com.atlassian.confluence.pages.thumbnail.renderer

Class DelegatingThumbnailRenderer

java.lang.Object

com.atlassian.confluence.pages.thumbnail.renderer.DelegatingThumbnailRenderer

public class DelegatingThumbnailRenderer
extends Object

Thumbnail renderer that uses different strategies to render a thumbnail.

Images will be resized using a high quality renderer if possible and a streaming renderer if they exceed a certain width or height.

Constructor Summary

Constructors

Constructor and Description
DelegatingThumbnailRenderer(com.atlassian.core.util.thumbnail.Thumber thumber, AttachmentManager attachmentManager) Create a DelegatingThumbnailRenderer using an adaptive strategy that take the available memory into account to decide if we use the higher quality rendering or the lower quality stream based rendering (less memory consumption).
DelegatingThumbnailRenderer(com.atlassian.core.util.thumbnail.Thumber thumber, AttachmentManager attachmentManager, int rasterSizeThresholdPx) Create a DelegatingThumbnailRenderer that will use the lower quality stream based rendering if the image exceeds the rasterSizeThresholdPx (height or width in px).
DelegatingThumbnailRenderer(com.atlassian.core.util.thumbnail.Thumber thumber, AttachmentManager attachmentManager, com.google.common.base.Predicate<Dimensions> rasterBasedRenderingThreshold) Deprecated. since 7.0.1 , use DelegatingThumbnailRenderer(Thumber, AttachmentManager, Predicate)
DelegatingThumbnailRenderer(com.atlassian.core.util.thumbnail.Thumber thumber, AttachmentManager attachmentManager, Predicate<ImageDimensions> rasterBasedRenderingThreshold) Create a DelegatingThumbnailRenderer that will use the rasterBasedRenderingThreshold Predicate to decide if it's going to use the stream based (lower quality but low memory consumption) or the raster based renderer (higher quality but high memory consumption).

Method Summary

Modifier and Type	Method and Description
com.atlassian.core.util.thumbnail.Thumbnail	retrieveOrCreateThumbNail(@NonNull Attachment attachment, File thumbnailFile, int maxWidth, int maxHeight) Create a new or return an existing Thumbnail for this attachment.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DelegatingThumbnailRenderer

public DelegatingThumbnailRenderer(com.atlassian.core.util.thumbnail.Thumber thumber,
                                   AttachmentManager attachmentManager)

Create a DelegatingThumbnailRenderer using an adaptive strategy that take the available memory into account to decide if we use the higher quality rendering or the lower quality stream based rendering (less memory consumption).

DelegatingThumbnailRenderer

public DelegatingThumbnailRenderer(com.atlassian.core.util.thumbnail.Thumber thumber,
                                   AttachmentManager attachmentManager,
                                   int rasterSizeThresholdPx)

Create a DelegatingThumbnailRenderer that will use the lower quality stream based rendering if the image exceeds the rasterSizeThresholdPx (height or width in px).

DelegatingThumbnailRenderer

@Deprecated
public DelegatingThumbnailRenderer(com.atlassian.core.util.thumbnail.Thumber thumber,
                                               AttachmentManager attachmentManager,
                                               com.google.common.base.Predicate<Dimensions> rasterBasedRenderingThreshold)

Deprecated. since 7.0.1 , use DelegatingThumbnailRenderer(Thumber, AttachmentManager, Predicate)

Create a DelegatingThumbnailRenderer that will use the rasterBasedRenderingThreshold Predicate to decide if it's going to use the stream based (lower quality but low memory consumption) or the raster based renderer (higher quality but high memory consumption).

Parameters:

thumber - Thumber instance to use

attachmentManager - The attachment manager that will be used to retrieve the image data

rasterBasedRenderingThreshold - Predicate used to determine if the raster or stream based image rendering should be used. The Predicate.apply(T) method should return true for the given Dimensions if the raster based (memory intensive) rendering approach can be used.

DelegatingThumbnailRenderer

public DelegatingThumbnailRenderer(com.atlassian.core.util.thumbnail.Thumber thumber,
                                   AttachmentManager attachmentManager,
                                   Predicate<ImageDimensions> rasterBasedRenderingThreshold)

Create a DelegatingThumbnailRenderer that will use the rasterBasedRenderingThreshold Predicate to decide if it's going to use the stream based (lower quality but low memory consumption) or the raster based renderer (higher quality but high memory consumption).

Parameters:

thumber - Thumber instance to use

attachmentManager - The attachment manager that will be used to retrieve the image data

rasterBasedRenderingThreshold - Predicate used to determine if the raster or stream based image rendering should be used. The Predicate.test(Object) method should return true for the given Dimensions if the raster based (memory intensive) rendering approach can be used.

Since:

7.0.1

Method Detail

retrieveOrCreateThumbNail

public com.atlassian.core.util.thumbnail.Thumbnail retrieveOrCreateThumbNail(@NonNull Attachment attachment,
                                                                             File thumbnailFile,
                                                                             int maxWidth,
                                                                             int maxHeight)
                                                                      throws ThumbnailRenderException

Create a new or return an existing Thumbnail for this attachment. Thumbnails will always be PNG thumbnails!

Parameters:

attachment - - The attachment that contains the image data. Cannot be null.

thumbnailFile - - The thumbnail file that will be used to store the rendered thumbnail

maxWidth - - The maximum width of the thumbnail - this renderer maintains the aspect ratio of the original image

maxHeight - - The maximum height of the thumbnail - this renderer maintains the aspect ratio of the original image

Returns:

Thumbnail in PNG format that is at most maxWidthxmaxHeight, never returns null

Throws:

ThumbnailRenderException - if the thumbnail cannot be created.