★ APPLICATIONS ★ DIVERS ★ MENU UTILITY ★ |
| Menu Utility (The Amstrad User) | Applications Divers |
The following two modules can be used whenever you need a menu for any program. They evolved because I am currently writing business application packages. I wanted all any menus to have only alpha-key selection, as I dislike saving menus with 1, 2, 3 etc. I wanted to be able to use the command "ON A GOSUB 1000, 2000, 3000 " etc. but this only works with numeric inputs. So the problem was that I needed to convert alpha inputs to numeric codes. Hence the line A-(ASC(A$)-64, lis converts alpha inputs to numeric inputs.. The ASCII code for Capital A is 65, so when you hit "A" le program takes it as 65, subtracts 64 and leaves it as 1, input B as 2 etc. I had to ensure that all inputs were uppercase - this was easy with A$=UPPER$(A$). With that problem solved, I wanted the cursor flashing on-screen when waiting for an input. This was solved with a simple little sub-routine which locates where you want the cursor to appear, prints the cursor, drops to the delay sub-routine, returns, prints CHR$(8) which brings the print position back one space en prints CHR$(16) which blanks out the cursor, the program then drops to the delay sub-routine again, and turns to the line that starts the process over again, The line IF A$<>"" THEN RETURN, ensures that the subb-routine keeps looping until an input is detected. When a input is detected it returns to the routine that handles the put. I have written three routines (two are presented in this article), "MENU/10" for MODE 1 with a menu for 10 options. The next "MENU/13" for MODE 2 with a menu for 13 options. I've included quite a few REM statements to hopefully explain what is happening throughout. I have set myself up with a complete bank of these routines, when I need a menu with anything from 2 to 20 options I just MERGE them from tape, (soon to be disk). I have used CHR$(224) for my cursor, I plan on using this cursor as a feature of all my packages so 1 would appreciate it if other writers choose another character. I hope someone can use these little routines, I enjoyed writing them a great deal. I am still refining them as I am trying to get the response delay a little shorter, maybe someone else has got some ideas. By the way, I didn't invent the flashing cursor sub-routine, part of it came from "AMSTRAD COMPUTING" by Ian Sinclair. This is a top book, I cannot recommend it highly enough. NOTES
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