Tk Source Code

Note that peers are really peers. Deleting the
.QW original
text widget will not cause any other peers to be deleted, or otherwise
affected.
.PP
See below for the \fIpathName \fBpeer\fR widget command that controls the
creation of peer widgets.
.SH "ASYNCHRONOUS UPDATE OF LINE HEIGHTS"
.PP
In order to maintain a responsive user-experience, the text widget calculates
lines metrics (line heights in pixels) asynchronously. Because of this, some
commands of the text widget may return wrong results if the asynchronous
calculations are not finished at the time of calling. This applies to
\fIpathName \fBcount -ypixels\fR and \fIpathName \fByview\fR.
.PP
Again for performance reasons, it would not be appropriate to let these
commands always wait for the end of the update calculation each time they are
called. In most use cases of these commands a more or less inaccurate result
does not really matter compared to execution speed.
.PP
In case accurate result is needed (and if the text widget is managed by a
geometry manager), one can resort to \fIpathName \fBsync\fR and \fIpathName
\fBpendingsync\fR to control the synchronization of the view of text widgets.
.PP
The \fB<<WidgetViewSync>>\fR virtual event fires when the line heights of the
text widget becomes obsolete (due to some editing command or configuration
change), and again when the internal data of the text widget are back in sync
with the widget view. The detail field (%d substitution) is either true (when
the widget is in sync) or false (when it is not).
.PP
\fIpathName \fBsync\fR, \fIpathName \fBpendingsync\fR and
\fB<<WidgetViewSync>>\fR apply to each text widget independently of its peers.
.PP
Examples of use:
.CS
## Example 1:
# immediately complete line metrics at any cost (GUI unresponsive)
$w sync
$w yview moveto $fraction

## Example 2:
# synchronously wait for up-to-date line metrics (GUI responsive)
# before executing the scheduled command, but don't block execution flow
$w sync -command [list $w yview moveto $fraction]

## Example 3:
# init
set yud($w) 0
proc updateaction w {
\&set ::yud($w) 1
\&# any other update action here...
}
# runtime, synchronously wait for up-to-date line metrics (GUI responsive)
$w sync -command [list updateaction $w]
vwait yud($w)
$w yview moveto $fraction

## Example 4:
# init
set todo($w) {}
proc updateaction w {
\&foreach cmd $::todo($w) {uplevel #0 $cmd}
\&set todo($w) {}
}
# runtime
lappend todo($w) [list $w yview moveto $fraction]
$w sync -command [list updateaction $w]

## Example 5:
# init
set todo($w) {}
bind $w <<WidgetViewSync>> {
\&if {%d} {
\&\&foreach cmd $todo(%W) {eval $cmd}
\&\&set todo(%W) {}
\&}
}
# runtime
if {![$w pendingsync]} {
\&$w yview moveto $fraction
} else {
\&lappend todo($w) [list $w yview moveto $fraction]
}
.CE
.SH "WIDGET COMMAND"
.PP
The \fBtext\fR command creates a new Tcl command whose name is the same as the
path name of the text's window. This command may be used to invoke various
operations on the widget. It has the following general form:
.CS
\fIpathName option \fR?\fIarg arg ...\fR?

\fB\-indices\fR, \fB\-lines\fR, \fB\-xpixels\fR and \fB\-ypixels\fR. The
default value, if no option is specified, is \fB\-indices\fR. There is an
additional possible option \fB\-update\fR which is a modifier. If given (and
if the text widget is managed by a geometry manager), then all subsequent
options ensure that any possible out of date information is recalculated.
This currently only has any effect for the \fB\-ypixels\fR count (which, if
\fB\-update\fR is not given, will use the text widget's current cached value
for each line). This \fB\-update\fR option is obsoleted by \fIpathName
\fBsync\fR, \fIpathName \fBpendingsync\fR and \fB<<WidgetViewSync>>\fR.  The
count options are interpreted as follows:
.RS
.IP \fB\-chars\fR
count all characters, whether elided or not. Do not count embedded windows or
images.
.IP \fB\-displaychars\fR
count all non-elided characters.
.IP \fB\-displayindices\fR

