Struct gtk::TextIter [−][src]
pub struct TextIter(_);
Expand description
You may wish to begin by reading the [text widget conceptual overview][TextWidget] which gives an overview of all the objects and data types related to the text widget and how they work together.
Implementations
Moves backward by one character offset. Returns true if movement
was possible; if self was the first in the buffer (character
offset 0), backward_char() returns false for convenience when
writing loops.
Returns
whether movement was possible
Moves count characters backward, if possible (if count would move
past the start or end of the buffer, moves to the start or end of
the buffer). The return value indicates whether the iterator moved
onto a dereferenceable position; if the iterator didn’t move, or
moved onto the end iterator, then false is returned. If count is 0,
the function does nothing and returns false.
count
number of characters to move
Returns
whether self moved and is dereferenceable
Moves up to count cursor positions. See
forward_cursor_position() for details.
count
number of positions to move
Returns
true if we moved and the new position is dereferenceable
Same as forward_find_char(), but goes backward from self.
pred
function to be called on each character
limit
search limit, or None for none
Returns
whether a match was found
Moves self to the start of the previous line. Returns true if
self could be moved; i.e. if self was at character offset 0, this
function returns false. Therefore if self was already on line 0,
but not at the start of the line, self is snapped to the start of
the line and the function returns true. (Note that this implies that
in a loop calling this function, the line number may not change on
every iteration, if your first iteration is on line 0.)
Returns
whether self moved
Moves count lines backward, if possible (if count would move
past the start or end of the buffer, moves to the start or end of
the buffer). The return value indicates whether the iterator moved
onto a dereferenceable position; if the iterator didn’t move, or
moved onto the end iterator, then false is returned. If count is 0,
the function does nothing and returns false. If count is negative,
moves forward by 0 - count lines.
count
number of lines to move backward
Returns
whether self moved and is dereferenceable
Same as forward_search(), but moves backward.
match_end will never be set to a TextIter located after self, even if
there is a possible match_start before or at self.
str
search string
flags
bitmask of flags affecting the search
limit
location of last possible match_start, or None for start of buffer
Returns
whether a match was found
match_start
return location for start of match, or None
match_end
return location for end of match, or None
Moves backward to the previous sentence start; if self is already at
the start of a sentence, moves backward to the next one. Sentence
boundaries are determined by Pango and should be correct for nearly
any language (if not, the correct fix would be to the Pango text
boundary algorithms).
Returns
true if self moved and is not the end iterator
Calls backward_sentence_start() up to count times,
or until it returns false. If count is negative, moves forward
instead of backward.
count
number of sentences to move
Returns
true if self moved and is not the end iterator
Moves backward to the next toggle (on or off) of the
TextTag tag, or to the next toggle of any tag if
tag is None. If no matching tag toggles are found,
returns false, otherwise true. Does not return toggles
located at self, only toggles before self. Sets self
to the location of the toggle, or the start of the buffer
if no toggle is found.
tag
Returns
whether we found a tag toggle before self
Moves self forward to the previous visible cursor position. See
backward_cursor_position() for details.
Returns
true if we moved and the new position is dereferenceable
Moves up to count visible cursor positions. See
backward_cursor_position() for details.
count
number of positions to move
Returns
true if we moved and the new position is dereferenceable
Moves self to the start of the previous visible line. Returns true if
self could be moved; i.e. if self was at character offset 0, this
function returns false. Therefore if self was already on line 0,
but not at the start of the line, self is snapped to the start of
the line and the function returns true. (Note that this implies that
in a loop calling this function, the line number may not change on
every iteration, if your first iteration is on line 0.)
Returns
whether self moved
Moves count visible lines backward, if possible (if count would move
past the start or end of the buffer, moves to the start or end of
the buffer). The return value indicates whether the iterator moved
onto a dereferenceable position; if the iterator didn’t move, or
moved onto the end iterator, then false is returned. If count is 0,
the function does nothing and returns false. If count is negative,
moves forward by 0 - count lines.
count
number of lines to move backward
Returns
whether self moved and is dereferenceable
Moves backward to the previous visible word start. (If self is currently
on a word start, moves backward to the next one after that.) Word breaks
are determined by Pango and should be correct for nearly any
language (if not, the correct fix would be to the Pango word break
algorithms).
Returns
true if self moved and is not the end iterator
Calls backward_visible_word_start() up to count times.
count
number of times to move
Returns
true if self moved and is not the end iterator
Moves backward to the previous word start. (If self is currently on a
word start, moves backward to the next one after that.) Word breaks
are determined by Pango and should be correct for nearly any
language (if not, the correct fix would be to the Pango word break
algorithms).
Returns
true if self moved and is not the end iterator
Calls backward_word_start() up to count times.
count
number of times to move
Returns
true if self moved and is not the end iterator
Returns true if tag is toggled on at exactly this point. If tag
is None, returns true if any tag is toggled on at this point.
