TEGetOffset

Obtain a character offset associated with a screen point

#include <TextEdit.h> TextEdit

short TEGetOffset(thePt, hTE );

Point thePt; in local coordinates; usually a mouseDown Point

TEHandle hTE; handle of an edit record

returns an offset within the data at TERec.hText

TEGetOffset returns an offset which you can use to identify the character

associated with a point on the screen. This works with both types of

edit record.

thePt is the point, in local coordinates. It is usually a value obtained from

the where field of the EventRecord structure (and converted to local

coordinates via GlobalToLocal).

hTE is a handle obtained via TENew (old style TextEdit record) or

TEStylNew (new style TextEdit record). It leads to a

variable-length TERec structure and identifies the edit record of

interest.

Returns: a short; an offset within the edit record's text of the character that

is currently drawn at thePt.

Notes: TEGetOffset lets you look up the text associated with a

mouseDown. Thus, you can "micro-manage" the functions usually performed

by TEClick or TEKey, et al. The following code uses this offset to replace

the character at a mouse click:

short theOffset;

CharsHandle theChars;

char *cp;

GlobalToLocal( &evp->where ); /* local coordinates */

HLock( hTE);

theOffset = TEGetOffset( evp->where, hTE );

theChars = TEGetText(hTE);

cp = *theChars;

cp[theOffset]='X';

InvalRect( &(*hTE)->viewRect ); /* way to force redraw */

TEGetOffset works for old-format as well as new-format edit records.

Use TEGetPoint for the inverse operation (locate a screen point

associated with a particular character).

Referenced by (9):