.TP
\fIpathName \fBpeer names\fR
.
Returns a list of peers of this widget (this does not include the widget
itself). The order within this list is undefined.
.RE
.TP
\fIpathName \fBpendingsync\fR
Returns 1 if the line heights calculations are not up-to-date, 0 otherwise.
.TP
\fIpathName \fBreplace\fR \fIindex1 index2 chars\fR ?\fItagList chars tagList ...\fR?
Replaces the range of characters between \fIindex1\fR and \fIindex2\fR
with the given characters and tags.  See the section on \fIpathName
\fBinsert\fR for an explanation of the handling of the \fItagList...\fR
arguments, and the section on \fIpathName
\fBdelete\fR for an explanation of the handling of the indices.  If
\fIindex2\fR corresponds to an index earlier in the text than
\fIindex1\fR, an error will be generated.
.RS
.PP
The deletion and insertion are arranged so that no unnecessary scrolling of
the window or movement of insertion cursor occurs. In addition the undo/redo
stack are correctly modified, if undo operations are active in the text
widget. The command returns an empty string.

.
Adjusts the view in the window so that the character given by \fIindex\fR is
completely visible. If \fIindex\fR is already visible then the command does
nothing. If \fIindex\fR is a short distance out of view, the command adjusts
the view just enough to make \fIindex\fR visible at the edge of the window.
If \fIindex\fR is far out of view, then the command centers \fIindex\fR in the
window.
.TP
\fIpathName \fBsync\fR ?\fB-command \fIcommand\fR?
Controls the synchronization of the view of the text widget.
.RS
.TP
\fIpathName \fBsync\fR
Immediately brings the line metrics up-to-date by forcing computation of any
outdated line heights. The command returns immediately if there is no such
outdated line heights, otherwise it returns only at the end of the computation.
The command returns an empty string.
.TP
\fIpathName \fBsync -command \fIcommand\fR
Schedules \fIcommand\fR to be executed (by the event loop) exactly once as soon
as all line heights are up-to-date. If there are no pending line metrics
calculations, the scheduling is immediate. The command returns the empty
string. \fBbgerror\fR is called on \fIcommand\fR failure.
.RE
.TP
\fIpathName \fBtag \fIoption \fR?\fIarg arg ...\fR?
.
This command is used to manipulate tags. The exact behavior of the command
depends on the \fIoption\fR argument that follows the \fBtag\fR argument. The
following forms of the command are currently supported:
.RS

static int		TextEditUndo(TkText *textPtr);
static int		TextEditRedo(TkText *textPtr);
static Tcl_Obj *	TextGetText(const TkText *textPtr,
			    const TkTextIndex *index1,
			    const TkTextIndex *index2, int visibleOnly);
static void		GenerateModifiedEvent(TkText *textPtr);
static void		UpdateDirtyFlag(TkSharedText *sharedPtr);
static void		RunAfterSyncCmd(ClientData clientData);
static void		TextPushUndoAction(TkText *textPtr,
			    Tcl_Obj *undoString, int insert,
			    const TkTextIndex *index1Ptr,
			    const TkTextIndex *index2Ptr);
static int		TextSearchIndexInLine(const SearchSpec *searchSpecPtr,
			    TkTextLine *linePtr, int byteIndex);
static int		TextPeerCmd(TkText *textPtr, Tcl_Interp *interp,

    register TkText *textPtr = clientData;
    int result = TCL_OK;
    int index;

    static const char *const optionStrings[] = {
	"bbox", "cget", "compare", "configure", "count", "debug", "delete",
	"dlineinfo", "dump", "edit", "get", "image", "index", "insert",
	"mark", "peer", "pendingsync", "replace", "scan", "search",
	"see", "sync", "tag", "window", "xview", "yview", NULL
    };
    enum options {
	TEXT_BBOX, TEXT_CGET, TEXT_COMPARE, TEXT_CONFIGURE, TEXT_COUNT,
	TEXT_DEBUG, TEXT_DELETE, TEXT_DLINEINFO, TEXT_DUMP, TEXT_EDIT,
	TEXT_GET, TEXT_IMAGE, TEXT_INDEX, TEXT_INSERT, TEXT_MARK,
	TEXT_PEER, TEXT_PENDINGSYNC, TEXT_REPLACE, TEXT_SCAN,
	TEXT_SEARCH, TEXT_SEE, TEXT_SYNC, TEXT_TAG, TEXT_WINDOW,
	TEXT_XVIEW, TEXT_YVIEW
    };

