Atom protocols[2];

        // The WM_DELETE_WINDOW ICCCM protocol
        // Basic window close notification protocol
        if (_glfw.x11.WM_DELETE_WINDOW)
            protocols[count++] = _glfw.x11.WM_DELETE_WINDOW;

        // The _NET_WM_PING EWMH protocol
        // Tells the WM to ping the GLFW window and flag the application as
        // unresponsive if the WM doesn't get a reply within a few seconds
        if (_glfw.x11.NET_WM_PING)
            protocols[count++] = _glfw.x11.NET_WM_PING;

        if (count > 0)
        {
            XSetWMProtocols(_glfw.x11.display, window->x11.handle,
                            protocols, count);
        }
    }

    if (_glfw.x11.NET_WM_PID)
    {
        const pid_t pid = getpid();

        XChangeProperty(_glfw.x11.display,  window->x11.handle,
                        _glfw.x11.NET_WM_PID, XA_CARDINAL, 32,
                        PropModeReplace,
                        (unsigned char*) &pid, 1);
    }

    // Set ICCCM WM_HINTS property
    {
        XWMHints* hints = XAllocWMHints();
        if (!hints)
        {
            _glfwInputError(GLFW_OUT_OF_MEMORY,
                            "X11: Failed to allocate WM hints");
            return GL_FALSE;
        }

        hints->flags = StateHint;
        hints->initial_state = NormalState;

        XSetWMHints(_glfw.x11.display, window->x11.handle, hints);
        XFree(hints);
    }

    // Set ICCCM WM_NORMAL_HINTS property (even if no parts are set)
    {
        XSizeHints* hints = XAllocSizeHints();
        hints->flags = 0;

        if (wndconfig->monitor)
        {
            hints->flags |= PPosition;
            _glfwPlatformGetMonitorPos(wndconfig->monitor, &hints->x, &hints->y);
        }
        else
        {
            // HACK: Explicitly setting PPosition to any value causes some WMs,
            //       notably Compiz and Metacity, to honor the position of
            //       unmapped windows set by XMoveWindow
            hints->flags |= PPosition;
            hints->x = hints->y = 0;
        }

        if (!wndconfig->resizable)
        {
            hints->flags |= (PMinSize | PMaxSize);
            hints->min_width  = hints->max_width  = wndconfig->width;
            hints->min_height = hints->max_height = wndconfig->height;
        }

        XSetWMNormalHints(_glfw.x11.display, window->x11.handle, hints);
        XFree(hints);
    }

    // Set ICCCM WM_CLASS property
    // HACK: Until a mechanism for specifying the application name is added, the
    //       initial window title is used as the window class name
    if (strlen(wndconfig->title))
    {
        XClassHint* hint = XAllocClassHint();
        hint->res_name = (char*) wndconfig->title;
        hint->res_class = (char*) wndconfig->title;

        XSetClassHint(_glfw.x11.display, window->x11.handle, hint);
        XFree(hint);
    }

    if (_glfw.x11.xi.available)
    {
        // Select for XInput2 events

        XIEventMask eventmask;
        unsigned char mask[] = { 0 };

        eventmask.deviceid = 2;
        eventmask.mask_len = sizeof(mask);
        eventmask.mask = mask;
        XISetMask(mask, XI_Motion);

        XISelectEvents(_glfw.x11.display, window->x11.handle, &eventmask, 1);
    }

    if (_glfw.x11.XdndAware)
    {
        // Announce support for Xdnd (drag and drop)
        const Atom version = 5;
        XChangeProperty(_glfw.x11.display, window->x11.handle,
                        _glfw.x11.XdndAware, XA_ATOM, 32,
                        PropModeReplace, (unsigned char*) &version, 1);
    }

    if (_glfw.x11.NET_REQUEST_FRAME_EXTENTS)
    {
        // Ensure _NET_FRAME_EXTENTS is set, allowing glfwGetWindowFrameSize to
        // function before the window is mapped

        XEvent event;
        memset(&event, 0, sizeof(event));

        event.type = ClientMessage;
        event.xclient.window = window->x11.handle;
        event.xclient.format = 32; // Data is 32-bit longs
        event.xclient.message_type = _glfw.x11.NET_REQUEST_FRAME_EXTENTS;

        XSendEvent(_glfw.x11.display,
                   _glfw.x11.root,
                   False,
                   SubstructureNotifyMask | SubstructureRedirectMask,
                   &event);
        XIfEvent(_glfw.x11.display, &event, isFrameExtentsEvent, (XPointer) window);
    }

    _glfwPlatformSetWindowTitle(window, wndconfig->title);

    XRRSelectInput(_glfw.x11.display, window->x11.handle,
                   RRScreenChangeNotifyMask);

