(SST) ShlWAPI.pas Version 1.08

Developer Reference
PERCEIVED Type Definition
The PERCEIVED type introduces a symbolic name for a signed, 32-bit integer It is defined for compatibility and use with values that are stored/transmitted as a PERCEIVED type in calls to the ShlWAPI.dll function AssocGetPerceivedType.
Global (i.e. variables of this type can be declared in any unit that uses/includes the unit in which it is defined/declared).
A variable of this type accepts a single 32-bit (4 byte), signed, integer value in the range from 2147483648 to (and including) 2147483647. However, typically it is used to store one the following constants.
Constant/Symbolic Name Value Description
PERCEIVED_TYPE_FIRST -3 This is the lowest value that may be specified as a PERCEIVED type.
PERCEIVED_TYPE_CUSTOM -3 Although it is referred to in the remarks section of the doc. on the function and it is described as denoting that "the file's perceived type as defined in the registry is not a known type", this does little to elucidate this (ordinal) value's usage, particularly in light of the fact, that this is already amply covered by PERCEIVED_TYPE_UNSPECIFIED (and/or PERCEIVED_TYPE_UNKNOWN, if need be). It is, therefore, our assumption, that this value is meant to signify that it has a perceived type, but this has not yet been assigned an ordinal value in the PERCEIVED, enumerated type and/or the source of the assignation (registry, dll, etc.) cannot be determined. However, this remains to be clarified by Microsoft.
PERCEIVED_TYPE_UNSPECIFIED -2 The pertinent sources did not render any information on the perceived type of the specified suffix/extension.
PERCEIVED_TYPE_FOLDER -1 According to the Microsoft documentation this value is unused and should therefore not be returned.
PERCEIVED_TYPE_UNKNOWN 0 According to the Microsoft documentation, this value is an internal, initialization value that is never returned to the caller.
PERCEIVED_TYPE_TEXT 1 Files with this suffix/extension are assumed to contain largely or exclusively plain (i.e. unformatted) text.
PERCEIVED_TYPE_IMAGE 2 Files with this suffix/extension are perceived as having a graphic file format and/or being digitized pictures.
PERCEIVED_TYPE_AUDIO 3 Files with this suffix/extension are perceived as being files that are used to record, store, and/or reproduce sounds.
PERCEIVED_TYPE_VIDEO 4 Files with this suffix/extension are perceived as being files that are used to store, record, and/or reproduce a sequence of pictures.
PERCEIVED_TYPE_COMPRESSED 5 Files with this suffix/extension are perceived as having been reduced in size or supporting size reduction by means that preserve the essence of the file's contents.
PERCEIVED_TYPE_DOCUMENT 6 Files with this suffix/extension are files that were typically created by user-level software but don't fall into any of the other categories (e.g. text, video, etc.) Examples for file extensions that (commonly) fall into this category are .rtf and .doc.
PERCEIVED_TYPE_SYSTEM 7 This suffix/extension denotes files as an inherent part of or vital to the operating system.
PERCEIVED_TYPE_APPLICATION 8 The file suffix/extension is perceived as part of a software application. Note, that not only binary executables can fall into this category.
PERCEIVED_TYPE_CONTACTS 10 Under Windows Vista and later, files with the specified suffix/extension are perceived as files that act as databases/containers for information that can be/is used to establish channels of communication between persons or hardware.
PERCEIVED_TYPE_LAST 10 This is the highest value that may be specified as a PERCEIVED type.
This type definintion was introduced for compatibility with the original, Microsoft C/C++ declaration of the PERCEIVED enumerated type, as the Pascal language/compiler allocates less memory and does not permit assigning specific (negative) values to the elements of user defined, enumerated, ordinal types.
For an example that uses this type definition, please refer to the description of the AssocGetPerceivedType function.
Unit Declared in ShlWAPI.pas
Library ShlWAPI.dcu/ShlWAPI.obj
See Also
AssocGetPerceivedType, PERCEIVEDFLAG
Windows APIs: AssocGetPerceivedType. PERCEIVED, PERCEIVEDFLAG.

Document/Contents version 1.00
Page/URI last updated on 07.12.2023
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