Xic is most efficiently used with a three-button mouse, trackball, or other input device. The three buttons are normally numbered from the left, with the mouse pointing upward. This manual will refer to buttons by their number according to this convention.
A two-button mouse, as commonly used with PC hardware, does not provide button 2 (the ``middle'' button). Although a three-button pointing device is recommended, in current Xic releases the important button 2 operations can be simulated using button 1 or 3, while holding a modifier key. Thus, for many users, a two-button mouse should be entirely adequate.
In short, button 1 is used for basic point and click operations and menu selections. The middle button, button 2, is used for pan operations in drawing windows, and the right button, button 3, is used for zooming in the drawing windows.
In addition, drawing windows respond to mouse wheel events. The basic action is vertical scrolling, however if Shift is held, the window will scroll horizontally. If Ctrl is held (which overrides Shift) the display will zoom in or out. The mouse wheel sensitivity can be changed with the MouseWheel variable. A mouse wheel will also provide scrolling capability in text windows and the help viewer on most systems.
Button 1 (the left button) is used for point operations in the drawing windows, and for activating command buttons and sliders in menus and pop-ups. In most cases, a ``point operation'' can be effected in two ways: click twice, or hold and drag. If the pointer does not move too much as button 1 is pressed and released, a single point is defined, and most commands will prompt the user to point a second time to complete the operation. If button 1 is held while the pointer moves, upon release the operation is completed, using the press and release coordinates. A rectangle defining the two positions is typically ghost-drawn while the point operation is in progress.
The delay interval which is used to differentiate a ``click'' from a ``hold'' or ``drag'' can be adjusted by setting the SelectTime variable with the !set command. The default value is 250 milliseconds, and the adjustable range is 100-1000 milliseconds. Some users may find that setting the delay to a larger value improves the ability to differentiate between the operations described below.
Outside of any command, button 1 performs selection, move/copy, and stretch operations. The Shift and Ctrl keys act as modifiers for the button 1 presses. The following sections describe the normal operations.
If Shift, Ctrl, and Alt are all held while button 1 is pressed, a ``no-operation'' (button 4) press is simulated. This performs no action, but updates the coordinate readout window.
If Shift and Ctrl are both held while clicking on a physical cell instance or electrical subcircuit, a sub-window will appear containing the contents of the subcell or subcircuit. In electrical mode, the new window will display the subcell schematic, and be a proxy for the main window for hypertext, including plot reference points. Clicking in the sub-window will assign hypertext reference points, as if one clicked in the main window (see 3.1.3). This is how one can get hypertext references of assign plot points from a cell that is shown as an instance symbolically.
Clicking on a selected non-pcell instance with only the Ctrl key held will bring up the Property Editor panel (see 10.10), with the clicked-on instance as the current object. If the instance is a pcell instantiation, the Parameters panel (see 5.3) appears, allowing the user to reparameterize the instance.