# RDSpeechReaderView

`RDSpeechReaderView` provides bounded, on-device text-to-speech playback for
ReadViewSDK readers. It uses `AVSpeechSynthesizer` and does not upload book
content or create exportable audio files.

## Install

```ruby
pod 'RDSpeechReaderView'
pod 'RDPDFReaderView/Speech'
pod 'RDEpubReaderView/Speech'
```

The host app must enable the **Audio, AirPlay, and Picture in Picture**
background mode to continue reading after it enters the background.

## Use with PDF

```swift
let provider = reader.makeSpeechContentProvider()
let speech = RDSpeechReaderController(contentProvider: provider)
try await speech.start()
```

The PDF adapter reads `RDPDFReaderTextRun` values supplied by the host or by
PDFKit. Image-only PDFs require an OCR-backed provider before they can speak.

For automatic page navigation and temporary read-aloud highlighting, create a
PDF session instead:

```swift
let session = reader.makeSpeechSession()
try await session.start(from: 0)
```

## Use with EPUB

```swift
let session = reader.makeSpeechSession()
try await session.start()
```

EPUB/TXT 会话默认从当前阅读位置开始。文本重排 EPUB 与 TXT 会临时高亮当前朗读范围，
并且只在朗读跨页时定位；朗读位置使用 EPUB `href` 与 UTF-16 文本偏移，因此用户修改
字体或页面大小后仍可稳定恢复。