IDWriteFontDownloadQueue interface (dwrite_3.h)

Interface that enqueues download requests for remote fonts, characters, glyphs, and font fragments. Provides methods to asynchronously execute a download, cancel pending downloads, and be notified of download completion. Callbacks to listeners will occur on the downloading thread, and objects must be must be able to handle calls on their methods from other threads at any time.

Inheritance

The IDWriteFontDownloadQueue interface inherits from the IUnknown interface. IDWriteFontDownloadQueue also has these types of members:

Methods

The IDWriteFontDownloadQueue interface has these methods.

IDWriteFontDownloadQueue::AddListener Registers a client-defined listener object that receives download notifications. All registered listener's DownloadCompleted will be called after BeginDownloadcompletes.
IDWriteFontDownloadQueue::BeginDownload Begins an asynchronous download operation. The download operation executes in the background until it completes or is cancelled by a CancelDownload call.
IDWriteFontDownloadQueue::CancelDownload Removes all download requests from the queue and cancels any active download operations.
IDWriteFontDownloadQueue::GetGenerationCount Gets the current generation number of the download queue, which is incremented every time after a download completes, whether failed or successful. This cookie value can be compared against cached data to determine if it is stale.
IDWriteFontDownloadQueue::IsEmpty Determines whether the download queue is empty. Note that the queue does not include requests that are already being downloaded. Calling BeginDownloadclears the queue.
IDWriteFontDownloadQueue::RemoveListener Unregisters a notification handler that was previously registered using AddListener.

Requirements

Requirement	Value
Minimum supported client	Windows 10 [desktop apps only]
Minimum supported server	Windows Server 2016 [desktop apps only]
Target Platform	Windows
Header	dwrite_3.h