/*
 * This event handling stuff was inspired on Tk.
 */

#include "WINGsP.h"


/* table to map event types to event masks */
static unsigned long eventMasks[] = {
    0,
    0,
    KeyPressMask,                       /* KeyPress */
    KeyReleaseMask,                     /* KeyRelease */
    ButtonPressMask,                    /* ButtonPress */
    ButtonReleaseMask,                  /* ButtonRelease */
    PointerMotionMask|PointerMotionHintMask|ButtonMotionMask
    |Button1MotionMask|Button2MotionMask|Button3MotionMask
    |Button4MotionMask|Button5MotionMask,
    /* MotionNotify */
    EnterWindowMask,                    /* EnterNotify */
    LeaveWindowMask,                    /* LeaveNotify */
    FocusChangeMask,                    /* FocusIn */
    FocusChangeMask,                    /* FocusOut */
    KeymapStateMask,                    /* KeymapNotify */
    ExposureMask,                       /* Expose */
    ExposureMask,                       /* GraphicsExpose */
    ExposureMask,                       /* NoExpose */
    VisibilityChangeMask,               /* VisibilityNotify */
    SubstructureNotifyMask,             /* CreateNotify */
    StructureNotifyMask,                /* DestroyNotify */
    StructureNotifyMask,                /* UnmapNotify */
    StructureNotifyMask,                /* MapNotify */
    SubstructureRedirectMask,           /* MapRequest */
    StructureNotifyMask,                /* ReparentNotify */
    StructureNotifyMask,                /* ConfigureNotify */
    SubstructureRedirectMask,           /* ConfigureRequest */
    StructureNotifyMask,                /* GravityNotify */
    ResizeRedirectMask,                 /* ResizeRequest */
    StructureNotifyMask,                /* CirculateNotify */
    SubstructureRedirectMask,           /* CirculateRequest */
    PropertyChangeMask,                 /* PropertyNotify */
    0,                                  /* SelectionClear */
    0,                                  /* SelectionRequest */
    0,                                  /* SelectionNotify */
    ColormapChangeMask,                 /* ColormapNotify */
    ClientMessageMask,		        /* ClientMessage */
    0,			                /* Mapping Notify */
};



/* hook for other toolkits or wmaker process their events */
static WMEventHook *extraEventHandler=NULL;





/*
 * WMCreateEventHandler--
 * 	Create an event handler and put it in the event handler list for the
 * view. If the same callback and clientdata are already used in another
 * handler, the masks are OR'ed.
 *
 */
void
WMCreateEventHandler(WMView *view, unsigned long mask, WMEventProc *eventProc,
                     void *clientData)
{
    W_EventHandler *hPtr;
    WMArrayIterator iter;

    WM_ITERATE_ARRAY(view->eventHandlers, hPtr, iter) {
        if (hPtr->clientData==clientData && hPtr->proc==eventProc) {
            hPtr->eventMask |= mask;
            return;
        }
    }

    hPtr = wmalloc(sizeof(W_EventHandler));

    /* select events for window */
    hPtr->eventMask = mask;
    hPtr->proc = eventProc;
    hPtr->clientData = clientData;

    WMAddToArray(view->eventHandlers, hPtr);
}


static int
matchHandler(void *item, void *cdata)
{
#define H1 ((W_EventHandler*)item)
#define H2 ((W_EventHandler*)cdata)

    return (H1->eventMask==H2->eventMask && H1->proc==H2->proc &&
            H1->clientData==H2->clientData);
}


/*
 * WMDeleteEventHandler--
 * 	Delete event handler matching arguments from windows
 * event handler list.
 *
 */
void
WMDeleteEventHandler(WMView *view, unsigned long mask, WMEventProc *eventProc,
                     void *clientData)
{
    W_EventHandler tmp;

    tmp.eventMask = mask;
    tmp.proc = eventProc;
    tmp.clientData = clientData;
    WMRemoveFromArrayMatching(view->eventHandlers, matchHandler, (void*)&tmp);
}


static Time
getEventTime(WMScreen *screen, XEvent *event)
{
    switch (event->type) {
    case ButtonPress:
    case ButtonRelease:
        return event->xbutton.time;
    case KeyPress:
    case KeyRelease:
        return event->xkey.time;
    case MotionNotify:
        return event->xmotion.time;
    case EnterNotify:
    case LeaveNotify:
        return event->xcrossing.time;
    case PropertyNotify:
        return event->xproperty.time;
    case SelectionClear:
        return event->xselectionclear.time;
    case SelectionRequest:
        return event->xselectionrequest.time;
    case SelectionNotify:
        return event->xselection.time;
    default:
        return screen->lastEventTime;
    }
}


void
W_CallDestroyHandlers(W_View *view)
{
    XEvent event;
    WMArrayIterator iter;
    W_EventHandler *hPtr;


    event.type = DestroyNotify;
    event.xdestroywindow.window = view->window;
    event.xdestroywindow.event = view->window;