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "option ?arg ...?");
	return TCL_ERROR;
    }

    }
    case TEXT_MARK:
	result = TkTextMarkCmd(textPtr, interp, objc, objv);
	break;
    case TEXT_PEER:
	result = TextPeerCmd(textPtr, interp, objc, objv);
	break;
    case TEXT_PENDINGSYNC: {
        if (objc != 2) {
            Tcl_WrongNumArgs(interp, 2, objv, NULL);
            result = TCL_ERROR;
            goto done;
        }
        Tcl_SetObjResult(interp,
                Tcl_NewBooleanObj(TkTextPendingsync(textPtr)));
        break;
    }
    case TEXT_REPLACE: {
	const TkTextIndex *indexFromPtr, *indexToPtr;

	if (objc < 5) {
	    Tcl_WrongNumArgs(interp, 2, objv,
		    "index1 index2 chars ?tagList chars tagList ...?");
	    result = TCL_ERROR;

	break;
    case TEXT_SEARCH:
	result = TextSearchCmd(textPtr, interp, objc, objv);
	break;
    case TEXT_SEE:
	result = TkTextSeeCmd(textPtr, interp, objc, objv);
	break;
    case TEXT_SYNC: {
	if (objc == 4) {
	    Tcl_Obj *cmd = objv[3];
	    const char *option = Tcl_GetString(objv[2]);
	    if (strncmp(option, "-command", objv[2]->length)) {
		Tcl_AppendResult(interp, "wrong option \"", option, "\": should be \"-command\"", NULL);
		result = TCL_ERROR;
		goto done;
	    }
	    Tcl_IncrRefCount(cmd);
	    if (TkTextPendingsync(textPtr)) {
		if (textPtr->afterSyncCmd) {
		    Tcl_DecrRefCount(textPtr->afterSyncCmd);
		}
		textPtr->afterSyncCmd = cmd;
	    } else {
		textPtr->afterSyncCmd = cmd;
                Tcl_DoWhenIdle(RunAfterSyncCmd, (ClientData) textPtr);
	    }
	    break;
	} else if (objc != 2) {
	    Tcl_WrongNumArgs(interp, 2, objv, "?-command command?");
	    result = TCL_ERROR;
	    goto done;
	}
	if (textPtr->afterSyncCmd) {
	    Tcl_DecrRefCount(textPtr->afterSyncCmd);
	}
	textPtr->afterSyncCmd = NULL;
	TkTextUpdateLineMetrics(textPtr, 1,
		TkBTreeNumLines(textPtr->sharedTextPtr->tree, textPtr), -1);
	break;
    }
    case TEXT_TAG:
	result = TkTextTagCmd(textPtr, interp, objc, objv);
	break;
    case TEXT_WINDOW:
	result = TkTextWindowCmd(textPtr, interp, objc, objv);
	break;
    case TEXT_XVIEW:

    if (textPtr->insertBlinkHandler != NULL) {
	Tcl_DeleteTimerHandler(textPtr->insertBlinkHandler);
    }

    textPtr->tkwin = NULL;
    textPtr->refCount--;
    Tcl_DeleteCommandFromToken(textPtr->interp, textPtr->widgetCmd);
    if (textPtr->afterSyncCmd){
	Tcl_DecrRefCount(textPtr->afterSyncCmd);
	textPtr->afterSyncCmd = NULL;
    }
    if (textPtr->refCount == 0) {
	ckfree(textPtr);
    }
}

/*
 *----------------------------------------------------------------------

    if (sharedTextPtr->isDirty == 0 || oldDirtyFlag == 0) {
	for (textPtr = sharedTextPtr->peers; textPtr != NULL;
		textPtr = textPtr->next) {
	    GenerateModifiedEvent(textPtr);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * RunAfterSyncCmd --
 *
 *	This function is called by the event loop and executes the command
 *      scheduled by [.text sync -command $cmd].
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Anything may happen, depending on $cmd contents.
 *
 *----------------------------------------------------------------------
 */

static void
RunAfterSyncCmd(
    ClientData clientData)		/* Information about text widget. */
{
    register TkText *textPtr = (TkText *) clientData;
    int code;

    if ((textPtr->tkwin == NULL) || (textPtr->flags & DESTROYED)) {
        /*
        * The widget has been deleted. Don't do anything.
        */

        if (--textPtr->refCount == 0) {
            ckfree((char *) textPtr);
        }
        return;
    }

