Class

Selection (engine/model)

@ckeditor/ckeditor5-engine/src/model/selection

class

Selection is a set of ranges. It has a direction specified by its anchor and focus (it can be forward or backward). Additionally, selection may have its own attributes (think – whether text typed in in this selection should have those attributes – e.g. whether you type a bolded text).

Filtering

Properties

  • anchor : Position | null

    readonly

    Selection anchor. Anchor is the position from which the selection was started. If a user is making a selection by dragging the mouse, the anchor is where the user pressed the mouse button (the beggining of the selection).

    Anchor and focus define the direction of the selection, which is important when expanding/shrinking selection. The focus moves, while the anchor should remain in the same place.

    Anchor is always set to the start or end position of the last of selection's ranges. Whether it is the start or end depends on the specified options.backward. See the setTo() method.

    May be set to null if there are no ranges in the selection.

    Related:

  • focus : Position | null

    readonly

    Selection focus. Focus is the position where the selection ends. If a user is making a selection by dragging the mouse, the focus is where the mouse cursor is.

    May be set to null if there are no ranges in the selection.

    Related:

  • isBackward : Boolean

    readonly

    Specifies whether the selection's focus precedes the selection's anchor.

  • isCollapsed : Boolean

    readonly

    Whether the selection is collapsed. Selection is collapsed when there is exactly one range in it and it is collapsed.

  • rangeCount : Number

    readonly

    Returns the number of ranges in the selection.

  • _attrs : Map.<String, *>

    protected

    List of attributes set on current selection.

  • _ranges : Array.<Range>

    protected

    Stores selection ranges.

  • _lastRangeBackward : Boolean

    private

    Specifies whether the last added range was added as a backward or forward range.

Methods

  • constructor( selectable, [ placeOrOffset ], [ options ] = { [options.backward] } )

    Creates a new selection instance based on the given selectable or creates an empty selection if no arguments were passed.

    // Creates empty selection without ranges.
    const selection = writer.createSelection();
    
    // Creates selection at the given range.
    const range = writer.createRange( start, end );
    const selection = writer.createSelection( range );
    
    // Creates selection at the given ranges
    const ranges = [ writer.createRange( start1, end2 ), writer.createRange( star2, end2 ) ];
    const selection = writer.createSelection( ranges );
    
    // Creates selection from the other selection.
    // Note: It doesn't copies selection attributes.
    const otherSelection = writer.createSelection();
    const selection = writer.createSelection( otherSelection );
    
    // Creates selection from the given document selection.
    // Note: It doesn't copies selection attributes.
    const documentSelection = model.document.selection;
    const selection = writer.createSelection( documentSelection );
    
    // Creates selection at the given position.
    const position = writer.createPositionFromPath( root, path );
    const selection = writer.createSelection( position );
    
    // Creates selection at the given offset in the given element.
    const paragraph = writer.createElement( 'paragraph' );
    const selection = writer.createSelection( paragraph, offset );
    
    // Creates a range inside an element which starts before the
    // first child of that element and ends after the last child of that element.
    const selection = writer.createSelection( paragraph, 'in' );
    
    // Creates a range on an item which starts before the item and ends
    // just after the item.
    const selection = writer.createSelection( paragraph, 'on' );

    Selection's constructor allow passing additional options ('backward') as the last argument.

    // Creates backward selection.
    const selection = writer.createSelection( range, { backward: true } );

    Parameters

    selectable : Selectable
    [ placeOrOffset ] : Number | 'before' | 'end' | 'after' | 'on' | 'in'

    Sets place or offset of the selection.

    [ options ] : Object
    Properties
    [ options.backward ] : Boolean

    Sets this selection instance to be backward.

  • containsEntireContent( [ element ] ) → Boolean

    Checks whether the selection contains the entire content of the given element. This means that selection must start at a position touching the element's start and ends at position touching the element's end.

    By default, this method will check whether the entire content of the selection's current root is selected. Useful to check if e.g. the user has just pressed Ctrl + A.

    Parameters

    [ element ] : Element

    Defaults to this.anchor.root

    Returns

    Boolean
  • delegate( events ) → EmitterMixinDelegateChain

    mixed

    Delegates selected events to another Emitter. For instance:

    emitterA.delegate( 'eventX' ).to( emitterB );
    emitterA.delegate( 'eventX', 'eventY' ).to( emitterC );

    then eventX is delegated (fired by) emitterB and emitterC along with data:

    emitterA.fire( 'eventX', data );

    and eventY is delegated (fired by) emitterC along with data:

    emitterA.fire( 'eventY', data );

    Parameters

    events : String

    Event names that will be delegated to another emitter.