    _glfwPlatformGetWindowPos(window, &window->x11.xpos, &window->x11.ypos);
    _glfwPlatformGetWindowSize(window, &window->x11.width, &window->x11.height);

    return GL_TRUE;
}

// Hide the mouse cursor
//
static void hideCursor(_GLFWwindow* window)
{
    XUngrabPointer(_glfw.x11.display, CurrentTime);
    XDefineCursor(_glfw.x11.display, window->x11.handle, _glfw.x11.cursor);
}

// Disable the mouse cursor
//
static void disableCursor(_GLFWwindow* window)
{
    XGrabPointer(_glfw.x11.display, window->x11.handle, True,
                 ButtonPressMask | ButtonReleaseMask | PointerMotionMask,
                 GrabModeAsync, GrabModeAsync,
                 window->x11.handle, _glfw.x11.cursor, CurrentTime);
}

// Restores the mouse cursor
//
static void restoreCursor(_GLFWwindow* window)
{
    XUngrabPointer(_glfw.x11.display, CurrentTime);

    if (window->cursor)
    {
        XDefineCursor(_glfw.x11.display, window->x11.handle,
                      window->cursor->x11.handle);
    }
    else
        XUndefineCursor(_glfw.x11.display, window->x11.handle);
}

// Enter fullscreen mode
//
static void enterFullscreenMode(_GLFWwindow* window)
{
    if (_glfw.x11.saver.count == 0)
    {
        // Remember old screen saver settings
        XGetScreenSaver(_glfw.x11.display,
                        &_glfw.x11.saver.timeout,
                        &_glfw.x11.saver.interval,
                        &_glfw.x11.saver.blanking,
                        &_glfw.x11.saver.exposure);

        // Disable screen saver
        XSetScreenSaver(_glfw.x11.display, 0, 0, DontPreferBlanking,
                        DefaultExposures);
    }

    _glfw.x11.saver.count++;

    _glfwSetVideoMode(window->monitor, &window->videoMode);

    if (_glfw.x11.NET_WM_BYPASS_COMPOSITOR)
    {
        const unsigned long value = 1;

        XChangeProperty(_glfw.x11.display,  window->x11.handle,
                        _glfw.x11.NET_WM_BYPASS_COMPOSITOR, XA_CARDINAL, 32,
                        PropModeReplace, (unsigned char*) &value, 1);
    }

    if (_glfw.x11.NET_WM_STATE && _glfw.x11.NET_WM_STATE_FULLSCREEN)
    {
        int x, y;
        _glfwPlatformGetMonitorPos(window->monitor, &x, &y);
        _glfwPlatformSetWindowPos(window, x, y);

        if (_glfw.x11.NET_ACTIVE_WINDOW)
        {
            // Ask the window manager to raise and focus the GLFW window
            // Only focused windows with the _NET_WM_STATE_FULLSCREEN state end
            // up on top of all other windows ("Stacking order" in EWMH spec)

            XEvent event;
            memset(&event, 0, sizeof(event));

            event.type = ClientMessage;
            event.xclient.window = window->x11.handle;
            event.xclient.format = 32; // Data is 32-bit longs
            event.xclient.message_type = _glfw.x11.NET_ACTIVE_WINDOW;
            event.xclient.data.l[0] = 1; // Sender is a normal application
            event.xclient.data.l[1] = 0; // We don't really know the timestamp

            XSendEvent(_glfw.x11.display,
                       _glfw.x11.root,
                       False,
                       SubstructureNotifyMask | SubstructureRedirectMask,
                       &event);
        }

        // Ask the window manager to make the GLFW window a fullscreen window
        // Fullscreen windows are undecorated and, when focused, are kept
        // on top of all other windows

        XEvent event;
        memset(&event, 0, sizeof(event));

        event.type = ClientMessage;
        event.xclient.window = window->x11.handle;
        event.xclient.format = 32; // Data is 32-bit longs
        event.xclient.message_type = _glfw.x11.NET_WM_STATE;
        event.xclient.data.l[0] = _NET_WM_STATE_ADD;
        event.xclient.data.l[1] = _glfw.x11.NET_WM_STATE_FULLSCREEN;
        event.xclient.data.l[2] = 0; // No secondary property
        event.xclient.data.l[3] = 1; // Sender is a normal application

        XSendEvent(_glfw.x11.display,
                   _glfw.x11.root,
                   False,
                   SubstructureNotifyMask | SubstructureRedirectMask,
                   &event);
    }
    else if (window->x11.overrideRedirect)
    {
        // In override-redirect mode we have divorced ourselves from the
        // window manager, so we need to do everything manually

        GLFWvidmode mode;
        _glfwPlatformGetVideoMode(window->monitor, &mode);

        XRaiseWindow(_glfw.x11.display, window->x11.handle);
        XSetInputFocus(_glfw.x11.display, window->x11.handle,
                       RevertToParent, CurrentTime);
        XMoveWindow(_glfw.x11.display, window->x11.handle, 0, 0);
        XResizeWindow(_glfw.x11.display, window->x11.handle,
                      mode.width, mode.height);
    }
}

