resize editor when resizing window

[micropolis] / src / tk / tktxtag.c

/* 
 * tkTextTag.c --
 *
 *      This module implements the "tag" subcommand of the widget command
 *      for text widgets, plus most of the other high-level functions
 *      related to tags.
 *
 * Copyright 1992 Regents of the University of California.
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies.  The University of California
 * makes no representations about the suitability of this
 * software for any purpose.  It is provided "as is" without
 * express or implied warranty.
 */

#ifndef lint
static char rcsid[] = "$Header: /user6/ouster/wish/RCS/tkTextTag.c,v 1.3 92/07/28 15:38:59 ouster Exp $ SPRITE (Berkeley)";
#endif

#include "default.h"
#include "tkconfig.h"
#include "tk.h"
#include "tktext.h"

/*
 * Information used for parsing tag configuration information:
 */

static Tk_ConfigSpec tagConfigSpecs[] = {
    {TK_CONFIG_BORDER, "-background", (char *) NULL, (char *) NULL,
        (char *) NULL, Tk_Offset(TkTextTag, border), TK_CONFIG_NULL_OK},
    {TK_CONFIG_BITMAP, "-bgstipple", (char *) NULL, (char *) NULL,
        (char *) NULL, Tk_Offset(TkTextTag, bgStipple), TK_CONFIG_NULL_OK},
    {TK_CONFIG_PIXELS, "-borderwidth", (char *) NULL, (char *) NULL,
        "0", Tk_Offset(TkTextTag, borderWidth), TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_BITMAP, "-fgstipple", (char *) NULL, (char *) NULL,
        (char *) NULL, Tk_Offset(TkTextTag, fgStipple), TK_CONFIG_NULL_OK},
    {TK_CONFIG_FONT, "-font", (char *) NULL, (char *) NULL,
        (char *) NULL, Tk_Offset(TkTextTag, fontPtr), TK_CONFIG_NULL_OK},
    {TK_CONFIG_COLOR, "-foreground", (char *) NULL, (char *) NULL,
        (char *) NULL, Tk_Offset(TkTextTag, fgColor), TK_CONFIG_NULL_OK},
    {TK_CONFIG_RELIEF, "-relief", (char *) NULL, (char *) NULL,
        "flat", Tk_Offset(TkTextTag, relief), TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_BOOLEAN, "-underline", (char *) NULL, (char *) NULL,
        "false", Tk_Offset(TkTextTag, underline), TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
        (char *) NULL, 0, 0}
};


/*
 * The following definition specifies the maximum number of characters
 * needed in a string to hold a position specifier.
 */

#define POS_CHARS 30

/*
 * Forward declarations for procedures defined later in this file:
 */

static void             ChangeTagPriority _ANSI_ARGS_((TkText *textPtr,
                            TkTextTag *tagPtr, int prio));
static TkTextTag *      FindTag _ANSI_ARGS_((Tcl_Interp *interp,
                            TkText *textPtr, char *tagName));
static void             SortTags _ANSI_ARGS_((int numTags,
                            TkTextTag **tagArrayPtr));
static int              TagSortProc _ANSI_ARGS_((CONST VOID *first,
                            CONST VOID *second));
static void             TextDoEvent _ANSI_ARGS_((TkText *textPtr,
                            XEvent *eventPtr));
\f
/*
 *--------------------------------------------------------------
 *
 * TkTextTagCmd --
 *
 *      This procedure is invoked to process the "tag" options of
 *      the widget command for text widgets. See the user documentation
 *      for details on what it does.
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      See the user documentation.
 *
 *--------------------------------------------------------------
 */

int
TkTextTagCmd(textPtr, interp, argc, argv)
    register TkText *textPtr;   /* Information about text widget. */
    Tcl_Interp *interp;         /* Current interpreter. */
    int argc;                   /* Number of arguments. */
    char **argv;                /* Argument strings.  Someone else has already
                                 * parsed this command enough to know that
                                 * argv[1] is "tag". */
{
    int length, line1, ch1, line2, ch2, i, addTag;
    char c;
    char *fullOption;
    register TkTextTag *tagPtr;

