Converter Metric to and from U.S. (OOP example + GUI example)

First we will see the OOP part. We have a class Converter which make two objects, Metric and US. Because each one need some literals, strings and numeric, we use two stack objects, which each hold a series of data. Using the symbol ! before a stack object we place the items of stack object, not the object to the calling stack. The items from stack objects just moved to the new stack, so d1 and d2 would have zero length just at the call to class constructor, for each one. We will see a Part 2 which we can use it

Part I

Let d1=Stack, d2=Stack Stack d1 {       data "Metric units", 1, 3       data .01, "Centimeters", "cm", 1, "Meters", "m", 1000,"Kilometers", "km" } Stack d2 {       data "U.S. units", .3048, 4       data 0.0254,"Inches","in", 0.3048, "Feet", "ft", 0.91441, "Yards", "yd", 1613, "Miles","mi" } Class Converter { private:       MUnit$, MUsmall$       Unit=1       inventory Units public:       Final msg$="{0}{1} converted to {2}{3}"       Property LastUnit${Value}=""       Function Convert2Meters(V as double, Unit$="Unit", rd=-1) {             .[LastUnit]$<="m"             if rd<0 then                   =V*.Units(Ucase$(Unit$))(0)             else                   =Round(V*.Units(Ucase$(Unit$))(0), rd)             end if       }       Function GetSmall$(Unit$="Unit") {             =.Units$(Ucase$(Unit$))(1)       }       Function Convert(Val,Unit1$,To, ToPrint=false) {             nVal=.Convert2Meters(Val,Unit1$)             fVal=To(nVal)             if ToPrint then                   print Format$(.msg$, Val, .GetSmall$(Unit1$), fVal, To.Unit$)             end if             =fVal       }       Function ConvertFunc(Unit1$, t) {             U=.Units(Ucase$(Unit1$))(0)*t(1)             =lambda U (Val, rd=-1) -> {                   if rd<0 then                         =Val*U                   else                         =round(Val*U,rd)                   end if             }       }             Module ShowConvertion(Val,Unit1$,To) {             nVal=.Convert2Meters(Val,Unit1$)             print Format$(.msg$, Val, .GetSmall$(Unit1$), To(nVal), To.Unit$)       }       Value (Unit$) {             Try Ok {                   f=.Units(Ucase$(Unit$))(0)             }             if Error or Not Ok then Error "No such unit:"+Unit$             if f==0 then Error "Something wrong with unit:"+Unit$             Group ret {             Private:                   factor=f             Public:                   Unit$                   Value (V) {                         =V/.factor                   }             }             ret.Unit$=.GetSmall$(Unit$)             =Group(Ret)       } Class:       Module Converter {             Def uVal as double=1             read .Name$,.Unit, M             For i=1 to M                   read uVal, Unit$, usmall$                   if uVal==.Unit then                         .MUnit$<=Unit$                         .MUsmall$<=usmall$                         Append .Units,"UNIT":=(.Unit, usmall$)                   End if                   Append .Units,Ucase$(Unit$):=(uVal, usmall$)             Next i       } } Metric=Converter(!d1) US=Converter(!d2)

Copy this code after part1  to a module Conv1

Inches=Metric.Convert(75,"Centimeters", US("Inches")) US.ShowConvertion Inches,"Inches", Metric("Centimeters") US.ShowConvertion Inches,"Inches", US("feet") US.ShowConvertion 100,"Miles", US("feet") Metric.ShowConvertion 200, "Kilometers", US("Miles") Metric.ShowConvertion 20, "Kilometers", Metric("Meters") Miles=Metric.Convert(500,"Meters", US("Miles"), True) Print miles;"mi" Yards=Metric.Convert(500,"Meters", US("Yards"), True) Print Yards;"yd" \\ We can make lambda functions for faster calculation AnyCentimeterToInches=Metric.ConvertFunc("Centimeters", US("Inches")) Print AnyCentimeterToInches(75, 3);"in"  ' 29.528  Inches Print AnyCentimeterToInches(30, 2);"in"  ' 11.81   ' Inches Print "Kilometers to Miles" AnyKilometersToMiles=Metric.ConvertFunc("Kilometers", US("Miles")) For i=10 to 180 step 10       Print i,"km  ->", AnyKilometersToMiles(i, 0),"mi" next i

