Struct CTLine

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#[repr(C)]
pub struct CTLine { /* private fields */ }

Available on crate feature CTLine only.

Expand description

Apple’s documentation

Implementations§

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impl CTLine

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pub unsafe fn with_attributed_string( attr_string: &CFAttributedString, ) -> CFRetained<CTLine>

Creates a single immutable line object directly from an attributed string.

This will allow clients who need very simple line generation to create a line without needing to create a typesetter object. The typesetting will be done under the hood. Without a typesetter object, the line cannot be properly broken. However, for simple things like text labels and other things, this is not an issue.

Parameter attrString: The attributed string which the line will be created for.

Returns: This function will return a reference to a CTLine object.

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pub unsafe fn truncated_line( self: &CTLine, width: c_double, truncation_type: CTLineTruncationType, truncation_token: Option<&CTLine>, ) -> Option<CFRetained<CTLine>>

Creates a truncated line from an existing line.

Parameter line: The line that you want to create a truncated line for.

Parameter width: The width at which truncation will begin. The line will be truncated if its width is greater than the width passed in this.

Parameter truncationType: The type of truncation to perform if needed.

Parameter truncationToken: This token will be added to the point where truncation took place to indicate that the line was truncated. Usually, the truncation token is the ellipsis character (U+2026). If this parameter is set to NULL, then no truncation token is used, and the line is simply cut off. The line specified in truncationToken should have a width less than the width specified by the width parameter. If the width of the line specified in truncationToken is greater, this function will return NULL if truncation is needed.

Returns: This function will return a reference to a truncated CTLine object if the call was successful. Otherwise, it will return NULL.

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pub unsafe fn justified_line( self: &CTLine, justification_factor: CGFloat, justification_width: c_double, ) -> Option<CFRetained<CTLine>>

Creates a justified line from an existing line.

Parameter line: The line that you want to create a justified line for.

Parameter justificationFactor: Allows for full or partial justification. When set to 1.0 or greater indicates, full justification will be performed. If less than 1.0, varying degrees of partial justification will be performed. If set to 0 or less, then no justification will be performed.

Parameter justificationWidth: The width to which the resultant line will be justified. If justificationWidth is less than the actual width of the line, then negative justification will be performed (“text squishing”).

Returns: This function will return a reference to a justified CTLine object if the call was successful. Otherwise, it will return NULL.

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pub unsafe fn glyph_count(self: &CTLine) -> CFIndex

Returns the total glyph count for the line object.

The total glyph count is equal to the sum of all of the glyphs in the glyph runs forming the line.

Parameter line: The line that you want to obtain the glyph count for.

Returns: The total glyph count for the line passed in.

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pub unsafe fn glyph_runs(self: &CTLine) -> CFRetained<CFArray>

Returns the array of glyph runs that make up the line object.

Parameter line: The line that you want to obtain the glyph run array for.

Returns: A CFArrayRef containing the CTRun objects that make up the line.

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pub unsafe fn string_range(self: &CTLine) -> CFRange

Gets the range of characters that originally spawned the glyphs in the line.

Parameter line: The line that you want to obtain the string range from.

Returns: A CFRange that contains the range over the backing store string that spawned the glyphs. If the function fails for any reason, an empty range will be returned.

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pub unsafe fn pen_offset_for_flush( self: &CTLine, flush_factor: CGFloat, flush_width: c_double, ) -> c_double

Gets the pen offset required to draw flush text.

Parameter line: The line that you want to obtain a flush position from.

Parameter flushFactor: Specifies what kind of flushness you want. A flushFactor of 0 or less indicates left flush. A flushFactor of 1.0 or more indicates right flush. Flush factors between 0 and 1.0 indicate varying degrees of center flush, with a value of 0.5 being totally center flush.

Parameter flushWidth: Specifies the width that the flushness operation should apply to.

Returns: A value which can be used to offset the current pen position for the flush operation.

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pub unsafe fn draw(self: &CTLine, context: &CGContext)

Available on crate feature objc2-core-graphics only.

Draws a line.

This is a convenience call, since the line could be drawn run-by-run by getting the glyph runs and accessing the glyphs out of them. This call may leave the graphics context in any state and does not flush the context after drawing. This call also expects a text matrix with y values increasing from bottom to top; a flipped text matrix may result in misplaced diacritics.

Parameter line: The line that you want to draw.

Parameter context: The context to which the line will be drawn.

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pub unsafe fn typographic_bounds( self: &CTLine, ascent: mut CGFloat, descent: mut CGFloat, leading: *mut CGFloat, ) -> c_double

Calculates the typographic bounds for a line.

A line’s typographic width is the distance to the rightmost glyph advance width edge. Note that this distance includes trailing whitespace glyphs.

Parameter line: The line that you want to calculate the typographic bounds for.

