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Centiwrite 1.10 Developer's Kit and User's Manual Both Items Copyright 1988 Andrew M. Saucci, Jr. Note that you may also inspect the copyright notice of the file CENTWR55.TPU by entering "copy centwr55.tpu /b con" at the DOS prompt. Ignore all the beeping and stumbling and wait for this command to finish executing. Also, if your copy of the compressed version of the Kit is named "CWDKIT.ARC" you should rename it "CWDKIT55.ARC". **************************************************************************** Centiwrite 1.10 Developer's Kit User's Manual ========== ==== =========== === ====== ====== Copyright 1988 Andrew M. Saucci, Jr. What's to Follow 1. Introduction 2. About the Author 3. The Interface of the Unit 4. What You'll Need to Compile 5. The Basic Principles 6. A Sample Calling Program 7. Analysis of the Sample Program 8. The Initial Values 9. Initializing the Array 10. How to Overlay the Unit 11. Compatibility Consideration 12. For Extra Punch in Your Program 13. Down to Brass Tacks 14. Boilerplate 15. To All Those Who Helped 16. Coming Attractions 17. It's Alive! ============================================================================= Introduction Congratulations on having acquired this useful developer's tool. Now you can have an "instant editor" in your own programs whenever you need to include the capability to create short memos, notes, or letters. This file will attempt to show you how to incorporate the Centiwrite 1.10 editor into your Turbo Pascal programs. If you are unfamiliar with this editor, you should definitely obtain a copy of the stand-alone version of Centiwrite and read its User's Manual. This explains in detail the operation of the editor. Of course, as a "developer" (one of the initiated), you'll gain access to some features not used in the stand-alone version. ============================================================================= About the Author Andrew M. Saucci, Jr. was graduated with distinction from the New York Institute of Technology with a master's degree in computer science. He received a bachelor's degree in computer science from Hofstra University. A member of the Association of Shareware Professionals (ASP) and the Association for Computing Machinery (ACM), Mr. Saucci has programmed in Turbo Pascal for over one year. He is also the author of the program The Holy Rosary. Mr. Saucci can be reached at any of the following electronic mail addresses: CompuServe 72117,241 Delphi ASAUCCI Genie A.SAUCCI3 BIX ASAUCCI Comments about any of his products are most welcome; however, please allow one week for a response to your initial inquiry. After that, an "active" mailbox is checked daily. Also, for guaranteed service, use the regular mail facility of your service rather than a bulletin board area, or send a regular mail note saying to check the bulletin board. One week is a "worst case" situation. Often, mailboxes are checked more frequently. ============================================================================= The Interface of the Unit unit centwr55; interface uses dos, crt; type scarray= array [1..62] of string[85]; commstruc= record screline: scarray; lastring, initWhereX, initWhereY: byte; CurAttr, StdAttr, MessAttr, WarnAttr: byte; passkey: integer; TimeOutInterval, NextTimeOut, oldhours: word; BlankChar: char; insmode, RetCtrlKeys, ShowStatusLine, TimeOut: boolean; end; function nextword (sentence: string): integer; function lastword (sentence: string): integer; function isletter (charcode: char): boolean; function isdigit (charcode: char): boolean; function datestring: string; function timestring: string; function CheckSumVidBuf (x1, y1, count: byte): word; function BufChar (xlimit, ylimit: byte): byte; procedure AnalyzeKey (var inkey: integer; var scancode: byte); procedure DelWord (var sentence: string; position: integer); procedure Centiwrite (var infoexch: commstruc); implementation { Implementation would follow here. } Each of the variables used in the "commstruc" (for "communications structure" record is described below. screline: The strings which represent each line of the text to a maximum of 62. This accomodates 25-, 43-, and 50-line screens. lastring: The number of currently "valid" strings in screline. Because a line consisting solely of a carriage return (ASCII 13-10) is represented by a null string, "lastring" indicates how many lines of screline are currently being used. Note that in an empty file, lastring is 1. initWhereX: The initial x-coordinate of the cursor on entry to the editor. initWhereY: The initial y-coordinate of the cursor on entry to the editor. CurAttr: The color attribute of the cursor. You can use any valid attribute. If the foreground and background are the same, the Centiwrite