/*
 * Smithsonian Astrophysical Observatory, Cambridge, MA, USA
 * This code has been modified under the terms listed below and is made
 * available under the same terms.
 */

/*
 *	Copyright 1998 George A Howlett.
 *
 *	Permission is hereby granted, free of charge, to any person obtaining
 *	a copy of this software and associated documentation files (the
 *	"Software"), to deal in the Software without restriction, including
 *	without limitation the rights to use, copy, modify, merge, publish,
 *	distribute, sublicense, and/or sell copies of the Software, and to
 *	permit persons to whom the Software is furnished to do so, subject to
 *	the following conditions:
 *
 *	The above copyright notice and this permission notice shall be
 *	included in all copies or substantial portions of the Software.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *	EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *	MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *	NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *	LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *	OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *	WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include "bltC.h"

extern "C" {
#include "bltInt.h"
#include "bltBind.h"
};

#define MAX_STATIC_TAGS	64

static Tk_EventProc BindProc;

typedef struct _Blt_BindTable BindTable;

/*
 * Binding table procedures.
 */
#define REPICK_IN_PROGRESS (1<<0)
#define LEFT_GRABBED_ITEM  (1<<1)

#define ALL_BUTTONS_MASK						\
  (Button1Mask | Button2Mask | Button3Mask | Button4Mask | Button5Mask)

#ifndef VirtualEventMask
#define VirtualEventMask    (1L << 30)
#endif

#define ALL_VALID_EVENTS_MASK					\
  (ButtonMotionMask | Button1MotionMask | Button2MotionMask |	\
   Button3MotionMask | Button4MotionMask | Button5MotionMask |	\
   ButtonPressMask | ButtonReleaseMask | EnterWindowMask |	\
   LeaveWindowMask | KeyPressMask | KeyReleaseMask |		\
   PointerMotionMask | VirtualEventMask)

  static int buttonMasks[] =
    {0, Button1Mask, Button2Mask, Button3Mask, Button4Mask, Button5Mask};


/*
 * How to make drag&drop work?
 *
 *	Right now we generate pseudo <Enter> <Leave> events within button grab
 *	on an object.  They're marked NotifyVirtual instead of NotifyAncestor.
 *	A better solution: generate new-style virtual <<DragEnter>>
 *	<<DragMotion>> <<DragLeave>> events.  These virtual events don't have
 *	to exist as "real" event sequences, like virtual events do now.
 */

/*
 *---------------------------------------------------------------------------
 *
 * DoEvent --
 *
 *	This procedure is called to invoke binding processing for a new event
 *	that is associated with the current item for a legend.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Depends on the bindings for the legend.  A binding script could delete
 *	an entry, so callers should protect themselves with Tcl_Preserve and
 *	Tcl_Release.
 *
 *---------------------------------------------------------------------------
 */
static void DoEvent(BindTable *bindPtr, XEvent *eventPtr, 
		    ClientData item, ClientData context)
{
  Blt_List tagList;

  if (!bindPtr->tkwin || !bindPtr->bindingTable)
    return;

  if ((eventPtr->type == KeyPress) || (eventPtr->type == KeyRelease)) {
    item = bindPtr->focusItem;
    context = bindPtr->focusContext;
  }
  if (!item)
    return;

  // Invoke the binding system.
  tagList = Blt_List_Create(BLT_ONE_WORD_KEYS);
  if (!bindPtr->tagProc) {
    Blt_List_Append(tagList, Tk_GetUid("all"), 0);
    Blt_List_Append(tagList, (char *)item, 0);
  }
  else
    (*bindPtr->tagProc)(bindPtr, item, context, tagList);

  if (Blt_List_GetLength(tagList) > 0) {
    ClientData staticTags[MAX_STATIC_TAGS];
    ClientData *tagArray = staticTags;
    int nTags = Blt_List_GetLength(tagList);
    if (nTags >= MAX_STATIC_TAGS) {
      tagArray = (ClientData*)malloc(sizeof(ClientData) * nTags);
	    
    } 
    nTags = 0;
    for (Blt_ListNode node = Blt_List_FirstNode(tagList); node != NULL;
	 node = Blt_List_NextNode(node)) {
      tagArray[nTags++] = (ClientData)Blt_List_GetKey(node);
    }
    Tk_BindEvent(bindPtr->bindingTable, eventPtr, bindPtr->tkwin, nTags, 
		 tagArray);
    if (tagArray != staticTags) {
      free(tagArray);
    }
  }
  Blt_List_Destroy(tagList);
}

static void PickCurrentItem(BindTable *bindPtr,	XEvent *eventPtr)
{
  ClientData newItem, oldItem;
  ClientData newContext;