Note that if begins_tag() returns true, it means that self is
at the beginning of the tagged range, and that the
character at self is inside the tagged range. In other
words, unlike ends_tag(), if begins_tag() returns
true, has_tag() will also return true for the same
parameters.
Deprecated since 3.20
Use starts_tag() instead.
tag
Returns
whether self is the start of a range tagged with tag
Considering the default editability of the buffer, and tags that
affect editability, determines whether text inserted at self would
be editable. If text inserted at self would be editable then the
user should be allowed to insert text at self.
TextBufferExt::insert_interactive() uses this function to decide
whether insertions are allowed at a given position.
default_editability
true if text is editable by default
Returns
whether text inserted at self would be editable
Returns whether the character at self is within an editable region
of text. Non-editable text is “locked” and can’t be changed by the
user via TextView. This function is simply a convenience
wrapper around [attributes()][Self::attributes()]. If no tags applied
to this text affect editability, default_setting will be returned.
You don’t want to use this function to decide whether text can be
inserted at self, because for insertion you don’t want to know
whether the char at self is inside an editable range, you want to
know whether a new character inserted at self would be inside an
editable range. Use can_insert() to handle this
case.
default_setting
true if text is editable by default
Returns
whether self is inside an editable range
Returns true if self points to the start of the paragraph
delimiter characters for a line (delimiters will be either a
newline, a carriage return, a carriage return followed by a
newline, or a Unicode paragraph separator character). Note that an
iterator pointing to the \n of a \r\n pair will not be counted as
the end of a line, the line ends before the \r. The end iterator is
considered to be at the end of a line, even though there are no
paragraph delimiter chars there.
Returns
whether self is at the end of a line
Returns true if tag is toggled off at exactly this point. If tag
is None, returns true if any tag is toggled off at this point.
Note that if ends_tag() returns true, it means that self is
at the end of the tagged range, but that the character
at self is outside the tagged range. In other words,
unlike starts_tag(), if ends_tag() returns true,
has_tag() will return false for the same parameters.
tag
Returns
whether self is the end of a range tagged with tag
Moves self forward by one character offset. Note that images
embedded in the buffer occupy 1 character slot, so
forward_char() may actually move onto an image instead
of a character, if you have images in your buffer. If self is the
end iterator or one character before it, self will now point at
the end iterator, and forward_char() returns false for
convenience when writing loops.
Returns
whether self moved and is dereferenceable
Moves count characters if possible (if count would move past the
start or end of the buffer, moves to the start or end of the
buffer). The return value indicates whether the new position of
self is different from its original position, and dereferenceable
(the last iterator in the buffer is not dereferenceable). If count
is 0, the function does nothing and returns false.
count
number of characters to move, may be negative
Returns
whether self moved and is dereferenceable
Moves self forward by a single cursor position. Cursor positions
are (unsurprisingly) positions where the cursor can appear. Perhaps
surprisingly, there may not be a cursor position between all
characters. The most common example for European languages would be
a carriage return/newline sequence. For some Unicode characters,
the equivalent of say the letter “a” with an accent mark will be
represented as two characters, first the letter then a “combining
mark” that causes the accent to be rendered; so the cursor can’t go
between those two characters. See also the PangoLogAttr-struct and
pango_break() function.
Returns
true if we moved and the new position is dereferenceable
Moves up to count cursor positions. See
forward_cursor_position() for details.
count
number of positions to move
Returns
true if we moved and the new position is dereferenceable
Advances self, calling pred on each character. If
pred returns true, returns true and stops scanning.
If pred never returns true, self is set to limit if
limit is non-None, otherwise to the end iterator.
pred
a function to be called on each character
limit
search limit, or None for none
Returns
whether a match was found
Moves self to the start of the next line. If the iter is already on the
last line of the buffer, moves the iter to the end of the current line.
If after the operation, the iter is at the end of the buffer and not
dereferencable, returns false. Otherwise, returns true.
Returns
whether self can be dereferenced
Moves count lines forward, if possible (if count would move
past the start or end of the buffer, moves to the start or end of
the buffer). The return value indicates whether the iterator moved
onto a dereferenceable position; if the iterator didn’t move, or
moved onto the end iterator, then false is returned. If count is 0,
the function does nothing and returns false. If count is negative,
moves backward by 0 - count lines.
count
number of lines to move forward
Returns
whether self moved and is dereferenceable
Searches forward for str. Any match is returned by setting
match_start to the first character of the match and match_end to the
first character after the match. The search will not continue past
limit. Note that a search is a linear or O(n) operation, so you
may wish to use limit to avoid locking up your UI on large
buffers.
match_start will never be set to a TextIter located before self, even if
there is a possible match_end after or at self.
str
a search string
flags
flags affecting how the search is done
limit
location of last possible match_end, or None for the end of the buffer
Returns
whether a match was found
match_start
return location for start of match, or None
match_end
return location for end of match, or None
Moves forward to the next sentence end. (If self is at the end of
a sentence, moves to the next end of sentence.) Sentence
boundaries are determined by Pango and should be correct for nearly
any language (if not, the correct fix would be to the Pango text
boundary algorithms).