The idea is to make a lambda function every time we decide the names of units from one object to other. The converter object return another object (look the value member), which need the name of the unit as a parameter. So US("Miles") returtn an object, but not a converter object. This object also has a value and need a parameter too. Because we want to read another value, we use a group and not a lambda function. Final the ConvertFunc()  function return a lambda function which combine the factors to make a fast multiplication (without using objects).

The last part, the Converter.

Now copy the part one and the code below to a new module say Conv2. Now we place a user interface, and we can insert in two text boxes values, and we can change from dropboxes the units for each system. Also a thread show the time (and refresh the status bar).

Function Local2() is an updated function from info big file (info.gsb), which included in M2000 setup. This used to validate the input string. Validation done without the decimal point. This attatched after this stage. The validation for decimal point happen before the call to Local2() on the ValidString event for each TextBox. A Call Local calls a function as a sub, so we place the same name space (here the Conv2 module is the current name space).

Use Locale 1033 for engilsh or Locale 1032 for greek as first statement. This control the decimal point character, so 1032 set "," (use Monitor statement in M2000 console, to see the state of M2000 Environment).

def SkipValidation1=True, SkipValidation2=True declare Convertion form declare TEXTBOX1 TEXTBOX form Convertion declare COMBO1 COMBOBOX form Convertion declare TEXTBOX2 TEXTBOX form Convertion declare COMBO2 COMBOBOX form Convertion layer Convertion {       LineSpace 60       window 10, 12000, 5000;       Cls 1, 0       gradient #aa9933,1       totalwidth=scale.x } boxwidth=totalwidth-2000 method TEXTBOX1, "MOVE", 1000, 1000, boxwidth method COMBO1, "MOVE", 1000, 1800, boxwidth method TEXTBOX2, "MOVE", 1000, 2600, boxwidth method COMBO2, "MOVE", 1000, 3400, boxwidth with Convertion, "TITLE", "M2000 Example: Converter " \\ ADJUST PROPERTIES FOR CONTROLS \\ FROM SOME PROPERTIES  WE WANT SOME IDENTIFIERS TO BOUND TO with COMBO1, "EDIT", false,"UseOnlyTheList", true,"ShowAlways", false with COMBO1, "ListText" as ITEM1$, "Text" as COMBO1$, "label","Units:" ITEM1$={Centimeters             Meters             Kilometers             } COMBO1$="Meters" with COMBO2, "EDIT", false,"UseOnlyTheList", true,"ShowAlways", false with COMBO2, "ListText" as ITEM2$, "Text" as COMBO2$, "label","Units:" ITEM2$={Inches             Feet             Yards             Miles             } COMBO2$="Yards" with TEXTBOX1, "Prompt", "Metric: ", "VarText" as textbox1.value$ with TEXTBOX1, "ThisKind" as TK1$,"ShowAlways", true TK1$=" "+Metric.GetSmall$(COMBO1$) textbox1.value$="0" with TEXTBOX2, "Prompt", "U.S.: ", "VarText" as textbox2.value$ with TEXTBOX2, "ThisKind" as TK2$,"ShowAlways", true TK2$=" "+US.GetSmall$(COMBO2$) textbox2.value$="0" const fstr$="{0} <=> {1}" caption$=format$(fstr$, combo1$, combo2$) FromText1=Metric.ConvertFunc(Combo1$, US(combo2$)) FromText2=US.ConvertFunc(Combo2$, Metric(combo1$)) Function Local2(new Feed$, z) {       \\ this Function can be used from other Integer       \\ this$ and thispos, exist just before the call of this Function       local sgn$       