Busca uma janela de itens usando o itemID especificado como referência. Esse
método é chamado pelo MediaManager quando precisa de mais itens da fila, geralmente
provenientes de uma solicitação do remetente. Se nextCount ou prevCount forem definidos, fetchItems somente retornará itens depois ou antes do item de referência. Se nextCount e prevCount forem definidos, uma janela de itens
incluindo itemId será retornada.
Inicializa a fila com requestData. Chamado quando o receptor recebe uma nova solicitação cast.framework.messages.Command.LOAD. Se isso retornar ou
for resolvido para null, a implementação de enfileiramento padrão vai criar uma fila
com base em queueData.items ou no único item de mídia nos dados da solicitação
LOAD.
Define o item atual como itemId. Chamado por MediaManager
quando muda o item em reprodução no momento.
Parâmetro
itemId
number
O ID exclusivo do item.
onItemsInserted
onItemsInserted(items, insertBefore)
Um callback que indica que os itens a seguir foram inseridos na fila receptora nesta sessão. Uma implementação baseada na nuvem pode atualizar a fila com base nessas novas informações.
ID do item localizado
imediatamente após a lista inserida. Se o ID não for fornecido, a lista inserida será anexada ao final da fila.
onItemsRemoved
onItemsRemoved(itemIds)
Um callback que indica que os itens a seguir foram removidos da
fila do receptor nesta sessão. Uma implementação baseada na nuvem pode atualizar a fila com base nessas novas informações.
Parâmetro
itemIds
Matriz de números
Os códigos dos itens que foram removidos
O valor não pode ser nulo.
onItemsReordered
onItemsReordered(items, insertBefore)
Um callback que indica que os itens a seguir foram reordenados.
[null,null,["Última atualização 2025-07-25 UTC."],[[["\u003cp\u003e\u003ccode\u003eQueueBase\u003c/code\u003e provides a foundational structure for managing media queues within the Cast framework.\u003c/p\u003e\n"],["\u003cp\u003eIt offers methods to initialize, fetch, and manipulate queue items, including shuffling and unshuffling.\u003c/p\u003e\n"],["\u003cp\u003eDevelopers can extend this base class to implement custom queueing logic for their Cast receiver applications.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eQueueBase\u003c/code\u003e interacts with \u003ccode\u003eMediaManager\u003c/code\u003e to handle queue updates and playback transitions.\u003c/p\u003e\n"],["\u003cp\u003eCallbacks are provided to inform developers about queue modifications like insertions, removals, and reordering.\u003c/p\u003e\n"]]],["The `QueueBase` class manages a media queue, fetching, initializing, and modifying items. Key actions include `fetchItems` to retrieve a range of items based on a reference ID, `initialize` to set up the queue upon a load request, and `nextItems`/`prevItems` to get items following or preceding a given item. Other methods handle updates like `onItemsInserted`, `onItemsRemoved`, `onItemsReordered`, and also manage playback order using `shuffle` and `unshuffle`. The `onCurrentItemIdChanged` method is called when an item is playing.\n"],null,["# Class: QueueBase\n\ncast.[framework](/cast/docs/reference/web_receiver/cast.framework).QueueBase\n============================================================================\n\nclass static\n\nBase implementation of a queue.\n\nConstructor\n-----------\n\n### QueueBase\n\nnew\nQueueBase()\n\nMethods\n-------\n\n### fetchItems\n\nfetchItems(itemId, nextCount, prevCount) returns (non-null Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem) or non-null Promise containing non-null Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem))\n\nFetches a window of items using the specified `itemID` as reference. This\nmethod is called by `MediaManager` when it needs more queue items, often\nstemming from a sender request. If either `nextCount` or `prevCount` are\nset, `fetchItems` will only return items after or before the reference\nitem. If both `nextCount` and `prevCount` are set, a window of items\nincluding `itemId` will be returned.\n\n| #### Parameter ||\n|-----------|---------------------------------------------------|\n| itemId | number The ID of the reference item. |\n| nextCount | number Number of items after the reference item. |\n| prevCount | number Number of items before the reference item. |\n\nReturns\n\n: `(non-null Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)` or non-null Promise containing non-null Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)`)`\n\n### initialize\n\ninitialize(requestData) returns ([cast.framework.messages.QueueData](/cast/docs/reference/web_receiver/cast.framework.messages.QueueData) or non-null Promise containing nullable [cast.framework.messages.QueueData](/cast/docs/reference/web_receiver/cast.framework.messages.QueueData))\n\nInitializes the queue with `requestData`. Called when the receiver\ngets a new `cast.framework.messages.Command.LOAD` request. If this returns or\nresolves to `null`, the default queueing implementation will create a queue\nbased on `queueData.items` or on the single media item in the `LOAD`\nrequest data.