  // Check whether or not a button is down.  If so, we'll log entry and exit
  // into and out of the current item, but not entry into any other item.
  // This implements a form of grabbing equivalent to what the X server does
  // for windows.
  int buttonDown = (bindPtr->state & ALL_BUTTONS_MASK);
  if (!buttonDown)
    bindPtr->flags &= ~LEFT_GRABBED_ITEM;

  /*
   * Save information about this event in the widget.  The event in the
   * widget is used for two purposes:
   *
   * 1. Event bindings: if the current item changes, fake events are
   *    generated to allow item-enter and item-leave bindings to trigger.
   * 2. Reselection: if the current item gets deleted, can use the
   *    saved event to find a new current item.
   * Translate MotionNotify events into EnterNotify events, since that's
   * what gets reported to item handlers.
   */

  if (eventPtr != &bindPtr->pickEvent) {
    if ((eventPtr->type == MotionNotify) ||
	(eventPtr->type == ButtonRelease)) {
      bindPtr->pickEvent.xcrossing.type = EnterNotify;
      bindPtr->pickEvent.xcrossing.serial = eventPtr->xmotion.serial;
      bindPtr->pickEvent.xcrossing.send_event =
	eventPtr->xmotion.send_event;
      bindPtr->pickEvent.xcrossing.display = eventPtr->xmotion.display;
      bindPtr->pickEvent.xcrossing.window = eventPtr->xmotion.window;
      bindPtr->pickEvent.xcrossing.root = eventPtr->xmotion.root;
      bindPtr->pickEvent.xcrossing.subwindow = None;
      bindPtr->pickEvent.xcrossing.time = eventPtr->xmotion.time;
      bindPtr->pickEvent.xcrossing.x = eventPtr->xmotion.x;
      bindPtr->pickEvent.xcrossing.y = eventPtr->xmotion.y;
      bindPtr->pickEvent.xcrossing.x_root = eventPtr->xmotion.x_root;
      bindPtr->pickEvent.xcrossing.y_root = eventPtr->xmotion.y_root;
      bindPtr->pickEvent.xcrossing.mode = NotifyNormal;
      bindPtr->pickEvent.xcrossing.detail = NotifyNonlinear;
      bindPtr->pickEvent.xcrossing.same_screen
	= eventPtr->xmotion.same_screen;
      bindPtr->pickEvent.xcrossing.focus = False;
      bindPtr->pickEvent.xcrossing.state = eventPtr->xmotion.state;
    } else {
      bindPtr->pickEvent = *eventPtr;
    }
  }
  bindPtr->activePick = 1;

  /*
   * If this is a recursive call (there's already a partially completed call
   * pending on the stack; it's in the middle of processing a Leave event
   * handler for the old current item) then just return; the pending call
   * will do everything that's needed.
   */
  if (bindPtr->flags & REPICK_IN_PROGRESS)
    return;

  /*
   * A LeaveNotify event automatically means that there's no current item,
   * so the check for closest item can be skipped.
   */
  newContext = NULL;
  if (bindPtr->pickEvent.type != LeaveNotify) {
    int x, y;

    x = bindPtr->pickEvent.xcrossing.x;
    y = bindPtr->pickEvent.xcrossing.y;
    newItem = (*bindPtr->pickProc) (bindPtr->clientData, x, y, &newContext);
  }
  else
    newItem = NULL;

  // Nothing to do:  the current item hasn't changed.
  if (((newItem == bindPtr->currentItem) && 
       (newContext == bindPtr->currentContext)) && 
      ((bindPtr->flags & LEFT_GRABBED_ITEM) == 0))
    return;

  /*
   * Simulate a LeaveNotify event on the previous current item and an
   * EnterNotify event on the new current item.  Remove the "current" tag
   * from the previous current item and place it on the new current item.
   */
  oldItem = bindPtr->currentItem;
  Tcl_Preserve(oldItem);
  Tcl_Preserve(newItem);

  if ((bindPtr->currentItem != NULL) &&
      ((newItem != bindPtr->currentItem) || 
       (newContext != bindPtr->currentContext)) && 
      ((bindPtr->flags & LEFT_GRABBED_ITEM) == 0)) {
    XEvent event;

    event = bindPtr->pickEvent;
    event.type = LeaveNotify;
    /*
     * If the event's detail happens to be NotifyInferior the binding
     * mechanism will discard the event.  To be consistent, always use
     * NotifyAncestor.
     */
    event.xcrossing.detail = NotifyAncestor;

    bindPtr->flags |= REPICK_IN_PROGRESS;
    DoEvent(bindPtr, &event, bindPtr->currentItem, bindPtr->currentContext);
    bindPtr->flags &= ~REPICK_IN_PROGRESS;

