PluggableAdaptor subclass:#TypeConverter

	instanceVariableNames:''

	classVariableNames:''

	poolDictionaries:''

	category:'Interface-Support-Models'

!

!TypeConverter class methodsFor:'documentation'!

documentation

"

    a typeConverter can be used as an editFields model

    (remember, that an editField expects a string in its model),

    to convert the fields string value to some object and vice versa.

    Its main use is when building interfaces with inputFields,

    where the datum to be entered is a non-string and you

    want to have the entered value be converted automatically.

    (and vice versa, to convert the datum to a string).

    No real new functionality is added here - all is inherited

    from PluggableAdapter; however, some specialized instance creation

    methods are added here..

    Notice: 

        this class was implemented using protocol information

        from alpha testers - it may not be complete or compatible to

        the corresponding ST-80 class. 

        If you encounter any incompatibilities, please forward a note 

        describing the incompatibility verbal (i.e. no code) to the ST/X team.

    [author:]

        Claus Gittinger

"

!

examples 

"

    convert a number to a string:

                                                                        [exBegin]

        |v t i|

        v := 1 asValue.

        t := HorizontalPanelView new.

        t extent:200@50.

        t horizontalLayout:#fitSpace.

        i := EditField in:t.

        i model:(TypeConverter onNumberValue:v).

        t open.

        (Delay forSeconds:3) wait.

        v value:2.

                                                                        [exEnd]

    convert a date to a string:

                                                                        [exBegin]

        |d v|

        v := nil asValue.

        d := DialogBox new.

        d addInputFieldOn:(TypeConverter onDateValue:v).

        d addOkButton.

        d open.

        d accepted ifTrue:[

            Transcript showCR:v value

        ]

                                                                        [exEnd]

"

! !

!TypeConverter class methodsFor:'instance creation'!

onDateValue:aValueHolder

    "create and return a typeConverter, which retrieves

     a date via #value, and converts

     a date-string to a date via #value:.

     Useful as an editFields model, which operates on some

     date value (or aspectAdaptor, which adapts to a numeric slot)"

    ^ (self on:aValueHolder) dateToText

    "Modified: 21.2.1997 / 18:46:11 / cg"

    "Created: 4.3.1997 / 12:30:49 / cg"

!

onNumberValue:aValueHolder

    "create and return a typeConverter, which retrieves

     a values string representation via #value, and converts

     a number-string to a value via #value:.

     Useful as an editFields model, which operates on some

     numeric value (or aspectAdaptor, which adapts to a numeric slot)"

    ^ (self on:aValueHolder) numberToText

    "Modified: 21.2.1997 / 18:46:11 / cg"

!

onNumberValue:aValueHolder format:formatString

    "create and return a typeConverter, which retrieves

     a values string representation via #value, and converts

     a number-string to a value via #value:.

     Useful as an editFields model, which operates on some

     numeric value (or aspectAdaptor, which adapts to a numeric slot)"

    ^ (self on:aValueHolder) numberToTextFormattedBy:formatString

    "Created: 4.3.1997 / 11:51:25 / cg"

    "Modified: 4.3.1997 / 11:51:41 / cg"

!

onSymbolValue:aValueHolder

    "create and return a typeConverter, which retrieves

     a symbol-values string representation via #value, and converts

     a string to a symbol via #value:.

     Useful as an editFields model, which operates on some

     numeric value (or aspectAdaptor, which adapts to a numeric slot)"

    ^ (self on:aValueHolder) symbolOrNil

    "Modified: 21.2.1997 / 18:46:11 / cg"

!

onTimeValue:aValueHolder

    "create and return a typeConverter, which retrieves

     a time via #value, and converts

     a time-string to a time via #value:.

     Useful as an editFields model, which operates on some

     date value (or aspectAdaptor, which adapts to a numeric slot)"

    ^ (self on:aValueHolder) timeToText

    "Modified: 21.2.1997 / 18:46:11 / cg"

    "Created: 4.3.1997 / 11:52:10 / cg"

! !

!TypeConverter methodsFor:'accessing'!

subject

    "return the cobverted subject"

    ^ model

    "Created: 21.2.1997 / 18:45:12 / cg"

!

value:newValue

    "convert and change"

    self setValue:newValue

    "Created: 21.2.1997 / 18:45:39 / cg"

! !

!TypeConverter methodsFor:'standard converters'!

arrayLiteralOrSymbolOrNil

    "setup the converter to convert from a string to either a literal

     Array or a symbol and vice versa. 

     Invalid strings (i.e. empty) are converted to nil;

     nil values are converted to an empty string.

     This is a very special converter (for the GUI builder) 

     - probably not belonging to here"

    self

        getBlock:[:model |

                |symbolValue|

                (symbolValue := model value) isNil ifTrue:[

                    String new

                ] ifFalse:[

                    symbolValue isArray ifTrue:[

                        symbolValue storeString

                    ] ifFalse:[

                        '#' , symbolValue asString

                    ]

                ]]

        putBlock:

                [:model :string |

                |value s|

                string isEmpty ifTrue:[

                    value := nil

                ] ifFalse:[

                    s := string withoutSeparators.

                    (s startsWith:'#(') ifTrue:[

                        value := Array readFrom:s onError:nil

                    ] ifFalse:[

                        (s startsWith:'#') ifTrue:[

                            s := s copyFrom:2

                        ].

