InfTextBuffer

InfTextBuffer — Interface for the text storage of an InfTextSession

Stability Level

Unstable, unless otherwise indicated

Functions

Signals

void text-erased Run First
void text-inserted Run First

Types and Values

Object Hierarchy

    GInterface
    ╰── InfTextBuffer

Prerequisites

InfTextBuffer requires InfBuffer and GObject.

Known Implementations

InfTextBuffer is implemented by InfTextDefaultBuffer and InfTextFixlineBuffer.

Includes

#include <libinftext/inf-text-buffer.h>

Description

InfTextBuffer is an interface on top of InfBuffer which represents a text buffer in a similar way as GtkTextBuffer. InfTextBuffer can be used as the buffer of an InfTextSession, allowing the session to insert text written by remote users and access text written by local users and send it to everyone else.

See InfTextDefaultBuffer for a simple implementation based on InfTextChunk. However, in GUI collaborative editing clients this interface should be implemented in a more sophisticated way, such that the text of a document is not stored twice in memory. InfTextGtkBuffer does this for GTK+ based user interfaces.

Functions

inf_text_buffer_get_encoding ()

const gchar *
inf_text_buffer_get_encoding (InfTextBuffer *buffer);

Returns the character encoding that the buffer uses. This means that all InfTextChunk return values are encoded in this encoding and all InfTextChunk parameters are expected to be encoded in that encoding.

Parameters

buffer

A InfTextBuffer.

 

Returns

The character encoding for buffer .


inf_text_buffer_get_length ()

guint
inf_text_buffer_get_length (InfTextBuffer *buffer);

Returns the number of characters in buffer .

Parameters

buffer

A InfTextBuffer.

 

Returns

The length of buffer .


inf_text_buffer_get_slice ()

InfTextChunk *
inf_text_buffer_get_slice (InfTextBuffer *buffer,
                           guint pos,
                           guint len);

Reads len characters, starting at pos , from the buffer, and returns them as a InfTextChunk.

Parameters

buffer

A InfTextBuffer.

 

pos

Character offset of where to start extracting.

 

len

Number of characters to extract.

 

Returns

A InfTextChunk.

[transfer full]


inf_text_buffer_insert_text ()

void
inf_text_buffer_insert_text (InfTextBuffer *buffer,
                             guint pos,
                             gconstpointer text,
                             gsize bytes,
                             guint len,
                             InfUser *user);

Inserts text into buffer as written by author . text must be encoded in the character encoding of the buffer, see inf_text_buffer_get_encoding().

Parameters

buffer

A InfTextBuffer.

 

pos

A character offset into buffer .

 

text (type=guint8*) (array length=bytes) (transfer none)

A pointer to the text to insert.

 

len

The length (in characters) of text .

 

bytes

The length (in bytes) of text .

 

user

A InfUser that has inserted the new text, or NULL.

[allow-none]

inf_text_buffer_insert_chunk ()

void
inf_text_buffer_insert_chunk (InfTextBuffer *buffer,
                              guint pos,
                              InfTextChunk *chunk,
                              InfUser *user);

Inserts a InfTextChunk into buffer . user must not necessarily be the author of chunk (chunk may even consist of multiple segments). This happens when undoing a delete operation that erased another user's text.

Parameters

buffer

A InfTextBuffer.

 

pos

A character offset into buffer .

 

chunk

A InfTextChunk.

[transfer none]

user

A InfUser inserting chunk , or NULL.

[allow-none]

inf_text_buffer_erase_text ()

void
inf_text_buffer_erase_text (InfTextBuffer *buffer,
                            guint pos,
                            guint len,
                            InfUser *user);

Erases characters from the text buffer.

Parameters

buffer

A InfTextBuffer.

 

pos

The position to begin deleting characters from.

 

len

The amount of characters to delete.

 

user

A InfUser that erases the text, or NULL.

[allow-none]

inf_text_buffer_create_begin_iter ()

InfTextBufferIter *
inf_text_buffer_create_begin_iter (InfTextBuffer *buffer);

Creates a InfTextBufferIter pointing to the first segment of buffer . A InfTextBufferIter is used to traverse the buffer contents in steps of so-called segments each of which is written by the same user. The function returns NULL if there are no segments (i.e. the buffer is empty).

The iterator stays valid as long as the buffer remains unmodified and must be freed with inf_text_buffer_destroy_iter() before.

Parameters

buffer

A InfTextBuffer.

 

Returns

A InfTextBufferIter to be freed by inf_text_buffer_destroy_iter() when done using it, or NULL.