    Returns

    EmitterMixinDelegateChain
  • fire( eventOrInfo, [ args ] ) → *

    mixed

    Fires an event, executing all callbacks registered for it.

    The first parameter passed to callbacks is an EventInfo object, followed by the optional args provided in the fire() method call.

    Parameters

    eventOrInfo : String | EventInfo

    The name of the event or EventInfo object if event is delegated.

    [ args ] : *

    Additional arguments to be passed to the callbacks.

    Returns

    *

    By default the method returns undefined. However, the return value can be changed by listeners through modification of the evt.return's property (the event info is the first param of every callback).

  • getAttribute( key ) → *

    Gets an attribute value for given key or undefined if that attribute is not set on the selection.

    Parameters

    key : String

    Key of attribute to look for.

    Returns

    *

    Attribute value or undefined.

  • getAttributeKeys() → Iterable.<String>

    Returns iterable that iterates over this selection's attribute keys.

    Returns

    Iterable.<String>
  • getAttributes() → Iterable.<*>

    Returns iterable that iterates over this selection's attributes.

    Attributes are returned as arrays containing two items. First one is attribute key and second is attribute value. This format is accepted by native Map object and also can be passed in Node constructor.

    Returns

    Iterable.<*>
  • getFirstPosition() → Position | null

    Returns the first position in the selection. First position is the position that is before any other position in the selection.

    Returns null if there are no ranges in selection.

    Returns

    Position | null
  • getFirstRange() → Range | null

    Returns a copy of the first range in the selection. First range is the one which start position is before start position of all other ranges (not to confuse with the first range added to the selection).

    Returns null if there are no ranges in selection.

    Returns

    Range | null
  • getLastPosition() → Position | null

    Returns the last position in the selection. Last position is the position that is after any other position in the selection.

    Returns null if there are no ranges in selection.

    Returns

    Position | null
  • getLastRange() → Range | null

    Returns a copy of the last range in the selection. Last range is the one which end position is after end position of all other ranges (not to confuse with the range most recently added to the selection).

    Returns null if there are no ranges in selection.

    Returns

    Range | null
  • getRanges() → Iterable.<Range>

    Returns an iterable object that iterates over copies of selection ranges.

    Returns

    Iterable.<Range>
  • getSelectedBlocks() → Iterable.<Element>

    Gets elements of type "block" touched by the selection.

    This method's result can be used for example to apply block styling to all blocks covered by this selection.

    Note: getSelectedBlocks() always returns the deepest block.

    In this case the function will return exactly all 3 paragraphs:

    <paragraph>[a</paragraph>
    <quote>
        <paragraph>b</paragraph>
    </quote>
    <paragraph>c]d</paragraph>

    In this case the paragraph will also be returned, despite the collapsed selection:

    <paragraph>[]a</paragraph>

    Special case: If a selection ends at the beginning of a block, that block is not returned as from user perspective this block wasn't selected. See #984 for more details.

    <paragraph>[a</paragraph>
    <paragraph>b</paragraph>
    <paragraph>]c</paragraph> // this block will not be returned

    Returns

    Iterable.<Element>
  • getSelectedElement() → Element | null

    Returns the selected element. Element is considered as selected if there is only one range in the selection, and that range contains exactly one element. Returns null if there is no selected element.

    Returns

    Element | null
  • getTopMostBlocks() → Iterable.<Element>

    Returns blocks that aren't nested in other selected blocks.

    In this case the method will return blocks A, B and E because C & D are children of block B:

    [<blockA></blockA>
    <blockB>
        <blockC></blockC>
        <blockD></blockD>
    </blockB>
    <blockE></blockE>]

    Note: To get all selected blocks use getSelectedBlocks().

    Returns

    Iterable.<Element>
  • hasAttribute( key ) → Boolean

    Checks if the selection has an attribute for given key.

    Parameters

    key : String

    Key of attribute to check.

    Returns

    Boolean

    true if attribute with given key is set on selection, false otherwise.

  • is( type ) → Boolean

    Checks whether this object is of the given.

    selection.is( 'selection' ); // -> true
    selection.is( 'model:selection' ); // -> true
    
    selection.is( 'view:selection' ); // -> false
    selection.is( 'range' ); // -> false

    Check the entire list of model objects which implement the is() method.

