GES.Layer

g GES.Extractable GES.Extractable GES.Layer GES.Layer GES.Extractable->GES.Layer GES.MetaContainer GES.MetaContainer GES.MetaContainer->GES.Layer GObject.GInterface GObject.GInterface GObject.GInterface->GES.Extractable GObject.GInterface->GES.MetaContainer GObject.InitiallyUnowned GObject.InitiallyUnowned GObject.InitiallyUnowned->GES.Layer GObject.Object GObject.Object GObject.Object->GObject.InitiallyUnowned

Subclasses:None

Methods

Inherited:GObject.Object (37), GES.Extractable (3), GES.MetaContainer (40)
Structs:GObject.ObjectClass (5)
class new ()
  add_asset (asset, start, inpoint, duration, track_types)
  add_asset_full (asset, start, inpoint, duration, track_types)
  add_clip (clip)
  add_clip_full (clip)
  get_active_for_track (track)
  get_auto_transition ()
  get_clips ()
  get_clips_in_interval (start, end)
  get_duration ()
  get_priority ()
  get_timeline ()
  is_empty ()
  remove_clip (clip)
  set_active_for_tracks (active, tracks)
  set_auto_transition (auto_transition)
  set_priority (priority)
  set_timeline (timeline)

Virtual Methods

Inherited:GObject.Object (7), GES.Extractable (3)
  do_object_added (object)
  do_object_removed (object)

Properties

Name Type Flags Short Description
auto-transition bool r/w whether the transitions are added
priority int r/w The priority of the layer deprecated

Signals

Inherited:GObject.Object (1), GES.MetaContainer (1)
Name Short Description
active-changed Will be emitted whenever the layer is activated or deactivated for some GES.Track.
clip-added Will be emitted after the clip is added to the layer.
clip-removed Will be emitted after the clip is removed from the layer.

Fields

Inherited:GObject.Object (1), GES.MetaContainer (1)
Name Type Access Description
max_nle_priority int r  
min_nle_priority int r  
parent GObject.InitiallyUnowned r  
timeline GES.Timeline r the GES.Timeline where this layer is being used.

Class Details

class GES.Layer(**kwargs)
Bases:GObject.InitiallyUnowned, GES.Extractable, GES.MetaContainer
Abstract:No
Structure:GES.LayerClass

GES.Layer-s are responsible for collecting and ordering GES.Clip-s.

A layer within a timeline will have an associated priority, corresponding to their index within the timeline. A layer with the index/priority 0 will have the highest priority and the layer with the largest index will have the lowest priority (the order of priorities, in this sense, is the _reverse_ of the numerical ordering of the indices). GES.Timeline.move_layer() should be used if you wish to change how layers are prioritised in a timeline.

Layers with higher priorities will have their content priorities over content from lower priority layers, similar to how layers are used in image editing. For example, if two separate layers both display video content, then the layer with the higher priority will have its images shown first. The other layer will only have its image shown if the higher priority layer has no content at the given playtime, or is transparent in some way. Audio content in separate layers will simply play in addition.

classmethod new()[source]
Returns:A new layer.
Return type:GES.Layer

Creates a new layer.

add_asset(asset, start, inpoint, duration, track_types)[source]
Parameters:
Returns:

The newly created clip.

Return type:

GES.Clip

See GES.Layer.add_asset_full(), which also gives an error.

add_asset_full(asset, start, inpoint, duration, track_types)[source]
Parameters:
Raises:

GLib.Error

Returns:

The newly created clip.

Return type:

GES.Clip

Extracts a new clip from an asset and adds it to the layer with the given properties.

New in version 1.18.

add_clip(clip)[source]
Parameters:clip (GES.Clip) – The clip to add
Returns:True if clip was properly added to self, or False if self refused to add clip.
Return type:bool

See GES.Layer.add_clip_full(), which also gives an error.

add_clip_full(clip)[source]
Parameters:clip (GES.Clip) – The clip to add
Raises:GLib.Error
Returns:True if clip was properly added to self, or False if self refused to add clip.
Return type:bool

Adds the given clip to the layer. If the method succeeds, the layer will take ownership of the clip.

This method will fail and return False if clip already resides in some layer. It can also fail if the additional clip breaks some compositional rules (see GES.TimelineElement).

New in version 1.18.

get_active_for_track(track)[source]
Parameters:track (GES.Track) – The GES.Track to check if self is currently active for
Returns:True if self is active for track, or False otherwise.
Return type:bool

Gets whether the layer is active for the given track. See GES.Layer.set_active_for_tracks().

New in version 1.18.

get_auto_transition()[source]
Returns:True if transitions are automatically added to self.
Return type:bool

Gets the GES.Layer :auto-transition of the layer.

get_clips()[source]
Returns:A list of clips in self.
Return type:[GES.Clip]

Get the GES.Clip-s contained in this layer.

get_clips_in_interval(start, end)[source]
Parameters:
  • start (int) – Start of the interval
  • end (int) – End of the interval
Returns:

A list of GES.Clip-s that intersect the interval [start, end) in self.