Returns
true if self moved and is not the end iterator
Calls forward_sentence_end() count times (or until
forward_sentence_end() returns false). If count is
negative, moves backward instead of forward.
count
number of sentences to move
Returns
true if self moved and is not the end iterator
Moves self forward to the “end iterator,” which points one past the last
valid character in the buffer. char() called on the
end iterator returns 0, which is convenient for writing loops.
Moves the iterator to point to the paragraph delimiter characters,
which will be either a newline, a carriage return, a carriage
return/newline in sequence, or the Unicode paragraph separator
character. If the iterator is already at the paragraph delimiter
characters, moves to the paragraph delimiter characters for the
next line. If self is on the last line in the buffer, which does
not end in paragraph delimiters, moves to the end iterator (end of
the last line), and returns false.
Returns
true if we moved and the new location is not the end iterator
Moves forward to the next toggle (on or off) of the
TextTag tag, or to the next toggle of any tag if
tag is None. If no matching tag toggles are found,
returns false, otherwise true. Does not return toggles
located at self, only toggles after self. Sets self to
the location of the toggle, or to the end of the buffer
if no toggle is found.
tag
Returns
whether we found a tag toggle after self
Moves self forward to the next visible cursor position. See
forward_cursor_position() for details.
Returns
true if we moved and the new position is dereferenceable
Moves up to count visible cursor positions. See
forward_cursor_position() for details.
count
number of positions to move
Returns
true if we moved and the new position is dereferenceable
Moves count visible lines forward, if possible (if count would move
past the start or end of the buffer, moves to the start or end of
the buffer). The return value indicates whether the iterator moved
onto a dereferenceable position; if the iterator didn’t move, or
moved onto the end iterator, then false is returned. If count is 0,
the function does nothing and returns false. If count is negative,
moves backward by 0 - count lines.
count
number of lines to move forward
Returns
whether self moved and is dereferenceable
Moves forward to the next visible word end. (If self is currently on a
word end, moves forward to the next one after that.) Word breaks
are determined by Pango and should be correct for nearly any
language (if not, the correct fix would be to the Pango word break
algorithms).
Returns
true if self moved and is not the end iterator
Calls forward_visible_word_end() up to count times.
count
number of times to move
Returns
true if self moved and is not the end iterator
Moves forward to the next word end. (If self is currently on a
word end, moves forward to the next one after that.) Word breaks
are determined by Pango and should be correct for nearly any
language (if not, the correct fix would be to the Pango word break
algorithms).
Returns
true if self moved and is not the end iterator
Calls forward_word_end() up to count times.
count
number of times to move
Returns
true if self moved and is not the end iterator
Returns the number of bytes in the line containing self,
including the paragraph delimiters.
Returns
number of bytes in the line
Returns the number of characters in the line containing self,
including the paragraph delimiters.
Returns
number of characters in the line
A convenience wrapper around [attributes()][Self::attributes()],
which returns the language in effect at self. If no tags affecting
language apply to self, the return value is identical to that of
default_language().
Returns
language in effect at self
Returns the line number containing the iterator. Lines in
a TextBuffer are numbered beginning with 0 for the first
line in the buffer.
Returns
a line number
Returns the byte index of the iterator, counting
from the start of a newline-terminated line.
Remember that TextBuffer encodes text in
UTF-8, and that characters can require a variable
number of bytes to represent.
Returns
distance from start of line, in bytes
Returns the character offset of the iterator, counting from the start of a newline-terminated line. The first character on the line has offset 0.
Returns
offset from start of line
Returns the character offset of an iterator.
Each character in a TextBuffer has an offset,
starting with 0 for the first character in the buffer.
Use TextBufferExt::iter_at_offset() to convert an
offset back into an iterator.
Returns
a character offset
Returns the text in the given range. A “slice” is an array of characters encoded in UTF-8 format, including the Unicode “unknown” character 0xFFFC for iterable non-character elements in the buffer, such as images. Because images are encoded in the slice, byte and character offsets in the returned array will correspond to byte offsets in the text buffer. Note that 0xFFFC can occur in normal text as well, so it is not a reliable indicator that a pixbuf or widget is in the buffer.
end
iterator at end of a range
Returns
slice of text from the buffer
Returns text in the given range. If the range
contains non-text elements such as images, the character and byte
offsets in the returned string will not correspond to character and
byte offsets in the buffer. If you want offsets to correspond, see
slice().
end
iterator at end of a range
Returns
array of characters from the buffer
Returns a list of TextTag that are toggled on or off at this
point. (If toggled_on is true, the list contains tags that are
toggled on.) If a tag is toggled on at self, then some non-empty
range of characters following self has that tag applied to it. If
a tag is toggled off, then some non-empty range following self
does not have the tag applied to it.
toggled_on
true to get toggled-on tags
Returns
tags toggled at this point
Returns the number of bytes from the start of the
line to the given self, not counting bytes that
are invisible due to tags with the “invisible” flag
toggled on.
