Streamlining your code

Chapter 4 - Consolidate event handlers

- StPendl StPendl Oct 29, 2011
The next thing is to introduce one event handler for all the radio buttons to further simplify our code.

The best way to introduce a single event handler for multiple controls is by using a subroutine, which receives the handle of the control as the first argument.
Parsing the passed handle allows us to determine, which control we have to apply our actions on.

To keep track of the current value of our four bands we introduce four global variables:
    GLOBAL Band1value, Band2value, Band3value, Band4value

In a second attempt we replace all the individual set event handlers by our unified subroutine and a dummy event handler for the reset action.
    radiobutton #w.Blackr1  , "", SetBandValue,[none] ,75, 45,20,20'Black=0
    radiobutton #w.Brownr1  , "", SetBandValue,[none] ,75, 85,20,20'Brown=1
    radiobutton #w.Redr1    , "", SetBandValue,[none] ,75,125,20,20'Red=2
    radiobutton #w.Oranger1 , "", SetBandValue,[none] ,75,165,20,20'Orange=3
    radiobutton #w.Yellowr1 , "", SetBandValue,[none] ,75,205,20,20'Yellow=4
    radiobutton #w.Greenr1  , "", SetBandValue,[none] ,75,245,20,20'Green=5
    radiobutton #w.Bluer1   , "", SetBandValue,[none] ,75,285,20,20'Blue=6
    radiobutton #w.Violetr1 , "", SetBandValue,[none] ,75,325,20,20'Violet=7
    radiobutton #w.Grayr1   , "", SetBandValue,[none] ,75,365,20,20'Gray=8
    radiobutton #w.Whiter1  , "", SetBandValue,[none] ,75,405,20,20'White=9
 
    ' and so forth

We want to utilize the unified event handler for the fourth band too, so we need to change the extension to follow the same naming convention.
    radiobutton #w.Goldr4   , "", SetBandValue,[none] ,385, 45,20,20'Gold=5%
    radiobutton #w.Silverr4 , "", SetBandValue,[none] ,385, 85,20,20'Silver=10%
    radiobutton #w.Noner4   , "", SetBandValue,[none] ,385,125,20,20'None=20%

Now we can replace the four [Band...] event handlers by our single subroutine with heavy use of SELECT..CASE blocks:
[none]
    WAIT
 
[quit]
    close #w
    END
 
SUB SetBandValue Handle$
    ' parse handle of calling control
    Band = val(Right$(Handle$, 1))
    ColorName$ = Mid$(Handle$, 4, Len(Handle$)-5)
 
    ' get position of color
    FOR i = 1 to 10
        if Colors$(i,1) = ColorName$ then exit for
        if i < 4 then if Tolerances$(i,1) = ColorName$ then exit for
    NEXT
 
    ' if we had no match exit
    If i = 11 Then Exit Sub
 
    ' calculate the values
    Select Case Band
        Case 1
        Band1value = (i-1) * 10
 
        Case 2
        Band2value = i-1
 
        Case 3
        Band3value = 10 ^ (i-1)
 
        Case 4
        Band4value = i*5
        if Band4value = 15 then Band4value = 20
 
        Case Else
        Exit Sub
    End Select
 
    ' get the band color
    Select Case Band
        Case 1, 2, 3
        ColorValue$ = Colors$(i,2)
 
        Case 4
        ColorValue$ = Tolerances$(i,2)
 
        Case Else
        Exit Sub
    End Select
 
    GBhandle$ = "#w.Band"; Band
    #GBhandle$ "cls;down;fill "; ColorValue$; ";flush"
 
    vv=(Band1value+Band2value)*Band3value
 
    Select Case
        Case vv>=1000000
        #w.Ohm "Resistance Value=";vv/1000000;" M Ohm"
 
        Case vv>=1000
        #w.Ohm "Resistance Value=";vv/1000;" K Ohm"
 
        Case Else
        #w.Ohm "Resistance Value=";vv;" Ohm"
    End Select
 
    if Band4value>0 then #w.Tole "Tolerance Value =";"  +/- ";Band4value;"%"
END SUB

The complete code now looks like this.

