>Interaction hints<p>>Another interesting thing here is that when you do something like drawing a line, for example, you get these nice visual hints here, just above the status bar:<p>>Interaction hints<p>>The idea is coming from Blender obviously, and it would make a lot of sense to use this in applications like GIMP and Inkscape. Here is a good reason why.<p>The first place I ever saw this feature was on the Lisp Machine. It was called the "mouse-documentation" line.<p>Operating the Lisp Machine:<p><a href="http://bitsavers.informatik.uni-stuttgart.de/pdf/symbolics/LM-2/Operating_the_Lisp_Machine.pdf" rel="nofollow noreferrer">http://bitsavers.informatik.uni-stuttgart.de/pdf/symbolics/L...</a><p>>1.3 The Mouse (pp. 3)<p>>The mouse is a pointing device that can be moved around on a flat surface. These motions are sensed by the Lisp Machine, which usually responds by moving the cursor around on the screen in a corresponding manner. The shape of the cursor varies, depending on context. See chapter 10, page 40.<p>>There are three buttons on the mouse, called Left, Middle and Right. They are used to specify operations to be performed. Typically the user points at something with the mouse and specifies an operatin by clicking the mouse buttons. Rapid double clicks are conventionally distinguished from single clicks. Thus, in any specific context, there are up to sex operations that can be performed with the mouse, invoked by Left, Left Double, Middle, Middle Double, Right, and Right Double. Some of these operations are local to particular programs such as the editor, and some are defined more widely across the system.<p>>Typically operations available by clicking the mouse button are listed at the bottom of the screen. This display changes as you move the mouse around or run different programs.<p>>Sometimes holding a mouse button down continuously for a period of time may also be defined to perform some operation, for example drawing a curve on the screen. This will be indicated by the word "Hold". For example, "Middle Hold" means to click the middle mouse button down and hold it down, releasing it only when the operation is complete. "Left Double Hold"means to click the left mouse button twice, holding it down the second time until the operation is complete.<p>>Occasionally a long click is distinguished from a short one, as a Morse Code dash is distinguished from a dot. In cases it doesn't matter exactly how long the button is held down, as long as it is perceptibly longer than the usual rapid sgtrike. Such a click will be described by the word "Long" as in "Right Long".<p>>The mouse is completely "soft", like the keyboard: The Lisp Machine can be programmed to interpret the mouse in any desired fashion. The protocol that has been chosen, however, is extremely general and should suffice for almost all needs.<p>[...]<p>>2.1 The Geography of the Display [...]<p>>2.1.2 The Who-Line and Run-Lights (pp. 5) [...]<p>>Above the who-line there is a line of mouse-documentation, which is displayed in inverse video to make it easy to move your eyes to it from someplace else on the screen. This line tells you what the buttons on the mouse would do if you clicked them with the mouse where it currently is. If the line is blank, it means the default mouse buttons are in effect; clicking Left will select the window pointed-to, and clicking Right will get you the system menu (these are explained later).