Timeline (ExoPlayer library)

java.lang.Object
- com.google.android.exoplayer2.Timeline

Direct Known Subclasses:

AbstractConcatenatedTimeline, FakeTimeline, ForwardingTimeline, MaskingMediaSource.PlaceholderTimeline, SinglePeriodTimeline
```
public abstract class Timeline
extends Object
```
A flexible representation of the structure of media. A timeline is able to represent the structure of a wide variety of media, from simple cases like a single media file through to complex compositions of media such as playlists and streams with inserted ads. Instances are immutable. For cases where media is changing dynamically (e.g. live streams), a timeline provides a snapshot of the current state.
A timeline consists of Windows and Periods.
- A Timeline.Window usually corresponds to one playlist item. It may span one or more periods and it defines the region within those periods that's currently available for playback. The window also provides additional information such as whether seeking is supported within the window and the default position, which is the position from which playback will start when the player starts playing the window.
- A Timeline.Period defines a single logical piece of media, for example a media file. It may also define groups of ads inserted into the media, along with information about whether those ads have been loaded and played.
The following examples illustrate timelines for various use cases.
Single media file or on-demand stream

A timeline for a single media file or on-demand stream consists of a single period and window. The window spans the whole period, indicating that all parts of the media are available for playback. The window's default position is typically at the start of the period (indicated by the black dot in the figure above).
Playlist of media files or on-demand streams

A timeline for a playlist of media files or on-demand streams consists of multiple periods, each with its own window. Each window spans the whole of the corresponding period, and typically has a default position at the start of the period. The properties of the periods and windows (e.g. their durations and whether the window is seekable) will often only become known when the player starts buffering the corresponding file or stream.
Live stream with limited availability

A timeline for a live stream consists of a period whose duration is unknown, since it's continually extending as more content is broadcast. If content only remains available for a limited period of time then the window may start at a non-zero position, defining the region of content that can still be played. The window will return true from Timeline.Window.isLive() to indicate it's a live stream and Timeline.Window.isDynamic will be set to true as long as we expect changes to the live window. Its default position is typically near to the live edge (indicated by the black dot in the figure above).
Live stream with indefinite availability

A timeline for a live stream with indefinite availability is similar to the Live stream with limited availability case, except that the window starts at the beginning of the period to indicate that all of the previously broadcast content can still be played.
Live stream with multiple periods

This case arises when a live stream is explicitly divided into separate periods, for example at content boundaries. This case is similar to the Live stream with limited availability case, except that the window may span more than one period. Multiple periods are also possible in the indefinite availability case.
On-demand stream followed by live stream

This case is the concatenation of the Single media file or on-demand stream and Live stream with multiple periods cases. When playback of the on-demand stream ends, playback of the live stream will start from its default position near the live edge.
On-demand stream with mid-roll ads

This case includes mid-roll ad groups, which are defined as part of the timeline's single period. The period can be queried for information about the ad groups and the ads they contain.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`Timeline.Period`	Holds information about a period in a `Timeline`.
`static class`	`Timeline.Window`	Holds information about a window in a `Timeline`.

Field Summary

Fields
Modifier and Type Field Description

static Timeline EMPTY
An empty timeline.

Fields
Modifier and Type	Field	Description
`static Timeline`	`EMPTY`	An empty timeline.

Constructor Summary

Constructors
Constructor Description

Timeline()