    if (argc < 3) {
        Tcl_AppendResult(interp, "wrong # args: should be \"",
                argv[0], " tag option ?arg arg ...?\"", (char *) NULL);
        return TCL_ERROR;
    }
    c = argv[2][0];
    length = strlen(argv[2]);
    if ((c == 'a') && (strncmp(argv[2], "add", length) == 0)) {
        fullOption = "add";
        addTag = 1;

        addAndRemove:
        if ((argc != 5) && (argc != 6)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " tag ", fullOption, " tagName index1 ?index2?\"",
                    (char *) NULL);
            return TCL_ERROR;
        }
        tagPtr = TkTextCreateTag(textPtr, argv[3]);
        if (TkTextGetIndex(interp, textPtr, argv[4], &line1, &ch1) != TCL_OK) {
            return TCL_ERROR;
        }
        if (argc == 6) {
            if (TkTextGetIndex(interp, textPtr, argv[5], &line2, &ch2)
                    != TCL_OK) {
                return TCL_ERROR;
            }
        } else {
            line2 = line1;
            ch2 = ch1+1;
        }
        if (TK_TAG_AFFECTS_DISPLAY(tagPtr)) {
            TkTextRedrawTag(textPtr, line1, ch1, line2, ch2, tagPtr, !addTag);
        }
        TkBTreeTag(textPtr->tree, line1, ch1, line2, ch2, tagPtr, addTag);

        /*
         * If the tag is "sel" then grab the selection if we're supposed
         * to export it and don't already have it.  Also, invalidate
         * partially-completed selection retrievals.
         */

        if (tagPtr == textPtr->selTagPtr) {
            if (addTag && textPtr->exportSelection
                    && !(textPtr->flags & GOT_SELECTION)) {
                Tk_OwnSelection(textPtr->tkwin, TkTextLostSelection,
                        (ClientData) textPtr);
                textPtr->flags |= GOT_SELECTION;
            }
            textPtr->selOffset = -1;
        }
    } else if ((c == 'b') && (strncmp(argv[2], "bind", length) == 0)) {
        if ((argc < 4) || (argc > 6)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " tag bind tagName ?sequence? ?command?\"",
                    (char *) NULL);
            return TCL_ERROR;
        }
        tagPtr = TkTextCreateTag(textPtr, argv[3]);

        /*
         * Make a binding table if the widget doesn't already have
         * one.
         */

        if (textPtr->bindingTable == NULL) {
            textPtr->bindingTable = Tk_CreateBindingTable(interp);
        }

        if (argc == 6) {
            int append = 0;
            unsigned long mask;

            if (argv[5][0] == 0) {
                return Tk_DeleteBinding(interp, textPtr->bindingTable,
                        (ClientData) tagPtr, argv[4]);
            }
            if (argv[5][0] == '+') {
                argv[5]++;
                append = 1;
            }
            mask = Tk_CreateBinding(interp, textPtr->bindingTable,
                    (ClientData) tagPtr, argv[4], argv[5], append);
            if (mask == 0) {
                return TCL_ERROR;
            }
            if (mask & ~(ButtonMotionMask|Button1MotionMask|Button2MotionMask
                    |Button3MotionMask|Button4MotionMask|Button5MotionMask
                    |ButtonPressMask|ButtonReleaseMask|EnterWindowMask
                    |LeaveWindowMask|KeyPressMask|KeyReleaseMask
                    |PointerMotionMask)) {
                Tk_DeleteBinding(interp, textPtr->bindingTable,
                        (ClientData) tagPtr, argv[4]);
                Tcl_ResetResult(interp);
                Tcl_AppendResult(interp, "requested illegal events; ",
                        "only key, button, motion, and enter/leave ",
                        "events may be used", (char *) NULL);
                return TCL_ERROR;
            }
        } else if (argc == 5) {
            char *command;
    
            command = Tk_GetBinding(interp, textPtr->bindingTable,
                    (ClientData) tagPtr, argv[4]);
            if (command == NULL) {
                return TCL_ERROR;
            }
            interp->result = command;
        } else {
            Tk_GetAllBindings(interp, textPtr->bindingTable,
                    (ClientData) tagPtr);
        }
    } else if ((c == 'c') && (strncmp(argv[2], "configure", length) == 0)) {
        if (argc < 4) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " tag configure tagName ?option? ?value? ",
                    "?option value ...?\"", (char *) NULL);
            return TCL_ERROR;
        }
        tagPtr = TkTextCreateTag(textPtr, argv[3]);
        if (argc == 4) {
            return Tk_ConfigureInfo(interp, textPtr->tkwin, tagConfigSpecs,
                    (char *) tagPtr, (char *) NULL, 0);
        } else if (argc == 5) {
            return Tk_ConfigureInfo(interp, textPtr->tkwin, tagConfigSpecs,
                    (char *) tagPtr, argv[4], 0);
        } else {
            int result;

