Purpose: Create and design a drawing program simmiliar to paint, utilizing a GUI (Graphical User Iterface).
Operations:
• draw line
• draw triangle
• draw polygon
• select/unselect one-to-many objects at a time
• delete one-to-many objects at a time
• insert label
• save
• open
• undo/redo
• move
Drawing a Triangle:
• The triangle is specified by clicking on three points. The system responds
as follows: Button click changes cursor. Shows a point after one click; after 2 clicks, shows a line
between two clicked points; after 3 clicks, shows triangle and cursor returns to default. Undo/Redo
should remove/restore entire triangle.
Drawing a polygon:
• Button click changes cursor. After one left click, show point; after 2 left clicks show line; add a line
after each left click. If right button is clicked, a line is added between first left click and the last
left click and cursor returns to default. Undo/Redo should remove/restore entire polygon.
Moving an item:
• Some item(or items) have to be selected when move is invoked; otherwise move has no effect. When
the move button is clicked, cursor changes. Mouse has to be clicked, dragged some distance, and
released; all the selected items will be translated by that distance. Note that if mouse is clicked
at (x1, y1) and released at (x2, y2) all the selected items must be translated by (x2-x1),
(y2-y1). This will require that all items have a translate() method; see how the Delete operation
is implemented for a similar example. Undo/Redo should reverse/repeat the translation.
Drawing Panel:
