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 are the fine and precise configuration of these tools.
Configuring tool parameters can happen anywhere; from almost continuously during a work session - to once in the users lifetime.
Changing tool set-ups will never break the user’s workflow.