C. The user interface The comfortab

C. The user interface
The comfortable and intuitive user interface was one of
our main objectives in developing Higres. The system's main
window contains a toolbar that provides a quick access to
frequently used menu commands and object type selection
for creation of new objects. The status bar displays menu and
toolbar hints and other useful information on current edit
operation.
The system uses two basic modes: view and edit. In the
view mode it is possible only to open/close fragments and
fragment windows, but the scrolling operations are extended
with mouse scrolling. In the edit mode the left mouse button
is used to select objects and the right mouse button displays
the popup menu, in which the user can choose the operation
he/she wants to perform. It is also possible to create new
objects by selecting commands in this menu. The left mouse
button can be also used to move vertices, fragments, labels
texts and edge bends, and resize vertices and fragments. All
edit operations are gathered in a single edit mode. To our
opinion, it is more useful approach (especially for
inexperienced users) than division into several modes.
However, for adherents of the last case we provide two
additional modes. Their usage is optional but in some cases
they may be useful: the "creation" mode for object creation
and "labels" mode for labels editing.
Other interface features include the following: almost
unlimited number of undo levels; optimized screen update;
automatic elimination of objects overlapping; automatic
vertex size adjusting; grid with several parameters; a number
of options that configure the user interface; online help
available for each menu, dialog box and editor mode.