// Leave fullscreen mode
//
static void leaveFullscreenMode(_GLFWwindow* window)
{
    _glfwRestoreVideoMode(window->monitor);

    _glfw.x11.saver.count--;

    if (_glfw.x11.saver.count == 0)
    {
        // Restore old screen saver settings
        XSetScreenSaver(_glfw.x11.display,
                        _glfw.x11.saver.timeout,
                        _glfw.x11.saver.interval,
                        _glfw.x11.saver.blanking,
                        _glfw.x11.saver.exposure);
    }

    if (_glfw.x11.NET_WM_BYPASS_COMPOSITOR)
    {
        const unsigned long value = 0;

        XChangeProperty(_glfw.x11.display,  window->x11.handle,
                        _glfw.x11.NET_WM_BYPASS_COMPOSITOR, XA_CARDINAL, 32,
                        PropModeReplace, (unsigned char*) &value, 1);
    }

    if (_glfw.x11.NET_WM_STATE && _glfw.x11.NET_WM_STATE_FULLSCREEN)
    {
        // Ask the window manager to make the GLFW window a normal window
        // Normal windows usually have frames and other decorations

        XEvent event;
        memset(&event, 0, sizeof(event));

        event.type = ClientMessage;
        event.xclient.window = window->x11.handle;
        event.xclient.format = 32; // Data is 32-bit longs
        event.xclient.message_type = _glfw.x11.NET_WM_STATE;
        event.xclient.data.l[0] = _NET_WM_STATE_REMOVE;
        event.xclient.data.l[1] = _glfw.x11.NET_WM_STATE_FULLSCREEN;
        event.xclient.data.l[2] = 0; // No secondary property
        event.xclient.data.l[3] = 1; // Sender is a normal application

        XSendEvent(_glfw.x11.display,
                   _glfw.x11.root,
                   False,
                   SubstructureNotifyMask | SubstructureRedirectMask,
                   &event);
    }
}

// Process the specified X event
//
static void processEvent(XEvent *event)
{
    _GLFWwindow* window = NULL;

    if (event->type != GenericEvent)
    {
        window = _glfwFindWindowByHandle(event->xany.window);
        if (window == NULL)
        {
            // This is an event for a window that has already been destroyed
            return;
        }
    }

    switch (event->type)
    {
        case KeyPress:
        {
            const int key = translateKey(event->xkey.keycode);
            const int mods = translateState(event->xkey.state);
            const int character = translateChar(&event->xkey);

            _glfwInputKey(window, key, event->xkey.keycode, GLFW_PRESS, mods);

            if (character != -1)
                _glfwInputChar(window, character);

            break;
        }

        case KeyRelease:
        {
            const int key = translateKey(event->xkey.keycode);
            const int mods = translateState(event->xkey.state);

            if (!_glfw.x11.xkb.detectable)
            {
                // XKB detectable key repeat is not supported on this server
                // For key repeats we will get KeyRelease/KeyPress pairs with
                // similar or identical time stamps.  User selected key repeat
                // filtering is handled in _glfwInputKey/_glfwInputChar.
                if (XEventsQueued(_glfw.x11.display, QueuedAfterReading))
                {
                    XEvent nextEvent;
                    XPeekEvent(_glfw.x11.display, &nextEvent);

                    if (nextEvent.type == KeyPress &&
                        nextEvent.xkey.window == event->xkey.window &&
                        nextEvent.xkey.keycode == event->xkey.keycode)
                    {
                        // This last check is a hack to work around key repeats
                        // leaking through due to some sort of time drift
                        // Toshiyuki Takahashi can press a button 16 times per
                        // second so it's fairly safe to assume that no human is
                        // pressing the key 50 times per second (value is ms)
                        if ((nextEvent.xkey.time - event->xkey.time) < 20)
                        {
                            // This is a server-generated key repeat event
                            // Do not report anything for this event
                            break;
                        }
                    }
                }
            }

            _glfwInputKey(window, key, event->xkey.keycode, GLFW_RELEASE, mods);
            break;
        }

        case ButtonPress:
        {
            const int mods = translateState(event->xbutton.state);

            if (event->xbutton.button == Button1)
                _glfwInputMouseClick(window, GLFW_MOUSE_BUTTON_LEFT, GLFW_PRESS, mods);
            else if (event->xbutton.button == Button2)
                _glfwInputMouseClick(window, GLFW_MOUSE_BUTTON_MIDDLE, GLFW_PRESS, mods);
            else if (event->xbutton.button == Button3)
                _glfwInputMouseClick(window, GLFW_MOUSE_BUTTON_RIGHT, GLFW_PRESS, mods);