    Tcl_Preserve((ClientData) textPtr->interp);
    code = Tcl_EvalObjEx(textPtr->interp, textPtr->afterSyncCmd, TCL_EVAL_GLOBAL);
    if (code == TCL_ERROR) {
        Tcl_AddErrorInfo(textPtr->interp, "\n    (text sync)");
        Tcl_BackgroundError(textPtr->interp);
    }
    Tcl_Release((ClientData) textPtr->interp);
    Tcl_DecrRefCount(textPtr->afterSyncCmd);
    textPtr->afterSyncCmd = NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * SearchPerform --
 *
 *	Overall control of search process. Is given a pattern, a starting

    int undo;			/* Non-zero means the undo/redo behaviour is
				 * enabled. */
    int maxUndo;		/* The maximum depth of the undo stack
				 * expressed as the maximum number of compound
				 * statements. */
    int autoSeparators;		/* Non-zero means the separators will be
				 * inserted automatically. */
    Tcl_Obj *afterSyncCmd;	/* Command to be executed when lines are up to
                                 * date */
} TkText;

/*
 * Flag values for TkText records:
 *
 * GOT_SELECTION:		Non-zero means we've already claimed the
 *				selection.

MODULE_SCOPE int	TkTextMarkCmd(TkText *textPtr, Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
MODULE_SCOPE int	TkTextMarkNameToIndex(TkText *textPtr,
			    const char *name, TkTextIndex *indexPtr);
MODULE_SCOPE void	TkTextMarkSegToIndex(TkText *textPtr,
			    TkTextSegment *markPtr, TkTextIndex *indexPtr);
MODULE_SCOPE void	TkTextEventuallyRepick(TkText *textPtr);
MODULE_SCOPE Bool	TkTextPendingsync(TkText *textPtr);
MODULE_SCOPE void	TkTextPickCurrent(TkText *textPtr, XEvent *eventPtr);
MODULE_SCOPE void	TkTextPixelIndex(TkText *textPtr, int x, int y,
			    TkTextIndex *indexPtr, int *nearest);
MODULE_SCOPE Tcl_Obj *	TkTextNewIndexObj(TkText *textPtr,
			    const TkTextIndex *indexPtr);
MODULE_SCOPE void	TkTextRedrawRegion(TkText *textPtr, int x, int y,
			    int width, int height);

static int		DlineXOfIndex(TkText *textPtr,
			    DLine *dlPtr, int byteIndex);
static int		TextGetScrollInfoObj(Tcl_Interp *interp,
			    TkText *textPtr, int objc,
			    Tcl_Obj *const objv[], double *dblPtr,
			    int *intPtr);
static void		AsyncUpdateLineMetrics(ClientData clientData);
static void		GenerateWidgetViewSyncEvent(TkText *textPtr, Bool InSync);
static void		AsyncUpdateYScrollbar(ClientData clientData);
static int              IsStartOfNotMergedLine(TkText *textPtr,
                            CONST TkTextIndex *indexPtr);

/*
 * Result values returned by TextGetScrollInfoObj:
 */

     * Update the lines in blocks of about 24 recalculations, or 250+ lines
     * examined, so we pass in 256 for 'doThisMuch'.
     */

    lineNum = TkTextUpdateLineMetrics(textPtr, lineNum,
	    dInfoPtr->lastMetricUpdateLine, 256);

    dInfoPtr->currentMetricUpdateLine = lineNum;

    if (tkTextDebug) {
	char buffer[2 * TCL_INTEGER_SPACE + 1];

	sprintf(buffer, "%d %d", lineNum, dInfoPtr->lastMetricUpdateLine);
	LOG("tk_textInvalidateLine", buffer);
    }

