HFSQL thumbnails

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Accessing the databases: summary

Analysis shared between earlier WINDEV applications and WINDEV 24 applications

Assisted management of HFSQL errors

Automatic modification of data files

Automatic modification of data files: new date format

Browsing the HFSQL data files

Communication by GPRS

Connecting to a database via RPC

Errors while managing data files

Filtering a data file, a view or a query

Functions for HFSQL management

HFSQL data files exceeding 2 gigabytes

HFSQL in network mode on a server running Windows NT4, 2000, XP or 2003

HFSQL thumbnails

HFSQL: Change of name

Hyper File functions available for backward compatibility

Locking data files: correspondence between WINDEV 5.5 and the later versions

Management errors specific to Native Accesses

Managing NULL in HFSQL

Managing aliases on the data files

Managing connections

Managing space characters in the searches?

Managing the Unicode format in the HFSQL files

Managing the automatic identifiers when adding a record

Modifying the query content

Native Access access

Native XML Access

Optimizing the remote access

Partial indexing of memos

Remote access (RPC on HFSQL)

SQL functions: Special case

Search and full-text index

Synchronizing data (Windows CE)

The .REP file

The HFSQL views

The composite keys

The different types of browse available in SQL

Unalterable data files

WDModFic : Tool for automatic modification of data files

Overview
How to proceed?
Managing HFSQL thumbnails
WLanguage properties associated with the HFSQL thumbnails
Notes
Size of control displaying the image and size of thumbnail
Number of thumbnails
Limitations
Version 9 and earlier

WINDEV

WEBDEV

WINDEV Mobile

Others

See also

HFSQL thumbnails

Overview

To optimize the display of images in your application or in your site, you have the ability to use HFSQL thumbnails.

A HFSQL thumbnail corresponds to an image automatically generated from an image stored in a HFSQL binary memo. One or more thumbnails of different sizes can be generated for each HFSQL binary memo item.

For example, the "ProductImage" item allows you to generate two HFSQL thumbnails:

a small thumbnail used in a Looper control,
a larger thumbnail used in the product forms.

The thumbnail that best suits the control used to display the image will be automatically selected by the HFSQL engine.

Notes:

We advise you to display the thumbnails in a Thumbnail control (and not in an Image control).
The thumbnails are not available when accessing a database via Remote access.

To use the HFSQL thumbnails in Linux, the libfreetype6 library (libfreetype.so.6) must be installed on the current computer.

Versions 17 and later

This feature is now available for the iPhone/iPad applications.

New in version 17

This feature is now available for the iPhone/iPad applications.

Remark: From version 19, HFSQL is the new name of HyperFileSQL.

How to proceed?

Managing HFSQL thumbnails

To manage the HFSQL thumbnails:

In the data model editor, select the data file containing the HFSQL binary memo item.
Double-click the data file to display the description of items.
Select the requested item.
Check "Automatic management of thumbnails" and click the "Edit" button.
Specify the width and height (in pixels) of each thumbnail to generate.
Validate.

Note: The HFSQL thumbnails of an item are automatically generated:

when writing the corresponding record (HAdd or HWrite),
when modifying the value of the item (HModify),
during the automatic modification of data files.

WLanguage properties associated with the HFSQL thumbnails

The following WLanguage properties are used to manage the HFSQL thumbnails:


Versions 10 and later InfoThumbnailGeneration New in version 10 InfoThumbnailGeneration InfoThumbnailGeneration	..InfoThumbnailGeneration is used to find out whether the thumbnails of an item have been successfully generated.
Versions 10 and later MaxThumbnailHeight New in version 10 MaxThumbnailHeight MaxThumbnailHeight	..MaxThumbnailHeight is used to find out and modify the maximum height of an item thumbnail.
Versions 10 and later MaxThumbnailWidth New in version 10 MaxThumbnailWidth MaxThumbnailWidth	..MaxThumbnailWidth is used to find out and modify the maximum width of an item thumbnail.
Versions 10 and later NbDescribedThumbnail New in version 10 NbDescribedThumbnail NbDescribedThumbnail	..NbDescribedThumbnail is used to find out the number of thumbnails described for an item.
Versions 10 and later NbThumbnail New in version 10 NbThumbnail NbThumbnail	..NbThumbnail is used to find out the number of thumbnails generated for an item.
Versions 10 and later Thumbnail New in version 10 Thumbnail Thumbnail	..Thumbnail is used to: find out the value of an item thumbnail. This item was defined in the data model editor or by programming. find out and modify the image associated with a Thumbnail control.

Notes

Size of control displaying the image and size of thumbnail

The thumbnail that best suits the size of the control used to display the image will be automatically selected by the HFSQL engine.

If the size of the control used to display the image exceeds the size of the largest thumbnail, the image displayed in the control will correspond to the initial image found in the HFSQL binary memo.

Number of thumbnails

In most cases, one or two thumbnails are defined for each HFSQL binary memo. However, several thumbnails can be defined when the image is displayed in several controls of different sizes.

Note: The larger the number of thumbnails per item is, the larger the size of the corresponding HFSQL binary memo will be.

Limitations

The thumbnails are available:

in HFSQL Classic and in HFSQL Mobile: for the items found in a data file, in a view or in a query.
in HFSQL Client/Server: for the items found in a data file only.

The thumbnails are available in HFSQL Client/Server on the items of a data file.

Version 9 and earlier

The HFSQL thumbnails are not available in version 9 and earlier. Therefore, the records written by a HFSQL 9 (or earlier) engine cannot contain any HFSQL thumbnail.

The table below presents the use of binary memos and thumbnails in an application in version 9 (or earlier) and in an application in version 19 that uses the same data files:


	Application (or site) in version 9 and earlier	Application (or site) in version 19
New record written by a HFSQL engine version 9 or earlier	Image displayed: Binary Memo	Image displayed: Binary Memo
New record written by a HFSQL engine version 10 and later	Image displayed: Binary Memo	Image displayed: Thumbnail
Record written by a HFSQL engine version 9 (or earlier) and modified in version 19 (the value of the binary memo item is modified)	Image displayed: Binary Memo	Image displayed: Thumbnail