    WM_ITERATE_ARRAY(view->eventHandlers, hPtr, iter) {
        if (hPtr->eventMask & StructureNotifyMask) {
            (*hPtr->proc)(&event, hPtr->clientData);
        }
    }
}



void
WMSetViewNextResponder(WMView *view, WMView *responder)
{
    /* set the widget to receive keyboard events that aren't handled
     * by this widget */

    view->nextResponder = responder;
}


void
WMRelayToNextResponder(WMView *view, XEvent *event)
{
    unsigned long mask = eventMasks[event->xany.type];

    if (view->nextResponder) {
        WMView *next = view->nextResponder;
        W_EventHandler *hPtr;
        WMArrayIterator iter;

        WM_ITERATE_ARRAY(next->eventHandlers, hPtr, iter) {
            if ((hPtr->eventMask & mask)) {
                (*hPtr->proc)(event, hPtr->clientData);
            }
        }
    }
}


int
WMHandleEvent(XEvent *event)
{
    W_EventHandler *hPtr;
    W_View *view, *toplevel;
    unsigned long mask;
    Window window;
    WMArrayIterator iter;

    if (event->type == MappingNotify) {
        XRefreshKeyboardMapping(&event->xmapping);
        return True;
    }

    if (XFilterEvent(event, None) == True) {
        return False;
    }

    mask = eventMasks[event->xany.type];

    window = event->xany.window;

    /* diferentiate SubstructureNotify with StructureNotify */
    if (mask == StructureNotifyMask) {
        if (event->xmap.event != event->xmap.window) {
            mask = SubstructureNotifyMask;
            window = event->xmap.event;
        }
    }
    view = W_GetViewForXWindow(event->xany.display, window);

    if (!view) {
        if (extraEventHandler)
            (extraEventHandler)(event);

        return False;
    }

    view->screen->lastEventTime = getEventTime(view->screen, event);

    toplevel = W_TopLevelOfView(view);

    if (event->type == SelectionNotify || event->type == SelectionClear
        || event->type == SelectionRequest) {
        /* handle selection related events */
        W_HandleSelectionEvent(event);

    }

    /* if it's a key event, redispatch it to the focused control */
    if (mask & (KeyPressMask|KeyReleaseMask)) {
        W_View *focused = W_FocusedViewOfToplevel(toplevel);

        if (focused) {
            view = focused;
        }
    }

    /* compress Motion events */
    if (event->type == MotionNotify && !view->flags.dontCompressMotion) {
        while (XPending(event->xmotion.display)) {
            XEvent ev;
            XPeekEvent(event->xmotion.display, &ev);
            if (ev.type == MotionNotify
                && event->xmotion.window == ev.xmotion.window
                && event->xmotion.subwindow == ev.xmotion.subwindow) {
                /* replace events */
                XNextEvent(event->xmotion.display, event);
            } else break;
        }
    }

    /* compress expose events */
    if (event->type == Expose && !view->flags.dontCompressExpose) {
        while (XCheckTypedWindowEvent(event->xexpose.display, view->window,
                                      Expose, event));
    }


    if (view->screen->modalLoop && toplevel!=view->screen->modalView
        && !toplevel->flags.worksWhenModal) {
        if (event->type == KeyPress || event->type == KeyRelease
            || event->type == MotionNotify || event->type == ButtonPress
            || event->type == ButtonRelease
            || event->type == FocusIn || event->type == FocusOut) {
            return True;
        }
    }

    /* do balloon stuffs */
    if (event->type == EnterNotify)
        W_BalloonHandleEnterView(view);
    else if (event->type == LeaveNotify)
        W_BalloonHandleLeaveView(view);

    /* This is a hack. It will make the panel be secure while
     * the event handlers are handled, as some event handler
     * might destroy the widget. */
    W_RetainView(toplevel);