            result = Tk_ConfigureWidget(interp, textPtr->tkwin, tagConfigSpecs,
                    argc-4, argv+4, (char *) tagPtr, 0);
            /*
             * If the "sel" tag was changed, be sure to mirror information
             * from the tag back into the text widget record.   NOTE: we
             * don't have to free up information in the widget record
             * before overwriting it, because it was mirrored in the tag
             * and hence freed when the tag field was overwritten.
             */

            if (tagPtr == textPtr->selTagPtr) {
                textPtr->selBorder = tagPtr->border;
                textPtr->selBorderWidth = tagPtr->borderWidth;
                textPtr->selFgColorPtr = tagPtr->fgColor;
            }
            TkTextRedrawTag(textPtr, 0, 0, TkBTreeNumLines(textPtr->tree),
                    0, tagPtr, 1);
            return result;
        }
    } else if ((c == 'd') && (strncmp(argv[2], "delete", length) == 0)) {
        Tcl_HashEntry *hPtr;

        if (argc < 4) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " tag delete tagName tagName ...\"",
                    (char *) NULL);
            return TCL_ERROR;
        }
        for (i = 3; i < argc; i++) {
            hPtr = Tcl_FindHashEntry(&textPtr->tagTable, argv[i]);
            if (hPtr == NULL) {
                continue;
            }
            tagPtr = (TkTextTag *) Tcl_GetHashValue(hPtr);
            if (tagPtr == textPtr->selTagPtr) {
                interp->result = "can't delete selection tag";
                return TCL_ERROR;
            }
            if (TK_TAG_AFFECTS_DISPLAY(tagPtr)) {
                TkTextRedrawTag(textPtr, 0, 0, TkBTreeNumLines(textPtr->tree),
                        0, tagPtr, 1);
            }
            TkBTreeTag(textPtr->tree, 0, 0, TkBTreeNumLines(textPtr->tree),
                    0, tagPtr, 0);
            Tcl_DeleteHashEntry(hPtr);
            if (textPtr->bindingTable != NULL) {
                Tk_DeleteAllBindings(textPtr->bindingTable,
                        (ClientData) tagPtr);
            }
        
            /*
             * Update the tag priorities to reflect the deletion of this tag.
             */

            ChangeTagPriority(textPtr, tagPtr, textPtr->numTags-1);
            textPtr->numTags -= 1;
            TkTextFreeTag(tagPtr);
        }
    } else if ((c == 'l') && (strncmp(argv[2], "lower", length) == 0)) {
        TkTextTag *tagPtr2;
        int prio;

        if ((argc != 4) && (argc != 5)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " tag lower tagName ?belowThis?\"",
                    (char *) NULL);
            return TCL_ERROR;
        }
            tagPtr = FindTag(interp, textPtr, argv[3]);
        if (tagPtr == NULL) {
            return TCL_ERROR;
        }
        if (argc == 5) {
            tagPtr2 = FindTag(interp, textPtr, argv[4]);
            if (tagPtr2 == NULL) {
                return TCL_ERROR;
            }
            if (tagPtr->priority < tagPtr2->priority) {
                prio = tagPtr2->priority - 1;
            } else {
                prio = tagPtr2->priority;
            }
        } else {
            prio = 0;
        }
        ChangeTagPriority(textPtr, tagPtr, prio);
        TkTextRedrawTag(textPtr, 0, 0, TkBTreeNumLines(textPtr->tree),
                0, tagPtr, 1);
    } else if ((c == 'n') && (strncmp(argv[2], "names", length) == 0)
            && (length >= 2)) {
        TkTextTag **arrayPtr;
        int arraySize;
        TkTextLine *linePtr;

        if ((argc != 3) && (argc != 4)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " tag names ?index?\"",
                    (char *) NULL);
            return TCL_ERROR;
        }
        if (argc == 3) {
            Tcl_HashSearch search;
            Tcl_HashEntry *hPtr;

