Toolbar and menus
A toolbar and two menus provide access to commands and configuration options. An information bar gives data on the state of play for the current puzzle.
The Toolbar is a set of buttons which execute the most common program commands:
- Undo until consistent(<<)
- Give hint(?)
- Apply simple filter exhaustively(s)
- Simple filter(S)
- Naked pairs(N2)
- Naked triples(N3)
- Naked quads(N4)
- Hidden singles(H1)
- Hidden pairs(H2)
- Hidden triples(H3)
- Locked candidates 1(L1)
- Locked candidates 2(L2)
The File menu provides access to new puzzles, allows puzzle saving, checks puzzles for having a unique solution, controls the difficulty rating system, controls the help and hint status, sets cell and candidate colours, sets the symbols used, the current hint search strategy and allows general configuration.
The Edit menu contains exactly the same options as those available from the Toolbar.
The five numbers at the base of the puzzle grid give the Puzzle Number, the number of steps taken by the user (Clicks), the number of states recorded (History), the remaining "Information content" of the puzzle and the number of seconds (Time) since the puzzle was started.
Almost all the parameters which govern the look of the program can be set by the user and so the program can take on many appearances. Via the Configure panel (Figure 2.) the user can set twelve numerical variables, three font sizes, three relief values; and thirteen colourings can be set to any of 216 shades. Note that the font for the Toolbar is also used for the "Show difficulty" and "Select puzzle" windows. The selected settings can be saved to a file which is named .sg_preferences.txt. When the program starts it automatically looks for this file and, if it is found, loads its values. The names given to the variables are close to those used by the Tk language. If their meaning is not obvious, try changing them and see what alters. "Little buttons" refers to the candidate buttons, "Big buttons" the big buttons in the centre of each cell. Unless the corresponding "borderwidth" is non-zero, changing relief values will have no effect.
Default font sizes
Some people have complained about the default font sizes which appear the first time SourGumdrop is run. For most they are too small, but were chosen to fit on laptops with small screens. Please use the "Configure SourGumdrop" option in the File menu to the set the fonts to an appropriate size for your screen. The "Save" option will make sure they are used in future.
Although the symbols 1-9 are the most widely used characters for Sudoku puzzles, via the File menu option "Set symbols: letters" the program provides the option of switching to grids written using the letters 'E','T','A','O','N','I','H','S','R'. This can be reversed with the option "Set symbols: numbers". Some may find it quite disconcerting: their pattern spotting ability suddenly greatly diminished. So, a useful option for jaded experts? An example is shown in Figure 3.
When the user requests a hint the program searches using one of two strategies. The first, Most effective, finds the hint which can remove the most candidates. The second, Simplest hint, finds the least difficult hint - i.e. the one with the lowest algorithm score. The choice of which one to employ is set using the "Set search strategy" option in the File menu.