"
 COPYRIGHT (c) 1992 by Claus Gittinger
              All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"

Object subclass:#Font
       instanceVariableNames:'family face style size encoding
                              device fontId replacementFont
                              ascent descent height width isFixedWidth
                              minWidth maxWidth'
       classVariableNames:'Lobby Replacements'
       poolDictionaries:''
       category:'Graphics-Support'
!

Font comment:'
COPYRIGHT (c) 1992 by Claus Gittinger
              All Rights Reserved
'!

!Font class methodsFor:'documentation'!

copyright
"
 COPYRIGHT (c) 1992 by Claus Gittinger
              All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"
!

version
"
$Header: /cvs/stx/stx/libview/Font.st,v 1.8 1994-06-03 00:52:31 claus Exp $
"
!

documentation
"
    Font represents fonts in a device independent manner; after being
    created using 'Font family:family face:face style:style size:size',
    the returned font is not associated to a specific device.

    To get a device font, any font can be sent the message
    'aFont on:aDevice' which returns an instance of Font which is
    associated to a device (it returns the receiver, if that is already
    associated to that device).

    For proper operation, each graphics operation working with fonts
    must get a device font before doing the draw.
    Most draw methods in DeviceDrawable do that automatically for you, 
    before doing the draw.

    Sometimes, a font cannot be represented on a device, then a replacement
    font is chosen and kept in the replacementFont instance variable. 

    Instance variables:

    family          <String>        the fonts family ('courier', 'helvetica' etc)
    face            <String>        the fonts face ('bold', 'medium' etc)
    style           <String>        the fonts style ('roman', 'italic', 'oblique')
    size            <String>        the fonts size (not in pixels) 
    encoding        <Symbol>        the fonts encoding (usually #iso8859)

    device          <Object>        the device the font is associated to, or nil
    fontId          <Object>        the id of the font on that device, or nil
    replacement     <Font>          the replacement font or nil

    ascent          <Integer>       the fonts ascent in device units on device
    descent         <Integer>       the fonts descent in device units on device
    height          <Integer>       the fonts height in device units on device
    width           <Integer>       the character width in device units on device
                                    (for variable fonts, its the width of a space)
    isFixedWidth    <Boolean>       true if font is a fixed width font
    minWidth        <Integer>       width of the smallest-width character in
                                    in device units on device
    maxWidth        <Integer>       width of the largest-width character in
                                    in device units on device

    class variables:

    Lobby           <Registry>      keeps track of all known fonts

    Replacements    <Dictionary>    replacement fonts
"
! !

!Font class methodsFor:'initialization'!

initialize
    "initialize the font tracking array"

    Lobby isNil ifTrue:[
        Lobby := Registry new.

        "want to be informed when returning from snapshot"
        ObjectMemory addDependent:self.

        Replacements := Dictionary new.

        Replacements at:'clean'                  put:'courier'.
        Replacements at:'fixed'                  put:'courier'.
        Replacements at:'new century schoolbook' put:'times'.
        Replacements at:'lucida'                 put:'helvetica'.
        Replacements at:'lucidabright'           put:'helvetica'.
        Replacements at:'lucidatypewriter'       put:'courier'.
        Replacements at:'charter'                put:'times'.
        Replacements at:'terminal'               put:'courier'.
    ]
!

flushDeviceFonts
    "unassign all fonts from their device"

    Lobby contentsDo:[:aFont |
        aFont restored.
        Lobby changed:aFont
    ]
!

update:something
    (something == #restarted) ifTrue:[
        self flushDeviceFonts
    ]
! !

!Font class methodsFor:'instance creation'!

family:familyString face:faceString style:styleString size:sizeNum
    "returns a font for given family, face, style and size. 
     The returned font is not associated to a specific device"

    ^ self family:familyString
           face:faceString
           style:styleString
           size:sizeNum
           encoding:#iso8859
!

family:familyString face:faceString style:styleString size:sizeNum encoding:encodingSym
    "returns a font for given family, face, style, size and encoding. 
     The returned font is not associated to s specific device"

    |family  "<String>"
     newFont "<Font>" |

    (familyString at:1) isUppercase ifTrue:[
        family := familyString asLowercase
    ] ifFalse:[
        family := familyString
    ].

    "look if this font is already known"

    Lobby contentsDo:[:aFont |
        (aFont family = family) ifTrue:[
            (aFont face = faceString) ifTrue:[
                (aFont style = styleString) ifTrue:[
                     (aFont size == sizeNum) ifTrue:[
                        (encodingSym isNil or:[aFont encoding == encodingSym]) ifTrue:[
                            ^ aFont
                        ]
                    ]
                ]
            ]
        ]
    ].
    newFont := self basicNew setFamily:familyString
                                  face:faceString
                                 style:styleString
                                  size:sizeNum
                              encoding:encodingSym
                                device:nil.
    Lobby register:newFont.
    ^ newFont
! !

!Font methodsFor:'instance release'!

disposed
    "some Font has been collected - tell it to the x-server"

    fontId notNil ifTrue:[
        device releaseFont:fontId.
    ]
! !