    Parameters

    type : String

    Returns

    Boolean
  • isEqual( otherSelection ) → Boolean

    Checks whether this selection is equal to the given selection. Selections are equal if they have the same directions, the same number of ranges and all ranges from one selection equal to ranges from the another selection.

    Parameters

    otherSelection : Selection | DocumentSelection

    Selection to compare with.

    Returns

    Boolean

    true if selections are equal, false otherwise.

  • listenTo( emitter, event, callback, [ options ] = { [options.priority] } )

    mixed

    Registers a callback function to be executed when an event is fired in a specific (emitter) object.

    Events can be grouped in namespaces using :. When namespaced event is fired, it additionally fires all callbacks for that namespace.

    // myEmitter.on( ... ) is a shorthand for myEmitter.listenTo( myEmitter, ... ).
    myEmitter.on( 'myGroup', genericCallback );
    myEmitter.on( 'myGroup:myEvent', specificCallback );
    
    // genericCallback is fired.
    myEmitter.fire( 'myGroup' );
    // both genericCallback and specificCallback are fired.
    myEmitter.fire( 'myGroup:myEvent' );
    // genericCallback is fired even though there are no callbacks for "foo".
    myEmitter.fire( 'myGroup:foo' );

    An event callback can stop the event and set the return value of the fire method.

    Parameters

    emitter : Emitter

    The object that fires the event.

    event : String

    The name of the event.

    callback : function

    The function to be called on event.

    [ options ] : Object

    Additional options.

    Properties
    [ options.priority ] : PriorityString | Number

    The priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.

    Defaults to 'normal'

    Defaults to {}

  • off( event, callback )

    mixed

    Stops executing the callback on the given event. Shorthand for this.stopListening( this, event, callback ).

    Parameters

    event : String

    The name of the event.

    callback : function

    The function to stop being called.

  • on( event, callback, [ options ] = { [options.priority] } )

    mixed

    Registers a callback function to be executed when an event is fired.

    Shorthand for this.listenTo( this, event, callback, options ) (it makes the emitter listen on itself).

    Parameters

    event : String

    The name of the event.

    callback : function

    The function to be called on event.

    [ options ] : Object

    Additional options.

    Properties
    [ options.priority ] : PriorityString | Number

    The priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.

    Defaults to 'normal'

    Defaults to {}

  • once( event, callback, [ options ] = { [options.priority] } )

    mixed

    Registers a callback function to be executed on the next time the event is fired only. This is similar to calling on followed by off in the callback.

    Parameters

    event : String

    The name of the event.

    callback : function

    The function to be called on event.

    [ options ] : Object

    Additional options.

    Properties
    [ options.priority ] : PriorityString | Number

    The priority of this event callback. The higher the priority value the sooner the callback will be fired. Events having the same priority are called in the order they were added.

    Defaults to 'normal'

    Defaults to {}

  • removeAttribute( key )

    Removes an attribute with given key from the selection.

    If given attribute was set on the selection, fires the event-change:range event with removed attribute key.

    Parameters

    key : String

    Key of attribute to remove.

    Fires

  • setAttribute( key, value )

    Sets attribute on the selection. If attribute with the same key already is set, it's value is overwritten.

    If the attribute value has changed, fires the event-change:range event with the attribute key.

    Parameters

    key : String

    Key of attribute to set.

    value : *

    Attribute value.

    Fires

  • setFocus( itemOrPosition, [ offset ] )

    Moves focus to the specified location.

    The location can be specified in the same form as writer.createPositionAt() parameters.

    Parameters

    itemOrPosition : Item | Position
    [ offset ] : Number | 'end' | 'before' | 'after'

    Offset or one of the flags. Used only when first parameter is a model item.

    Fires

  • setTo( selectable, [ placeOrOffset ], [ options ] = { [options.backward] } )

    Sets this selection's ranges and direction to the specified location based on the given selectable.