            // Modern X provides scroll events as mouse button presses
            else if (event->xbutton.button == Button4)
                _glfwInputScroll(window, 0.0, 1.0);
            else if (event->xbutton.button == Button5)
                _glfwInputScroll(window, 0.0, -1.0);
            else if (event->xbutton.button == Button6)
                _glfwInputScroll(window, -1.0, 0.0);
            else if (event->xbutton.button == Button7)
                _glfwInputScroll(window, 1.0, 0.0);

            else
            {
                // Additional buttons after 7 are treated as regular buttons
                // We subtract 4 to fill the gap left by scroll input above
                _glfwInputMouseClick(window,
                                     event->xbutton.button - 4,
                                     GLFW_PRESS,
                                     mods);
            }

            break;
        }

        case ButtonRelease:
        {
            const int mods = translateState(event->xbutton.state);

            if (event->xbutton.button == Button1)
            {
                _glfwInputMouseClick(window,
                                     GLFW_MOUSE_BUTTON_LEFT,
                                     GLFW_RELEASE,
                                     mods);
            }
            else if (event->xbutton.button == Button2)
            {
                _glfwInputMouseClick(window,
                                     GLFW_MOUSE_BUTTON_MIDDLE,
                                     GLFW_RELEASE,
                                     mods);
            }
            else if (event->xbutton.button == Button3)
            {
                _glfwInputMouseClick(window,
                                     GLFW_MOUSE_BUTTON_RIGHT,
                                     GLFW_RELEASE,
                                     mods);
            }
            else if (event->xbutton.button > Button7)
            {
                // Additional buttons after 7 are treated as regular buttons
                // We subtract 4 to fill the gap left by scroll input above
                _glfwInputMouseClick(window,
                                     event->xbutton.button - 4,
                                     GLFW_RELEASE,
                                     mods);
            }
            break;
        }

        case EnterNotify:
        {
            _glfwInputCursorEnter(window, GL_TRUE);
            break;
        }

        case LeaveNotify:
        {
            _glfwInputCursorEnter(window, GL_FALSE);
            break;
        }

        case MotionNotify:
        {
            if (event->xmotion.x != window->x11.warpPosX ||
                event->xmotion.y != window->x11.warpPosY)
            {
                // The cursor was moved by something other than GLFW

                int x, y;

                if (window->cursorMode == GLFW_CURSOR_DISABLED)
                {
                    if (_glfw.focusedWindow != window)
                        break;

                    x = event->xmotion.x - window->x11.cursorPosX;
                    y = event->xmotion.y - window->x11.cursorPosY;
                }
                else
                {
                    x = event->xmotion.x;
                    y = event->xmotion.y;
                }

                _glfwInputCursorMotion(window, x, y);
            }

            window->x11.cursorPosX = event->xmotion.x;
            window->x11.cursorPosY = event->xmotion.y;
            break;
        }

        case ConfigureNotify:
        {
            if (event->xconfigure.width != window->x11.width ||
                event->xconfigure.height != window->x11.height)
            {
                _glfwInputFramebufferSize(window,
                                          event->xconfigure.width,
                                          event->xconfigure.height);

                _glfwInputWindowSize(window,
                                     event->xconfigure.width,
                                     event->xconfigure.height);

                window->x11.width = event->xconfigure.width;
                window->x11.height = event->xconfigure.height;
            }

            if (event->xconfigure.x != window->x11.xpos ||
                event->xconfigure.y != window->x11.ypos)
            {
                _glfwInputWindowPos(window,
                                    event->xconfigure.x,
                                    event->xconfigure.y);

                window->x11.xpos = event->xconfigure.x;
                window->x11.ypos = event->xconfigure.y;
            }

            break;
        }

        case ClientMessage:
        {
            // Custom client message, probably from the window manager

            if (event->xclient.message_type == None)
                break;

            if (event->xclient.message_type == _glfw.x11.WM_PROTOCOLS)
            {
                if (_glfw.x11.WM_DELETE_WINDOW &&
                    (Atom) event->xclient.data.l[0] == _glfw.x11.WM_DELETE_WINDOW)
                {
                    // The window manager was asked to close the window, for example by
                    // the user pressing a 'close' window decoration button

