'\"'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.'\"'\" See the file "license.terms" for information on usage and redistribution'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.'\" '\" SCCS: @(#) CanvTxtInfo.3 1.8 96/03/26 18:03:51'\" .so man.macros.TH Tk_CanvasTextInfo 3 4.0 Tk "Tk Library Procedures".BS.SH NAMETk_CanvasTextInfo \- additional information for managing text items in canvases.SH SYNOPSIS.nf\fB#include <tk.h>\fR.spTk_CanvasTextInfo *\fBTk_CanvasGetTextInfo\fR(\fIcanvas\fR).SH ARGUMENTS.AS Tk_Canvas canvas.AP Tk_Canvas canvas inA token that identifies a particular canvas widget..BE.SH DESCRIPTION.PPTextual canvas items are somewhat more complicated to manage thanother items, due to things like the selection and the input focus.\fBTk_CanvasGetTextInfo\fR may be invoked by a type managerto obtain additional information needed for items that display text.The return value from \fBTk_CanvasGetTextInfo\fR is a pointer toa structure that is shared between Tk and all the items that displaytext.The structure has the following form:.CStypedef struct Tk_CanvasTextInfo {	Tk_3DBorder \fIselBorder\fR;	int \fIselBorderWidth\fR;	XColor *\fIselFgColorPtr\fR;	Tk_Item *\fIselItemPtr\fR;	int \fIselectFirst\fR;	int \fIselectLast\fR;	Tk_Item *\fIanchorItemPtr\fR;	int \fIselectAnchor\fR;	Tk_3DBorder \fIinsertBorder\fR;	int \fIinsertWidth\fR;	int \fIinsertBorderWidth\fR;	Tk_Item *\fIfocusItemPtr\fR;	int \fIgotFocus\fR;	int \fIcursorOn\fR;} Tk_CanvasTextInfo;.CEThe \fBselBorder\fR field identifies a Tk_3DBorder that should beused for drawing the background under selected text.\fIselBorderWidth\fR gives the width of the raised border aroundselected text, in pixels.\fIselFgColorPtr\fR points to an XColor that describes the foregroundcolor to be used when drawing selected text.\fIselItemPtr\fR points to the item that is currently selected, orNULL if there is no item selected or if the canvas doesn't have theselection.\fIselectFirst\fR and \fIselectLast\fR give the indices of the firstand last selected characters in \fIselItemPtr\fR, as returned by the\fIindexProc\fR for that item.\fIanchorItemPtr\fR points to the item that currently has the selectionanchor;  this is not necessarily the same as \fIselItemPtr\fR.\fIselectAnchor\fR is an index that identifies the anchor positionwithin \fIanchorItemPtr\fR.\fIinsertBorder\fR contains a Tk_3DBorder to use when drawing theinsertion cursor;  \fIinsertWidth\fR gives the total width of theinsertion cursor in pixels, and \fIinsertBorderWidth\fR gives thewidth of the raised  border around the insertion cursor.\fIfocusItemPtr\fR identifies the item that currently has the inputfocus, or NULL if there is no such item.\fIgotFocus\fR is 1 if the canvas widget has the input focus and0 otherwise.\fIcursorOn\fR is 1 if the insertion cursor should be drawn in\fIfocusItemPtr\fR and 0 if it should not be drawn;  this fieldis toggled on and off by Tk to make the cursor blink..PPThe structure returned by \fBTk_CanvasGetTextInfo\fRis shared between Tk and the type managers;  typically the type managercalls \fBTk_CanvasGetTextInfo\fR once when an item is created andthen saves the pointer in the item's record.Tk will update information in the Tk_CanvasTextInfo;  for example,a \fBconfigure\fR widget command might change the \fIselBorder\fRfield, or a \fBselect\fR widget command might change the \fIselectFirst\fRfield, or Tk might change \fIcursorOn\fR in order to make the insertioncursor flash on and off during successive redisplays..PPType managers should treat all of the fields of the Tk_CanvasTextInfostructure as read-only, except for \fIselItemPtr\fR, \fIselectFirst\fR,\fIselectLast\fR, and \fIselectAnchor\fR.Type managers may change \fIselectFirst\fR, \fIselectLast\fR, and\fIselectAnchor\fR to adjust for insertions and deletions in theitem (but only if the item is the current owner of the selection oranchor, as determined by \fIselItemPtr\fR or \fIanchorItemPtr\fR).If all of the selected text in the item is deleted, the item shouldset \fIselItemPtr\fR to NULL to indicate that there is no longer aselection..SH KEYWORDScanvas, focus, insertion cursor, selection, selection anchor, text