    'Resistor Calculator.bas
    'Author: salaion Yahoo! Group
    'Date: 27.11.10
    '
    ' List of Colors at http://en.wikipedia.org/wiki/List_of_colors
    '
    ' 27.11.10 00:18:50 - Initial as posted
    ' 27.11.10 00:21:40 - added array for colors and reduced redundant code for color boxes
    ' 27.11.10 00:34:07 - replaced duplicate command strings by variables
    ' 27.11.10 02:22:16 - consolidated event handler
 
    nomainwin
    WindowWidth = 850:WindowHeight = 600
    UpperLeftX=int( (DisplayWidth- WindowWidth) /2)
    UpperLeftY=int( (DisplayHeight- WindowHeight) /2)
    BackgroundColor$ = "green"
 
    GLOBAL Band1value, Band2value, Band3value, Band4value
 
    dim Colors$(10,2), Tolerances$(3,2)
 
[Colors]
    DATA "Black",  "  0   0   0"
    DATA "Brown",  "170 100  20"
    DATA "Red",    "255   0   0"
    DATA "Orange", "255 180   0"
    DATA "Yellow", "255 255   0"
    DATA "Green",  " 45 157  40"
    DATA "Blue",   "  0   0 255"
    DATA "Violet", "170   0 180"
    DATA "Gray",   "127 127 127"
    DATA "White",  "255 255 255"
 
[Tolerances]
    DATA "Gold",   "212 175  55"
    DATA "Silver", "200 200 250"
    DATA "None",   " 21 228 255"
 
    'Fill the arrays
    RESTORE [Colors]
 
    FOR i = 1 to 10
        READ ColorName$, ColorValue$
        Colors$(i,1) = ColorName$
        Colors$(i,2) = ColorValue$
    NEXT
 
    RESTORE [Tolerances]
 
    FOR i = 1 to 3
        READ ColorName$, ColorValue$
        Tolerances$(i,1) = ColorName$
        Tolerances$(i,2) = ColorValue$
    NEXT
 
    STATICTEXT #w.Ohm, "" , 500, 200, 300, 20
    STATICTEXT #w.Tole,"" , 500, 230, 300, 20
 
    STATICTEXT #w,Colors$( 1,1),  10,  42, 50, 20
    STATICTEXT #w,Colors$( 2,1),  10,  82, 50, 20
    STATICTEXT #w,Colors$( 3,1),  10, 122, 50, 20
    STATICTEXT #w,Colors$( 4,1),  10, 162, 50, 20
    STATICTEXT #w,Colors$( 5,1),  10, 202, 50, 20
    STATICTEXT #w,Colors$( 6,1),  10, 242, 50, 20
    STATICTEXT #w,Colors$( 7,1),  10, 282, 50, 20
    STATICTEXT #w,Colors$( 8,1),  10, 322, 50, 20
    STATICTEXT #w,Colors$( 9,1),  10, 362, 50, 20
    STATICTEXT #w,Colors$(10,1),  10, 402, 50, 20
 
    STATICTEXT #w,Tolerances$(1,1), 470,  42, 50, 20
    STATICTEXT #w,Tolerances$(2,1), 470,  82, 50, 20
    STATICTEXT #w,Tolerances$(3,1), 470, 122, 50, 20
 
 
    STATICTEXT #w,"K=Kilo " , 500, 300,100, 20
    STATICTEXT #w,"M=Mega " , 500, 330,100, 20
    STATICTEXT #w,"Light Blue is The Default Color of Resistance " , 500, 360,400, 20
 
    'Band1
    groupbox #w.FirstDigit, "First Digit", 70,10,80,430
    radiobutton #w.Blackr1  , "", SetBandValue,[none] ,75, 45,20,20'Black=0
    radiobutton #w.Brownr1  , "", SetBandValue,[none] ,75, 85,20,20'Brown=1
    radiobutton #w.Redr1    , "", SetBandValue,[none] ,75,125,20,20'Red=2
    radiobutton #w.Oranger1 , "", SetBandValue,[none] ,75,165,20,20'Orange=3
    radiobutton #w.Yellowr1 , "", SetBandValue,[none] ,75,205,20,20'Yellow=4
    radiobutton #w.Greenr1  , "", SetBandValue,[none] ,75,245,20,20'Green=5
    radiobutton #w.Bluer1   , "", SetBandValue,[none] ,75,285,20,20'Blue=6
    radiobutton #w.Violetr1 , "", SetBandValue,[none] ,75,325,20,20'Violet=7
    radiobutton #w.Grayr1   , "", SetBandValue,[none] ,75,365,20,20'Gray=8
    radiobutton #w.Whiter1  , "", SetBandValue,[none] ,75,405,20,20'White=9
 
    'Band2
    groupbox #w.SecondtDigit, "Second Digit", 180,10,80,430
    radiobutton #w.Blackr2  , "", SetBandValue,[none] ,185, 45,20,20'Black=0
    radiobutton #w.Brownr2  , "", SetBandValue,[none] ,185, 85,20,20'Brown=1
    radiobutton #w.Redr2    , "", SetBandValue,[none] ,185,125,20,20'Red=2
    radiobutton #w.Oranger2 , "", SetBandValue,[none] ,185,165,20,20'Orange=3
    radiobutton #w.Yellowr2 , "", SetBandValue,[none] ,185,205,20,20'Yellow=4
    radiobutton #w.Greenr2  , "", SetBandValue,[none] ,185,245,20,20'Green=5
    radiobutton #w.Bluer2   , "", SetBandValue,[none] ,185,285,20,20'Blue=6
    radiobutton #w.Violetr2 , "", SetBandValue,[none] ,185,325,20,20'Violet=7
    radiobutton #w.Grayr2   , "", SetBandValue,[none] ,185,365,20,20'Gray=8
    radiobutton #w.Whiter2  , "", SetBandValue,[none] ,185,405,20,20'White=9
 