editor assumes that the blinking hardware cursor is being used, and the software cursor is disabled. The cursor will appear as a blinking CHARACTER if a background color greater than 7 is used. StdAttr: The normal color attribute of the editor. MessAttr: The color attribute for messages which appear on the status line. WarnAttr: The color attribute for the word "Overstrike" when visible. TimeOutInterval: The number of minutes between timeouts. If this is set to zero, timeouts are disabled. NextTimeOut: Time in minutes of the next timeout. If the next timeout is at 4:43, this variable could have the values 43, 103, 163, ... through 65535 (the maximum for a word), or (43+ 60*n), where n is the number of hours to the next timeout. On the hour, NextTimeOut is decremented by 60 (if it exceeds 59). oldhours: Hours at the last time check. This is passed as part of the structure because the calling program must initialize it before the first call to Centiwrite. You should re-initialize it if you leave Centiwrite for more than an hour. Basically, this is used as a "rollover" flag. passkey: The character passed back to the main program when Centiwrite does not define a function for it. (This is now an INTEGER.) BlankChar: The character that is displayed at the cursor position when the character at that position is either ASCII zero, ASCII 32 (blank), or ASCII 255. All of these normally appear as a blank, and you may need to choose an alternate character, particularly for those using monochrome monitors. You may select any character except ASCII 7, 8, 10, or 13. insmode: If true, then the editor is in Insert mode. Otherwise, Overstrike mode is used. RetCtrlKeys: Set this to true if you want control keys (ASCII 1 to 31, except 8, 9, and 13) returned to the calling program. Otherwise, set it to false so that Ctrl-L, for example, will insert an ASCII 12 (form-feed). Even if control keys are returned, using the Alt+ numeric keypad method of entering characters will always insert the appropriate character, except for ASCII 7, 8, 10, and 13, which are ignored. Backspace, Tab, and Enter are never returned this way. ShowStatusLine: Set this flag to true if you require the status line, which shows the current state of Insert/Overstrike and the current position on the screen. If this is set to false, no status line is displayed and the top line is available for editing. When ShowStatusLine is false, the Insert key is returned to the calling procedure for action, so that any display or indication of the Insert/ Overstrike mode that the caller maintains (in lieu of the status line) may be updated by the caller. Also, the F5, F8, and Ctrl-F8 keys are ignored (because they use the status line for their display). TimeOut: When set to true, TimeOut indicates that the calling procedure has received control on account of a timeout, and that the appropriate timeout procedures or functions should be executed. Otherwise, the caller received control because of an unrecognized or Ctrl-key. The functions and procedures which are included are summarized next. nextword: Returns the position of the next word in a string. In the string "for he's a jolly good fellow", nextword returns 4. If no "next word" is found, the return value is the length of the string plus 1. lastword: Returns the position of the last word in a string. In the string "which nobody can deny", lastword returns 18. If the string is a single word, the return value is 1. datestring: Returns the current system date in the form "Monday, May 26, 1988". timestring: Returns the current system time in the form "10:45:44 PM". CheckSumVidBuf: Returns a checksum of the characters in the video buffer starting at a given location (in REAL coordinates-- not those recognized by the CRT unit) and continuing for count characters. This procedure is not used by the editor, but is included because it is important to all programmers who want to discourage tampering with their programs. (Real coordinates start at 0,0 and are not relative to the current window.) BufChar: Returns the character at the cursor location and advances the cursor one column to the right, or to the beginning of the next line. "xlimit" is the x-coordinate (again, in real coordinates) at which the cursor should wrap to the next line. "ylimit" is the y-coordinate of the bottom of the screen. If the cursor is in the lower right corner of the screen, the character is returned but the cursor is not advanced. This function is also not used by the editor, but it is the function that the stand-alone version of Centiwrite uses to load a screen into the editor. Now you can use it, too! AnalyzeKey: Substitute keyboard reading procedure (for ReadKey). A single call returns all pertinent keyboard information-- no need to make multiple calls