[transfer full][allow-none]


inf_text_buffer_create_end_iter ()

InfTextBufferIter *
inf_text_buffer_create_end_iter (InfTextBuffer *buffer);

Creates a InfTextBufferIter pointing to the last segment of buffer . A InfTextBufferIter is used to traverse the buffer contents in steps of so-called segments each of which is written by the same user. The function returns NULL if there are no segments (i.e. the buffer is empty).

The iterator stays valid as long as the buffer remains unmodified and must be freed with inf_text_buffer_destroy_iter() before.

Parameters

buffer

A InfTextBuffer.

 

Returns

A InfTextBufferIter to be freed by inf_text_buffer_destroy_iter() when done using it, or NULL.

[transfer full][allow-none]


inf_text_buffer_destroy_iter ()

void
inf_text_buffer_destroy_iter (InfTextBuffer *buffer,
                              InfTextBufferIter *iter);

Destroys a InfTextBufferIter created by inf_text_buffer_create_begin_iter() or inf_text_buffer_create_end_iter().

Parameters

buffer

A InfTextBuffer.

 

iter

A InfTextBufferIter pointing into buffer .

[transfer full]

inf_text_buffer_iter_next ()

gboolean
inf_text_buffer_iter_next (InfTextBuffer *buffer,
                           InfTextBufferIter *iter);

Moves iter to point to the next segment in the buffer. If iter already points to the last segment, iter is left unmodified and the function returns FALSE.

Parameters

buffer

A InfTextBuffer.

 

iter

A InfTextBufferIter pointing into buffer .

 

Returns

Whether iter was moved.


inf_text_buffer_iter_prev ()

gboolean
inf_text_buffer_iter_prev (InfTextBuffer *buffer,
                           InfTextBufferIter *iter);

Moves iter to point to the previous segment in the buffer. If iter already points to the first segment, iter is left unmodified and the function returns FALSE.

Parameters

buffer

A InfTextBuffer.

 

iter

A InfTextBufferIter pointing into buffer .

 

Returns

Whether iter was moved.


inf_text_buffer_iter_get_text ()

gpointer
inf_text_buffer_iter_get_text (InfTextBuffer *buffer,
                               InfTextBufferIter *iter);

Returns the text of the segment iter points to. It is encoded in buffer 's encoding (see inf_text_buffer_get_encoding()).

Parameters

buffer

A InfTextBuffer.

 

iter

A InfTextBufferIter pointing into buffer .

 

Returns

The text of the segment iter points to. Free with g_free() when done using it.

[transfer full]


inf_text_buffer_iter_get_offset ()

guint
inf_text_buffer_iter_get_offset (InfTextBuffer *buffer,
                                 InfTextBufferIter *iter);

Returns the offset of the first character in the segment iter points to, in characters.

Parameters

buffer

A InfTextBuffer.

 

iter

A InfTextBufferIter pointing into buffer .

 

Returns

The offset of the first character in the segment iter points to.


inf_text_buffer_iter_get_length ()

guint
inf_text_buffer_iter_get_length (InfTextBuffer *buffer,
                                 InfTextBufferIter *iter);

Returns the length of the segment iter points to, in characters.

Parameters

buffer

A InfTextBuffer.

 

iter

A InfTextBufferIter pointing into buffer .

 

Returns

The number of characters of the segment iter points to.


inf_text_buffer_iter_get_bytes ()

gsize
inf_text_buffer_iter_get_bytes (InfTextBuffer *buffer,
                                InfTextBufferIter *iter);

Returns the length of the segment iter points to, in bytes.

Parameters

buffer

A InfTextBuffer.

 

iter

A InfTextBufferIter pointing into buffer .

 

Returns

The number of bytes of the segment iter points to.


inf_text_buffer_iter_get_author ()

guint
inf_text_buffer_iter_get_author (InfTextBuffer *buffer,
                                 InfTextBufferIter *iter);

Returns the user ID of the user that has written the segment iter points to.

Parameters

buffer

A InfTextBuffer.

 

iter

A InfTextBufferIter pointing into buffer .

 

Returns

The user ID of the user that wrote the segment iter points to.


inf_text_buffer_text_inserted ()

void
inf_text_buffer_text_inserted (InfTextBuffer *buffer,
                               guint pos,
                               InfTextChunk *chunk,
                               InfUser *user);

Emits the “text-inserted” signal. This is meant to be used by interface implementations in their insert_text function, or when text was inserted by other means.

Parameters

buffer

A InfTextBuffer.

 

pos

A character offset into buffer .

 

chunk

A InfTextChunk.

 

user

A InfUser inserting chunk , or NULL.

[allow-none]

inf_text_buffer_text_erased ()

void
inf_text_buffer_text_erased (InfTextBuffer *buffer,
                             guint pos,
                             InfTextChunk *chunk,
                             InfUser *user);

Emits the “text-erased” signal. This is meant to be used by interface implementations in their erase_text function, or when text was erased by other means.