            arrayPtr = (TkTextTag **) ckalloc((unsigned)
                    (textPtr->numTags * sizeof(TkTextTag *)));
            for (i = 0, hPtr = Tcl_FirstHashEntry(&textPtr->tagTable, &search);
                    hPtr != NULL; i++, hPtr = Tcl_NextHashEntry(&search)) {
                arrayPtr[i] = (TkTextTag *) Tcl_GetHashValue(hPtr);
            }
            arraySize = textPtr->numTags;
        } else {
            if (TkTextGetIndex(interp, textPtr, argv[3], &line1, &ch1)
                    != TCL_OK) {
                return TCL_ERROR;
            }
            linePtr = TkBTreeFindLine(textPtr->tree, line1);
            if (linePtr == NULL) {
                return TCL_OK;
            }
            arrayPtr = TkBTreeGetTags(textPtr->tree, linePtr, ch1, &arraySize);
            if (arrayPtr == NULL) {
                return TCL_OK;
            }
        }
        SortTags(arraySize, arrayPtr);
        for (i = 0; i < arraySize; i++) {
            tagPtr = arrayPtr[i];
            Tcl_AppendElement(interp, tagPtr->name, 0);
        }
        ckfree((char *) arrayPtr);
    } else if ((c == 'n') && (strncmp(argv[2], "nextrange", length) == 0)
            && (length >= 2)) {
        TkTextSearch tSearch;
        char position[POS_CHARS];

        if ((argc != 5) && (argc != 6)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " tag nextrange tagName index1 ?index2?\"",
                    (char *) NULL);
            return TCL_ERROR;
        }
        tagPtr = FindTag((Tcl_Interp *) NULL, textPtr, argv[3]);
        if (tagPtr == NULL) {
            return TCL_OK;
        }
        if (TkTextGetIndex(interp, textPtr, argv[4], &line1, &ch1) != TCL_OK) {
            return TCL_ERROR;
        }
        if (argc == 5) {
            line2 = TkBTreeNumLines(textPtr->tree);
            ch2 = 0;
        } else if (TkTextGetIndex(interp, textPtr, argv[5], &line2, &ch2)
                != TCL_OK) {
            return TCL_ERROR;
        }

        /*
         * The search below is a bit tricky.  Rather than use the B-tree
         * facilities to stop the search at line2.ch2, let it search up
         * until the end of the file but check for a position past line2.ch2
         * ourselves.  The reason for doing it this way is that we only
         * care whether the *start* of the range is before line2.ch2;  once
         * we find the start, we don't want TkBTreeNextTag to abort the
         * search because the end of the range is after line2.ch2.
         */

        TkBTreeStartSearch(textPtr->tree, line1, ch1,
                TkBTreeNumLines(textPtr->tree), 0, tagPtr, &tSearch);
        if (!TkBTreeNextTag(&tSearch)) {
             return TCL_OK;
        }
        if (!TkBTreeCharTagged(tSearch.linePtr, tSearch.ch1, tagPtr)) {
            if (!TkBTreeNextTag(&tSearch)) {
                return TCL_OK;
            }
        }
        if ((tSearch.line1 > line2) || ((tSearch.line1 == line2)
                && (tSearch.ch1 >= ch2))) {
            return TCL_OK;
        }
        TkTextPrintIndex(tSearch.line1, tSearch.ch1, position);
        Tcl_AppendElement(interp, position, 0);
        TkBTreeNextTag(&tSearch);
        TkTextPrintIndex(tSearch.line1, tSearch.ch1, position);
        Tcl_AppendElement(interp, position, 0);
    } else if ((c == 'r') && (strncmp(argv[2], "raise", length) == 0)
            && (length >= 3)) {
        TkTextTag *tagPtr2;
        int prio;