!Font methodsFor:'getting a device font'!

on:aDevice
    "create a new Font representing the same font as
     myself on aDevice; if one already exists, return the one."

    |newFont id rep|

    "if I am already assigned to that device ..."
    (device == aDevice) ifTrue:[^ self].

    "first look if not already there"
    Lobby contentsDo:[:aFont |
        (aDevice == aFont device) ifTrue:[
            (size == aFont size) ifTrue:[
                (family = aFont family) ifTrue:[
                    (face = aFont face) ifTrue:[
                        (style = aFont style) ifTrue:[
                            (encoding == aFont encoding) ifTrue:[
                                ^ aFont
                            ]
                        ]
                    ]
                ]
            ]
        ]
    ].

    "ask that device for the font"
    id := aDevice getFontWithFamily:family face:face style:style size:size encoding:encoding.
    id isNil ifTrue:[
        "oops did not work - (device has no such font)"

        rep := self replacementFontOn:aDevice.
        device isNil ifTrue:[
            device := aDevice.
            replacementFont := rep.
            Lobby changed:self.
            ^ self
        ].
        newFont := (self class basicNew)
                     setFamily:family face:face style:style size:size encoding:encoding device:aDevice.
        newFont setReplacementFont:rep.
        Lobby register:newFont.
        ^ newFont
    ].

    "receiver was not associated - do it now"
    device isNil ifTrue:[
        device := aDevice.
        fontId := id.

        self getFontInfos.
        Lobby changed:self.
        ^ self
    ].

    "receiver was already associated to another device - need a new font"
    newFont := (self class basicNew) setFamily:family 
                                          face:face
                                         style:style
                                          size:size
                                      encoding:encoding
                                        device:aDevice.
    newFont setFontId:id.
    newFont getFontInfos.
    Lobby register:newFont.
    ^ newFont
!

replacementFontOn:aDevice
    "return a replacement font for the receiver - this is needed, if
     an image is restored on another type of display, or one which has
     a different set of fonts."

    |id f alternative|

    alternative := Replacements at:family.
    alternative notNil ifTrue:[
        id := aDevice getFontWithFamily:alternative
                                   face:face
                                  style:style 
                                   size:size
                               encoding:encoding.
        id notNil ifTrue:[
            ('replaced ' , family , '- with ' , alternative , '-font') print.
        ] ifFalse:[
            id := aDevice getDefaultFont.
            ('replaced ' , family , '- with default-font') print.
        ]
    ].
    id isNil ifTrue:[
        "oops did not work - this is a serious an error"
        self error:'cannot get default font'.
        ^ nil
    ].
    f := self class basicNew.
    f setDevice:aDevice fontId:id.
    f getFontInfos.
    Lobby register:f.
    ^ f
! !

!Font methodsFor:'instance creation'!

bold
    "return the bold font corresponding to the receiver"

    ^ self class family:family face:'bold' style:style size:size encoding:encoding
! !

!Font methodsFor:'private'!

setFamily:familyString face:faceString style:styleString size:sizeNum encoding:encodingSym device:aDevice
    family := familyString.
    face := faceString.
    style := styleString.
    size := sizeNum.
    encoding := encodingSym.
    device := aDevice
!

restored
    device := nil.
    fontId := nil.
    replacementFont := nil
!

setReplacementFont:aFont
    replacementFont := aFont
!

setDevice:aDevice
    device := aDevice
!

setFontId:aFontId
    fontId := aFontId
!

setDevice:aDevice fontId:aFontId
    device := aDevice.
    fontId := aFontId
!

getFontInfos
    replacementFont isNil ifTrue:[
        ascent := device ascentOf:fontId.
        descent := device descentOf:fontId.
        height := descent + ascent.
        width := device widthOf:' ' inFont:fontId.
        minWidth := device minWidthOfFont:fontId.
        maxWidth := device maxWidthOfFont:fontId.
    ] ifFalse:[
        ascent := replacementFont ascent.
        descent := replacementFont descent.
        height := descent + ascent.
        width := replacementFont width.
        minWidth := replacementFont minWidth.
        maxWidth := replacementFont maxWidth.
    ].
    isFixedWidth := minWidth == maxWidth
! !

!Font methodsFor:'comparing'!

= aFont
    "two fonts are considered equal, if the font-name components are;
     independent of the device, the font is on"

    (aFont isKindOf:Font) ifTrue:[
        (size == aFont size) ifTrue:[
            (family = aFont family) ifTrue:[
                (face = aFont face) ifTrue:[
                    (style = aFont style) ifTrue:[
                        (encoding == aFont encoding) ifTrue:[
                            ^ true
                        ]
                    ]
                ]
            ]
        ]
    ].
    ^ false
! !

