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interface OnHeaderDecodedListener
Interface for changing the default settings of a decode.
Supply an instance to decodeDrawable or decodeBitmap, which will call onHeaderDecoded (in the same thread) once the size is known. The implementation of onHeaderDecoded can then change the decode settings as desired.
Summary
| Public methods |
| abstract Unit |
Called by ImageDecoder when the header has been decoded and the image size is known.
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Public methods
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Last updated 2025-02-10 UTC.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-02-10 UTC."],[],[],null,["# ImageDecoder.OnHeaderDecodedListener\n\nAdded in [API level 28](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)\n\nOnHeaderDecodedListener\n=======================\n\n*** ** * ** ***\n\nKotlin \\|[Java](/reference/android/graphics/ImageDecoder.OnHeaderDecodedListener \"View this page in Java\") \n\n```\ninterface OnHeaderDecodedListener\n```\n\n|------------------------------------------------------------|\n| [android.graphics.ImageDecoder.OnHeaderDecodedListener](#) |\n\nInterface for changing the default settings of a decode.\n\nSupply an instance to [decodeDrawable](/reference/kotlin/android/graphics/ImageDecoder#decodeDrawable(android.graphics.ImageDecoder.Source,%20android.graphics.ImageDecoder.OnHeaderDecodedListener)) or [decodeBitmap](/reference/kotlin/android/graphics/ImageDecoder#decodeBitmap(android.graphics.ImageDecoder.Source,%20android.graphics.ImageDecoder.OnHeaderDecodedListener)), which will call [onHeaderDecoded](#onHeaderDecoded(android.graphics.ImageDecoder,%20android.graphics.ImageDecoder.ImageInfo,%20android.graphics.ImageDecoder.Source)) (in the same thread) once the size is known. The implementation of [onHeaderDecoded](#onHeaderDecoded(android.graphics.ImageDecoder,%20android.graphics.ImageDecoder.ImageInfo,%20android.graphics.ImageDecoder.Source)) can then change the decode settings as desired.\n\nSummary\n-------\n\n| Public methods ||\n|---------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| abstract [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [onHeaderDecoded](#onHeaderDecoded(android.graphics.ImageDecoder,%20android.graphics.ImageDecoder.ImageInfo,%20android.graphics.ImageDecoder.Source))`(`decoder:` `[ImageDecoder](/reference/kotlin/android/graphics/ImageDecoder)`, `info:` `[ImageDecoder.ImageInfo](/reference/kotlin/android/graphics/ImageDecoder.ImageInfo)`, `source:` `[ImageDecoder.Source](/reference/kotlin/android/graphics/ImageDecoder.Source)`)` Called by [ImageDecoder](/reference/kotlin/android/graphics/ImageDecoder) when the header has been decoded and the image size is known. |\n\nPublic methods\n--------------\n\n### onHeaderDecoded\n\nAdded in [API level 28](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) \n\n```\nabstract fun onHeaderDecoded(\n decoder: ImageDecoder, \n info: ImageDecoder.ImageInfo, \n source: ImageDecoder.Source\n): Unit\n```\n\nCalled by [ImageDecoder](/reference/kotlin/android/graphics/ImageDecoder) when the header has been decoded and the image size is known.\n\n| Parameters ||\n|-----------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `decoder` | [ImageDecoder](/reference/kotlin/android/graphics/ImageDecoder): the object performing the decode, for changing its default settings. This value cannot be `null`. |\n| `info` | [ImageDecoder.ImageInfo](/reference/kotlin/android/graphics/ImageDecoder.ImageInfo): information about the encoded image. This value cannot be `null`. |\n| `source` | [ImageDecoder.Source](/reference/kotlin/android/graphics/ImageDecoder.Source): object that created `decoder`. This value cannot be `null`. |"]]
