Introduction

DFRM stands for Dynamic FoRMs. It allows to GEM programmer to build dynamically forms without using an external resource file and then an resource editor. Menu object trees are handled too. This approach has several advantages :

• DFRM handles position and alignment of objects that facilitates the work of resource designing (it is an awfull and hard work with a resource editor).
• As DFRM is dynamic, programs having to build its forms depending on its execution can find with DFRM a very powerfull solution.
• Like external resource, DFRM can specified object coordonnates in pixel unit or in unit depending on screen resolution (only usefull for the old ST-low and ST-middle resolution) or on the size of system used.
• It is very efficient to write macro objects (see functions like dfrm_new_slider()) as ''ready to use'' objects. In a resource editor you have to copy-paste, change size, ...

However, one can argue the support of multilanguage is not so easy as well as using a loadable resource. But using the small program 'dfrmstr' provided in these package, a simple text editor and a make program, the maintenance of multilanguage become easier than the classic way with an resource edit (see lang.c example).

The usage of DFRM is very similar to libraries such as GTK (for X-windows): individual objects are created then added in a hierarchical object tree. Directives of spacing between objects, alignement and justification can be set.

Using the powerful facilities of event catching of WinDom, functions and data can be attached to each object in a form. In fact, usage of catching event function is really necessarly because there is no natural way to know before form building the index of objects (objects are dynamics). Then the classic handling of form events (object selection) can not be performed via a C-switch statement.

To finish, this library is designing to work with WinDom but an adaptation to other GEM libraries will be very easy. In the same idea, if you want adding custom object, look at, for example, the source of dfrm_new_text() in dfrm.c, it is really easy !

Have fun! Dominique Béréziat, October 2002.