    /*
     * If we're not in the middle of a long-line calculation (metricEpoch==-1)
     * and we've reached the last line, then we're done.
     */

    if (dInfoPtr->metricEpoch == -1
	    && lineNum == dInfoPtr->lastMetricUpdateLine) {
	/*
	 * We have looped over all lines, so we're done. We must release our
	 * refCount on the widget (the timer token was already set to NULL
	 * above). If there is a registered aftersync command, run that first.
	 */

        if (textPtr->afterSyncCmd) {
            int code;
            Tcl_Preserve((ClientData) textPtr->interp);
            code = Tcl_EvalObjEx(textPtr->interp, textPtr->afterSyncCmd,
                    TCL_EVAL_GLOBAL);
	    if (code == TCL_ERROR) {
                Tcl_AddErrorInfo(textPtr->interp, "\n    (text sync)");
                Tcl_BackgroundError(textPtr->interp);
	    }
            Tcl_Release((ClientData) textPtr->interp);
            Tcl_DecrRefCount(textPtr->afterSyncCmd);
            textPtr->afterSyncCmd = NULL;
	}

        /*
         * Fire the <<WidgetViewSync>> event since the widget view is in sync
         * with its internal data (actually it will be after the next trip
         * through the event loop, because the widget redraws at idle-time).
         */

        GenerateWidgetViewSyncEvent(textPtr, 1);

	textPtr->refCount--;
	if (textPtr->refCount == 0) {
	    ckfree(textPtr);
	}
	return;
    }


    /*
     * Re-arm the timer. We already have a refCount on the text widget so no
     * need to adjust that.
     */

    dInfoPtr->lineUpdateTimer = Tcl_CreateTimerHandler(1,
	    AsyncUpdateLineMetrics, textPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * GenerateWidgetViewSyncEvent --
 *
 *      Send the <<WidgetViewSync>> event related to the text widget
 *      line metrics asynchronous update.
 *      This is equivalent to:
 *         event generate $textWidget <<WidgetViewSync>> -detail $s
 *      where $s is the sync status: true (when the widget view is in
 *      sync with its internal data) or false (when it is not).
 *
 * Results:
 *      None
 *
 * Side effects:
 *      If corresponding bindings are present, they will trigger.
 *
 *----------------------------------------------------------------------
 */

static void
GenerateWidgetViewSyncEvent(
    TkText *textPtr,		/* Information about text widget. */
    Bool InSync)                /* True if in sync, false otherwise */
{
    union {XEvent general; XVirtualEvent virtual;} event;

    memset(&event, 0, sizeof(event));
    event.general.xany.type = VirtualEvent;
    event.general.xany.serial = NextRequest(Tk_Display(textPtr->tkwin));
    event.general.xany.send_event = False;
    event.general.xany.window = Tk_WindowId(textPtr->tkwin);
    event.general.xany.display = Tk_Display(textPtr->tkwin);
    event.virtual.name = Tk_GetUid("WidgetViewSync");
    event.virtual.user_data = Tcl_NewBooleanObj(InSync);
    Tk_HandleEvent(&event.general);
}

/*
 *----------------------------------------------------------------------
 *
 * TkTextUpdateLineMetrics --
 *
 *	This function updates the pixel height calculations of a range of

     * Now re-set the current update calculations.
     */

    if (dInfoPtr->lineUpdateTimer == NULL) {
	textPtr->refCount++;
	dInfoPtr->lineUpdateTimer = Tcl_CreateTimerHandler(1,
		AsyncUpdateLineMetrics, textPtr);
        GenerateWidgetViewSyncEvent(textPtr, 0);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TkTextFindDisplayLineEnd --

	dInfoPtr->metricEpoch = -1;

	if (dInfoPtr->lineUpdateTimer == NULL) {
	    textPtr->refCount++;
	    dInfoPtr->lineUpdateTimer = Tcl_CreateTimerHandler(1,
		    AsyncUpdateLineMetrics, textPtr);
            GenerateWidgetViewSyncEvent(textPtr, 0);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *

	break;
    case TKTEXT_SCROLL_UNITS:
	YScrollByLines(textPtr, count);
	break;
    }
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * TkTextPendingsync --
 *
 *	This function checks if any line heights are not up-to-date.
 *
 * Results:
 *	Returns a boolean true if it is the case, or false if all line
 *      heights are up-to-date.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