                    _glfwInputWindowCloseRequest(window);
                }
                else if (_glfw.x11.NET_WM_PING &&
                        (Atom) event->xclient.data.l[0] == _glfw.x11.NET_WM_PING)
                {
                    // The window manager is pinging the application to ensure it's
                    // still responding to events

                    event->xclient.window = _glfw.x11.root;
                    XSendEvent(_glfw.x11.display,
                            event->xclient.window,
                            False,
                            SubstructureNotifyMask | SubstructureRedirectMask,
                            event);
                }
            }
            else if (event->xclient.message_type == _glfw.x11.XdndEnter)
            {
                // A drag operation has entered the window
                // TODO: Check if UTF-8 string is supported by the source
            }
            else if (event->xclient.message_type == _glfw.x11.XdndDrop)
            {
                // The drag operation has finished dropping on
                // the window, ask to convert it to a UTF-8 string
                _glfw.x11.xdnd.source = event->xclient.data.l[0];
                XConvertSelection(_glfw.x11.display,
                                  _glfw.x11.XdndSelection,
                                  _glfw.x11.UTF8_STRING,
                                  _glfw.x11.XdndSelection,
                                  window->x11.handle, CurrentTime);
            }
            else if (event->xclient.message_type == _glfw.x11.XdndPosition)
            {
                // The drag operation has moved over the window
                const int absX = (event->xclient.data.l[2] >> 16) & 0xFFFF;
                const int absY = (event->xclient.data.l[2]) & 0xFFFF;
                int x, y;

                _glfwPlatformGetWindowPos(window, &x, &y);
                _glfwInputCursorMotion(window, absX - x, absY - y);

                // Reply that we are ready to copy the dragged data
                XEvent reply;
                memset(&reply, 0, sizeof(reply));

                reply.type = ClientMessage;
                reply.xclient.window = event->xclient.data.l[0];
                reply.xclient.message_type = _glfw.x11.XdndStatus;
                reply.xclient.format = 32;
                reply.xclient.data.l[0] = window->x11.handle;
                reply.xclient.data.l[1] = 1; // Always accept the dnd with no rectangle
                reply.xclient.data.l[2] = 0; // Specify an empty rectangle
                reply.xclient.data.l[3] = 0;
                reply.xclient.data.l[4] = _glfw.x11.XdndActionCopy;

                XSendEvent(_glfw.x11.display, event->xclient.data.l[0],
                           False, NoEventMask, &reply);
                XFlush(_glfw.x11.display);
            }

            break;
        }

        case SelectionNotify:
        {
            if (event->xselection.property)
            {
                // The converted data from the drag operation has arrived
                char* data;
                const int result =
                    _glfwGetWindowProperty(event->xselection.requestor,
                                           event->xselection.property,
                                           event->xselection.target,
                                           (unsigned char**) &data);

                if (result)
                {
                    int i, count;
                    char** names = parseUriList(data, &count);

                    _glfwInputDrop(window, count, (const char**) names);

                    for (i = 0;  i < count;  i++)
                        free(names[i]);
                    free(names);
                }

                XFree(data);

                XEvent reply;
                memset(&reply, 0, sizeof(reply));

                reply.type = ClientMessage;
                reply.xclient.window = _glfw.x11.xdnd.source;
                reply.xclient.message_type = _glfw.x11.XdndFinished;
                reply.xclient.format = 32;
                reply.xclient.data.l[0] = window->x11.handle;
                reply.xclient.data.l[1] = result;
                reply.xclient.data.l[2] = _glfw.x11.XdndActionCopy;

                // Reply that all is well
                XSendEvent(_glfw.x11.display, _glfw.x11.xdnd.source,
                           False, NoEventMask, &reply);
                XFlush(_glfw.x11.display);
            }

            break;
        }

        case MapNotify:
        {
            _glfwInputWindowVisibility(window, GL_TRUE);
            break;
        }

        case UnmapNotify:
        {
            _glfwInputWindowVisibility(window, GL_FALSE);
            break;
        }

        case FocusIn:
        {
            if (event->xfocus.mode == NotifyNormal)
            {
                _glfwInputWindowFocus(window, GL_TRUE);

                if (window->cursorMode == GLFW_CURSOR_DISABLED)
                    disableCursor(window);
            }

            break;
        }

        case FocusOut:
        {
            if (event->xfocus.mode == NotifyNormal)
            {
                _glfwInputWindowFocus(window, GL_FALSE);

                if (window->cursorMode == GLFW_CURSOR_DISABLED)
                    restoreCursor(window);
            }

            break;
        }

        case Expose:
        {
            _glfwInputWindowDamage(window);
            break;
        }

        case PropertyNotify:
        {
            if (event->xproperty.atom == _glfw.x11.WM_STATE &&
                event->xproperty.state == PropertyNewValue)
            {
                struct {
                    CARD32 state;
                    Window icon;
                } *state = NULL;

                if (_glfwGetWindowProperty(window->x11.handle,
                                           _glfw.x11.WM_STATE,
                                           _glfw.x11.WM_STATE,
                                           (unsigned char**) &state) >= 2)
                {
                    if (state->state == IconicState)
                        _glfwInputWindowIconify(window, GL_TRUE);
                    else if (state->state == NormalState)
                        _glfwInputWindowIconify(window, GL_FALSE);
                }