    WM_ITERATE_ARRAY(view->eventHandlers, hPtr, iter) {
        if ((hPtr->eventMask & mask)) {
            (*hPtr->proc)(event, hPtr->clientData);
        }
    }
#if 0
    /* pass the event to the top level window of the widget */
    /* TODO: change this to a responder chain */
    if (view->parent != NULL) {
        vPtr = view;
        while (vPtr->parent != NULL)
            vPtr = vPtr->parent;

        WM_ITERATE_ARRAY(vPtr->eventHandlers, hPtr, iter) {
            if (hPtr->eventMask & mask) {
                (*hPtr->proc)(event, hPtr->clientData);
            }
        }
    }
#endif
    /* save button click info to track double-clicks */
    if (view->screen->ignoreNextDoubleClick) {
        view->screen->ignoreNextDoubleClick = 0;
    } else {
        if (event->type == ButtonPress) {
            view->screen->lastClickWindow = event->xbutton.window;
            view->screen->lastClickTime = event->xbutton.time;
        }
    }

    if (event->type == ClientMessage) {
        /* must be handled at the end, for such message can destroy the view */
        W_HandleDNDClientMessage(toplevel, &event->xclient);
    }

    W_ReleaseView(toplevel);

    return True;
}


int
WMIsDoubleClick(XEvent *event)
{
    W_View *view;

    if (event->type != ButtonPress)
        return False;

    view = W_GetViewForXWindow(event->xany.display, event->xbutton.window);

    if (!view)
        return False;

    if (view->screen->lastClickWindow != event->xbutton.window)
        return False;

    if (event->xbutton.time - view->screen->lastClickTime
        < WINGsConfiguration.doubleClickDelay) {
        view->screen->lastClickTime = 0;
        view->screen->lastClickWindow = None;
        view->screen->ignoreNextDoubleClick = 1;
        return True;
    } else
        return False;
}


/*
 * Check for X and input events. If X events are present input events will
 * not be checked.
 *
 * Return value: True if a X event is available or any input event was
 *               processed, false otherwise (including return because of
 *               some timer handler expired).
 *
 *  If waitForInput is False, it will just peek for available input and return
 * without processing. Return vaue will be True if input is available.
 *
 *  If waitForInput is True, it will wait until an input event arrives on the
 * registered input handlers and ConnectionNumber(dpy), or will return when
 * a timer handler expires if no input event arrived until then.
 */
static Bool
waitForEvent(Display *dpy, unsigned long xeventmask, Bool waitForInput)
{
    XSync(dpy, False);
    if (xeventmask==0) {
        if (XPending(dpy))
            return True;
    } else {
        XEvent ev;
        if (XCheckMaskEvent(dpy, xeventmask, &ev)) {
            XPutBackEvent(dpy, &ev);
            return True;
        }
    }

    return W_HandleInputEvents(waitForInput, ConnectionNumber(dpy));
}


void
WMNextEvent(Display *dpy, XEvent *event)
{
    /* Check any expired timers */
    W_CheckTimerHandlers();

    while (XPending(dpy) == 0) {
        /* Do idle and timer stuff while there are no input or X events */
        while (!waitForEvent(dpy, 0, False) && W_CheckIdleHandlers()) {
            /* dispatch timer events */
            W_CheckTimerHandlers();
        }

        /*
         * Make sure that new events did not arrive while we were doing
         * timer/idle stuff. Or we might block forever waiting for
         * an event that already arrived.
         */
        /* wait for something to happen or a timer to expire */
        waitForEvent(dpy, 0, True);

        /* Check any expired timers */
        W_CheckTimerHandlers();
    }

    XNextEvent(dpy, event);
}


void
WMMaskEvent(Display *dpy, long mask, XEvent *event)
{
    /* Check any expired timers */
    W_CheckTimerHandlers();

    while (!XCheckMaskEvent(dpy, mask, event)) {
        /* Do idle and timer stuff while there are no input or X events */
        while (!waitForEvent(dpy, mask, False) && W_CheckIdleHandlers()) {
            W_CheckTimerHandlers();
        }

        if (XCheckMaskEvent(dpy, mask, event))
            return;

        /* Wait for input on the X connection socket or another input handler */
        waitForEvent(dpy, mask, True);

        /* Check any expired timers */
        W_CheckTimerHandlers();
    }
}


Bool
WMScreenPending(WMScreen *scr)
{
    if (XPending(scr->display))
        return True;
    else
        return False;
}


WMEventHook*
WMHookEventHandler(WMEventHook *handler)
{
    WMEventHook *oldHandler = extraEventHandler;

    extraEventHandler = handler;

    return oldHandler;
}