Bool
TkTextPendingsync(
    TkText *textPtr)		/* Information about text widget. */
{
    TextDInfo *dInfoPtr = textPtr->dInfoPtr;

    return (
        ((dInfoPtr->metricEpoch == -1) &&
         (dInfoPtr->lastMetricUpdateLine == dInfoPtr->currentMetricUpdateLine)) ?
        0 : 1);
}

/*
 *--------------------------------------------------------------
 *
 * TkTextScanCmd --
 *
 *	This function is invoked to process the "scan" option for the widget

} -returnCodes {error} -result {wrong # args: should be ".t option ?arg ...?"}
test text-3.2 {TextWidgetCmd procedure} -setup {
    text .t
} -body {
    .t gorp 1.0 z 1.2
} -cleanup {
    destroy .t
} -returnCodes {error} -result {bad option "gorp": must be bbox, cget, compare, configure, count, debug, delete, dlineinfo, dump, edit, get, image, index, insert, mark, peer, pendingsync, replace, scan, search, see, sync, tag, window, xview, or yview}

test text-4.1 {TextWidgetCmd procedure, "bbox" option} -setup {
    text .t
} -body {
    .t bbox
} -cleanup {
    destroy .t

Line 4
bOy GIrl .#@? x_yz
!@#$%
Line 7"
    .t co 1.0 z 1.2
} -cleanup {
    destroy .t
} -returnCodes {error} -result {ambiguous option "co": must be bbox, cget, compare, configure, count, debug, delete, dlineinfo, dump, edit, get, image, index, insert, mark, peer, pendingsync, replace, scan, search, see, sync, tag, window, xview, or yview}
# "configure" option is already covered above

test text-7.1 {TextWidgetCmd procedure, "debug" option} -setup {
    text .t
} -body {
    .t debug 0 1
} -cleanup {
    destroy .t
} -returnCodes {error} -result {wrong # args: should be ".t debug boolean"}
test text-7.2 {TextWidgetCmd procedure, "debug" option} -setup {
    text .t
} -body {
    .t de 0 1
} -cleanup {
    destroy .t
} -returnCodes {error} -result {ambiguous option "de": must be bbox, cget, compare, configure, count, debug, delete, dlineinfo, dump, edit, get, image, index, insert, mark, peer, pendingsync, replace, scan, search, see, sync, tag, window, xview, or yview}
test text-7.3 {TextWidgetCmd procedure, "debug" option} -setup {
    text .t
} -body {
    .t debug true
    .t deb
} -cleanup {
    destroy .t

    }
    .t tag configure hidden -elide true
    .t tag add hidden 5.7 11.0
    update
    # next line to be fully sure that asynchronous line heights calculation is
    # up-to-date otherwise this test may fail (depending on the computer
    # performance), especially when the . toplevel has small height
    .t sync
    set y1 [lindex [.t yview] 1]
    .t count -displaylines 5.0 11.0
    set y2 [lindex [.t yview] 1]
    .t count -displaylines 5.0 12.0
    set y3 [lindex [.t yview] 1]
    list [expr {$y1 == $y2}] [expr {$y1 == $y3}]
} -cleanup {

    lappend res [.t index "end -2 indices"]
    lappend res [.t index "end -2 display indices"]
    lappend res [.t index "end -2 display chars"]
} -cleanup {
    destroy .t
} -result {1 0 0 1 0 2.0 4.0 4.0 4.0 3.0 3.0 3.0 2.0 1.0 1.0}

test text-11a.1 {TextWidgetCmd procedure, "pendingsync" option} -setup {
    destroy .yt
} -body {
    text .yt
    list [catch {.yt pendingsync mytext} msg] $msg
} -cleanup {
    destroy .yt
} -result {1 {wrong # args: should be ".yt pendingsync"}}
test text-11a.2 {TextWidgetCmd procedure, "pendingsync" option} -setup {
    destroy .top.yt .top
} -body {
    toplevel .top
    pack [text .top.yt]
    set content {}
    for {set i 1} {$i < 300} {incr i} {
        append content [string repeat "$i " 15] \n
    }
    .top.yt insert 1.0 $content
    # wait for end of line metrics calculation to get correct $fraction1
    # as a reference
    while {[.top.yt pendingsync]} {update}
    .top.yt yview moveto 1
    set fraction1 [lindex [.top.yt yview] 0]
    set res [expr {$fraction1 > 0}]
    .top.yt delete 1.0 end
    .top.yt insert 1.0 $content
    # ensure the test is relevant
    lappend res [.top.yt pendingsync]
    # asynchronously wait for completion of line metrics calculation
    while {[.top.yt pendingsync]} {update}
    .top.yt yview moveto $fraction1
    set fraction2 [lindex [.top.yt yview] 0]
    lappend res [expr {$fraction1 == $fraction2}]
} -cleanup {
    destroy .top.yt .top
} -result {1 1 1}