    'Band3
    groupbox #w.Multiplier, "Multiplier", 280,10,80,430
    radiobutton #w.Blackr3  , "", SetBandValue,[none] ,285, 45,20,20'Black=0
    radiobutton #w.Brownr3  , "", SetBandValue,[none] ,285, 85,20,20'Brown=1
    radiobutton #w.Redr3    , "", SetBandValue,[none] ,285,125,20,20'Red=2
    radiobutton #w.Oranger3 , "", SetBandValue,[none] ,285,165,20,20'Orange=3
    radiobutton #w.Yellowr3 , "", SetBandValue,[none] ,285,205,20,20'Yellow=4
    radiobutton #w.Greenr3  , "", SetBandValue,[none] ,285,245,20,20'Green=5
    radiobutton #w.Bluer3   , "", SetBandValue,[none] ,285,285,20,20'Blue=6
    radiobutton #w.Violetr3 , "", SetBandValue,[none] ,285,325,20,20'Violet=7
    radiobutton #w.Grayr3   , "", SetBandValue,[none] ,285,365,20,20'Gray=8
    radiobutton #w.Whiter3  , "", SetBandValue,[none] ,285,405,20,20'White=9
 
    'Band4
    groupbox #w.Tolerance, "Tolerance", 380,10,80,430
    radiobutton #w.Goldr4   , "", SetBandValue,[none] ,385, 45,20,20'Gold=5%
    radiobutton #w.Silverr4 , "", SetBandValue,[none] ,385, 85,20,20'Silver=10%
    radiobutton #w.Noner4   , "", SetBandValue,[none] ,385,125,20,20'None=20%
 
    'Fram
    graphicbox #w.add, 530,60,292,30'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    stylebits #w.add, 0,_WS_BORDER, 0,0
 
    graphicbox #w.up, 523,53,306,7
    stylebits #w.up, 0,_WS_BORDER, 0,0'
 
    graphicbox #w.down, 523,90,306,7
    stylebits #w.down, 0,_WS_BORDER, 0,0'
 
    graphicbox #w.side1, 523,53,7,44
    stylebits #w.side1, 0,_WS_BORDER, 0,0'
 
    graphicbox #w.adds2, 822,53,7,44
    stylebits #w.adds2, 0,_WS_BORDER, 0,0'
 
    'Band1
    graphicbox #w.Black1 , 100, 40,30,30
    graphicbox #w.Brown1 , 100, 80,30,30
    graphicbox #w.Red1   , 100,120,30,30
    graphicbox #w.Orange1, 100,160,30,30
    graphicbox #w.Yellow1, 100,200,30,30
    graphicbox #w.Green1 , 100,240,30,30
    graphicbox #w.Blue1  , 100,280,30,30
    graphicbox #w.Violet1, 100,320,30,30
    graphicbox #w.Gray1  , 100,360,30,30
    graphicbox #w.White1 , 100,400,30,30
 
    'Band2
    graphicbox #w.Black2 , 210, 40,30,30
    graphicbox #w.Brown2 , 210, 80,30,30
    graphicbox #w.Red2   , 210,120,30,30
    graphicbox #w.Orange2, 210,160,30,30
    graphicbox #w.Yellow2, 210,200,30,30
    graphicbox #w.Green2 , 210,240,30,30
    graphicbox #w.Blue2  , 210,280,30,30
    graphicbox #w.Violet2, 210,320,30,30
    graphicbox #w.Gray2  , 210,360,30,30
    graphicbox #w.White2 , 210,400,30,30
 
    'Band3
    graphicbox #w.Black3 , 310, 40,30,30
    graphicbox #w.Brown3 , 310, 80,30,30
    graphicbox #w.Red3   , 310,120,30,30
    graphicbox #w.Orange3, 310,160,30,30
    graphicbox #w.Yellow3, 310,200,30,30
    graphicbox #w.Green3 , 310,240,30,30
    graphicbox #w.Blue3  , 310,280,30,30
    graphicbox #w.Violet3, 310,320,30,30
    graphicbox #w.Gray3  , 310,360,30,30
    graphicbox #w.White3 , 310,400,30,30
 