    // Removes all selection's ranges.
    selection.setTo( null );
    
    // Sets selection to the given range.
    const range = writer.createRange( start, end );
    selection.setTo( range );
    
    // Sets selection to given ranges.
    const ranges = [ writer.createRange( start1, end2 ), writer.createRange( star2, end2 ) ];
    selection.setTo( ranges );
    
    // Sets selection to other selection.
    // Note: It doesn't copies selection attributes.
    const otherSelection = writer.createSelection();
    selection.setTo( otherSelection );
    
    // Sets selection to the given document selection.
    // Note: It doesn't copies selection attributes.
    const documentSelection = new DocumentSelection( doc );
    selection.setTo( documentSelection );
    
    // Sets collapsed selection at the given position.
    const position = writer.createPositionFromPath( root, path );
    selection.setTo( position );
    
    // Sets collapsed selection at the position of the given node and an offset.
    selection.setTo( paragraph, offset );

    Creates a range inside an element which starts before the first child of that element and ends after the last child of that element.

    selection.setTo( paragraph, 'in' );

    Creates a range on an item which starts before the item and ends just after the item.

    selection.setTo( paragraph, 'on' );

    Selection#setTo()' method allow passing additional options (backward) as the last argument.

    // Sets backward selection.
    const selection = writer.createSelection( range, { backward: true } );

    Parameters

    selectable : Selectable
    [ placeOrOffset ] : Number | 'before' | 'end' | 'after' | 'on' | 'in'

    Sets place or offset of the selection.

    [ options ] : Object
    Properties
    [ options.backward ] : Boolean

    Sets this selection instance to be backward.

  • stopDelegating( [ event ], [ emitter ] )

    mixed

    Stops delegating events. It can be used at different levels:

    • To stop delegating all events.
    • To stop delegating a specific event to all emitters.
    • To stop delegating a specific event to a specific emitter.

    Parameters

    [ event ] : String

    The name of the event to stop delegating. If omitted, stops it all delegations.

    [ emitter ] : Emitter

    (requires event) The object to stop delegating a particular event to. If omitted, stops delegation of event to all emitters.

  • stopListening( [ emitter ], [ event ], [ callback ] )

    mixed

    Stops listening for events. It can be used at different levels:

    • To stop listening to a specific callback.
    • To stop listening to a specific event.
    • To stop listening to all events fired by a specific object.
    • To stop listening to all events fired by all objects.

    Parameters

    [ emitter ] : Emitter

    The object to stop listening to. If omitted, stops it for all objects.

    [ event ] : String

    (Requires the emitter) The name of the event to stop listening to. If omitted, stops it for all events from emitter.

    [ callback ] : function

    (Requires the event) The function to be removed from the call list for the given event.

  • _checkRange( range )

    protected

    Checks if given range intersects with ranges that are already in the selection. Throws an error if it does.

    Parameters

    range : Range

    Range to check.

  • _popRange()

    protected

    Removes most recently added range from the selection.

  • _pushRange( range )

    protected

    Adds given range to internal ranges array. Throws an error if given range is intersecting with any range that is already stored in this selection.

    Parameters

    range : Range

    Range to add.

  • _removeAllRanges()

    protected

    Deletes ranges from internal range array. Uses _popRange to ensure proper ranges removal.

  • _setRanges( newRanges, [ isLastBackward ] )

    protected

    Replaces all ranges that were added to the selection with given array of ranges. Last range of the array is treated like the last added range and is used to set anchor and focus. Accepts a flag describing in which direction the selection is made.

    Parameters

    newRanges : Iterable.<Range>

    Ranges to set.

    [ isLastBackward ] : Boolean

    Flag describing if last added range was selected forward - from start to end (false) or backward - from end to start (true).

    Defaults to false

    Fires

Events

  • change:attribute( eventInfo, directChange, attributeKeys )

    Fired when selection attribute changed.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    directChange : Boolean

    In case of Selection class it is always set to true which indicates that the selection change was caused by a direct use of selection's API. The DocumentSelection, however, may change because its attributes were directly changed through the writer or because its position was changed in the model and its attributes were refreshed (which means an indirect change). The indirect change does not occur in case of normal (detached) selections because they are "static" (as "not live") which mean that they are not updated once the document changes.

    attributeKeys : Array.<String>

    Array containing keys of attributes that changed.

  • change:range( eventInfo, directChange )

    Fired when selection range(s) changed.

    Parameters

    eventInfo : EventInfo

    An object containing information about the fired event.

    directChange : Boolean

    In case of Selection class it is always set to true which indicates that the selection change was caused by a direct use of selection's API. The DocumentSelection, however, may change because its position was directly changed through the writer or because its position was changed because the structure of the model has been changed (which means an indirect change). The indirect change does not occur in case of normal (detached) selections because they are "static" (as "not live") which mean that they are not updated once the document changes.