                XFree(state);
            }

            break;
        }

        case SelectionClear:
        {
            _glfwHandleSelectionClear(event);
            break;
        }

        case SelectionRequest:
        {
            _glfwHandleSelectionRequest(event);
            break;
        }

        case DestroyNotify:
            return;

        case GenericEvent:
        {
            if (event->xcookie.extension == _glfw.x11.xi.majorOpcode &&
                XGetEventData(_glfw.x11.display, &event->xcookie))
            {
                if (event->xcookie.evtype == XI_Motion)
                {
                    XIDeviceEvent* data = (XIDeviceEvent*) event->xcookie.data;

                    window = _glfwFindWindowByHandle(data->event);
                    if (window)
                    {
                        if (data->event_x != window->x11.warpPosX ||
                            data->event_y != window->x11.warpPosY)
                        {
                            // The cursor was moved by something other than GLFW

                            double x, y;

                            if (window->cursorMode == GLFW_CURSOR_DISABLED)
                            {
                                if (_glfw.focusedWindow != window)
                                    break;

                                x = data->event_x - window->x11.cursorPosX;
                                y = data->event_y - window->x11.cursorPosY;
                            }
                            else
                            {
                                x = data->event_x;
                                y = data->event_y;
                            }

                            _glfwInputCursorMotion(window, x, y);
                        }

                        window->x11.cursorPosX = data->event_x;
                        window->x11.cursorPosY = data->event_y;
                    }
                }
            }

            XFreeEventData(_glfw.x11.display, &event->xcookie);
            break;
        }

        default:
        {
            switch (event->type - _glfw.x11.randr.eventBase)
            {
                case RRScreenChangeNotify:
                {
                    XRRUpdateConfiguration(event);
                    break;
                }
            }

            break;
        }
    }
}


//////////////////////////////////////////////////////////////////////////
//////                       GLFW internal API                      //////
//////////////////////////////////////////////////////////////////////////

// Return the GLFW window corresponding to the specified X11 window
//
_GLFWwindow* _glfwFindWindowByHandle(Window handle)
{
    _GLFWwindow* window;

    if (XFindContext(_glfw.x11.display,
                     handle,
                     _glfw.x11.context,
                     (XPointer*) &window) != 0)
    {
        return NULL;
    }

    return window;
}

// Retrieve a single window property of the specified type
// Inspired by fghGetWindowProperty from freeglut
//
unsigned long _glfwGetWindowProperty(Window window,
                                     Atom property,
                                     Atom type,
                                     unsigned char** value)
{
    Atom actualType;
    int actualFormat;
    unsigned long itemCount, bytesAfter;

    XGetWindowProperty(_glfw.x11.display,
                       window,
                       property,
                       0,
                       LONG_MAX,
                       False,
                       type,
                       &actualType,
                       &actualFormat,
                       &itemCount,
                       &bytesAfter,
                       value);

    if (type != AnyPropertyType && actualType != type)
        return 0;

    return itemCount;
}


//////////////////////////////////////////////////////////////////////////
//////                       GLFW platform API                      //////
//////////////////////////////////////////////////////////////////////////

int _glfwPlatformCreateWindow(_GLFWwindow* window,
                              const _GLFWwndconfig* wndconfig,
                              const _GLFWctxconfig* ctxconfig,
                              const _GLFWfbconfig* fbconfig)
{
    if (!_glfwCreateContext(window, ctxconfig, fbconfig))
        return GL_FALSE;

    if (!createWindow(window, wndconfig))
        return GL_FALSE;

    if (wndconfig->monitor)
    {
        _glfwPlatformShowWindow(window);
        enterFullscreenMode(window);
    }

    return GL_TRUE;
}

void _glfwPlatformDestroyWindow(_GLFWwindow* window)
{
    if (window->monitor)
        leaveFullscreenMode(window);

    _glfwDestroyContext(window);

    if (window->x11.handle)
    {
        if (window->x11.handle ==
            XGetSelectionOwner(_glfw.x11.display, _glfw.x11.CLIPBOARD))
        {
            _glfwPushSelectionToManager(window);
        }

        XDeleteContext(_glfw.x11.display, window->x11.handle, _glfw.x11.context);
        XUnmapWindow(_glfw.x11.display, window->x11.handle);
        XDestroyWindow(_glfw.x11.display, window->x11.handle);
        window->x11.handle = (Window) 0;
    }

    if (window->x11.colormap)
    {
        XFreeColormap(_glfw.x11.display, window->x11.colormap);
        window->x11.colormap = (Colormap) 0;
    }