Returns
byte index of self with respect to the start of the line
Returns the offset in characters from the start of the
line to the given self, not counting characters that
are invisible due to tags with the “invisible” flag
toggled on.
Returns
offset in visible characters from the start of the line
Returns true if self points to a character that is part of a range tagged
with tag. See also starts_tag() and ends_tag().
tag
a TextTag
Returns
whether self is tagged with tag
Determines whether self is inside a sentence (as opposed to in
between two sentences, e.g. after a period and before the first
letter of the next sentence). Sentence boundaries are determined
by Pango and should be correct for nearly any language (if not, the
correct fix would be to the Pango text boundary algorithms).
Returns
true if self is inside a sentence.
Determines whether the character pointed by self is part of a
natural-language word (as opposed to say inside some whitespace). Word
breaks are determined by Pango and should be correct for nearly any language
(if not, the correct fix would be to the Pango word break algorithms).
Note that if starts_word() returns true, then this function
returns true too, since self points to the first character of the word.
Returns
true if self is inside a word
See forward_cursor_position() or PangoLogAttr or
pango_break() for details on what a cursor position is.
Returns
true if the cursor can be placed at self
Swaps the value of self and second if second comes before
self in the buffer. That is, ensures that self and second are
in sequence. Most text buffer functions that take a range call this
automatically on your behalf, so there’s no real reason to call it yourself
in those cases. There are some exceptions, such as in_range(),
that expect a pre-sorted range.
second
another TextIter
Moves iterator self to the start of the line line_number. If
line_number is negative or larger than the number of lines in the
buffer, moves self to the start of the last line in the buffer.
line_number
line number (counted from 0)
Same as set_line_offset(), but works with a
byte index. The given byte index must be at
the start of a character, it can’t be in the middle of a UTF-8
encoded character.
byte_on_line
a byte index relative to the start of self’s current line
Moves self within a line, to a new character
(not byte) offset. The given character offset must be less than or
equal to the number of characters in the line; if equal, self
moves to the start of the next line. See
set_line_index() if you have a byte index rather than
a character offset.
char_on_line
a character offset relative to the start of self’s current line
Sets self to point to char_offset. char_offset counts from the start
of the entire text buffer, starting with 0.
char_offset
a character number
Like set_line_index(), but the index is in visible
bytes, i.e. text with a tag making it invisible is not counted
in the index.
byte_on_line
a byte index
Like set_line_offset(), but the offset is in visible
characters, i.e. text with a tag making it invisible is not
counted in the offset.
char_on_line
a character offset
Returns true if self begins a paragraph,
i.e. if line_offset() would return 0.
However this function is potentially more efficient than
line_offset() because it doesn’t have to compute
the offset, it just has to see whether it’s 0.
Returns
whether self begins a line
This is supported on crate feature v3_20 only.
v3_20 only.Returns true if tag is toggled on at exactly this point. If tag
is None, returns true if any tag is toggled on at this point.
Note that if starts_tag() returns true, it means that self is
at the beginning of the tagged range, and that the
character at self is inside the tagged range. In other
words, unlike ends_tag(), if starts_tag() returns
true, has_tag() will also return true for the same
parameters.
tag
Returns
whether self is the start of a range tagged with tag
This is equivalent to (starts_tag() ||
ends_tag()), i.e. it tells you whether a range with
tag applied to it begins or ends at self.
tag
Returns
whether tag is toggled on or off at self
The Unicode character at this iterator is returned. (Equivalent to
operator* on a C++ iterator.) If the element at this iterator is a
non-character element, such as an image embedded in the buffer, the
Unicode “unknown” character 0xFFFC is returned. If invoked on
the end iterator, zero is returned; zero is not a valid Unicode character.
So you can write a loop which ends when char()
returns 0.
Returns
a Unicode character, or 0 if self is not dereferenceable
Trait Implementations
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
Returns the type identifier of Self.
Auto Trait Implementations
impl RefUnwindSafe for TextIterimpl UnwindSafe for TextIterBlanket Implementations
Mutably borrows from an owned value. Read more
impl<'a, T, C> FromValueOptional<'a> for T where
C: ValueTypeChecker<Error = ValueTypeMismatchOrNoneError>,
T: FromValue<'a, Checker = C>,