Parameter ascent: Upon return, this parameter will contain the ascent of the line. This may be set to NULL if not needed.

Parameter descent: Upon return, this parameter will contain the descent of the line. This may be set to NULL if not needed.

Parameter leading: Upon return, this parameter will contain the leading of the line. This may be set to NULL if not needed.

Returns: The typographic width of the line. If line is invalid, this function will always return zero.

See also: CTLineGetTrailingWhitespaceWidth

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pub unsafe fn bounds_with_options( self: &CTLine, options: CTLineBoundsOptions, ) -> CGRect

Calculates the bounds for a line.

Parameter line: The line that you want to calculate the bounds for.

Parameter options: Desired options or 0 if none.

Returns: The bounds of the line as specified by the type and options, such that the coordinate origin is coincident with the line origin and the rect origin is at the bottom left. If the line is invalid this function will return CGRectNull.

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pub unsafe fn trailing_whitespace_width(self: &CTLine) -> c_double

Calculates the trailing whitespace width for a line.

Parameter line: The line that you want to calculate the trailing whitespace width for. Creating a line for a width can result in a line that is actually longer than the desired width due to trailing whitespace. Normally this is not an issue due to whitespace being invisible, but this function may be used to determine what amount of a line’s width is due to trailing whitespace.

Returns: The width of the line’s trailing whitespace. If line is invalid, this function will always return zero.

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pub unsafe fn image_bounds(self: &CTLine, context: Option<&CGContext>) -> CGRect

Available on crate feature objc2-core-graphics only.

Calculates the image bounds for a line.

The image bounds for a line is the union of all non-empty glyph bounding rects, each positioned as it would be if drawn using CTLineDraw using the current context. Note that the result is ideal and does not account for raster coverage due to rendering. This function is purely a convenience for using glyphs as an image and should not be used for typographic purposes.

Parameter line: The line that you want to calculate the image bounds for.

Parameter context: The context which the image bounds will be calculated for or NULL, in which case the bounds are relative to CGPointZero.

Returns: A rectangle that tightly encloses the paths of the line’s glyphs, which will be translated by the supplied context’s text position. If the line is invalid, CGRectNull will be returned.

pub unsafe fn string_index_for_position( self: &CTLine, position: CGPoint, ) -> CFIndex

Performs hit testing.

This function can be used to determine the string index for a mouse click or other event. This string index corresponds to the character before which the next character should be inserted. This determination is made by analyzing the string from which a typesetter was created and the corresponding glyphs as embodied by a particular line.

Parameter line: The line being examined.

Parameter position: The location of the mouse click relative to the line’s origin.

Returns: The string index for the position. Relative to the line’s string range, this value will be no less than the first string index and no greater than one plus the last string index. In the event of failure, this function will return kCFNotFound.

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pub unsafe fn offset_for_string_index( self: &CTLine, char_index: CFIndex, secondary_offset: *mut CGFloat, ) -> CGFloat

Determines the graphical offset(s) for a string index.

This function returns the graphical offset(s) corresponding to a string index, suitable for movement between adjacent lines or for drawing a custom caret. For the former, the primary offset may be adjusted for any relative indentation of the two lines; a CGPoint constructed with the adjusted offset for its x value and 0.0 for its y value is suitable for passing to CTLineGetStringIndexForPosition. In either case, the primary offset corresponds to the portion of the caret that represents the visual insertion location for a character whose direction matches the line’s writing direction.

Parameter line: The line from which the offset is requested.

Parameter charIndex: The string index corresponding to the desired position.

Parameter secondaryOffset: An output parameter that will be set to the secondary offset along the baseline for charIndex. When a single caret is sufficient for a string index, this value will be the same as the primary offset, which is the return value of this function. This parameter may be NULL.

Returns: The primary offset along the baseline for charIndex, or 0.0 in the event of failure.

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pub unsafe fn enumerate_caret_offsets( self: &CTLine, block: &DynBlock<dyn Fn(c_double, CFIndex, bool, NonNull<bool>)>, )

Available on crate feature block2 only.

Enumerates caret offsets for characters in a line.

The provided block is invoked once for each logical caret edge in the line, in left-to-right visual order.

Parameter block: The offset parameter is relative to the line origin. The leadingEdge parameter of this block refers to logical order.

Methods from Deref<Target = CFType>§

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pub fn downcast_ref<T>(&self) -> Option<&T>
where T: ConcreteType,

Attempt to downcast the type to that of type T.

This is the reference-variant. Use CFRetained::downcast if you want to convert a retained type. See also ConcreteType for more details on which types support being converted to.

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pub fn retain_count(&self) -> usize

Get the reference count of the object.

This function may be useful for debugging. You normally do not use this function otherwise.

Beware that some things (like CFNumbers, small CFStrings etc.) may not have a normal retain count for optimization purposes, and can return usize::MAX in that case.