Parameters

buffer

A InfTextBuffer.

 

pos

The position to begin deleting characters from.

 

chunk

A InfTextChunk containing the erased text.

 

user

A InfUser that erases the text, or NULL.

[allow-none]

Types and Values

InfTextBuffer

typedef struct _InfTextBuffer InfTextBuffer;

InfTextBuffer is an opaque data type. You should only access it via the public API functions.


struct InfTextBufferInterface

struct InfTextBufferInterface {
  /* Virtual table */
  const gchar* (*get_encoding)(InfTextBuffer* buffer);

  guint(*get_length)(InfTextBuffer* buffer);

  InfTextChunk*(*get_slice)(InfTextBuffer* buffer,
                            guint pos,
                            guint len);

  void(*insert_text)(InfTextBuffer* buffer,
                     guint pos,
                     InfTextChunk* chunk,
                     InfUser* user);

  void(*erase_text)(InfTextBuffer* buffer,
                    guint pos,
                    guint len,
                    InfUser* user);

  InfTextBufferIter*(*create_begin_iter)(InfTextBuffer* buffer);

  InfTextBufferIter*(*create_end_iter)(InfTextBuffer* buffer);

  void(*destroy_iter)(InfTextBuffer* buffer,
                      InfTextBufferIter* iter);

  gboolean(*iter_next)(InfTextBuffer* buffer,
                       InfTextBufferIter* iter);

  gboolean(*iter_prev)(InfTextBuffer* buffer,
                       InfTextBufferIter* iter);

  gpointer(*iter_get_text)(InfTextBuffer* buffer,
                           InfTextBufferIter* iter);

  guint(*iter_get_offset)(InfTextBuffer* buffer,
                          InfTextBufferIter* iter);

  guint(*iter_get_length)(InfTextBuffer* buffer,
                          InfTextBufferIter* iter);

  gsize(*iter_get_bytes)(InfTextBuffer* buffer,
                         InfTextBufferIter* iter);

  guint(*iter_get_author)(InfTextBuffer* buffer,
                          InfTextBufferIter* iter);

  /* Signals */
  void(*text_inserted)(InfTextBuffer* buffer,
                       guint pos,
                       InfTextChunk* chunk,
                       InfUser* user);

  void(*text_erased)(InfTextBuffer* buffer,
                     guint pos,
                     InfTextChunk* chunk,
                     InfUser* user);
};

This structure contains virtual functions and signal handlers of the InfTextBuffer interface.

Members

get_encoding ()

Virtual function which returns the character coding of the buffer.

 

get_length ()

Virtual function to return the total length of the text in the buffer, in characters.

 

get_slice ()

Virtual function to extract a slice of text from the buffer.

 

insert_text ()

Virtual function to insert text into the buffer.

 

erase_text ()

Virtual function to remove text from the buffer.

 

create_begin_iter ()

Virtual function to create a InfTextBufferIter at the beginning of the buffer, used for traversing through buffer segments.

 

create_end_iter ()

Virtual function to create a InfTextBufferIter at the end of the buffer, used for traversing through buffer segments.

 

destroy_iter ()

Virtual function to destroy an iterator created with the create_begin_iter and create_end_iter functions.

 

iter_next ()

Virtual function to advance a InfTextBufferIter to the next segment.

 

iter_prev ()

Virtual function to retreat a InfTextBufferIter to the previous segment.

 

iter_get_text ()

Virtual function to obtain the text of a segment a InfTextBufferIter points to.

 

iter_get_offset ()

Virtual function to obtain the offset of the first character in the segment a InfTextBufferIter points to.

 

iter_get_length ()

Virtual function to obtain the length of a segment a InfTextBufferIter points to.

 

iter_get_bytes ()

Virtual function to obtain the number of bytes in a segment a InfTextBufferIter points to.

 

iter_get_author ()

Virtual function to obtain the author of the segment a InfTextBufferIter points to.

 

text_inserted ()

Default signal handler of the “text-inserted” signal.

 

text_erased ()

Default signal handler of the “text-erased” signal.

 

InfTextBufferIter

typedef struct _InfTextBufferIter InfTextBufferIter;

InfTextBufferIter is an opaque data type. You should only access it via the public API functions.

Signal Details

The “text-erased” signal

void
user_function (InfTextBuffer *inftextbuffer,
               guint          arg1,
               InfTextChunk  *arg2,
               InfUser       *arg3,
               gpointer       user_data)

Flags: Run First


The “text-inserted” signal

void
user_function (InfTextBuffer *inftextbuffer,
               guint          arg1,
               InfTextChunk  *arg2,
               InfUser       *arg3,
               gpointer       user_data)

Flags: Run First

See Also

InfTextDefaultBuffer