TextProcessing

public protocol TextProcessing

An object capable of intercepting and modifying the text and attributes in an EditorView when registered with the EditorView.

  • Name of the TextProcessor

    Declaration

    Swift

    var name: String { get }

  • Priority of the TextProcessor. An EditorView can have multiple TextProcessors registered. These will be executed in the order of Priority.

    Attention

    When a textProcessor with priority is set to .exclusive is executed, it will prevent all other registered TextProcessors from being executed. If multiple such TextProcessors are registered, only the one registered earlier is executed. When this happens, all other registered TextProcessors which are prevented from being executed receive processInterrupted with the range in which exclusive TextProcessor is executed. It is responsibility of these TextProcessors to do any cleanup/rollback if that needs to be done.

    Declaration

    Swift

    var priority: TextProcessingPriority { get }

  • Determines if the text should be changed in the editor.

    Note

    This function is invoked just before making the changes in the EditorView. Besides preventing changing text in Editor in certain cases, this may also be used to do additional processing like updating typingAttributes on EditorView based on presence of certain attributes.

    Default Implementation

    Declaration

    Swift

    func shouldProcess(_ editorView: EditorView, shouldProcessTextIn range: NSRange, replacementText text: String) -> Bool

    Parameters

    editor

    EditorView in which text is being changed.
    range

    Range where new text is going to be added.
    text

    Text to be inserted.

  • Invoked before changes are processed by the editor.

    Attention

    This is fired before the text has changed in the editor. This can be helpful if any state needs to be changed based on edited text. However, it should be noted that the changes are done only in process and not in this function owing to the lifecycle of TextKit components.

    Declaration

    Swift

    func willProcess(editor: EditorView, deletedText: NSAttributedString, insertedText: NSAttributedString, range: NSRange)

    Parameters

    editor

    EditorView in which text is being changed.
    deletedText

    Text that has been deleted, if any.
    insertedText

    Text that is inserted, if any.
    range

    Affected range

  • Allows to change attributes and text in the EditorView as the text is changed.

    Declaration

    Swift

    func process(editor: EditorView, range editedRange: NSRange, changeInLength delta: Int) -> Processed

    Parameters

    editor

    EditorView in which text is being changed.
    editedRange

    Current range that is being modified.
    delta

    Change in length of the text as a result of typing text. The length may be more than 1 if multiple characters are selected before content is typed. It may also happen if text containing a string is pasted.
    processed

    Set this to true is the TextProcessor has made any changes to the text or attributes in the EditorView

    Return Value

    Return true to indicate the processing had been done by the current processor. In case of .exclusive priority processors, returning true notifies all other processors of interruption.

  • Allows to change attributes and text in the EditorView as the text is changed.

    Default Implementation

    Declaration

    Swift

    func handleKeyWithModifiers(editor: EditorView, key: EditorKey, modifierFlags: UIKeyModifierFlags, range editedRange: NSRange)

    Parameters

    editor

    EditorView in which text is being changed.
    key

    EditorKey that is entered.
    modifierFlags

    The bit mask of modifier flags that were pressed with the key.
    editedRange

    Current range that is being modified.

  • Fired when processing has been interrupted by another TextProcessor running in the same pass. This allows TextProcessor to revert any changes that may not have been committed.

    Declaration

    Swift

    func processInterrupted(editor: EditorView, at range: NSRange)

    Parameters

    editor

    EditorView in which text is being changed.
    range

    Current range that is being modified.

  • Notifies the processor that the selected range has changed in the EditorView due to a reason other than typing text for e.g. moving cursor using keyboard, mouse or tap.

    Note

    This function is also called if the user selects text by dragging. Each individual character selection during drag operation results in an independent call to this function. If old or new range has zero length, it indicates the caret (insertion point). If the range object is nil, it indicates that there is no previous/current selection.

    Default Implementation

    Declaration

    Swift

    func selectedRangeChanged(editor: EditorView, oldRange: NSRange?, newRange: NSRange?)

    Parameters

    editor

    EditorView in which selected range changed
    oldRange

    Original range before the change
    newRange

    Current range after the change
  • didProcess(editor:) Default implementation

    Invoked after the text has been processed in the Editor.

    Default Implementation

    Declaration

    Swift

    func didProcess(editor: EditorView)

    Parameters

    editor

    EditorView in which text is changed.