to check for extended key codes. Extended key codes are returned in inkey as values in excess of 255-- for example, F6 is returned as 322. Note that "inkey" is an INTEGER variable. To get the value returned in "inkey", add 256 to the extended key code (F6 is 322, or 64+ 256). This procedure is now written in assembly language for extra speed. DelWord: Deletes the word starting at a given location in a string. Centiwrite: The editor itself. ============================================================================= What You'll Need to Compile In order to compile a program using Centiwrite, you need to copy CENTWR55.TPU into the directory where Turbo Pascal normally looks for your .TPU files. In version 5.5, this is one of the EXE & TPU directories specified under the Options/Directories menu selection. You will also need to add the line "uses centwr55;" to the the source file of the procedure that calls the editor. Check your Turbo Pascal manual for additional information on including units in your programs. Oh, yes, you'll also need Turbo Pascal version 5.5. For those concerned about needing to recompile for future versions of the compiler, the current plan is to update the unit whenever a new version of Turbo Pascal is released. Upgrades will be available for a modest charge. With the advent of Turbo Pascal 5.5, units may incorporate object- oriented programming techniques. This means that a unit such as this one could be distributed as a .TPU file, yet a user could make changes to it without the need for the source code. If possible, the Developer's Kit will be revised to take advantage of this opportunity. ============================================================================= The Basic Principles The Centiwrite editor is based upon an "array of strings" implementation. While not suitable for a large text editor or word processor, this approach is quite adequate for a simple program such as this. It allows a "quick and dirty" style, and is easily understandable. Each element in the array of strings represents a line of text on the screen. An "implied" carriage return ends each line. A count of the current number of lines is maintained at all times. A duplicate array is maintained in memory in order to facilitate the "Undo" feature (invoked by F3). Some may wonder why the video memory is not used to store the text, considering that the text is stored there anyway. Use of character strings allows the use of Turbo Pascal's string-handling procedures. Using video memory would mean writing substantially more code in order to duplicate the functions already available in the runtime library. This code would not only make the program larger, but would also need to be debugged. The Turbo Pascal string-handling routines (while not perfect) are already thoroughly debugged. ============================================================================= A Sample Calling Procedure The following program is an example of how to call the editor. program CallEditor (input, output); uses dos, crt, centwr55; var reg: registers; origcx: word; cwinfo: commstruc; i: byte; hours, minutes, seconds, hundredths: word; procedure SaveFile; begin writeln ('Code for saving a file would be here.'); delay (2500); end; procedure HelpProcedure; begin writeln ('Help! Help!'); delay (2500); end; begin reg.ah:= $03; reg.bh:= $00; intr ($10, reg); { Save old cursor } origcx:= reg.cx; reg.ah:= $01; reg.cx:= $2000; intr ($10, reg); { Disable hardware cursor } with cwinfo do { Allows unqualified variable references. } begin insmode:= true; { Initialize structure variables. } initWhereX:= 1; initWhereY:= 1; CurAttr:= $70; { Black on LightGray } StdAttr:= $17; { LightGray on Blue } MessAttr:= $20; { Black on Green } WarnAttr:= $4F; { White on Red } for i:= 1 to 25 do screline[i]:= ''; { empty file } lastring:= 1; passkey:= 0; RetCtrlKeys:= false; ShowStatusLine:= true; BlankChar:= #32; { pick the blank character because of the CurAttr we used } TimeOutInterval:= 5; { causes a timeout every five minutes } GetTime (hours, minutes, seconds, hundredths); NextTimeOut:= minutes+ TimeOutInterval; { set first timeout } oldhours:= hours; { initialize rollover flag } repeat window (1, 1, 80, 25); TextAttr:= $07; ClrScr; writeln ('Joe''s Program: Centiwrite Editor-- Alt-X to Exit'); window (1, 2, 80, 25); Centiwrite (cwinfo); { <------------- PLUG-IN EDITOR } window (1, 1, 80, 25); TextAttr:= $07; if TimeOut { Short-circuit the other tests-- passkey contains } then begin { values which have already been processed. } passkey:= 0; end; if ((passkey= 346) or (passkey= 316)) or (TimeOut) { If Alt-X, F2, or TimeOut, save the file. } then SaveFile; if passkey= 315 { F1 displays a list of keys and their functions. } then HelpProcedure; until ((passkey= 288) or (passkey= 346)); { Alt-D or Alt-X (exit condition) } end; { with statement } ClrScr; reg.ah:= $01; reg.cx:= origcx; intr ($10, reg); { restore cursor } end. { program } ============================================================================= Analysis of the Sample Program Take a close look at the sample program. Although it has been simplified in order to highlight the main points, its basic structure is the same as that of the stand-alone version of Centiwrite 1.10. You should be able to compile and run it. It gives initial values to the members of the structure, and then runs the editor in a repeat..until loop. Why a loop? This is the means you can use to add your own "frills" to the editor. Any time the Centiwrite editor sees a key that it does not recognize, such as F9, Alt-Z, or PageDown, the editor terminates and control returns to the calling procedure. Placing the editor in a loop gives you a chance to execute whatever procedures or functions you like before RETURNING control, or exiting if you like. For example, Alt-X is the "recommended" exit key. The editor takes no special action on seeing Alt-X; it merely exits just the same as it would for any other unrecognized key. The "until" condition "passkey=288" is what causes the sample program to terminate. To use F10 as an exit key, just change the condition to "passkey=324". Likewise, what displays help is "passkey=315"; to use Shift-F1, change to "passkey=340". Note that the editor recognizes all keys that return an ASCII value plus the following extended keys: arrow keys Shift-Tab Ctrl-Left arrow Alt- B E H T V Y Insert Home/End Ctrl-Right arrow F3 F5 F7 F8 Delete Ctrl-Home/End Ctrl-F8 The calling procedure is passed any other keys and may deal with them however it sees fit. The variable "passkey" will hold the value of the last key pressed. By using the flag RetCtrlKeys, you can specify additional keys to be returned. Notice the "window" statement just before the call to Centiwrite. This is absolutely necessary in order for the editor to establish its window boundaries and insure the integrity of its screen. The editor can operate in a window no narrower than 40 columns. It has not been tested in windows of fewer than 24 rows; however, it should work for any number of rows. (For a single row "window" you should use "liminput", the complete source code to which is found in the Deciwrite Developer's Kit.) If you specify a window size of fewer than 40 columns, greater than the screen width, or greater than the screen height, the result is unknown. The Centiwrite editor redraws its window each time it is called, and it leaves the screen in place when it exits. Therefore, you can put a window over it without any trouble. ============================================================================ The Initial Values The most important value in "commstruc" is "lastring". If you use an invalid value for lastring, the editor will become confused and behave erratically. Lastring should be 1 for an empty file. Otherwise, it reflects the number of currently valid strings in the array "screline". Example. If screline is this (line numbers added): [1] Now is the time for all good people. [2] We must mobilize now. [3] [4] May we have your support? then lastring is 4. If two carriage returns are added after line 4, as in [4] May we have your support? [5] [6] then lastring is 6. Lastring should only be changed when the number of lines in the text is changed. Here's an important note about carriage returns. The Centiwrite editor does NOT add the ASCII 13-10 combination explicitly to the text. Every string ends in an IMPLIED 13-10. If you write a file to disk, you must add the 13-10 yourself. This is easily done using a "writeln(screline[i])"-type statement. You need not delete a 13-10 on input, however, as the editor automatically removes these (as well as ASCII 7 and 8) from the text. You should, however, take care to format the input strings so that they do not contain embedded carriage returns that really belong at the end of a line. InitWhereX and initWhereY are used to position the cursor when the editor is called. For the first invocation, each of these should usually be set to 1, although any valid values are acceptable. Never position the cursor below the row "lastring", or erratic operation will result. When the editor passes control back to the calling procedure, the current cursor position is saved in initWhereX and initWhereY. It can then be reused if necessary when the editor is called again. Pressing F9 demonstrates this simply. The cursor position is saved; the editor returns control to the main program; the main program ignores the key (because no function has been defined for it there, either); and the editor regains control, positioning the cursor at the