    XFlush(_glfw.x11.display);
}

void _glfwPlatformSetWindowTitle(_GLFWwindow* window, const char* title)
{
#if defined(X_HAVE_UTF8_STRING)
    Xutf8SetWMProperties(_glfw.x11.display,
                         window->x11.handle,
                         title, title,
                         NULL, 0,
                         NULL, NULL, NULL);
#else
    // This may be a slightly better fallback than using XStoreName and
    // XSetIconName, which always store their arguments using STRING
    XmbSetWMProperties(_glfw.x11.display,
                       window->x11.handle,
                       title, title,
                       NULL, 0,
                       NULL, NULL, NULL);
#endif

    if (_glfw.x11.NET_WM_NAME)
    {
        XChangeProperty(_glfw.x11.display,  window->x11.handle,
                        _glfw.x11.NET_WM_NAME, _glfw.x11.UTF8_STRING, 8,
                        PropModeReplace,
                        (unsigned char*) title, strlen(title));
    }

    if (_glfw.x11.NET_WM_ICON_NAME)
    {
        XChangeProperty(_glfw.x11.display,  window->x11.handle,
                        _glfw.x11.NET_WM_ICON_NAME, _glfw.x11.UTF8_STRING, 8,
                        PropModeReplace,
                        (unsigned char*) title, strlen(title));
    }

    XFlush(_glfw.x11.display);
}

void _glfwPlatformGetWindowPos(_GLFWwindow* window, int* xpos, int* ypos)
{
    Window child;
    int x, y;

    XTranslateCoordinates(_glfw.x11.display, window->x11.handle, _glfw.x11.root,
                          0, 0, &x, &y, &child);

    if (child)
    {
        int left, top;
        XTranslateCoordinates(_glfw.x11.display, window->x11.handle, child,
                              0, 0, &left, &top, &child);

        x -= left;
        y -= top;
    }

    if (xpos)
        *xpos = x;
    if (ypos)
        *ypos = y;
}

void _glfwPlatformSetWindowPos(_GLFWwindow* window, int xpos, int ypos)
{
    XMoveWindow(_glfw.x11.display, window->x11.handle, xpos, ypos);
    XFlush(_glfw.x11.display);
}

void _glfwPlatformGetWindowSize(_GLFWwindow* window, int* width, int* height)
{
    XWindowAttributes attribs;
    XGetWindowAttributes(_glfw.x11.display, window->x11.handle, &attribs);

    if (width)
        *width = attribs.width;
    if (height)
        *height = attribs.height;
}

void _glfwPlatformSetWindowSize(_GLFWwindow* window, int width, int height)
{
    if (window->monitor)
    {
        _glfwSetVideoMode(window->monitor, &window->videoMode);

        if (window->x11.overrideRedirect)
        {
            GLFWvidmode mode;
            _glfwPlatformGetVideoMode(window->monitor, &mode);
            XResizeWindow(_glfw.x11.display, window->x11.handle,
                          mode.width, mode.height);
        }
    }
    else
    {
        if (!window->resizable)
        {
            // Update window size restrictions to match new window size

            XSizeHints* hints = XAllocSizeHints();

            hints->flags |= (PMinSize | PMaxSize);
            hints->min_width  = hints->max_width  = width;
            hints->min_height = hints->max_height = height;

            XSetWMNormalHints(_glfw.x11.display, window->x11.handle, hints);
            XFree(hints);
        }

        XResizeWindow(_glfw.x11.display, window->x11.handle, width, height);
    }

    XFlush(_glfw.x11.display);
}

void _glfwPlatformGetFramebufferSize(_GLFWwindow* window, int* width, int* height)
{
    _glfwPlatformGetWindowSize(window, width, height);
}

void _glfwPlatformGetWindowFrameSize(_GLFWwindow* window,
                                     int* left, int* top,
                                     int* right, int* bottom)
{
    long* extents = NULL;

    if (_glfw.x11.NET_FRAME_EXTENTS == None)
        return;

    if (_glfwGetWindowProperty(window->x11.handle,
                               _glfw.x11.NET_FRAME_EXTENTS,
                               XA_CARDINAL,
                               (unsigned char**) &extents) == 4)
    {
        if (left)
            *left = extents[0];
        if (top)
            *top = extents[2];
        if (right)
            *right = extents[1];
        if (bottom)
            *bottom = extents[3];
    }

    if (extents)
        XFree(extents);
}

void _glfwPlatformIconifyWindow(_GLFWwindow* window)
{
    if (window->x11.overrideRedirect)
    {
        // Override-redirect windows cannot be iconified or restored, as those
        // tasks are performed by the window manager
        _glfwInputError(GLFW_API_UNAVAILABLE,
                        "X11: Iconification of full screen windows requires "
                        "a WM that supports EWMH");
        return;
    }

    XIconifyWindow(_glfw.x11.display, window->x11.handle, _glfw.x11.screen);
    XFlush(_glfw.x11.display);
}

void _glfwPlatformRestoreWindow(_GLFWwindow* window)
{
    if (window->x11.overrideRedirect)
    {
        // Override-redirect windows cannot be iconified or restored, as those
        // tasks are performed by the window manager
        _glfwInputError(GLFW_API_UNAVAILABLE,
                        "X11: Iconification of full screen windows requires "
                        "a WM that supports EWMH");
        return;
    }