test text-11a.11 {TextWidgetCmd procedure, "sync" option} -setup {
    destroy .yt
} -body {
    text .yt
    list [catch {.yt sync mytext} msg] $msg
} -cleanup {
    destroy .yt
} -result {1 {wrong # args: should be ".yt sync ?-command command?"}}
test text-11a.12 {TextWidgetCmd procedure, "sync" option} -setup {
    destroy .top.yt .top
} -body {
    toplevel .top
    pack [text .top.yt]
    set content {}
    for {set i 1} {$i < 30} {incr i} {
        append content [string repeat "$i " 15] \n
    }
    .top.yt insert 1.0 $content
    # wait for end of line metrics calculation to get correct $fraction1
    # as a reference
    .top.yt sync
    .top.yt yview moveto 1
    set fraction1 [lindex [.top.yt yview] 0]
    set res [expr {$fraction1 > 0}]
    # first case: do not wait for completion of line metrics calculation
    .top.yt delete 1.0 end
    .top.yt insert 1.0 $content
    .top.yt yview moveto $fraction1
    set fraction2 [lindex [.top.yt yview] 0]
    lappend res [expr {$fraction1 == $fraction2}]
    # second case: wait for completion of line metrics calculation
    .top.yt delete 1.0 end
    .top.yt insert 1.0 $content
    .top.yt sync
    .top.yt yview moveto $fraction1
    set fraction2 [lindex [.top.yt yview] 0]
    lappend res [expr {$fraction1 == $fraction2}]
} -cleanup {
    destroy .top.yt .top
} -result {1 0 1}

test text-11a.21 {TextWidgetCmd procedure, "sync" option with -command} -setup {
    destroy .yt
} -body {
    text .yt
    list [catch {.yt sync -comx foo} msg] $msg
} -cleanup {
    destroy .yt
} -result {1 {wrong option "-comx": should be "-command"}}
test text-11a.22 {TextWidgetCmd procedure, "sync" option with -command} -setup {
    destroy .top.yt .top
} -body {
    set res {}
    set ::x 0
    toplevel .top
    pack [text .top.yt]
    set content {}
    for {set i 1} {$i < 30} {incr i} {
        append content [string repeat "$i " 15] \n
    }
    .top.yt insert 1.0 $content
    # first case: line metrics calculation still running when launching 'sync -command'
    lappend res [.top.yt pendingsync]
    .top.yt sync -command [list set ::x 1]
    lappend res $::x
    # now finish line metrics calculations
    while {[.top.yt pendingsync]} {update}
    lappend res [.top.yt pendingsync] $::x
    # second case: line metrics calculation completed when launching 'sync -command'
    .top.yt sync -command [list set ::x 2]
    lappend res $::x
    vwait ::x
    lappend res $::x
} -cleanup {
    destroy .top.yt .top
} -result {1 0 0 1 1 2}

test text-11a.31 {"<<WidgetViewSync>>" event} -setup {
    destroy .top.yt .top
} -body {
    toplevel .top
    pack [text .top.yt]
    set content {}
    for {set i 1} {$i < 300} {incr i} {
        append content [string repeat "$i " 15] \n
    }
    .top.yt insert 1.0 $content
    update
    bind .top.yt <<WidgetViewSync>> { if {%d} {set yud(%W) 1} }
    # wait for end of line metrics calculation to get correct $fraction1
    # as a reference
    if {[.top.yt pendingsync]} {vwait yud(.top.yt)}
    .top.yt yview moveto 1
    set fraction1 [lindex [.top.yt yview] 0]
    set res [expr {$fraction1 > 0}]
    .top.yt delete 1.0 end
    .top.yt insert 1.0 $content
    # synchronously wait for completion of line metrics calculation
    # and ensure the test is relevant
    set waited 0
    if {[.top.yt pendingsync]} {set waited 1 ; vwait yud(.top.yt)}
    lappend res $waited
    .top.yt yview moveto $fraction1
    set fraction2 [lindex [.top.yt yview] 0]
    lappend res [expr {$fraction1 == $fraction2}]
} -cleanup {
    destroy .top.yt .top
} -result {1 1 1}