    'Band4
    graphicbox #w.Gold  , 410, 40,30,30
    graphicbox #w.Silver, 410, 80,30,30
    graphicbox #w.None  , 410,120,30,30
 
    'Selected  Bands of Body Resistance
    graphicbox #w.Band1, 155,470,15,35
    graphicbox #w.Band2, 185,470,15,35
    graphicbox #w.Band3, 215,470,15,35
    graphicbox #w.Band4, 255,470,15,35
 
    stylebits #w.Band1, 0,_WS_BORDER,0,0
    stylebits #w.Band2, 0,_WS_BORDER,0,0
    stylebits #w.Band3, 0,_WS_BORDER,0,0
    stylebits #w.Band4, 0,_WS_BORDER,0,0
 
    'General Body Resistance
    graphicbox #w.37, 130,470,168,35
    stylebits #w.37, 0,_WS_BORDER,0,0
 
    'Terminal Wires
    graphicbox #w.42,  80,485,50,5
    graphicbox #w.43, 300,485,50,5
 
    open "Resistor Calculator" for window_nf as #w
    #w "trapclose [quit]"
    #w "font Times_New_Roman 13"
 
    #w.add "cls;down;fill yellow;font Times_New_Roman 16 bold;color red;backcolor yellow"
    #w.add "place 5 20;\Resistor Color Code of 4 Bands"
    #w.add "flush"
 
    CommandString$ = "cls;down;fill blue;flush"
    #w.up    CommandString$
    #w.down  CommandString$
    #w.side1 CommandString$
    #w.adds2 CommandString$
 
    FOR Band = 1 to 3
        FOR Color = 1 to 10
            Handle$ = "#w."; Colors$(Color,1); Band
 
            #Handle$ "cls;down;fill "; Colors$(Color,2); ";flush"
        NEXT
    NEXT
 
    FOR Tolerance = 1 to 3
        Handle$ = "#w."; Tolerances$(Tolerance,1)
 
        #Handle$ "cls;down;fill "; Tolerances$(Tolerance,2); ";flush"
    NEXT
 
    'Color of Terminal Wires
    CommandString$ = "cls; down; fill 127 127 127;flush"
    #w.42 CommandString$
    #w.43 CommandString$
 
    'General Body Resistance Color
    CommandString$ = "cls; down; fill 21 228 255;flush"  'light blue
    #w.37 CommandString$
 
    #w.Band1 CommandString$
    #w.Band2 CommandString$
    #w.Band3 CommandString$
    #w.Band4 CommandString$
 
[none]
    WAIT
 
[quit]
    close #w
    END
 
SUB SetBandValue Handle$
    ' parse handle of calling control
    Band = val(Right$(Handle$, 1))
    ColorName$ = Mid$(Handle$, 4, Len(Handle$)-5)
 
    ' get position of color
    FOR i = 1 to 10
        if Colors$(i,1) = ColorName$ then exit for
        if i < 4 then if Tolerances$(i,1) = ColorName$ then exit for
    NEXT
 
    ' if we had no match exit
    If i = 11 Then Exit Sub
 
    Select Case Band
        Case 1
        Band1value = (i-1) * 10
 
        Case 2
        Band2value = i-1
 
        Case 3
        Band3value = 10 ^ (i-1)
 
        Case 4
        Band4value = i*5
        if Band4value = 15 then Band4value = 20
 
        Case Else
        Exit Sub
    End Select
 
    Select Case Band
        Case 1, 2, 3
        ColorValue$ = Colors$(i,2)
 
        Case 4
        ColorValue$ = Tolerances$(i,2)
 
        Case Else
        Exit Sub
    End Select
 
    GBhandle$ = "#w.Band"; Band
    #GBhandle$ "cls;down;fill "; ColorValue$; ";flush"
 
    vv=(Band1value+Band2value)*Band3value
 
    Select Case
        Case vv>=1000000
        #w.Ohm "Resistance Value=";vv/1000000;" M Ohm"
 
        Case vv>=1000
        #w.Ohm "Resistance Value=";vv/1000;" K Ohm"
 
        Case Else
        #w.Ohm "Resistance Value=";vv;" Ohm"
    End Select
 
    if Band4value>0 then #w.Tole "Tolerance Value =";"  +/- ";Band4value;"%"
END SUB

Chapter 1 - Starting the mission
Chapter 2 - Using arrays to reduce redundant code
Chapter 3 - Use variables for duplicate command strings
Chapter 4 - Consolidate event handlers
Chapter 5 - Apply mouse selection
Chapter 6 - Remove radio buttons
Chapter 7 - Use a single graphics box for the resistor display
Chapter 8 - Further reduce the amount of GUI controls (Using hot-spots)
Chapter 9 - Adding some eye-candy
Chapter 10 - Summary