    /*
     * Note: during DoEvent above, it's possible that bindPtr->newItem got
     * reset to NULL because the item was deleted.
     */
  }
  if (((newItem != bindPtr->currentItem) || 
       (newContext != bindPtr->currentContext)) && 
      (buttonDown)) {
    XEvent event;

    bindPtr->flags |= LEFT_GRABBED_ITEM;
    event = bindPtr->pickEvent;
    if ((newItem != bindPtr->newItem) || 
	(newContext != bindPtr->newContext)) {
      ClientData savedItem;
      ClientData savedContext;

      /*
       * Generate <Enter> and <Leave> events for objects during button
       * grabs.  This isn't standard. But for example, it allows one to
       * provide balloon help on the individual entries of the Hierbox
       * widget.
       */
      savedItem = bindPtr->currentItem;
      savedContext = bindPtr->currentContext;
      if (bindPtr->newItem != NULL) {
	event.type = LeaveNotify;
	event.xcrossing.detail = NotifyVirtual /* Ancestor */ ;
	bindPtr->currentItem = bindPtr->newItem;
	DoEvent(bindPtr, &event, bindPtr->newItem, bindPtr->newContext);
      }
      bindPtr->newItem = newItem;
      bindPtr->newContext = newContext;
      if (newItem != NULL) {
	event.type = EnterNotify;
	event.xcrossing.detail = NotifyVirtual /* Ancestor */ ;
	bindPtr->currentItem = newItem;
	DoEvent(bindPtr, &event, newItem, newContext);
      }
      bindPtr->currentItem = savedItem;
      bindPtr->currentContext = savedContext;
    }
    goto done;
  }
  /*
   * Special note:  it's possible that
   *		bindPtr->newItem == bindPtr->currentItem
   * here.  This can happen, for example, if LEFT_GRABBED_ITEM was set.
   */

  bindPtr->flags &= ~LEFT_GRABBED_ITEM;
  bindPtr->currentItem = bindPtr->newItem = newItem;
  bindPtr->currentContext = bindPtr->newContext = newContext;
  if (bindPtr->currentItem != NULL) {
    XEvent event;

    event = bindPtr->pickEvent;
    event.type = EnterNotify;
    event.xcrossing.detail = NotifyAncestor;
    DoEvent(bindPtr, &event, newItem, newContext);
  }
 done:
  Tcl_Release(newItem);
  Tcl_Release(oldItem);
}

static void BindProc(ClientData clientData, XEvent *eventPtr)
{
  BindTable *bindPtr = (BindTable*)clientData;
  int mask;

  Tcl_Preserve(bindPtr->clientData);
  /*
   * This code below keeps track of the current modifier state in
   * bindPtr->state.  This information is used to defer repicks of the
   * current item while buttons are down.
   */
  switch (eventPtr->type) {
  case ButtonPress:
  case ButtonRelease:
    mask = 0;
    if ((eventPtr->xbutton.button >= Button1) &&
	(eventPtr->xbutton.button <= Button5)) {
      mask = buttonMasks[eventPtr->xbutton.button];
    }
    /*
     * For button press events, repick the current item using the button
     * state before the event, then process the event.  For button release
     * events, first process the event, then repick the current item using
     * the button state *after* the event (the button has logically gone
     * up before we change the current item).
     */
    if (eventPtr->type == ButtonPress) {

      /*
       * On a button press, first repick the current item using the
       * button state before the event, the process the event.
       */

      bindPtr->state = eventPtr->xbutton.state;
      PickCurrentItem(bindPtr, eventPtr);
      bindPtr->state ^= mask;
      DoEvent(bindPtr, eventPtr, bindPtr->currentItem, 
	      bindPtr->currentContext);