saved location. Insmode, as explained earlier, is simply a flag. It's your choice-- set it however you like depending upon whether you want to start the editor in Insert mode or Overstrike mode. Passkey must be initialized. If a timeout occurs before the first key is pressed, the internal check of passkey will fail if passkey contains garbage. You must also initialize BlankChar, RetCtrlKeys, and ShowStatusLine. They are explained previously. You do not have to initialize TimeOut, because it is set to false each time the editor is called. ============================================================================ Initializing the Array You must initialize "screline" before using it. This can be done any way you like-- with assignment statements, reads, Move, etc. You should assign an initial value to "maxline" elements in screline, where "maxline" is equal to the maximum number of lines on the screen plus 1. Be sure to keep "lastring" synchronized with the actual number of elements of screline in use. ============================================================================= How to Overlay the Unit This unit is compiled using {$O+}. This means that you may overlay it using the methods outlined in Chapter 13 of the Turbo Pascal Reference Guide, just as you would do for any other unit compiled with {$O+}. If you do not want to overlay the unit, simply ignore this feature. While it has not been tested as an overlay, it should work just as well either way. ============================================================================= Compatibility Consideration The Centiwrite editor uses direct screen writes (through Turbo Pascal's CRT unit). This may cause problems, particularly with windowing environments such as Desqview or Concurrent DOS. If you need to write to the screen using the video BIOS functions, place the line "uses crt" in your main program and set the built-in CRT variable DirectVideo to "false". Otherwise, DirectVideo will be assumed to be "true". ============================================================================= For Extra Punch in Your Program If you want to use a "plug-in editor" in your program, but feel Centiwrite just isn't powerful enough, don't walk away feeling dejected. Here's good news! Also available is an editor similar to Centiwrite but ten times as powerful. It's Deciwrite! The Deciwrite Developer's Kit includes all the features of Centiwrite PLUS: 1. Automatic word wrap and paragraph reformatting. 2. Full support for binary files. 3. Time and date can be inserted into the text with one keystroke. 4. Full source code-- including liminput, a replacement for readln; dectohex and hextodec, hexadecimal conversion routines; and FileCheck, which checks for the existence of a file and determines if it is read-only; and more! What's more, if you're not sure, you can "lock in" the price of the Deciwrite Developer's Kit by buying the Centiwrite Developer's Kit NOW. You'll have one year to upgrade at the current price (plus $1 for shipping), PLUS you get a credit for what you paid for the Centiwrite Developer's Kit. What's to lose? Send electronic mail to the addresses listed earlier to learn how to take advantage of this great offer. Don't forget, too, that the Deciwrite Developer's Kit comes with a 30-day money-back guarantee no matter when you buy it. ============================================================================= Down to Brass Tacks As of July 1, 1989, this is the Centiwrite/Deciwrite price list. Individual License Site License *# Centiwrite 1.10 $20.00 $250.00 # Deciwrite 1.10 $30.00 $500.00 Deciwrite 1.10 Demo Disk $ 4.00 ******* *# Centiwrite 1.10 Developer's Kit $32.50 $550.00 Upgrade to later TP version $ 5.00 $ 60.00 # Deciwrite 1.10 Developer's Kit $75.00 $950.00 Disk replacement fee $ 3.00 none * These items may be ordered through the Public (Software) Library; others must be ordered directly from the author. # Please add $4.00 shipping & handling to these items. New York State residents and businesses MUST add their local sales tax or provide proof of exemption. Send electronic mail if you are uncertain of your local tax rate. Specify your address and county. The shipping and handling charge is NOT included in the calculation of sales tax. Residents of other states will in most cases be required to remit the appropriate tax directly to their state tax department. The Deciwrite Demo Disk includes one $3.00 discount off the purchase of Deciwrite 1.10. An individual license permits the user to operate the program on a single computer at a time, while a site license permits unlimited use within the confines of a contiguous area of the owner's property. These prices are guaranteed not to increase through October 1, 1989. Custom implementations of these programs are