The mouse

xfig is drawn with three mouse buttons, and almost every mode gives each button a different job (left: the main action, middle: a variation, right: cancel or another variation). RustFig keeps that exactly. The mouse indicator in the top strip always shows what the three buttons do right now.

Getting three buttons

What the buttons do

The three functions of each mode are listed in the mode's section (shapes, splines, move, copy, delete and the other editing topics). Typical patterns:

• Drawing: left adds the next point or starts the shape, middle is a variation (freehand, from the centre) or the final point, right cancels.
• Editing: left acts on the object clicked, middle often acts on a copy or restricts a move to horizontal or vertical, right is a variation or region action.
• Regions: every region action ("tag region", "delete region", "move region", "update region", "delete in region") takes either a rectangle or a lasso. Click two corners for a rectangle, or press and drag to draw a free-hand loop (the lasso); everything inside is used.

Shift

Holding Shift changes a button's job in some modes. While Shift is held, the mouse indicator shows the Shift meanings (likewise Ctrl, and Ctrl+Shift, show those buttons' meanings):

• While drawing a polyline, polygon, spline or arc: Shift+left removes the last point ("del point"). Shift+middle (not for arcs) finishes the object at the last point placed, without adding the clicked point ("finish here", a RustFig addition).
• Box, Arc-box, Picture: Shift+middle draws a square from its centre.
• Edit attributes: Shift+middle shows the object's comments in the message panel.
• Locate object: in every mode that picks an object (Move, Copy, Delete, Edit, Flip, Rotate, Scale, Convert, Align, Break, Open compound, Join/Split, Chop, Add/Move/Delete point, Update, Arrow, Open/close, Tangent), Shift+left click highlights the object under the pointer (its markers turn filled) without acting on it. Shift+left again highlights the next object under the pointer, front to back; after the last one the pointer position itself is marked, and the next Shift+left starts over. A click without Shift then acts on the highlighted object, not on the front-most one. This is how you reach an object hidden under another one. Changing the mode forgets the highlight. Shift+middle and Shift+right do nothing in these modes (xfig locates with every button; RustFig keeps them free for later use), except where xfig gives them their own meaning: in Edit Shift+middle shows the object's comments, and in Rotate and Flip Shift+right sets the centre or anchor, like the right button.

Ctrl

Holding Ctrl (Cmd on macOS) shows xfig's zoom functions: left starts a zoom box, middle pans to the origin, right unzooms (Zoom and view). With Ctrl and Shift in the editing modes, a click on a spline point changes its shape factor (Splines).

Markers and tags

In the editing modes small hollow squares (markers) sit on every object the mode can act on, so you see what to click. Markers stay while a mode waits for its next click (Join's second end, Chop's log, Align's object). Tagged objects show filled markers: objects you tagged with Glue or selected with Select, and the parts of a compound broken with "break and tag". Only Select, Glue and Break tag objects; the other modes act on the object you click and leave the tags as they are, so drawing or editing never tags anything by itself.

Clicking and dragging

Most placing operations work either way: press, drag and release, or click once to start and click again to finish. A click without movement picks the object under the pointer; the pointer picks within a few screen pixels of the line.

Wheel and trackpad

Scrolling pans the canvas, Ctrl+scroll or pinching zooms, and holding Space while dragging pans. On a touch screen, two fingers pan and pinch zooms, and holding one finger still for half a second acts as the right mouse button.