Work in progress
Tool options widgets
All UI elements are built from a few basic UI building blocks called widgets. A list with images of all current available GTK+ 2 widgets can be found at  and their respective GTK+ 3 counterparts at . Since GIMP has special needs it also has quite a few widgets of it's own, a number of them (the external accessible ones) can be found at . GIMP also has a number of additional internally used widgets, quite a few just extend basic GTK+ widget for specific needs, without altering the visual look and feel. However, there are also completely new widgets for specific needs like those used for pressure curves or the gimpspinscale a mix of a spin and scale button that can be found in a lot of tool options. A third category are meta widgets that mix together a few basic widgets in a certain fashion for a particular purpose, an example is the gimpscaleentry which consists of a label, scale slider and spinbutton (look at Tools->Color Tools->Brightness-Contrast menu). An exhaustive list is unneeded as most tooloptions only use a rather basic subset of aforementioned widgets, the following table is a list of those common widgets used in tool options and their GIMP counterparts.
Tools in GIMP enable hands-on manipulation of the compostion, direct on the canvas.
The tool options enable the fine and precise configurations that make the tool fit the job.
Configuring tool parameters can happen anywhere from; almost continuously during a work session - to once in a user's lifetime.
Changing tool set-ups will never break user’s workflows.