--- layout: default-layout title: ImageSourceAdapter - Dynamsoft Capture Vision Android Edition API Reference description: The class ImageSourceAdapter of Dynamsoft Capture Vision Android represents an interface for fetching and buffering images. keywords: image source adapter, Java, Kotlin needGenerateH3Content: true needAutoGenerateSidebar: true noTitleIndex: true --- # ImageSourceAdapter The `ImageSourceAdapter` class provides an interface for fetching and buffering images. It is an abstract class that needs to be implemented by a concrete class to provide actual functionality. ## Definition *Namespace:* com.dynamsoft.core.basic_structures *Assembly:* DynamsoftCaptureVisionBundle.aar ```java class ImageSourceAdapter ``` ## Methods | Method | Description | | ------ | ----------- | | [`ImageSourceAdapter`](#imagesourceadapter-1 ) | The constructor. | | [`addImageToBuffer`](#addimagetobuffer) | Adds an image to the internal buffer. | | [`clearBuffer`](#clearbuffer) | Clears all images from the buffer, resetting the state for new image fetching. | | [`getBufferOverflowProtectionMode`](#getbufferoverflowprotectionmode) | Get the current mode for handling buffer overflow. | | [`getColourChannelUsageType`](#getcolourchannelusagetype) | Get the current usage type for color channels in images. | | [`getImageCount`](#getimagecount) | Get the current number of images in the buffer. | | [`getImage`](#getimage) | Get a buffered image. Implementing classes should return a Promise that resolves with an instance of `ImageData`. | | [`getMaxImageCount`](#getmaximagecount) | Get the maximum number of images that can be buffered. | | [`hasImage`](#hasimage) | Checks if an image with the specified ID is present in the buffer. | | [`hasNextImageToFetch`](#hasnextimagetofetch) | Determines whether there are more images available to fetch. | | [`isBufferEmpty`](#isbufferempty) | Determines whether the buffer is currently empty. | | [`setBufferOverflowProtectionMode`](#setbufferoverflowprotectionmode) | Sets the behavior for handling new incoming images when the buffer is full. | | [`setColourChannelUsageType`](#setcolourchannelusagetype) | Sets the usage type for color channels in images. | | [`setErrorListener`](#seterrorlistener) | Sets an error listener to receive notifications about errors that occur during image source operations. | | [`setMaxImageCount`](#setmaximagecount) | Sets the maximum number of images that can be buffered at any time. | | [`setNextImageToReturn(imageId)`](#setnextimagetoreturnimageid) | Sets the processing priority of a specific image. This can affect the order in which images are returned by getImage. | | [`setNextImageToReturn(imageId,keepInBuffer)`](#setnextimagetoreturnimageidkeepinbuffer) | Sets the processing priority of a specific image. This can affect the order in which images are returned by getImage. | | [`startFetching`](#startfetching) | Start fetching images from the source to the Video Buffer of ImageSourceAdapter. | | [`stopFetching`](#stopfetching) | Stop fetching images from the source to the Video Buffer of ImageSourceAdapter. | ### ImageSourceAdapter The constructor. ```java ImageSourceAdapter(); ``` ### addImageToBuffer Adds an image to the internal buffer. ```java void addImageToBuffer(ImageData image); ``` **Parameters** `[in] image`: The ImageData object to add. ### clearBuffer Clears all images from the buffer, resetting the state for new image fetching. ```java void clearBuffer(); ``` ### getBufferOverflowProtectionMode Get the current mode for handling buffer overflow. ```java @EnumBufferOverflowProtectionMode int getBufferOverflowProtectionMode(); ``` ### getColourChannelUsageType Get the current usage type for color channels in images. ```java @EnumColourChannelUsageType int getColourChannelUsageType(); ``` ### getImageCount Get the current number of images in the buffer. ```java int getImageCount(); ``` **Return Value** The current number of images in the buffer. ### getImage Get an image from the Video Buffer. ```java ImageData getImage(); ``` **Return Value** An object of ImageData. * 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. ### getMaxImageCount Get the maximum number of images that can be buffered. ```java int getMaximumImageCount(); ``` **Return Value** The maximum capability of the Video Buffer. ### hasImage Checks if an image with the specified ID is present in the buffer. ```java boolean hasImage(int imageId); ``` **Parameters** `[in] imageId`: The imageId of image you want to check the availability. **Return Value** A boolean value that indicates whether the specified image is found in the video buffer. ### hasNextImageToFetch Determines whether there are more images available to fetch. ```java abstract boolean hasNextImageToFetch(); ``` **Return value** A boolean value that determines whether there are more images left to fetch. ### isBufferEmpty Determines whether the buffer is currently empty. ```java boolean isBufferEmpty(); ``` **Return Value** A boolean value that indicates whether the Video Buffer is empty. ### setBufferOverflowProtectionMode Sets the behavior for handling new incoming images when the buffer is full. ```java void setBufferOverflowProtectionMode(@EnumBufferOverflowProtectionMode int mode); ``` **Parameters** `[in] mode`: One of the `EnumBufferOverflowProtectionMode` that indicates the buffer overflow protection mode. **Return Value** The buffer overflow protection mode. ### setColourChannelUsageType Sets the usage type for color channels in images. ```java void setColourChannelUsageType(@EnumColourChannelUsageType int type); ``` **Parameters** `[in] type`: One of the [`EnumColourChannelUsageType`]({{ site.dcv_android_api }}core/enum/colour-channel-usage-type.html) that indicates whether the colour channel usage type. **Return Value** One of the [`EnumColourChannelUsageType`]({{ site.dcv_android_api }}core/enum/colour-channel-usage-type.html) that indicates whether the colour channel usage type. ### setErrorListener Sets an error listener to receive notifications about errors that occur during image source operations. ```java void setErrorListener(ImageSourceErrorListener listener); ``` **Parameters** `[in] listener`: A interface object of [`ImageSourceErrorListener`](image-source-error-listener.md) to receive the errors that occurs in the `ImageSourceAdapter`. ### setMaxImageCount Sets the maximum number of images that can be buffered at any time. ```java void setMaximumImageCount(int count); ``` **Parameters** `[in] count`: The maximum capability of the Video Buffer. ### setNextImageToReturn(imageId) Sets the processing priority of a specific image. This can affect the order in which images are returned by getImage. ```java boolean setNextImageToReturn(int imageId); ``` **Parameters** `[in] imageId`: The imageId of image you want to set as the "next image". **Return Value** A boolean value that indicates whether the specified image is successfully set as the "next image". ### setNextImageToReturn(imageId,keepInBuffer) Sets the processing priority of a specific image. This can affect the order in which images are returned by getImage. ```java boolean setNextImageToReturn(int imageId, boolean keepInBuffer) ``` **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 boolean 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`. ```java void startFetching(); ``` ### stopFetching Stop fetching images from the source to the Video Buffer of `ImageSourceAdapter`. ```java void stopFetching(); ```