    XMapWindow(_glfw.x11.display, window->x11.handle);
    XFlush(_glfw.x11.display);
}

void _glfwPlatformShowWindow(_GLFWwindow* window)
{
    XMapRaised(_glfw.x11.display, window->x11.handle);
    XFlush(_glfw.x11.display);
}

void _glfwPlatformHideWindow(_GLFWwindow* window)
{
    XUnmapWindow(_glfw.x11.display, window->x11.handle);
    XFlush(_glfw.x11.display);
}

void _glfwPlatformPollEvents(void)
{
    int count = XPending(_glfw.x11.display);
    while (count--)
    {
        XEvent event;
        XNextEvent(_glfw.x11.display, &event);
        processEvent(&event);
    }

    _GLFWwindow* window = _glfw.focusedWindow;
    if (window && window->cursorMode == GLFW_CURSOR_DISABLED)
    {
        int width, height;
        _glfwPlatformGetWindowSize(window, &width, &height);
        _glfwPlatformSetCursorPos(window, width / 2, height / 2);
    }
}

void _glfwPlatformWaitEvents(void)
{
    if (!XPending(_glfw.x11.display))
    {
        fd_set fds;
        const int fd = ConnectionNumber(_glfw.x11.display);

        FD_ZERO(&fds);
        FD_SET(fd, &fds);

        // select(1) is used instead of an X function like XNextEvent, as the
        // wait inside those are guarded by the mutex protecting the display
        // struct, locking out other threads from using X (including GLX)
        if (select(fd + 1, &fds, NULL, NULL, NULL) < 0)
            return;
    }

    _glfwPlatformPollEvents();
}

void _glfwPlatformPostEmptyEvent(void)
{
    XEvent event;
    _GLFWwindow* window = _glfw.windowListHead;

    memset(&event, 0, sizeof(event));
    event.type = ClientMessage;
    event.xclient.window = window->x11.handle;
    event.xclient.format = 32; // Data is 32-bit longs
    event.xclient.message_type = _glfw.x11._NULL;

    XSendEvent(_glfw.x11.display, window->x11.handle, False, 0, &event);
    XFlush(_glfw.x11.display);
}

void _glfwPlatformSetCursorPos(_GLFWwindow* window, double x, double y)
{
    // Store the new position so it can be recognized later
    window->x11.warpPosX = (int) x;
    window->x11.warpPosY = (int) y;

    XWarpPointer(_glfw.x11.display, None, window->x11.handle,
                 0,0,0,0, (int) x, (int) y);
}

void _glfwPlatformApplyCursorMode(_GLFWwindow* window)
{
    switch (window->cursorMode)
    {
        case GLFW_CURSOR_NORMAL:
            restoreCursor(window);
            break;
        case GLFW_CURSOR_HIDDEN:
            hideCursor(window);
            break;
        case GLFW_CURSOR_DISABLED:
            disableCursor(window);
            break;
    }
}

int _glfwPlatformCreateCursor(_GLFWcursor* cursor,
                              const GLFWimage* image,
                              int xhot, int yhot)
{
    int i;

    XcursorImage* native = XcursorImageCreate(image->width, image->height);
    if (native == NULL)
        return GL_FALSE;

    native->xhot = xhot;
    native->yhot = yhot;

    unsigned char* source = (unsigned char*) image->pixels;
    XcursorPixel* target = native->pixels;

    for (i = 0;  i < image->width * image->height;  i++, target++, source += 4)
    {
        *target = (source[3] << 24) |
                  (source[0] << 16) |
                  (source[1] <<  8) |
                   source[2];
    }

    cursor->x11.handle = XcursorImageLoadCursor(_glfw.x11.display, native);
    XcursorImageDestroy(native);

    if (cursor->x11.handle == None)
        return GL_FALSE;

    return GL_TRUE;
}

void _glfwPlatformDestroyCursor(_GLFWcursor* cursor)
{
    if (cursor->x11.handle)
        XFreeCursor(_glfw.x11.display, cursor->x11.handle);
}

void _glfwPlatformSetCursor(_GLFWwindow* window, _GLFWcursor* cursor)
{
    if (window->cursorMode == GLFW_CURSOR_NORMAL)
    {
        if (cursor)
            XDefineCursor(_glfw.x11.display, window->x11.handle, cursor->x11.handle);
        else
            XUndefineCursor(_glfw.x11.display, window->x11.handle);

        XFlush(_glfw.x11.display);
    }
}


//////////////////////////////////////////////////////////////////////////
//////                        GLFW native API                       //////
//////////////////////////////////////////////////////////////////////////

GLFWAPI Display* glfwGetX11Display(void)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    return _glfw.x11.display;
}

GLFWAPI Window glfwGetX11Window(GLFWwindow* handle)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    _GLFW_REQUIRE_INIT_OR_RETURN(None);
    return window->x11.handle;
}