Linking Multiple Text Entry Fields

by Gary Rosenzweig

Have you ever seen a set of text entry fields that are linked together so the user can just type right from one to the other? You might see this done for fields that let the user type a product serial number, a telephone number, or even a zip+4 code. If you are still not sure what I am talking about, check out this week's example movie below. These are just three regular text members set to editable and tab to next item. However, I have added Lingo code so that the insertion point immediately follows from one text member to the next after the maximum number of characters have been entered. I've also customized the fields so that only numerical digits can be entered, three in the first two boxes, and four in the last. The behavior I wrote to do this follows. The comments explain each section of code. I've allowed for customization, so numbers, letters, or additional characters can be specified. The getPropertyDescriptionList handler also determines how many characters will be allowed in the text member sprite. property s property pMaxChars property pAllowNumbers property pAllowLetters property pAlsoAllow on getPropertyDescriptionList me   list = [:]   addProp list, #pMaxChars, [#comment: "Maximum Number of Characters", #format: #integer, #default: 3]   addProp list, #pAllowNumbers, [#comment: "Allow Numbers", #format: #boolean, #default: TRUE]   addProp list, #pAllowLetters, [#comment: "Allow Letters", #format: #boolean, #default: TRUE]   addProp list, #pAlsoAllow, [#comment: "Also Allow", #format: #string, #default: ""]   return list end on beginSprite me   s = me.spriteNum   sprite(s).member.text = "" end on keyDown me   ok = FALSE   -- check to see if it is a number   if pAllowNumbers then     if "0123456789" contains the key then       ok = TRUE     end if   end if   -- check to see if it is a letter   if pAllowLetters then     if "ABCDEFGHIJKLMNOPQRSTUVWXYZ" contains the key then       ok = TRUE     end if   end if   -- see if it is another type of character   if pAlsoAllow contains the key then     ok = TRUE   end if   -- whatever happens, don't exceed max char   if sprite(me.spriteNum).member.text.length >= pMaxChars then     ok = FALSE   end if   -- pass teh characer if it is allowed   if ok then     pass          -- see if the backspace should be passed   else if the key = BACKSPACE then          if sprite(s).member.text.length = 0 then       -- if this is the beginning of this member, then backspace to       -- the previous member and delete the last character       if sprite(me.spriteNum-1).member.type = #text then         the keyboardFocusSprite = me.spriteNum - 1         textmem = sprite(s-1).member         textmem.text = textmem.text.char[1..textmem.text.length-1]         stopEvent       end if     else       -- this is a normal backspace       pass     end if        else if the key = TAB then     -- allow the user to tab, too     pass        else     -- stop all other characters     stopEvent   end if end on keyUp me   -- see if it is time to go to the next text member sprite   if sprite(me.spriteNum).member.text.length >= pMaxChars then     the keyboardFocusSprite = me.spriteNum + 1   end if end To use this code to link together text members, you need to place it on each of the text member sprites. Then, you need to make sure that they are in consecutive sprite channels. Check the example movie if you want to see how it fits together. I know this isn't the most exciting piece of code, but it can serve a purpose in the right application. It will certainly help a confused user to enter the right type of data. A sample Director 8 movie is available for download in Mac or Windows format. Gary Rosenzweig's two most recent books are: "Special Edition Using Director 8" -- The most comprehensive guide to Director ever, including tons of examples and demo movies. It's suitable for novices and experts alike. "Advanced Lingo for Games" -- How to make games with Director 7 and 8. This book comes complete with full source code for more than 20 complete games.