test text-11a.41 {"sync" "pendingsync" and <<WidgetViewSync>>} -setup {
    destroy .top.yt .top
} -body {
    set res {}
    toplevel .top
    pack [text .top.yt]
    set content {}
    for {set i 1} {$i < 300} {incr i} {
        append content [string repeat "$i " 50] \n
    }
    bind .top.yt <<WidgetViewSync>> {lappend res Sync:%d}
    .top.yt insert 1.0 $content
    vwait res  ; # event dealt with by the event loop, with %d==0 i.e. we're out of sync
    # ensure the test is relevant
    lappend res "Pending:[.top.yt pendingsync]"
    # - <<WidgetViewSync>> fires when sync returns if there was pending syncs 
    # - there is no more any pending sync after running 'sync'
    .top.yt sync
    vwait res  ; # event dealt with by the event loop, with %d==1 i.e. we're in sync again
    lappend res "Pending:[.top.yt pendingsync]"
    set res
} -cleanup {
    destroy .top.yt .top
} -result {Sync:0 Pending:1 Sync:1 Pending:0}

test text-12.1 {TextWidgetCmd procedure, "index" option} -setup {
    text .t
} -body {
    .t index
} -cleanup {
    destroy .t

} -returnCodes {error} -result {wrong # args: should be ".t index index"}
test text-12.3 {TextWidgetCmd procedure, "index" option} -setup {
    text .t
} -body {
    .t in a b
} -cleanup {
    destroy .t
} -returnCodes {error} -result {ambiguous option "in": must be bbox, cget, compare, configure, count, debug, delete, dlineinfo, dump, edit, get, image, index, insert, mark, peer, pendingsync, replace, scan, search, see, sync, tag, window, xview, or yview}
test text-12.4 {TextWidgetCmd procedure, "index" option} -setup {
    text .t
} -body {
    .t index @xyz
} -cleanup {
    destroy .t
} -returnCodes {error} -result {bad text index "@xyz"}

    .t peer names foo
} -cleanup {
    destroy .t
} -returnCodes {error} -result {wrong # args: should be ".t peer names"}
test text-33.3 {TextWidgetCmd procedure, "peer" option} -setup {
    text .t
} -body {
    .t pee names
} -cleanup {
    destroy .t
} -returnCodes {ok} -result {}
test text-33.4 {TextWidgetCmd procedure, "peer" option} -setup {
    text .t
} -body {
    .t peer names

	set result "italic font has much too much space"
    } else {
	set result "italic font measurement ok"
    }
} {italic font measurement ok}
destroy .tt

test textDisp-34.1 {Line heights recalculation problem: bug 2677890} -setup {
    pack [text .t1] -expand 1 -fill both



    set txt ""
    for {set i 1} {$i < 100} {incr i} {
        append txt "Line $i\n"
    }
    set result {}
} -body {
    .t1 insert end $txt
    .t1 debug 1
    set ge [winfo geometry .]
    scan $ge "%dx%d+%d+%d" width height left top
    update

    .t1 sync
    set negative 0
    bind .t1 <<WidgetViewSync>> { if {%d < 0} {set negative 1} }
    # Without the fix for bug 2677890, changing the width of the toplevel
    # will launch recomputation of the line heights, but will produce negative
    # number of still remaining outdated lines, which is obviously wrong.
    # Thus we use this way to check for regression regarding bug 2677890,
    # i.e. to check that the fix for this bug really is still in.
    wm geometry . "[expr {$width * 2}]x$height+$left+$top"
    update
    .t1 sync


    set negative
} -cleanup {
    destroy .t1
} -result {0}

test textDisp-35.1 {Init value of charHeight - Dancing scrollbar bug 1499165} -setup {
    pack [text .t1] -fill both -expand y -side left
    .t insert end "[string repeat a\nb\nc\n 500000]THE END\n"
    set res {}
} -body {
    .t see 10000.0