Querying the region Returns
YES if the region for this container is
a rectangle as large as the container size, otherwise
NO. For simple rectangular regions, the
text system can apply certain optimizations.
NSTextContainer always returns
YES. Subclasses that define more
complex regions must return NO.
This is the main method used by the text system for
querying the region and flowing text in it. It
takes a proposed line fragment rectangle and, if
possible, splits it into a valid line fragment
rectangle, and a remaining rectangle that can be
used in subsequent calls to this method.
sweepDir is the direction that text moves
inside the lines, and moveDir is the
direction lines move in, or NSLineDoesntMove if
the line may not move. The line sweep and line movement
may not both be in the same dimension, ie. both be
vertical, or both be horizontal. The method
returns the first (according to the sweep
direction) valid line fragment rectangle in the
proposed rectangle. This line fragment rectangle
is a sub-rectangle of the proposed rectangle in the
sweep direction, and has the same size in the other
direction. (Ie. if the sweep direction is left,
the line fragment rectangle must have the same height
as the proposed rectangle.) If there is no valid line
fragment rectangle in the proposed rectangle, the
proposed rectangle may be moved in the line
movement direction until there is one. If no valid
line fragment rectangle can be returned, the method
returns NSZeroRect. The remaining rectangle should
be set to the potentially valid part of the proposed
rectangle, after moving in the line movement
direction, that remains after the first line
fragment rectangle. The proposed rectangle may be
any rectangle; in particular, it may extend outside the
container size. The remaining rectangle does not
have to be or contain a valid line fragment rectangle.
Subclasses define regions by overriding this
method. Note: The TextContainerExample in the text
system example collection (TODO: link) contains an
example implementation of an NSTextContainer
subclass that defiens a non-trivial region, as
well as an interactive demonstration of this method.
It can also be used as a simple test of custom
subclasses. Note: Although a correct
NSTextContainer implementation must handle
all line sweep and movement directions, the current
standard typesetter will only call this method
with sweep right, and no movement or movement down.
Relying on this makes writing a subclass easier,
but it is not safe.
Managing the text network A text container
may be attached to one layout manager and one text
view. The text container is retained by the layout
manager, and retains the text view.
Replaces the layout manager of this text container
with aLayoutManager. This is done without
changing the rest of the text network, so
aLayoutManager will be connected to the
text storage and text containers that the current
layout manager is connected to.
The container size A text container has a
container size. The region defined by the text
container must be a subset of the rectangle of
this size with it's top-left corner in the origin.
Subclasses do not have to support arbitrary
sizes, and may choose to ignore
-setContainerSize:
completely. However, the size returned by
-containerSize
must be valid.
Line fragment padding The line fragment padding
is an amount of space left empty at each end of a line
fragment rectangle by the standard typesetter. The
default is 0.0.
Sets the NSTextView for this text container. Note that
a text view should be attached to a text container only
if the text container is attached to a layout manager
that can handle text views (eg. NSLayoutManager). The
text view is retained by the text container.
Automatic resizing A text container can be
set to automatically track the width and/or height of
its NSTextView (TODO: frame? bounds?). For more
information, see the documentation on
automatic resizing in NSTextView. (TODO: link)
When enabled, the automatic resizing is done by
calling
[NSTextContainer -setContainerSize:]
with the new size whenever the text view is resized.
Warning the underscore at the start of the
name of this instance variable indicates that, even
though it is not technically private, it is
intended for internal use within the package, and
you should not use the variable in other code.
Warning the underscore at the start of the
name of this instance variable indicates that, even
though it is not technically private, it is
intended for internal use within the package, and
you should not use the variable in other code.
Warning the underscore at the start of the
name of this instance variable indicates that, even
though it is not technically private, it is
intended for internal use within the package, and
you should not use the variable in other code.
Warning the underscore at the start of the
name of this instance variable indicates that, even
though it is not technically private, it is
intended for internal use within the package, and
you should not use the variable in other code.
Warning the underscore at the start of the
name of this instance variable indicates that, even
though it is not technically private, it is
intended for internal use within the package, and
you should not use the variable in other code.
Warning the underscore at the start of the
name of this instance variable indicates that, even
though it is not technically private, it is
intended for internal use within the package, and
you should not use the variable in other code.
Warning the underscore at the start of the
name of this instance variable indicates that, even
though it is not technically private, it is
intended for internal use within the package, and
you should not use the variable in other code.