    } else {

      /*
       * Button release: first process the event, with the button still
       * considered to be down.  Then repick the current item under the
       * assumption that the button is no longer down.
       */
      bindPtr->state = eventPtr->xbutton.state;
      DoEvent(bindPtr, eventPtr, bindPtr->currentItem, 
	      bindPtr->currentContext);
      eventPtr->xbutton.state ^= mask;
      bindPtr->state = eventPtr->xbutton.state;
      PickCurrentItem(bindPtr, eventPtr);
      eventPtr->xbutton.state ^= mask;
    }
    break;

  case EnterNotify:
  case LeaveNotify:
    bindPtr->state = eventPtr->xcrossing.state;
    PickCurrentItem(bindPtr, eventPtr);
    break;

  case MotionNotify:
    bindPtr->state = eventPtr->xmotion.state;
    PickCurrentItem(bindPtr, eventPtr);
    DoEvent(bindPtr, eventPtr, bindPtr->currentItem, 
	    bindPtr->currentContext);
    break;

  case KeyPress:
  case KeyRelease:
    bindPtr->state = eventPtr->xkey.state;
    PickCurrentItem(bindPtr, eventPtr);
    DoEvent(bindPtr, eventPtr, bindPtr->currentItem, 
	    bindPtr->currentContext);
    break;
  }
  Tcl_Release(bindPtr->clientData);
}

int Blt_ConfigureBindingsFromObj(Tcl_Interp* interp, BindTable *bindPtr,
				 ClientData item, int objc,
				 Tcl_Obj* const objv[])
{
  if (objc == 0) {
    Tk_GetAllBindings(interp, bindPtr->bindingTable, item);
    return TCL_OK;
  }

  const char *string = Tcl_GetString(objv[0]);
  const char *command;
  if (objc == 1) {
    command = Tk_GetBinding(interp, bindPtr->bindingTable, item, string);
    if (!command) {
      Tcl_ResetResult(interp);
      Tcl_AppendResult(interp, "invalid binding event \"", string, "\"", 
		       (char *)NULL);
      return TCL_ERROR;
    }
    Tcl_SetStringObj(Tcl_GetObjResult(interp), command, -1);
    return TCL_OK;
  }

  const char *seq = string;
  command = Tcl_GetString(objv[1]);

  if (command[0] == '\0')
    return Tk_DeleteBinding(interp, bindPtr->bindingTable, item, seq);

  unsigned long mask;
  if (command[0] == '+')
    mask = Tk_CreateBinding(interp, bindPtr->bindingTable, item, seq,
			    command + 1, 1);
  else
    mask = Tk_CreateBinding(interp, bindPtr->bindingTable, item, seq,
			    command, 0);

  if (!mask)
    return TCL_ERROR;

  if (mask & (unsigned)~ALL_VALID_EVENTS_MASK) {
    Tk_DeleteBinding(interp, bindPtr->bindingTable, item, seq);
    Tcl_ResetResult(interp);
    Tcl_AppendResult(interp, "requested illegal events; ",
		     "only key, button, motion, enter, leave, and virtual ",
		     "events may be used", (char *)NULL);
    return TCL_ERROR;
  }

  return TCL_OK;
}

Blt_BindTable Blt_CreateBindingTable(Tcl_Interp* interp, Tk_Window tkwin,
				     ClientData clientData,
				     Blt_BindPickProc *pickProc,
				     Blt_BindTagProc *tagProc)
{
  BindTable *bindPtr = (BindTable*)calloc(1, sizeof(BindTable));
  bindPtr->bindingTable = Tk_CreateBindingTable(interp);
  bindPtr->clientData = clientData;
  bindPtr->tkwin = tkwin;
  bindPtr->pickProc = pickProc;
  bindPtr->tagProc = tagProc;
  unsigned int mask = (KeyPressMask | KeyReleaseMask | ButtonPressMask |
		       ButtonReleaseMask | EnterWindowMask | LeaveWindowMask |
		       PointerMotionMask);
  Tk_CreateEventHandler(tkwin, mask, BindProc, bindPtr);

  return bindPtr;
}

void Blt_DestroyBindingTable(BindTable *bindPtr)
{
  Tk_DeleteBindingTable(bindPtr->bindingTable);
  unsigned int mask = (KeyPressMask | KeyReleaseMask | ButtonPressMask |
		       ButtonReleaseMask | EnterWindowMask | LeaveWindowMask |
		       PointerMotionMask);
  Tk_DeleteEventHandler(bindPtr->tkwin, mask, BindProc, bindPtr);
  free(bindPtr);
  bindPtr = NULL;
}

void Blt_PickCurrentItem(BindTable *bindPtr)
{
  if (bindPtr->activePick)
    PickCurrentItem(bindPtr, &bindPtr->pickEvent);
}

void Blt_DeleteBindings(BindTable *bindPtr, ClientData object)
{
  Tk_DeleteAllBindings(bindPtr->bindingTable, object);

