DSImageSourceAdapter

The ImageSourceAdapter class is an abstract class representing an adapter for image sources, providing a framework for fetching, buffering, and managing images from various sources. Implementations must provide specific mechanisms for image retrieval and handling.

Definition

Assembly: DynamsoftCaptureVisionBundle.xcframework

Objective-C
Swift

@interface DSImageSourceAdapter : NSObject

```
class ImageSourceAdapter : NSObject
```

Attributes & Methods

Attributes	Type	Description
`bufferEmpty`	BOOL	The read only property determines whether the buffer is currently empty.
`bufferOverflowProtectionMode`	DSBufferOverflowProtectionMode	Sets the behavior for handling new incoming images when the buffer is full.
`colourChannelUsageType`	colourChannelUsageType	Sets the usage type for color channels in images.
`imageCount`	NSUInteger	The property defines the current number of images in the buffer.
`maxImageCount`	NSUInteger	The property defines the maximum number of images that can be buffered.

Method	Description
`addImageToBuffer`	Adds an image to the internal buffer.
`clearBuffer`	Clears all images from the buffer, resetting the state for new image fetching.
`getImage`	Get a buffered image. Implementing classes should return a Promise that resolves with an instance of `DSImageData`.
`hasImage`	Checks if an image with the specified ID is present in the buffer.
`setErrorListener`	Sets an error listener to receive notifications about errors that occur during image source operations.
`setImageFetchState`	Determines whether there are more images left to fetch.
`setNextImageToReturn`	Sets the processing priority of a specific image. This can affect the order in which images are returned by `getImage`.
`startFetching`	Start fetching images from the source to the Video Buffer of ImageSourceAdapter.
`stopFetching`	Stop fetching images from the source to the Video Buffer of ImageSourceAdapter.

bufferEmpty

The read only property indicates whether the Video Buffer is empty.

Objective-C
Swift

@property (nonatomic, assign, readonly, getter=isBufferEmpty) BOOL bufferEmpty;

```
var isBufferEmpty: Bool { get }
```

bufferOverflowProtectionMode

Sets a mode that determines the action to take when there is a new incoming image and the buffer is full. You can either block the Video Buffer or push out the oldest image and append a new one.

Objective-C
Swift

@property (nonatomic, assign) DSBufferOverflowProtectionMode bufferOverflowProtectionMode;

var bufferOverflowProtectionMode:  BufferOverflowProtectionMode { get set }

colourChannelUsageType

The usage type of a color channel in an image.

Objective-C
Swift

@property (nonatomic, assign) DSColourChannelUsageType colourChannelUsageType;

var colourChannelUsageType: ColourChannelUsageType { get set }

hasNextImageToFetch

Determines whether there are more images left to fetch.

Objective-C
Swift

@property (nonatomic, assign) BOOL hasNextImageToFetch;

var hasNextImageToFetch: Bool { get set }

imageCount

The property defines current image count in the Video Buffer.

Objective-C
Swift

@property (nonatomic, readonly, assign) NSUInteger imageCount;

```
var imageCount: Int { get }
```

maxImageCount

The property defines the maximum capability of the Video Buffer.

Objective-C
Swift

@property (nonatomic, assign) NSUInteger maxImageCount;

```
var maxImageCount: Int { get set }
```

addImageToBuffer

Adds an image to the internal buffer.

Objective-C
Swift

- (void)addImageToBuffer:(DSImageData*)image;

func addImageToBuffer(image: ImageData)

Parameters

[in] image: The DSImageData object to add.

clearBuffer

Clears all images from the buffer, resetting the state for new image fetching.

Objective-C
Swift

```
- (void)clearBuffer;
```
```
func clearBuffer()
```

getImage

Get a buffered image. Implementing classes should return a Promise that resolves with an instance of DSImageData.

Objective-C
Swift

```
- (nullable DSImageData *)getImage;
```
```
func getImage() -> DSImageData?
```

Return Value

An object of DSImageData.

If an image is set as the “next image” by method setNextImageToReturn, return that image.
If no image is set as the “next image”, return the latest image.

hasImage

Checks if an image with the specified ID is present in the buffer.

Objective-C
Swift

```
- (BOOL)hasImage:(NSInteger)imageId;
```
```
func hasImage(imageId: Int) -> Bool
```

Parameters

[in] imageId: The imageId of image you want to check the availability.

Return Value

A BOOL value that indicates whether the specified image is found in the video buffer.

setErrorListener

Sets an error listener to receive notifications about errors that occur during image source operations.

Objective-C
Swift

- (void)setErrorListener:(nullable id<DSImageSourceErrorListener>)listener;

func setErrorListener(_ listener: ImageSourceErrorListener?)

Parameters

[in] listener: A delegate object of DSImageSourceErrorListener to receive the errors that occurs in the ImageSourceAdapter.

setImageFetchState

Determines whether there are more images left to fetch.

Objective-C
Swift

- (void)setImageFetchState:(BOOL)state;

```
func setImageFetchState(state: Bool)
```

Parameters

[in] state: The state of image fetching.

setNextImageToReturn

Sets the processing priority of a specific image. This can affect the order in which images are returned by getImage.

Objective-C
Swift

- (BOOL)setNextImageToReturn:(NSInteger)imageId
            keepInBuffer:(BOOL)keepInBuffer;

func setNextImageToReturn(imageId: Int, keepInBuffer: Bool) -> Bool

Parameters

[in] imageId: The imageId of image you want to set as the “next image”.
[in] keepInBuffer: Set this value to true so that the “next image” is protected from being pushed out before is it returned by method getImage.

Return Value

A BOOL value that indicates whether the specified image is successfully set as the “next image”.

startFetching

Start fetching images from the source to the Video Buffer of ImageSourceAdapter.

Objective-C
Swift

```
- (void)startFetching;
```
```
func startFetching()
```

stopFetching

Stop fetching images from the source to the Video Buffer of ImageSourceAdapter.

Objective-C
Swift

```
- (void)stopFetching;
```
```
func stopFetching()
```