DocumentPreviewCache
extends Object| java.lang.Object | |
| ↳ | com.pdftron.pdf.DocumentPreviewCache |
Class Overview
DocumentPreviewCache is a persistent cache that provides thumbnails for browsing in PDFNet. The cache is placed in the sub-directory 'trn_DocumentPreviewCache' of the PDFNet Resources folder, which can be set by calling PDFNet::SetPersistentCachePath. In the case the PersistentCachePath is not set the files will be stored in the system temp path (PDFNet::GetSystemTempPath()). The cache will be used by any PDFNet process that uses the resource path. If more than one PDFNet process is running concurrently, the first process to acquire a lock on the cache will use it. Subsequent processes will not read or modify the cache. DocumentPreviewCache will store references to generated JPG thumbnails and keeps track of the dimensions of the thumbnail and the filesize of the specific pdf documents. Furthermore it takes care that the size constraints (max_cache_bytes, max_disk_percentage) are met and in cleans the oldest (in terms of last request) thumbs from the cache in case of a overflow. If the user requests a file that is already in the cache and the requested thumb dimensions are smaller or equal than the ones of the cache-version the URL of the cached thumb is given back. If the dimensions are bigger the thumb gets rendered again, the old thumb gets replaced and the URL is given back. If the size of the pdf document changes the thumb will be rendered again even when there is a version of that thumbnail in the cache. In case that the user wants to suppress the re-rendering of that specific thumb (e.g. when the change on the pdf document was made on another page than the first page which is used for the thumb), IrrelevantChangeMade has to be called.
Summary
| Public Constructors | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| DocumentPreviewCache() | |||||||||||
| Public Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| static void |
cancelAllRequests()
CancelAllRequests cancels all pending requests.
| ||||||||||
| static void |
cancelRequest(String filepathOrUuid)
CancelRequest cancels all pending thumbnail requests associated with 'filepathOrUuid'.
| ||||||||||
| static void |
clearCache()
Remove the cache from the disk completely, deleting any thumbnails.
| ||||||||||
| static void |
createBitmapWithID(String uuid, Filter filter, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
createBitmapWithID gets the path to the thumbnail in the DocumentPreviewCache associated with the document with 'uuid'.
| ||||||||||
| static void |
createBitmapWithID(String uuid, PDFDoc doc, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
createBitmapWithID gets the path to the thumbnail in the DocumentPreviewCache associated with the document with 'uuid'.
| ||||||||||
| static void |
getBitmapWithID(String uuid, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
getBitmapWithID gets the path to the thumbnail in the DocumentPreviewCache associated with the document with 'uuid'.
| ||||||||||
| static void |
getBitmapWithID(String uuid, Filter filter, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
getBitmapWithID gets the path to the thumbnail in the DocumentPreviewCache associated with the document with 'uuid'.
| ||||||||||
| static void |
getBitmapWithPath(String filepath, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
getBitmapWithPath gets the path to the thumbnail in the DocumentPreviewCache associated with the document at 'filepath'.
| ||||||||||
| static void |
initialize(long max_cache_bytes, double max_disk_percentage)
Initialize the preview cache.
| ||||||||||
| static void |
irrelevantChangeMade(String filepath)
IrrelevantChangeMade should be called if the size of the pdf file at 'filepath' was changed but the thumbnail
should not be re-generated.
| ||||||||||
|
[Expand]
Inherited Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
From class
java.lang.Object
| |||||||||||
Public Constructors
public DocumentPreviewCache ()
Public Methods
public static void cancelAllRequests ()
CancelAllRequests cancels all pending requests. The PreviewHandler of each pending request will signal that the preview could not be found.
public static void cancelRequest (String filepathOrUuid)
CancelRequest cancels all pending thumbnail requests associated with 'filepathOrUuid'. If the cancel request is processed earlier than the path of the thumbnail could be retrieved the respective request will be cancelled and the PreviewHandler will signal that the thumb could not be found.
Parameters
| filepathOrUuid | - URL of pdf file or uuid |
|---|
public static void clearCache ()
Remove the cache from the disk completely, deleting any thumbnails. You may want to do this if you detect some kind of corruption, or if the user wants to clear out disk space used by your application.
public static void createBitmapWithID (String uuid, Filter filter, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
createBitmapWithID gets the path to the thumbnail in the DocumentPreviewCache associated with the document with 'uuid'. This method should be used together with getBitmapWithID. The decision if the thumb should be re-rendered is based on two factors. First if the current version fulfills the minimal dimensions 'min_x_size' x 'min_y_size' and second if the size of the pdf document hasn't changed. To signal an edit of the pdf document without a resulting re-rendering of the thumb see IrrelevantChangeMade.