                        value := s asSymbol

                    ]

                ].

                model value:value]

        updateBlock: [:m :a :p | true]

    "Modified: / 26.10.1997 / 13:50:32 / cg"

    "Created: / 26.10.1997 / 14:01:02 / cg"

!

dateOrNil

    "setup the converter to convert from a string to a date

     and vice versa. Invalid dates are converted to nil; likewise,

     a nil date is converted to an empty string."

    self

        getBlock:[:model |

                |date|

                (date := model value) isNil ifTrue:[

                    ''

                ] ifFalse:[

                    date printString

                ]]

        putBlock:

                [:model :string |

                |value|

                string isEmpty ifTrue:[

                    value := nil

                ] ifFalse:[

                    value := Date readFrom:string onError:nil

                ].

                model value:value]

        updateBlock: [:m :a :p | true]

    "Created: / 4.3.1997 / 11:56:36 / cg"

    "Modified: / 26.10.1997 / 13:51:06 / cg"

!

dateToText

    "setup the converter to convert from a string to a date

     and vice versa. Nil is converted to todays date-string,

     likewise, an empty string is converted back to todays date."

    self

        getBlock:[:model |

                |date|

                (date := model value) isNil ifTrue:[

                    Date today printString

                ] ifFalse:[

                    date printString

                ]]

        putBlock:

                [:model :string |

                |value|

                string isEmpty ifTrue:[

                    value := Date today

                ] ifFalse:[

                    value := Date readFrom:string onError:Date today

                ].

                model value:value]

        updateBlock: [:m :a :p | true]

    "Created: / 4.3.1997 / 12:32:19 / cg"

    "Modified: / 26.10.1997 / 13:52:00 / cg"

!

number

    "setup the converter to convert from a string to a number

     and vice versa. Invalid numbers are converted to nil."

    self numberToText

    "Created: 4.4.1997 / 12:46:14 / cg"

!

numberOrNil

    "setup the converter to convert from a string to a number

     and vice versa. Invalid numbers are converted to nil."

    self

        getBlock:[:model |

                |numericValue|

                (numericValue := model value) isNil ifTrue:[

                    String new

                ] ifFalse:[

                    numericValue printString

                ]]

        putBlock:

                [:model :string |

                |value|

                string isEmpty ifTrue:[

                    value := nil

                ] ifFalse:[

                    value := Number readFrom:string onError:nil

                ].

                model value:value]

        updateBlock: [:m :a :p | true]

    "Created: 21.2.1997 / 18:58:38 / cg"

!

numberOrSymbolOrNil

    "setup the converter to convert from a string to either a numeric literal

     or a symbol and vice versa. 

     Invalid strings (i.e. empty) are converted to nil;

     nil values are converted to an empty string.

     This is a very special converter (for the GUI builder) 

     - probably not belonging to here"

    self

        getBlock:[:model |

                |litValue|

                (litValue := model value) isNil ifTrue:[

                    String new

                ] ifFalse:[

                    litValue storeString

                ]]

        putBlock:

                [:model :string |

                |value s|

                string isEmpty ifTrue:[

                    value := nil

                ] ifFalse:[

                    value := Number readFrom:string onError:nil.

                    value isNil ifTrue:[

                        s := string withoutSeparators.

                        (s startsWith:'#') ifTrue:[

                            s := s copyFrom:2.

                            (s startsWith:$') ifTrue:[

                                s := s copyFrom:2 to:(s size - 1)

                            ].

                        ].

                        value := s asSymbol

                    ]

                ].

                model value:value]

        updateBlock: [:m :a :p | true]

    "Modified: / 26.10.1997 / 13:50:32 / cg"

    "Created: / 29.10.1997 / 15:49:26 / cg"

!

numberToText

    "setup the converter to convert from a string to a number

     and vice versa."

    self

        getBlock:[:model |

                |numericValue|

                (numericValue := model value) isNumber ifFalse:[

                    String new

                ] ifTrue:[

                    numericValue printString

                ]]

        putBlock:

                [:model :string |

                |value|

                string isEmpty ifTrue:[

                    value := 0

                ] ifFalse:[

                    value := string asNumber

                ].

                model value:value]

        updateBlock: [:m :a :p | true]

    "Created: / 21.2.1997 / 18:57:05 / cg"

    "Modified: / 29.10.1997 / 15:49:21 / cg"

!

numberToTextFormattedBy:formatString

    "setup the converter to convert from a string to a number

     and vice versa, using formatString.

     The formatString is currently ignored when numbers are converted

     from a string."

    self

        getBlock:[:model |

                |numericValue|

                (numericValue := model value) isNil ifTrue:[

                    String new

                ] ifFalse:[

                    PrintConverter print:numericValue formattedBy:formatString

                ]]

        putBlock:

                [:model :string |

                |value|

                string isEmpty ifTrue:[

                    value := 0

                ] ifFalse:[

                    value := string asNumber "asNumberFromFormatString:formatString"

                ].

                model value:value]

        updateBlock: [:m :a :p | true]

    "Modified: 21.2.1997 / 18:59:44 / cg"

!

smalltalkObject

    "setup the converter to convert from a string to any smalltalk object

     and vice versa. The string used is the objects storeString.

     Invalid strings (i.e. empty) are converted to nil.

     This is a very special converter (for the GUI builder) 

     - probably not belonging to here"

    self

        getBlock:[:model |

                     model value storeString , ' "' , model value class name , '" '

                 ]

        putBlock:

                [:model :string |

                    |value|

                    value := Object readFrom:string onError:nil.

                    model value:value

                ]

        updateBlock: [:m :a :p | true]

    "Modified: / 26.10.1997 / 13:50:32 / cg"

    "Created: / 29.10.1997 / 15:50:16 / cg"

!

symbolOrNil

    "setup the converter to convert from a string to a symbol

     and vice versa. Invalid symbols (i.e. empty) are converted to nil;

     nil values are converted to an empty string."

    self

        getBlock:[:model |