#[repr(transparent)]
pub struct TextIter { /* private fields */ }
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

Assigns the value of other to self. This function is not useful in applications, because iterators can be assigned with GtkTextIter i = j;. The function is used by language bindings.

other

another TextIter

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

Like forward_cursor_position(), but moves backward.

Returns

true if we moved

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

a TextTag, or None

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

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 is_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

Determines whether self ends a 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 at the end of a sentence.

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

a TextTag, or None

Returns

whether self is the end of a range tagged with tag

Determines whether self ends a natural-language word. 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 is at the end of a word

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

a TextTag, or None

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 self to the start of the next visible line. Returns true if there was a next line to move to, and false if self was simply moved to the end of the buffer and is now not dereferenceable, or if self was already at the end of the buffer.

Returns

whether self can be dereferenced

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 TextBuffer this iterator is associated with.

Returns

the buffer

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

If the location at self contains a child anchor, the anchor is returned (with no new reference count added). Otherwise, None is returned.

Returns

the anchor at self

A convenience wrapper around is_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 a list of all TextMark at this location. Because marks are not iterable (they don’t take up any “space” in the buffer, they are just marks in between iterable locations), multiple marks can exist in the same place. The returned list is not in any meaningful order.

Returns

list of TextMark

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

If the element at self is a pixbuf, the pixbuf is returned (with no new reference count added). Otherwise, None is returned.

Returns

the pixbuf at self

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 a list of tags that apply to self, in ascending order of priority (highest-priority tags are last). The TextTag in the list don’t have a reference added, but you have to free the list itself.

Returns

list of TextTag

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

Like slice(), but invisible text is not included. Invisible text is usually invisible because a TextTag with the “invisible” attribute turned on has been applied to it.

end

iterator at end of range

Returns

slice of text from the buffer

Like text(), but invisible text is not included. Invisible text is usually invisible because a TextTag with the “invisible” attribute turned on has been applied to it.

end

iterator at end of range

Returns

string containing visible text in the range

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

Checks whether self falls in the range [start, end). start and end must be in ascending order.

start

start of range

end

end of range

Returns

true if self is in the range

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

Returns true if self is the end iterator, i.e. one past the last dereferenceable iterator in the buffer. is_end() is the most efficient way to check whether an iterator is the end iterator.

Returns

whether self is the end iterator

Returns true if self is the first iterator in the buffer, that is if self has a character offset of 0.

Returns

whether self is the first in the buffer

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

Determines whether self begins a 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 at the start of a sentence.

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

a TextTag, or None

Returns

whether self is the start of a range tagged with tag

Determines whether self begins a natural-language word. 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 is at the start of a word

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

a TextTag, or None

Returns

whether tag is toggled on or off at self

Computes the effect of any tags applied to this spot in the text. The values parameter should be initialized to the default settings you wish to use if no tags are in effect. You’d typically obtain the defaults from TextViewExt::default_attributes().

is_attributes() will modify values, applying the effects of any tags present at self. If any tags affected values, the function returns true.

Returns

true if values was modified

values

a TextAttributes to be filled in

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

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
This method returns an Ordering between self and other. Read more
Compares and returns the maximum of two values. Read more
Compares and returns the minimum of two values. Read more
Restrict a value to a certain interval. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more
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
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
Returns the type identifier of Self.

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