        if ((argc != 4) && (argc != 5)) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " tag raise tagName ?aboveThis?\"",
                    (char *) NULL);
            return TCL_ERROR;
        }
        tagPtr = FindTag(interp, textPtr, argv[3]);
        if (tagPtr == NULL) {
            return TCL_ERROR;
        }
        if (argc == 5) {
            tagPtr2 = FindTag(interp, textPtr, argv[4]);
            if (tagPtr2 == NULL) {
                return TCL_ERROR;
            }
            if (tagPtr->priority <= tagPtr2->priority) {
                prio = tagPtr2->priority;
            } else {
                prio = tagPtr2->priority + 1;
            }
        } else {
            prio = textPtr->numTags-1;
        }
        ChangeTagPriority(textPtr, tagPtr, prio);
        TkTextRedrawTag(textPtr, 0, 0, TkBTreeNumLines(textPtr->tree),
                0, tagPtr, 1);
    } else if ((c == 'r') && (strncmp(argv[2], "ranges", length) == 0)
            && (length >= 3)) {
        TkTextSearch tSearch;
        char position[POS_CHARS];

        if (argc != 4) {
            Tcl_AppendResult(interp, "wrong # args: should be \"",
                    argv[0], " tag ranges tagName\"", (char *) NULL);
            return TCL_ERROR;
        }
        tagPtr = FindTag((Tcl_Interp *) NULL, textPtr, argv[3]);
        if (tagPtr == NULL) {
            return TCL_OK;
        }
        TkBTreeStartSearch(textPtr->tree, 0, 0, TkBTreeNumLines(textPtr->tree),
                0, tagPtr, &tSearch);
        while (TkBTreeNextTag(&tSearch)) {
            TkTextPrintIndex(tSearch.line1, tSearch.ch1, position);
            Tcl_AppendElement(interp, position, 0);
        }
    } else if ((c == 'r') && (strncmp(argv[2], "remove", length) == 0)
            && (length >= 2)) {
        fullOption = "remove";
        addTag = 0;
        goto addAndRemove;
    } else {
        Tcl_AppendResult(interp, "bad tag option \"", argv[2],
                "\":  must be add, bind, configure, delete, lower, ",
                "names, nextrange, raise, ranges, or remove",
                (char *) NULL);
        return TCL_ERROR;
    }
    return TCL_OK;
}
\f
/*
 *----------------------------------------------------------------------
 *
 * TkTextCreateTag --
 *
 *      Find the record describing a tag within a given text widget,
 *      creating a new record if one doesn't already exist.
 *
 * Results:
 *      The return value is a pointer to the TkTextTag record for tagName.
 *
 * Side effects:
 *      A new tag record is created if there isn't one already defined
 *      for tagName.
 *
 *----------------------------------------------------------------------
 */

TkTextTag *
TkTextCreateTag(textPtr, tagName)
    TkText *textPtr;            /* Widget in which tag is being used. */
    char *tagName;              /* Name of desired tag. */
{
    register TkTextTag *tagPtr;
    Tcl_HashEntry *hPtr;
    int new;

    hPtr = Tcl_CreateHashEntry(&textPtr->tagTable, tagName, &new);
    if (!new) {
        return (TkTextTag *) Tcl_GetHashValue(hPtr);
    }

    /*
     * No existing entry.  Create a new one, initialize it, and add a
     * pointer to it to the hash table entry.
     */

    tagPtr = (TkTextTag *) ckalloc(sizeof(TkTextTag));
    tagPtr->name = Tcl_GetHashKey(&textPtr->tagTable, hPtr);
    tagPtr->priority = textPtr->numTags;
    tagPtr->border = NULL;
    tagPtr->borderWidth = 1;
    tagPtr->relief = TK_RELIEF_FLAT;
    tagPtr->bgStipple = None;
    tagPtr->fgColor = NULL;
    tagPtr->fontPtr = NULL;
    tagPtr->fgStipple = None;
    tagPtr->underline = 0;
    textPtr->numTags++;
    Tcl_SetHashValue(hPtr, tagPtr);
    return tagPtr;
}
\f
/*
 *----------------------------------------------------------------------
 *
 * FindTag --
 *
 *      See if tag is defined for a given widget.
 *
 * Results:
 *      If tagName is defined in textPtr, a pointer to its TkTextTag
 *      structure is returned.  Otherwise NULL is returned and an
 *      error message is recorded in interp->result unless interp
 *      is NULL.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static TkTextTag *
FindTag(interp, textPtr, tagName)
    Tcl_Interp *interp;         /* Interpreter to use for error message;
                                 * if NULL, then don't record an error
                                 * message. */
    TkText *textPtr;            /* Widget in which tag is being used. */
    char *tagName;              /* Name of desired tag. */
{
    Tcl_HashEntry *hPtr;