Parameters
| uuid | - The uuid of the PDFDoc |
|---|---|
| filter | - Input filter for the Doc |
| min_x_size | - Minimal width of the thumbnail. |
| min_y_size | - Minimal height of the thumbnail. |
| proc | - A callback function that will be called after the thumbnail is retrieved, or if that retrieval fails. |
| custom_data | - Custom data to be passed to the PreviewHandler. |
public static void createBitmapWithID (String uuid, PDFDoc doc, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
createBitmapWithID gets the path to the thumbnail in the DocumentPreviewCache associated with the document with 'uuid'. This method should be used together with getBitmapWithID. The decision if the thumb should be re-rendered is based on two factors. First if the current version fulfills the minimal dimensions 'min_x_size' x 'min_y_size' and second if the size of the pdf document hasn't changed. To signal an edit of the pdf document without a resulting re-rendering of the thumb see IrrelevantChangeMade.
Parameters
| uuid | - The uuid of the PDFDoc |
|---|---|
| doc | - The PDFDoc whose thumbnail to create |
| min_x_size | - Minimal width of the thumbnail. |
| min_y_size | - Minimal height of the thumbnail. |
| proc | - A callback function that will be called after the thumbnail is retrieved, or if that retrieval fails. |
| custom_data | - Custom data to be passed to the PreviewHandler. |
public static void getBitmapWithID (String uuid, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
getBitmapWithID gets the path to the thumbnail in the DocumentPreviewCache associated with the document with 'uuid'. This method should be used together with createBitmapWithID. The decision if the thumb should be re-rendered is based on two factors. First if the current version fulfills the minimal dimensions 'min_x_size' x 'min_y_size' and second if the size of the pdf document hasn't changed. To signal an edit of the pdf document without a resulting re-rendering of the thumb see IrrelevantChangeMade.
Parameters
| uuid | - The uuid of the PDFDoc added by createBitmapWithID |
|---|---|
| min_x_size | - Minimal width of the thumbnail. |
| min_y_size | - Minimal height of the thumbnail. |
| proc | - A callback function that will be called after the thumbnail is retrieved, or if that retrieval fails. |
| custom_data | - Custom data to be passed to the PreviewHandler. |
public static void getBitmapWithID (String uuid, Filter filter, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
getBitmapWithID gets the path to the thumbnail in the DocumentPreviewCache associated with the document with 'uuid'. This method should be used together with createBitmapWithID. The decision if the thumb should be re-rendered is based on two factors. First if the current version fulfills the minimal dimensions 'min_x_size' x 'min_y_size' and second if the size of the pdf document hasn't changed. To signal an edit of the pdf document without a resulting re-rendering of the thumb see IrrelevantChangeMade.
Parameters
| uuid | - The uuid of the PDFDoc added by createBitmapWithID |
|---|---|
| min_x_size | - Minimal width of the thumbnail. |
| min_y_size | - Minimal height of the thumbnail. |
| proc | - A callback function that will be called after the thumbnail is retrieved, or if that retrieval fails. |
| custom_data | - Custom data to be passed to the PreviewHandler. |
public static void getBitmapWithPath (String filepath, int min_x_size, int min_y_size, PreviewHandler proc, Object custom_data)
getBitmapWithPath gets the path to the thumbnail in the DocumentPreviewCache associated with the document at 'filepath'. The decision if the thumb should be re-rendered is based on two factors. First if the current version fulfills the minimal dimensions 'min_x_size' x 'min_y_size' and second if the size of the pdf document hasn't changed. To signal an edit of the pdf document without a resulting re-rendering of the thumb see IrrelevantChangeMade.
Parameters
| filepath | - The URL of the pdf file. |
|---|---|
| min_x_size | - Minimal width of the thumbnail. |
| min_y_size | - Minimal height of the thumbnail. |
| proc | - A callback function that will be called after the thumbnail is retrieved, or if that retrieval fails. |
| custom_data | - Custom data to be passed to the PreviewHandler. |
public static void initialize (long max_cache_bytes, double max_disk_percentage)
Initialize the preview cache. If the cache already exists, it will shrink to conform to these limits immediately.
Parameters
| max_cache_bytes | The absolute maximum size on disk for the temporary preview cache in bytes. |
|---|---|
| max_disk_percentage | The maximum percentage of free disk space that the cache can take up (0 - 1.0). |
public static void irrelevantChangeMade (String filepath)
IrrelevantChangeMade should be called if the size of the pdf file at 'filepath' was changed but the thumbnail should not be re-generated. This should be done when no editing was done on the first page of the document. This method does not work on bitmaps associated with uuids
Parameters
| filepath | - URL of pdf file |
|---|