Constructors
Constructor	Description
`Timeline()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`boolean`	`equals(Object obj)`
`int`	`getFirstWindowIndex(boolean shuffleModeEnabled)`	Returns the index of the first window in the playback order depending on whether shuffling is enabled.
`abstract int`	`getIndexOfPeriod(Object uid)`	Returns the index of the period identified by its unique `Timeline.Period.uid`, or `C.INDEX_UNSET` if the period is not in the timeline.
`int`	`getLastWindowIndex(boolean shuffleModeEnabled)`	Returns the index of the last window in the playback order depending on whether shuffling is enabled.
`int`	`getNextPeriodIndex(int periodIndex, Timeline.Period period, Timeline.Window window, int repeatMode, boolean shuffleModeEnabled)`	Returns the index of the period after the period at index `periodIndex` depending on the `repeatMode` and whether shuffling is enabled.
`int`	`getNextWindowIndex(int windowIndex, int repeatMode, boolean shuffleModeEnabled)`	Returns the index of the window after the window at index `windowIndex` depending on the `repeatMode` and whether shuffling is enabled.
`Timeline.Period`	`getPeriod(int periodIndex, Timeline.Period period)`	Populates a `Timeline.Period` with data for the period at the specified index.
`abstract Timeline.Period`	`getPeriod(int periodIndex, Timeline.Period period, boolean setIds)`	Populates a `Timeline.Period` with data for the period at the specified index.
`Timeline.Period`	`getPeriodByUid(Object periodUid, Timeline.Period period)`	Populates a `Timeline.Period` with data for the period with the specified unique identifier.
`abstract int`	`getPeriodCount()`	Returns the number of periods in the timeline.
`Pair<Object,Long>`	`getPeriodPosition(Timeline.Window window, Timeline.Period period, int windowIndex, long windowPositionUs)`	Calls `getPeriodPosition(Window, Period, int, long, long)` with a zero default position projection.
`Pair<Object,Long>`	`getPeriodPosition(Timeline.Window window, Timeline.Period period, int windowIndex, long windowPositionUs, long defaultPositionProjectionUs)`	Converts (windowIndex, windowPositionUs) to the corresponding (periodUid, periodPositionUs).
`int`	`getPreviousWindowIndex(int windowIndex, int repeatMode, boolean shuffleModeEnabled)`	Returns the index of the window before the window at index `windowIndex` depending on the `repeatMode` and whether shuffling is enabled.
`abstract Object`	`getUidOfPeriod(int periodIndex)`	Returns the unique id of the period identified by its index in the timeline.
`Timeline.Window`	`getWindow(int windowIndex, Timeline.Window window)`	Populates a `Timeline.Window` with data for the window at the specified index.
`Timeline.Window`	`getWindow(int windowIndex, Timeline.Window window, boolean setTag)`	Deprecated. Use `getWindow(int, Window)` instead.
`abstract Timeline.Window`	`getWindow(int windowIndex, Timeline.Window window, long defaultPositionProjectionUs)`	Populates a `Timeline.Window` with data for the window at the specified index.
`abstract int`	`getWindowCount()`	Returns the number of windows in the timeline.
`int`	`hashCode()`
`boolean`	`isEmpty()`	Returns whether the timeline is empty.
`boolean`	`isLastPeriod(int periodIndex, Timeline.Period period, Timeline.Window window, int repeatMode, boolean shuffleModeEnabled)`	Returns whether the given period is the last period of the timeline depending on the `repeatMode` and whether shuffling is enabled.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - EMPTY
```
public static final Timeline EMPTY
```
    An empty timeline.
- Constructor Detail
  - Timeline
```
public Timeline()
```
- Method Detail
  - isEmpty
```
public final boolean isEmpty()
```
    Returns whether the timeline is empty.
  - getWindowCount
```
public abstract int getWindowCount()
```
    Returns the number of windows in the timeline.
  - getNextWindowIndex
```
public int getNextWindowIndex(int windowIndex,
                              @RepeatMode
                              int repeatMode,
                              boolean shuffleModeEnabled)
```
    Returns the index of the window after the window at index windowIndex depending on the repeatMode and whether shuffling is enabled.
    
    Parameters:
    
    windowIndex - Index of a window in the timeline.
    
    repeatMode - A repeat mode.
    
    shuffleModeEnabled - Whether shuffling is enabled.
    
    Returns:
    
    The index of the next window, or C.INDEX_UNSET if this is the last window.
  - getPreviousWindowIndex
```
public int getPreviousWindowIndex(int windowIndex,
                                  @RepeatMode
                                  int repeatMode,
                                  boolean shuffleModeEnabled)
```
    Returns the index of the window before the window at index windowIndex depending on the repeatMode and whether shuffling is enabled.
    