    hPtr = Tcl_FindHashEntry(&textPtr->tagTable, tagName);
    if (hPtr != NULL) {
        return (TkTextTag *) Tcl_GetHashValue(hPtr);
    }
    if (interp != NULL) {
        Tcl_AppendResult(interp, "tag \"", tagName,
                "\" isn't defined in text widget", (char *) NULL);
    }
    return NULL;
}
\f
/*
 *----------------------------------------------------------------------
 *
 * TkTextFreeTag --
 *
 *      This procedure is called when a tag is deleted to free up the
 *      memory and other resources associated with the tag.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Memory and other resources are freed.
 *
 *----------------------------------------------------------------------
 */

void
TkTextFreeTag(tagPtr)
    register TkTextTag *tagPtr;         /* Tag being deleted. */
{
    if (tagPtr->border != None) {
        Tk_Free3DBorder(tagPtr->border);
    }
    if (tagPtr->bgStipple != None) {
        Tk_FreeBitmap(tagPtr->bgStipple);
    }
    if (tagPtr->fgColor != None) {
        Tk_FreeColor(tagPtr->fgColor);
    }
    if (tagPtr->fgStipple != None) {
        Tk_FreeBitmap(tagPtr->fgStipple);
    }
    ckfree((char *) tagPtr);
}
\f
/*
 *----------------------------------------------------------------------
 *
 * SortTags --
 *
 *      This procedure sorts an array of tag pointers in increasing
 *      order of priority, optimizing for the common case where the
 *      array is small.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static void
SortTags(numTags, tagArrayPtr)
    int numTags;                /* Number of tag pointers at *tagArrayPtr. */
    TkTextTag **tagArrayPtr;    /* Pointer to array of pointers. */
{
    int i, j, prio;
    register TkTextTag **tagPtrPtr;
    TkTextTag **maxPtrPtr, *tmp;

    if (numTags < 2) {
        return;
    }
    if (numTags < 20) {
        for (i = numTags-1; i > 0; i--, tagArrayPtr++) {
            maxPtrPtr = tagPtrPtr = tagArrayPtr;
            prio = tagPtrPtr[0]->priority;
            for (j = i, tagPtrPtr++; j > 0; j--, tagPtrPtr++) {
                if (tagPtrPtr[0]->priority < prio) {
                    prio = tagPtrPtr[0]->priority;
                    maxPtrPtr = tagPtrPtr;
                }
            }
            tmp = *maxPtrPtr;
            *maxPtrPtr = *tagArrayPtr;
            *tagArrayPtr = tmp;
        }
    } else {
        qsort((VOID *) tagArrayPtr, numTags, sizeof (TkTextTag *),
                    TagSortProc);
    }
}
\f
/*
 *----------------------------------------------------------------------
 *
 * TagSortProc --
 *
 *      This procedure is called by qsort when sorting an array of
 *      tags in priority order.
 *
 * Results:
 *      The return value is -1 if the first argument should be before
 *      the second element (i.e. it has lower priority), 0 if it's
 *      equivalent (this should never happen!), and 1 if it should be
 *      after the second element.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

static int
TagSortProc(first, second)
    CONST VOID *first, *second;         /* Elements to be compared. */
{
    TkTextTag *tagPtr1, *tagPtr2;

    tagPtr1 = * (TkTextTag **) first;
    tagPtr2 = * (TkTextTag **) second;
    return tagPtr1->priority - tagPtr2->priority;
}
\f
/*
 *----------------------------------------------------------------------
 *
 * ChangeTagPriority --
 *
 *      This procedure changes the priority of a tag by modifying
 *      its priority and all other ones whose priority is affected
 *      by the change.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Priorities may be changed for some or all of the tags in
 *      textPtr.  The tags will be arranged so that there is exactly
 *      one tag at each priority level between 0 and textPtr->numTags-1,
 *      with tagPtr at priority "prio".
 *
 *----------------------------------------------------------------------
 */

static void
ChangeTagPriority(textPtr, tagPtr, prio)
    TkText *textPtr;                    /* Information about text widget. */
    TkTextTag *tagPtr;                  /* Tag whose priority is to be
                                         * changed. */
    int prio;                           /* New priority for tag. */
{
    int low, high, delta;
    register TkTextTag *tagPtr2;
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;