if feed$="" and this$="-" then thispos-- : exit       if left$(this$,1)="-" then sgn$="-": this$=mid$(this$, 2)       if this$<>Trim$(this$) then this$=Feed$ : thispos-- : exit       if Trim$(this$)="" then this$="0" : thispos=2 : exit       if instr(this$,"+")>0 and sgn$="-" then this$=filter$(this$, "+") : sgn$=""       if instr(this$,"-")>0 and sgn$="" then this$=filter$(this$, "-") : sgn$="-"       if filter$(this$,"0123456789")<>"" then this$=Feed$ : thispos-- : exit       if len(this$)>1 then While left$(this$,1)="0" {this$=mid$(this$, 2)}       this$=sgn$+this$       if Z<>0 then FEED$=this$: INSERT Z FEED$=de$: this$=FEED$: thispos++       if this$="-0" then this$="-" : thispos=2       } Function TextBox1.ValidString {       \\ this Function called direct from textbox       read new &this$, &thispos       if SkipValidation1 then exit function       local de$=locale$(14)       this$=replace$(de$, ".", this$)       local Z=INSTR(this$,"."), K$       if Z>0 then             K$=FILTER$(this$, ".")             if LEN(K$)+2<LEN(textbox1.value$) then                   this$=textbox1.value$                   this$=replace$(de$, ".", this$)                   Z=INSTR(this$, ".")                   K$=FILTER$(this$, ".")             END if             if z>0 then thispos--             this$=K$       End if       call local local2(textbox1.value$, Z) } Function TextBox2.ValidString {       \\ this Function called direct from textbox       read new &this$, &thispos       if SkipValidation2 then exit function       local de$=locale$(14)       this$=replace$(de$, ".", this$)       local Z=INSTR(this$, "."), K$       if Z>0 then             K$=FILTER$(this$, ".")             if LEN(K$)+2<LEN(textbox2.value$) then                   this$=textbox2.value$                   this$=replace$(de$, ".", this$)                   Z=INSTR(this$, de$)                   K$=FILTER$(this$, de$)             END if             if z>0 then thispos--             this$=K$       End if       call local local2(textbox2.value$, Z) } Function Combo1.dblclick {       caption$=format$(fstr$,combo1$, combo2$)       FromText1=Metric.ConvertFunc(Combo1$, US(combo2$))       FromText2=US.ConvertFunc(Combo2$, Metric(combo1$))       call local TextBox2.Enter()       TK1$=" "+Metric.GetSmall$(COMBO1$)       method Convertion, "refreshall" } Function Combo2.dblclick {       caption$=format$(fstr$, combo1$, combo2$)       FromText1=Metric.ConvertFunc(Combo1$, US(combo2$))       FromText2=US.ConvertFunc(Combo2$, Metric(combo1$))       call local TextBox1.Enter()       TK2$=" "+US.GetSmall$(COMBO2$)       method Convertion, "refreshall" } Function TextBox1.Enter {       SkipValidation2~       textbox2.value$=str$(Fromtext1(val(textbox1.value$, locale$(14))),"")       SkipValidation2~       clipboard textbox2.value$+" "+combo2$ } Function TextBox2.Enter {       SkipValidation1~       textbox1.value$=str$(Fromtext2(val(textbox2.value$, locale$(14))),"")       SkipValidation1~       clipboard textbox1.value$+" "+combo1$ } SkipValidation1=False SkipValidation2=False layer Convertion {       thread {             cursor 0, Height-1             print over $(7, width),~(#FFFFFF), Caption$+" | "+str$(now,"long time")             print part $(4, width),~(#FFFFFF), "George Karras 2020"       } as T1 interval 1000/60 } method Convertion, "SHOW", 1 threads Erase declare Convertion nothing

George Karras