    Parameters:
    
    windowIndex - Index of a window in the timeline.
    
    repeatMode - A repeat mode.
    
    shuffleModeEnabled - Whether shuffling is enabled.
    
    Returns:
    
    The index of the previous window, or C.INDEX_UNSET if this is the first window.
  - getLastWindowIndex
```
public int getLastWindowIndex(boolean shuffleModeEnabled)
```
    Returns the index of the last window in the playback order depending on whether shuffling is enabled.
    
    Parameters:
    
    shuffleModeEnabled - Whether shuffling is enabled.
    
    Returns:
    
    The index of the last window in the playback order, or C.INDEX_UNSET if the timeline is empty.
  - getFirstWindowIndex
```
public int getFirstWindowIndex(boolean shuffleModeEnabled)
```
    Returns the index of the first window in the playback order depending on whether shuffling is enabled.
    
    Parameters:
    
    shuffleModeEnabled - Whether shuffling is enabled.
    
    Returns:
    
    The index of the first window in the playback order, or C.INDEX_UNSET if the timeline is empty.
  - getWindow
```
public final Timeline.Window getWindow(int windowIndex,
                                       Timeline.Window window)
```
    Populates a Timeline.Window with data for the window at the specified index.
    
    Parameters:
    
    windowIndex - The index of the window.
    
    window - The Timeline.Window to populate. Must not be null.
    
    Returns:
    
    The populated Timeline.Window, for convenience.
  - getWindow
```
@Deprecated
public final Timeline.Window getWindow(int windowIndex,
                                       Timeline.Window window,
                                       boolean setTag)
```
    Deprecated.
    Use getWindow(int, Window) instead. Tags will always be set.
  - getWindow
```
public abstract Timeline.Window getWindow(int windowIndex,
                                          Timeline.Window window,
                                          long defaultPositionProjectionUs)
```
    Populates a Timeline.Window with data for the window at the specified index.
    
    Parameters:
    
    windowIndex - The index of the window.
    
    window - The Timeline.Window to populate. Must not be null.
    
    defaultPositionProjectionUs - A duration into the future that the populated window's default start position should be projected.
    
    Returns:
    
    The populated Timeline.Window, for convenience.
  - getPeriodCount
```
public abstract int getPeriodCount()
```
    Returns the number of periods in the timeline.
  - getNextPeriodIndex
```
public final int getNextPeriodIndex(int periodIndex,
                                    Timeline.Period period,
                                    Timeline.Window window,
                                    @RepeatMode
                                    int repeatMode,
                                    boolean shuffleModeEnabled)
```
    Returns the index of the period after the period at index periodIndex depending on the repeatMode and whether shuffling is enabled.
    
    Parameters:
    
    periodIndex - Index of a period in the timeline.
    
    period - A Timeline.Period to be used internally. Must not be null.
    
    window - A Timeline.Window to be used internally. Must not be null.
    
    repeatMode - A repeat mode.
    
    shuffleModeEnabled - Whether shuffling is enabled.
    
    Returns:
    
    The index of the next period, or C.INDEX_UNSET if this is the last period.
  - isLastPeriod
```
public final boolean isLastPeriod(int periodIndex,
                                  Timeline.Period period,
                                  Timeline.Window window,
                                  @RepeatMode
                                  int repeatMode,
                                  boolean shuffleModeEnabled)
```
    Returns whether the given period is the last period of the timeline depending on the repeatMode and whether shuffling is enabled.
    
    Parameters:
    
    periodIndex - A period index.
    
    period - A Timeline.Period to be used internally. Must not be null.
    
    window - A Timeline.Window to be used internally. Must not be null.
    
    repeatMode - A repeat mode.
    
    shuffleModeEnabled - Whether shuffling is enabled.
    