    if (prio < 0) {
        prio = 0;
    }
    if (prio >= textPtr->numTags) {
        prio = textPtr->numTags-1;
    }
    if (prio == tagPtr->priority) {
        return;
    } else if (prio < tagPtr->priority) {
        low = prio;
        high = tagPtr->priority-1;
        delta = 1;
    } else {
        low = tagPtr->priority+1;
        high = prio;
        delta = -1;
    }
    for (hPtr = Tcl_FirstHashEntry(&textPtr->tagTable, &search);
            hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
        tagPtr2 = (TkTextTag *) Tcl_GetHashValue(hPtr);
        if ((tagPtr2->priority >= low) && (tagPtr2->priority <= high)) {
            tagPtr2->priority += delta;
        }
    }
    tagPtr->priority = prio;
}
\f
/*
 *--------------------------------------------------------------
 *
 * TkTextBindProc --
 *
 *      This procedure is invoked by the Tk dispatcher to handle
 *      events associated with bindings on items.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Depends on the command invoked as part of the binding
 *      (if there was any).
 *
 *--------------------------------------------------------------
 */

void
TkTextBindProc(clientData, eventPtr)
    ClientData clientData;              /* Pointer to canvas structure. */
    XEvent *eventPtr;                   /* Pointer to X event that just
                                         * happened. */
{
    TkText *textPtr = (TkText *) clientData;
    int repick  = 0;

    Tk_Preserve((ClientData) textPtr);

    /*
     * This code simulates grabs for mouse buttons by refusing to
     * pick a new current character between the time a mouse button goes
     * down and the time when the last mouse button is released.
     */

    if (eventPtr->type == ButtonPress) {
        textPtr->flags |= BUTTON_DOWN;
    } else if (eventPtr->type == ButtonRelease) {
        int mask;

        switch (eventPtr->xbutton.button) {
            case Button1:
                mask = Button1Mask;
                break;
            case Button2:
                mask = Button2Mask;
                break;
            case Button3:
                mask = Button3Mask;
                break;
            case Button4:
                mask = Button4Mask;
                break;
            case Button5:
                mask = Button5Mask;
                break;
            default:
                mask = 0;
                break;
        }
        if ((eventPtr->xbutton.state & (Button1Mask|Button2Mask
                |Button3Mask|Button4Mask|Button5Mask)) == mask) {
            textPtr->flags &= ~BUTTON_DOWN;
            repick = 1;
        }
    } else if ((eventPtr->type == EnterNotify)
            || (eventPtr->type == LeaveNotify)) {
        TkTextPickCurrent(textPtr, eventPtr);
        goto done;
    } else if (eventPtr->type == MotionNotify) {
        TkTextPickCurrent(textPtr, eventPtr);
    }
    TextDoEvent(textPtr, eventPtr);
    if (repick) {
        unsigned int oldState;

        oldState = eventPtr->xbutton.state;
        eventPtr->xbutton.state &= ~(Button1Mask|Button2Mask
                |Button3Mask|Button4Mask|Button5Mask);
        TkTextPickCurrent(textPtr, eventPtr);
        eventPtr->xbutton.state = oldState;
    }

    done:
    Tk_Release((ClientData) textPtr);
}
\f
/*
 *--------------------------------------------------------------
 *
 * TkTextPickCurrent --
 *
 *      Find the topmost item in a canvas that contains a given
 *      location and mark the the current item.  If the current
 *      item has changed, generate a fake exit event on the old
 *      current item and a fake enter event on the new current
 *      item.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The current item for textPtr may change.  If it does,
 *      then the commands associated with item entry and exit
 *      could do just about anything.
 *
 *--------------------------------------------------------------
 */

void
TkTextPickCurrent(textPtr, eventPtr)
    register TkText *textPtr;           /* Text widget in which to select
                                         * current character. */
    XEvent *eventPtr;                   /* Event describing location of
                                         * mouse cursor.  Must be EnterWindow,
                                         * LeaveWindow, ButtonRelease, or
                                         * MotionNotify. */
{
    TkTextLine *linePtr;
    int ch;