\n\n| #### Parameter ||\n|-------------|----------------------------------------------------------------------------------------------------------------------------------------------|\n| requestData | [cast.framework.messages.LoadRequestData](/cast/docs/reference/web_receiver/cast.framework.messages.LoadRequestData) Value must not be null. |\n\nReturns\n\n: `(nullable `[cast.framework.messages.QueueData](/cast/docs/reference/web_receiver/cast.framework.messages.QueueData)` or non-null Promise containing nullable `[cast.framework.messages.QueueData](/cast/docs/reference/web_receiver/cast.framework.messages.QueueData)`)`\n\n### nextItems\n\nnextItems(itemId) returns (nullable Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem) or non-null Promise containing nullable Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem))\n\nReturns all items in the queue following `itemID`. This is called by\n`MediaManager`.\n\n| #### Parameter ||\n|--------|-----------------------------------------------|\n| itemId | Optional number The ID of the reference item. |\n\nReturns\n\n: `(nullable Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)` or non-null Promise containing nullable Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)`)`\n\n### onCurrentItemIdChanged\n\nonCurrentItemIdChanged(itemId)\n\nSets the current item to `itemId`. Called by `MediaManager`\nwhen it changes the currently-playing item.\n\n| #### Parameter ||\n|--------|------------------------------------|\n| itemId | number The unique ID for the item. |\n\n### onItemsInserted\n\nonItemsInserted(items, insertBefore)\n\nA callback that indicates that the following items have been inserted into\nthe receiver queue in this session. A cloud-based implementation might\nupdate its queue based on this new information.\n\n| #### Parameter ||\n|--------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| items | Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem) The items that were inserted. Value must not be null. |\n| insertBefore | Optional number ID of the item that was located immediately after the inserted list. If the ID is not provided, the inserted list was appended to the end of the queue. |\n\n### onItemsRemoved\n\nonItemsRemoved(itemIds)\n\nA callback that indicates that the following items have been removed from\nthe receiver queue in this session. A cloud-based implementation might\nupdate its queue based on this new information.\n\n| #### Parameter ||\n|---------|---------------------------------------------------------------------------------|\n| itemIds | Array of number The IDs of the items that were removed. Value must not be null. |\n\n### onItemsReordered\n\nonItemsReordered(items, insertBefore)\n\nA callback that indicates that the following items have been reordered.\n\n| #### Parameter ||\n|--------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| items | Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem) The IDs of the items that were reordered. Value must not be null. |\n| insertBefore | Optional number ID of the item that is located immediately after the reordered list. If `insertBefore` is not provided, the reordered list will be appended to the end of the queue. |\n\nSee also\n: [cast.framework.messages.QueueReorderRequestData#itemIds](/cast/docs/reference/web_receiver/cast.framework.messages.QueueReorderRequestData#itemIds) for more details.\n\n### prevItems\n\nprevItems(itemId) returns (nullable Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem) or non-null Promise containing nullable Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem))\n\nReturns all items before `itemID`. This is called by `MediaManager`.\n\n| #### Parameter ||\n|--------|-----------------------------------------------|\n| itemId | Optional number The ID of the reference item. |\n\nReturns\n\n: `(nullable Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)` or non-null Promise containing nullable Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)`)`\n\n### shuffle\n\nshuffle() returns (nullable Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem) or non-null Promise containing nullable Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem))\n\nShuffles the queue and returns new queue items. Returns `null` if the\noperation is not supported.\n\nReturns\n\n: `(nullable Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)` or non-null Promise containing nullable Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)`)`\n\n### unshuffle\n\nunshuffle() returns (nullable Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem) or non-null Promise containing nullable Array of non-null [cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem))\n\nUnshuffles the queue and returns new queue items. Returns `null` if the\noperation is not supported.\n\nReturns\n\n: `(nullable Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)` or non-null Promise containing nullable Array of non-null `[cast.framework.messages.QueueItem](/cast/docs/reference/web_receiver/cast.framework.messages.QueueItem)`)`"]]