!Font methodsFor:'accessing'!

family
    "return the family, a string"

    ^ family
!

face
    "return the face, a string"

    ^ face
!

style
    "return the style, a string"

    ^ style
!

size
    "return the size, a number"

    ^ size
!

encoding
    "return the encoding, a symbol such as #iso8859"

    ^ encoding
!

fontId
    "return the device-dependent font-id"

    ^ fontId
!

device
    "return the device I am on"

    ^ device
! !

!Font methodsFor:'errors'!

errorNoDevice
    "a query was made for device-specific info"

    self error:'query device independent font for for device specific info'
! !

!Font methodsFor:'queries'!

isFixedWidth
    "return true, if all characters have same width (as in courier"

    device isNil ifTrue:[
        self errorNoDevice
    ].
    ^ isFixedWidth
!

height
    "return the characters maximum height;
     That is the number of units (usually pixels) on the device"

    device isNil ifTrue:[
        self errorNoDevice
    ].
    ^ height
!

width
    "return the characters width;
     That is the number of units (usually pixels) on the device.
     For variable pitch fonts, the width of the space character is returned"

    device isNil ifTrue:[
        self errorNoDevice
    ].
    ^ width
!

minWidth
    "return the width of the smallest character;
     if the receiver is a fixed width font its the width of every character"

    device isNil ifTrue:[
        self errorNoDevice
    ].
    ^ minWidth
!

maxWidth
    "return the width of the widest character;
     if the receiver is a fixed width font its the width of every character"

    device isNil ifTrue:[
        self errorNoDevice
    ].
    ^ maxWidth
!

ascent
    "return the font-ascent i.e. the maximum of all characters;
     That is the number of units (usually pixels) above the baseline"

    device isNil ifTrue:[
        self errorNoDevice
    ].
    ^ ascent
!

descent
    "return the font-descent i.e. the maximum of all characters;
     That is the number of units (usually pixels) below the baseline"

    device isNil ifTrue:[
        self errorNoDevice
    ].
    ^ descent
!

widthOf:aStringOrText
    "return the width (device specific) of the argument;
     the argument may be a String or some Text;
     in the later case the width of the longest line in the text is returned"

    |this max|

    device isNil ifTrue:[
        self errorNoDevice.
        ^ 0
    ].
    replacementFont notNil ifTrue:[
        ^ replacementFont widthOf:aStringOrText
    ].

    (aStringOrText isString) ifTrue:[
        isFixedWidth ifFalse:[
            ^ device widthOf:aStringOrText inFont:fontId
        ].
        ^ width * aStringOrText size
    ].

    max := 0.
    isFixedWidth ifFalse:[
        aStringOrText do:[:line |
            line notNil ifTrue:[
                this := device widthOf:line inFont:fontId.
                (this > max) ifTrue:[max := this]
            ]
        ].
        ^ max
    ].

    aStringOrText do:[:lineString |
        this := lineString size.
        (this > max) ifTrue:[max := this]
    ].
    ^ max * width
!

widthOf:aString from:start to:stop
    "return the width of a substring"

    device isNil ifTrue:[
        self errorNoDevice.
        ^ 0
    ].
    replacementFont notNil ifTrue:[
        ^ replacementFont widthOf:aString from:start to:stop
    ].
    (stop < start) ifTrue:[^ 0].
    isFixedWidth ifFalse:[
        ^ device widthOf:aString from:start to:stop inFont:fontId
    ].
    ^ (stop - start + 1) * width
! !

!Font methodsFor:'st-80 queries'!

serif
    "return true, if this font has serifs"

    "this should be done in a better way ..."

    family = 'Times' ifTrue:[^ true].
    family = 'times' ifTrue:[^ true].
    ^ false.
!

fixedWidth
    "return true, if this font is a fixed width font -
     for st-80 compatibility"

    ^ self isFixedWidth
!

pixelSize
    "return the height of the font in pixels -
     for st-80 compatibility"

    ^ self height
!

italic
    "return true if this is an italic font -
     for st-80 compatibility"

    face = 'italic' ifTrue:[^ true].
    face = 'obligue' ifTrue:[^ true].
    ^ false
!

boldness
    "return the boldness of the characters in this font 0 .. 1 -
     for st-80 compatibility"

    style = 'roman' ifTrue:[^ 0.5].
    style = 'normal' ifTrue:[^ 0.5].
    style = 'bold' ifTrue:[^ 0.75].
    style = 'light' ifTrue:[^ 0.25].
    ^ 0.5
! !

!Font methodsFor:'printing & storing'!

printString
    face isNil ifTrue:[
        ^ 'a ' , family , '-Font'
    ].
    ^ 'a ' , family , '-' , face , '-' , style , '-' , size printString , '-Font'
!

storeString
    "return a String with a representation of myself, from which I can be
     recreated"

    ^ ('(Font family:' , family ,
       ' face:' , face ,
       ' style:' , style ,
       ' size:' , size printString ,
       ' encoding:' , encoding storeString , ')')
! !

!Font methodsFor: 'binary storage'!

readBinaryContentsFrom: stream manager: manager
    "tell the newly restored Font about restoration"

    super readBinaryContentsFrom: stream manager: manager.
    self restored
! !