    /*
     * If a button is down, then don't do anything at all;  we'll be
     * called again when all buttons are up, and we can repick then.
     * This implements a form of mouse grabbing.
     */

    if (textPtr->flags & BUTTON_DOWN) {
        return;
    }

    /*
     * Save information about this event in the widget for use if we have
     * to synthesize more enter and leave events later (e.g. because a
     * character was deleting, causing a new character to be underneath
     * the mouse cursor).  Also translate MotionNotify events into
     * EnterNotify events, since that's what gets reported to event
     * handlers when the current character changes.
     */

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

    linePtr = NULL;
    if (textPtr->pickEvent.type != LeaveNotify) {
        linePtr = TkTextCharAtLoc(textPtr, textPtr->pickEvent.xcrossing.x,
                textPtr->pickEvent.xcrossing.y, &ch);
    }

    /*
     * Simulate a LeaveNotify event on the previous current character and
     * an EnterNotify event on the new current character.  Also, move the
     * "current" mark to its new place.
     */

    if (textPtr->flags & IN_CURRENT) {
        if ((linePtr == textPtr->currentAnnotPtr->linePtr)
                && (ch == textPtr->currentAnnotPtr->ch)) {
            return;
        }
    } else {
        if (linePtr == NULL) {
            return;
        }
    }
    if (textPtr->flags & IN_CURRENT) {
        XEvent event;

        event = textPtr->pickEvent;
        event.type = LeaveNotify;
        TextDoEvent(textPtr, &event);
        textPtr->flags &= ~IN_CURRENT;
    }
    if (linePtr != NULL) {
        XEvent event;

        TkBTreeRemoveAnnotation(textPtr->currentAnnotPtr);
        textPtr->currentAnnotPtr->linePtr = linePtr;
        textPtr->currentAnnotPtr->ch = ch;
        TkBTreeAddAnnotation(textPtr->currentAnnotPtr);
        event = textPtr->pickEvent;
        event.type = EnterNotify;
        TextDoEvent(textPtr, &event);
        textPtr->flags |= IN_CURRENT;
    }
}
\f
/*
 *----------------------------------------------------------------------
 *
 * TkTextUnpickCurrent --
 *
 *      This procedure is called when the "current" character is
 *      deleted:  it synthesizes a "leave" event for the character.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      A binding associated with one of the tags on the current
 *      character may be triggered.
 *
 *----------------------------------------------------------------------
 */

void
TkTextUnpickCurrent(textPtr)
    TkText *textPtr;            /* Text widget information. */
{
    if (textPtr->flags & IN_CURRENT) {
        XEvent event;

        event = textPtr->pickEvent;
        event.type = LeaveNotify;
        TextDoEvent(textPtr, &event);
        textPtr->flags &= ~IN_CURRENT;
    }
}
\f
/*
 *--------------------------------------------------------------
 *
 * TextDoEvent --
 *
 *      This procedure is called to invoke binding processing
 *      for a new event that is associated with the current character
 *      for a text widget.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Depends on the bindings for the text.
 *
 *--------------------------------------------------------------
 */

static void
TextDoEvent(textPtr, eventPtr)
    TkText *textPtr;                    /* Text widget in which event
                                         * occurred. */
    XEvent *eventPtr;                   /* Real or simulated X event that
                                         * is to be processed. */
{
    TkTextTag **tagArrayPtr, **p1, **p2, *tmp;
    int numTags;

    if (textPtr->bindingTable == NULL) {
        return;
    }

    /*
     * Set up an array containing all of the tags that are associated
     * with the current character.  This array will be used to look
     * for bindings.  If there are no tags then there can't be any
     * bindings.
     */

    tagArrayPtr = TkBTreeGetTags(textPtr->tree,
            textPtr->currentAnnotPtr->linePtr, textPtr->currentAnnotPtr->ch,
            &numTags);
    if (numTags == 0) {
        return;
    }

    /*
     * Sort the array of tags.  SortTags sorts it backwards, so after it
     * returns we have to reverse the order in the array.
     */

    SortTags(numTags, tagArrayPtr);
    for (p1 = tagArrayPtr, p2 = tagArrayPtr + numTags - 1;
            p1 < p2;  p1++, p2--) {
        tmp = *p1;
        *p1 = *p2;
        *p2 = tmp;
    }

    /*
     * Invoke the binding system, then free up the tag array.
     */

    Tk_BindEvent(textPtr->bindingTable, eventPtr, textPtr->tkwin,
            numTags, (ClientData *) tagArrayPtr);
    ckfree((char *) tagArrayPtr);
}