FragmentOperations class - fragment_operations library

Constructors

FragmentOperations()

Properties

hashCode → int: The hash code for this object.
no setterinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toString() → String: A string representation of this object.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

adjustIndex(String s, int index) → int: Adjusts an index to avoid cutting through a grapheme cluster (e.g., emoji surrogate pairs, CJK variation selectors, combining marks). If the index falls inside a multi-code-unit grapheme cluster, moves it back to the start of that cluster.
cloneFragment(Fragment source, {String? text}) → Fragment: Creates a new fragment with the same styles as the source fragment. If text is provided, uses that text; otherwise uses the source fragment's text.
collectLeafFragments(FNode node) → List<Fragment>: Recursively collects all leaf fragments in order. A leaf fragment is a Fragment that is not an InlineContainerNode.
createFragmentWithPendingStyles(FluentDocument document, String text) → Fragment: Creates a new fragment with styles from the document's pending styles. Used when inserting new text at the cursor position.
deleteTextInFragment(Fragment fragment, int offset, {int count = 1}) → bool: Deletes count characters from fragment starting from offset. Returns false if the range is invalid. Optimised edge cases avoid temp substring allocations.
getGraphemeLengthAt(String s, int offset) → int: Calculates the number of UTF-16 code units to delete starting from offset to delete one complete grapheme cluster. Returns 1 for regular characters, 2 for surrogate pairs (emoji), and potentially more for complex clusters (e.g., CJK + variation selector, ZWJ sequences).
getPreviousGraphemeOffset(String s, int currentOffset) → int: Calculates the previous grapheme cluster offset in a string. Returns the start offset of the grapheme cluster that ends at currentOffset, handling surrogate pairs, CJK variation selectors, combining marks, and ZWJ sequences correctly.
insertTextInFragment(Fragment fragment, int offset, String text) → bool: Inserts text in fragment at offset. Returns false if offset is out of range. Optimised edge cases (prepend / append) avoid temp substring allocations.
mergeFragments(Fragment fragment, Fragment next) → void: Merges next into fragment (concatenates the text, then next must be removed from the container by the caller).
safeSubstring(String s, int start, [int? end]) → String: Safely extracts a substring, adjusting indices to avoid cutting through UTF-16 surrogate pairs (e.g., emoji). If end is not provided, extracts from start to the end of the string.
splitFragment(Fragment fragment, int offset) → ({Fragment left, Fragment right}): Splits fragment at offset: returns (left, right). The original fragment is mutated (becomes the left part). The right part is a new Fragment with the same style (cloneFragment).