  // If this is the object currently picked, we need to repick one.
  if (bindPtr->currentItem == object) {
    bindPtr->currentItem = NULL;
    bindPtr->currentContext = NULL;
  }
  if (bindPtr->newItem == object) {
    bindPtr->newItem = NULL;
    bindPtr->newContext = NULL;
  }
  if (bindPtr->focusItem == object) {
    bindPtr->focusItem = NULL;
    bindPtr->focusContext = NULL;
  }
}

/*
 * The following union is used to hold the detail information from an
 * XEvent (including Tk's XVirtualEvent extension).
 */
typedef union {
  KeySym	keySym;	    /* KeySym that corresponds to xkey.keycode. */
  int		button;	    /* Button that was pressed (xbutton.button). */
  Tk_Uid	name;	    /* Tk_Uid of virtual event. */
  ClientData	clientData; /* Used when type of Detail is unknown, and to
			     * ensure that all bytes of Detail are initialized
			     * when this structure is used in a hash key. */
} Detail;


/*
 * The following structure defines a pattern, which is matched against X
 * events as part of the process of converting X events into TCL commands.
 */
typedef struct {
  int eventType;		/* Type of X event, e.g. ButtonPress. */
  int needMods;		/* Mask of modifiers that must be
			 * present (0 means no modifiers are
			 * required). */
  Detail detail;		/* Additional information that must
				 * match event.  Normally this is 0,
				 * meaning no additional information
				 * must match.  For KeyPress and
				 * KeyRelease events, a keySym may
				 * be specified to select a
				 * particular keystroke (0 means any
				 * keystrokes).  For button events,
				 * specifies a particular button (0
				 * means any buttons are OK).  For virtual
				 * events, specifies the Tk_Uid of the
				 * virtual event name (never 0). */
} Pattern;

typedef struct {
  const char *name;		/* Name of modifier. */
  int mask;			/* Button/modifier mask value, such as
				 * Button1Mask. */
  int flags;			/* Various flags; see below for
				 * definitions. */
} EventModifier;

/*
 * Flags for EventModifier structures:
 *
 * DOUBLE -		Non-zero means duplicate this event,
 *			e.g. for double-clicks.
 * TRIPLE -		Non-zero means triplicate this event,
 *			e.g. for triple-clicks.
 * QUADRUPLE -		Non-zero means quadruple this event,
 *			e.g. for 4-fold-clicks.
 * MULT_CLICKS -	Combination of all of above.
 */

#define DOUBLE		(1<<0)
#define TRIPLE		(1<<1)
#define QUADRUPLE	(1<<2)
#define MULT_CLICKS	(DOUBLE|TRIPLE|QUADRUPLE)

#define META_MASK	(AnyModifier<<1)
#define ALT_MASK	(AnyModifier<<2)

typedef struct {
  const char *name;		/* Name of event. */
  int type;			/* Event type for X, such as
				 * ButtonPress. */
  int eventMask;		/* Mask bits (for XSelectInput)
				 * for this event type. */
} EventInfo;

/*
 * Note:  some of the masks below are an OR-ed combination of
 * several masks.  This is necessary because X doesn't report
 * up events unless you also ask for down events.  Also, X
 * doesn't report button state in motion events unless you've
 * asked about button events.
 */

/*
 * The defines and table below are used to classify events into
 * various groups.  The reason for this is that logically identical
 * fields (e.g. "state") appear at different places in different
 * types of events.  The classification masks can be used to figure
 * out quickly where to extract information from events.
 */

#define KEY			0x1
#define BUTTON			0x2
#define MOTION			0x4
#define CROSSING		0x8
#define FOCUS			0x10
#define EXPOSE			0x20
#define VISIBILITY		0x40
#define CREATE			0x80
#define DESTROY			0x100
#define UNMAP			0x200
#define MAP			0x400
#define REPARENT		0x800
#define CONFIG			0x1000
#define GRAVITY			0x2000
#define CIRC			0x4000
#define PROP			0x8000
#define COLORMAP		0x10000
#define VIRTUAL			0x20000
#define ACTIVATE		0x40000
#define	MAPREQ			0x80000
#define	CONFIGREQ		0x100000
#define	RESIZEREQ		0x200000
#define CIRCREQ			0x400000

#define KEY_BUTTON_MOTION_VIRTUAL	(KEY|BUTTON|MOTION|VIRTUAL)
#define KEY_BUTTON_MOTION_CROSSING	(KEY|BUTTON|MOTION|CROSSING|VIRTUAL)