The
TextHitInfo
class represents a character position in a text model, and a
bias, or "side," of the character. Biases are either
leading (the left edge, for a left-to-right character) or
trailing (the right edge, for a left-to-right character). Instances of
TextHitInfo
are used to specify caret and insertion positions within text.
For example, consider the text "abc". TextHitInfo.trailing(1) corresponds to the right side of the 'b' in the text.
TextHitInfo
is used primarily by TextLayout
and clients of TextLayout
. Clients of TextLayout
query TextHitInfo
instances for an insertion offset, where new text is inserted into the text model. The insertion offset is equal to the character position in the TextHitInfo
if the bias is leading, and one character after if the bias is trailing. The insertion offset for TextHitInfo.trailing(1) is 2.
Sometimes it is convenient to construct a TextHitInfo
with the same insertion offset as an existing one, but on the opposite character. The getOtherHit
method constructs a new TextHitInfo
with the same insertion offset as an existing one, with a hit on the character on the other side of the insertion offset. Calling getOtherHit
on trailing(1) would return leading(2). In general, getOtherHit
for trailing(n) returns leading(n+1) and getOtherHit
for leading(n) returns trailing(n-1).
Example:
Converting a graphical point to an insertion point within a text model
TextLayout layout = ...;
Point2D.Float hitPoint = ...;
TextHitInfo hitInfo = layout.hitTestChar(hitPoint.x, hitPoint.y);
int insPoint = hitInfo.getInsertionIndex();
// insPoint is relative to layout; may need to adjust for use
// in a text model