also available on request for modest additional fees. Send electronic mail to one of the addresses listed earlier. If you would like to use your Visa or MasterCard to register this program, you may order through the Public (Software) Library. The number to call for orders is 1-800-2424-PSL (1-800-242-4775). Information and questions about orders is available from the PSL at 713-665-7017. You may also write to the PSL at P.O. Box 35707, Houston, TX 77235-5705, or send electronic mail via CompuServe to 71355,470. When writing, you should sign your letter, include your card number and its expiration date, and specify that you want to register Centiwrite, (CWDKIT55.ARC), by Andrew M. Saucci, Jr. Please note that the PSL is not equipped to answer questions about Centiwrite itself. Such questions are best directed to one of the electronic mail addresses listed earlier. Also note that no surcharge is imposed on credit card orders. Make checks payable to Andrew M. Saucci, Jr. 641 Koelbel Ct Baldwin, NY 11510-3915. Please specify the disk size you require. You may wish to check one of the electronic mail addresses to verify that the above address is current. Please use this "physical" address ONLY for orders, unless you lack a modem. All other correspondence, including technical support questions, should be directed to one of the electronic mail addresses whenever possible. ============================================================================ Before Going to the Highest Court in the Land This program is produced by a member of the Association of Shareware Professionals (ASP). ASP wants to make sure that the shareware principle works for you. If you are unable to resolve a shareware-related problem with an ASP member by contacting the member directly, ASP may be able to help. The ASP Ombudsman can help you resolve a dispute or problem with an ASP member, but does not provide technical support for members' products. Please write to the ASP Ombudsman at P.O. Box 5786, Bellevue, WA 98006 or send a CompuServe message via EasyPlex to ASP Ombudsman 70007,3536. ============================================================================ Special Bonus All registered users of the Centiwrite Developer's Kit are also licensed to use the stand-alone version of Centiwrite (CWRITE.EXE) at no additional charge. CWRITE.EXE is included on the distribution disk that will be sent to you when your order is received. Also, registered users receive the source code for DIRALL.EXE, one of the programs provided to registered users of the stand-alone version of Centiwrite. DIRALL.EXE provides a regular directory listing, but highlights hidden files in boldface. A registered user is also entitled to unlimited telephone, U. S. mail, or electronic mail support. If such a user finds a bug within three months of purchase, it will either be fixed or the purchase price will be refunded. ============================================================================ Boilerplate Liability in the event of defects in Centiwrite 1.10 and/or the Centiwrite 1.10 Developer's Kit is expressly limited to replacement of the disk on which Centiwrite and/or the Developer's Kit was originally provided. No other liability of any sort is either implied or assumed. In particular, the user is responsible for all consequential damages, such as loss of income, loss of data, pain and suffering, etc. ============================================================================ To All Those Who Helped Thanks to all those who gave their assistance toward the completion of this program, especially Michael Day, Neil Rubenking, Scott Bussinger, and all the other helpful people who frequent Borland's Programming Forum A (BPROGA) on CompuServe. It's truly amazing! ============================================================================ Coming Attractions A plan to produce a full-size text editor based on Centiwrite and Deciwrite is in the works. Please use Centiwrite to write a short note describing a few of the features you would like to see in a text editor, particularly anything that is not found in other programs, and send it to one of the electronic mail addresses. The result could be a really good program. You might also indicate what incentives are most likely to cause you to purchase registered copies of programs distributed on a "try-before-you-buy" basis. Your suggestions will be most appreciated. ============================================================================ It's Alive! This program is not carved in stone. Many of you no doubt have extensive experience in this field, and your comments and suggestions are valuable and welcome. Send them to the electronic mail addresses listed. ============================= END OF FILE ===================================