QDrop is available for MacOS X (Tiger or later) and Windows (XP/Vista), and is compatible with 4D versions 2004.x to 11.x SQL or later.

QDrop offers a plug-in area that you can put on any 4D form and use as a drop zone. The QDrop area can be made big enough to cover the entire form window, or it can be placed behind specific form objects, other plug-in areas, and so on. QDrop can easily revamp those parts of a database that involve working with files and folders, and is particularly suited to image databases.

How it works

Each QDrop area can be configured to accept specific classes of files, using either filename extensions (on both platforms), or Uniform Type Identifiers (only on MacOS X). Note that 4-character MacOS filetypes are deprecated and they should no longer be used.

Instead of specifying individual file extensions, QDrop provides special constants called "magic file types" which collectively represent entire classes of files. Magic file types are:

• any* denotes that all files are accepted
• fold denotes that folders are accepted
• qti* means that all images understood by QuickTime are accepted (requires QuickTime)
• qtm* accepts all movie formats understood by QuickTime (requires QuickTime)

If, for example, you want to use QDrop for importing image files that you will subsequently handle with QPix, you don't need to configure the drop area separately for JPEG, GIF, PICT, TIFF, etc files. Simply configure it for "qti*" and all these types will be accepted. UTIs are also very handy for doing this (using, e.g. the "public/image" type), but they exist only on MacOS X.

Visual feedback as a result of accepted drop actions is customizable by the developer (width, color, inset).

Once accepted drag types are configured, the QDrop area will automatically react to the designated objects and also:

• users will get a visual feedback that the drag+drop is accepted
• developers will receive a drop event and they will be able to program how the drop action should be handled. .