    Returns:
    
    Whether the period of the given index is the last period of the timeline.
  - getPeriodPosition
```
public final Pair<Object,Long> getPeriodPosition(Timeline.Window window,
                                                 Timeline.Period period,
                                                 int windowIndex,
                                                 long windowPositionUs)
```
    Calls getPeriodPosition(Window, Period, int, long, long) with a zero default position projection.
  - getPeriodPosition
```
@Nullable
public final Pair<Object,Long> getPeriodPosition(Timeline.Window window,
                                                 Timeline.Period period,
                                                 int windowIndex,
                                                 long windowPositionUs,
                                                 long defaultPositionProjectionUs)
```
    Converts (windowIndex, windowPositionUs) to the corresponding (periodUid, periodPositionUs).
    
    Parameters:
    
    window - A Timeline.Window that may be overwritten.
    
    period - A Timeline.Period that may be overwritten.
    
    windowIndex - The window index.
    
    windowPositionUs - The window time, or C.TIME_UNSET to use the window's default start position.
    
    defaultPositionProjectionUs - If windowPositionUs is C.TIME_UNSET, the duration into the future by which the window's position should be projected.
    
    Returns:
    
    The corresponding (periodUid, periodPositionUs), or null if #windowPositionUs is C.TIME_UNSET, defaultPositionProjectionUs is non-zero, and the window's position could not be projected by defaultPositionProjectionUs.
  - getPeriodByUid
```
public Timeline.Period getPeriodByUid(Object periodUid,
                                      Timeline.Period period)
```
    Populates a Timeline.Period with data for the period with the specified unique identifier.
    
    Parameters:
    
    periodUid - The unique identifier of the period.
    
    period - The Timeline.Period to populate. Must not be null.
    
    Returns:
    
    The populated Timeline.Period, for convenience.
  - getPeriod
```
public final Timeline.Period getPeriod(int periodIndex,
                                       Timeline.Period period)
```
    Populates a Timeline.Period with data for the period at the specified index. Timeline.Period.id and Timeline.Period.uid will be set to null.
    
    Parameters:
    
    periodIndex - The index of the period.
    
    period - The Timeline.Period to populate. Must not be null.
    
    Returns:
    
    The populated Timeline.Period, for convenience.
  - getPeriod
```
public abstract Timeline.Period getPeriod(int periodIndex,
                                          Timeline.Period period,
                                          boolean setIds)
```
    Populates a Timeline.Period with data for the period at the specified index.
    
    Parameters:
    
    periodIndex - The index of the period.
    
    period - The Timeline.Period to populate. Must not be null.
    
    setIds - Whether Timeline.Period.id and Timeline.Period.uid should be populated. If false, the fields will be set to null. The caller should pass false for efficiency reasons unless the fields are required.
    
    Returns:
    
    The populated Timeline.Period, for convenience.
  - getIndexOfPeriod
```
public abstract int getIndexOfPeriod(Object uid)
```
    Returns the index of the period identified by its unique Timeline.Period.uid, or C.INDEX_UNSET if the period is not in the timeline.
    
    Parameters:
    
    uid - A unique identifier for a period.
    
    Returns:
    
    The index of the period, or C.INDEX_UNSET if the period was not found.
  - getUidOfPeriod
```
public abstract Object getUidOfPeriod(int periodIndex)
```
    Returns the unique id of the period identified by its index in the timeline.
    
    Parameters:
    
    periodIndex - The index of the period.
    
    Returns:
    
    The unique id of the period.
  - equals
```
public boolean equals(@Nullable
                      Object obj)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object

Class Timeline

Single media file or on-demand stream

Playlist of media files or on-demand streams

Live stream with limited availability

Live stream with indefinite availability

Live stream with multiple periods

On-demand stream followed by live stream

On-demand stream with mid-roll ads

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EMPTY

Constructor Detail

Timeline

Method Detail

isEmpty

getWindowCount

getNextWindowIndex

getPreviousWindowIndex

getLastWindowIndex

getFirstWindowIndex

getWindow

getWindow

getWindow

getPeriodCount

getNextPeriodIndex

isLastPeriod

getPeriodPosition

getPeriodPosition

getPeriodByUid

getPeriod

getPeriod

getIndexOfPeriod

getUidOfPeriod

equals

hashCode