Return type:

[GES.Clip]

Gets the clips within the layer that appear between start and end.

get_duration()[source]
Returns:The duration of self.
Return type:int

Retrieves the duration of the layer, which is the difference between the start of the layer (always time 0) and the end (which will be the end time of the final clip).

get_priority()[source]
Returns:The priority of self within its timeline.
Return type:int

Get the priority of the layer. When inside a timeline, this is its index in the timeline. See GES.Timeline.move_layer().

get_timeline()[source]
Returns:The timeline that self is currently part of, or None if it is not associated with any timeline.
Return type:GES.Timeline or None

Gets the timeline that the layer is a part of.

is_empty()[source]
Returns:True if self is empty, False if it contains at least one clip.
Return type:bool

Convenience method to check if the layer is empty (doesn’t contain any GES.Clip), or not.

remove_clip(clip)[source]
Parameters:clip (GES.Clip) – The clip to remove
Returns:True if clip was removed from self, or False if the operation failed.
Return type:bool

Removes the given clip from the layer.

set_active_for_tracks(active, tracks)[source]
Parameters:
  • active (bool) – Whether elements in tracks should be active or not
  • tracks ([GES.Track] or None) – The list of tracks self should be (de-)active in, or None to include all the tracks in the self’s timeline
Returns:

True if the operation worked False otherwise.

Return type:

bool

Activate or deactivate track elements in tracks (or in all tracks if tracks is None).

When a layer is deactivated for a track, all the GES.TrackElement-s in the track that belong to a GES.Clip in the layer will no longer be active in the track, regardless of their individual GES.TrackElement :active value.

Note that by default a layer will be active for all of its timeline’s tracks.

New in version 1.18.

set_auto_transition(auto_transition)[source]
Parameters:auto_transition (bool) – Whether transitions should be automatically added to the layer

Sets GES.Layer :auto-transition for the layer. Use GES.Timeline.set_auto_transition() if you want all layers within a GES.Timeline to have GES.Layer :auto-transition set to True. Use this method if you want different values for different layers (and make sure to keep GES.Timeline :auto-transition as False for the corresponding timeline).

set_priority(priority)[source]
Parameters:priority (int) – The priority to set

Sets the layer to the given priority. See GES.Layer :priority.

Deprecated since version 1.16.0: use GES.Timeline.move_layer instead. This deprecation means that you will not need to handle layer priorities at all yourself, GES will make sure there is never ‘gaps’ between layer priorities.

set_timeline(timeline)[source]
Parameters:timeline (GES.Timeline) –
do_object_added(object) virtual
Parameters:object (GES.Clip) –
do_object_removed(object) virtual
Parameters:object (GES.Clip) –

Signal Details

GES.Layer.signals.active_changed(layer, active, tracks)
Signal Name:

active-changed

Flags:

RUN_FIRST

Parameters:
  • layer (GES.Layer) – The object which received the signal
  • active (bool) – Whether layer has been made active or de-active in the tracks
  • tracks ([GES.Track]) – A list of GES.Track which have been activated or deactivated

Will be emitted whenever the layer is activated or deactivated for some GES.Track. See GES.Layer.set_active_for_tracks().

New in version 1.18.

GES.Layer.signals.clip_added(layer, clip)
Signal Name:

clip-added

Flags:

RUN_FIRST

Parameters:
  • layer (GES.Layer) – The object which received the signal
  • clip (GES.Clip) – The clip that was added

Will be emitted after the clip is added to the layer.

GES.Layer.signals.clip_removed(layer, clip)
Signal Name:

clip-removed

Flags:

RUN_FIRST

Parameters:
  • layer (GES.Layer) – The object which received the signal
  • clip (GES.Clip) – The clip that was removed

Will be emitted after the clip is removed from the layer.

Property Details

GES.Layer.props.auto_transition
Name:auto-transition
Type:bool
Default Value:False
Flags:READABLE, WRITABLE

Whether to automatically create a GES.TransitionClip whenever two GES.Source-s that both belong to a GES.Clip in the layer overlap. See GES.Timeline for what counts as an overlap.

When a layer is added to a GES.Timeline, if this property is left as False, but the timeline’s GES.Timeline :auto-transition is True, it will be set to True as well.

GES.Layer.props.priority
Name:priority
Type:int
Default Value:0
Flags:READABLE, WRITABLE

The priority of the layer in the GES.Timeline. 0 is the highest priority. Conceptually, a timeline is a stack of layers, and the priority of the layer represents its position in the stack. Two layers should not have the same priority within a given GES.Timeline.

Note that the timeline needs to be committed (with GES.Timeline.commit) for the change to be taken into account.

Deprecated since version 1.16.0: use GES.Timeline.move_layer instead. This deprecation means that you will not need to handle layer priorities at all yourself, GES will make sure there is never ‘gaps’ between layer priorities.