Smalltalk/X Webserver

Documentation of class 'CompoundFont':

Class: CompoundFont

Inheritance
Description
Class protocol
- instance creation
Instance protocol
Examples

Inheritance:

   Object
   |
   +--FontDescription
      |
      +--CompoundFont

Package:: stx:libview

Category:: Graphics-Support

Version:: rev: 1.13 date: 2023/08/02 11:47:58; user: cg; file: CompoundFont.st directory: libview; module: stx stc-classLibrary: libview

Description:

a CompountFont is a font which consists of character glyphs from multiple
other (base-)fonts; for each character code, an individual font may be given.

This has been mostly added to allow for non-EURO fonts to be used with ST/X,
by defining a mixedFont, which has an EURO-glyph at the desired character
position.
Do not hardCode usage of MixedFonts into your application, since they
might disappear in the future (when Unicode support has been fully 
implemented in ST/X, and Unicode fonts are generally available under X).
I.e. to use these fonts, add appropriate setup to the styleSheet,
or private.rc and use those fonts transparently.

[Instance variables:]

  baseFont                  <Font>          fallback (default-) font
  characterToFontMapping    <Dictionary>    maps characters to a fonts

[class variables:]

copyrightCOPYRIGHT (c) 1999 by Claus Gittinger / eXept Software AG
             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.

This is a demo example:

THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTOR ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTOR BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.

Class protocol:

instance creation

basedOn: aRealFont

Instance protocol:

accessing

baseFont: return the value of the instance variable 'baseFont' (automatically generated)
baseFont: something: set the value of the instance variable 'baseFont' (automatically generated)
glyphAt: char putFont: aFont: define an individual character to be drawn in another font
glyphsFrom: start to: stop putFont: aFont: define a range of characters to be drawn in another font
graphicsDevice: return the device I am on

converting

asSize: anotherPointSize: (comment from inherited method)
return another font corresponding to the receiver's family,
face and style but with another (point-) size

displaying

displayString: aString from: index1 to: index2 x: x0 y: y0 in: aGC opaque: opaque: this is only called for fonts which have a nil fontId,
and therefore use the replacementFont. Should never be called
for non-replacement fonts.

printing

userFriendlyName: (comment from inherited method)
return a user-friendly printed representation of the receiver

private

computeMaxBounds

fontFor: aCharacter

substringPartsOf: aString from: index1 to: index2 do: aBlock

helper - evaluate aBlock for parts of a string, which use the same font.
aBlock is invoked for consecutive substrings, passing the string,
the startIndex, endIndex and the font as arguments.

Usage example(s):

     |f|

     f := self new.
     f baseFont:#baseFont.
     f fontAt:$$ put:#font2.
     f substringPartsOf:'ae$a' from:1 to:8 
       do:[:s :i1 :i2 :f |
             Transcript 
                     show:i1; space;
                     show:i2; space;
                     showCR:f
          ]

queries

ascent: (comment from inherited method)
return the ascent - the number of pixels above the baseLine.
descent: (comment from inherited method)
return the descent - the number of pixels below the baseLine.
height: (comment from inherited method)
return the height - the number of pixels above plus below the baseLine.
isFixedWidth: return true, if this is a fixed pitch font
(i.e. all characters are of the same width)
maxAscent: (comment from inherited method)
return the font's maximum-ascent (i.e. the maximum of all characters);
That is the number of units (usually pixels) above the baseline.
maxDescent: (comment from inherited method)
return the font's maximum-descent (i.e. the maximum of all characters);
That is the number of units (usually pixels) below the baseline.
onDevice: aDevice: return a device representation of the receiver.
Since I am device independent, return the receiver.
size: (comment from inherited method)
return the size, a number
widthOf: aString from: index1 to: index2: (comment from inherited method)
return the width of a sub string

Examples:

a mixed font; all vowels are displayed in times; the rest in helvetica.

|font top list|

font := CompoundFont basedOn:(Font family:'courier' size:18).
#($a $e $i $o $u) do:[:char |
    font glyphAt:char putFont:(Font family:'times' size:18).
].
top := ScrollableView forView:(list := EditTextView new).
list font:font.
list list:#('a' 'z' 'aaa' 'zzz' 'azaz' 'zaza' 'aa' 'az' 'za' 'hello' 'abcdef' 'xyz').
top extent:200@200.
top open.

|font font2 top list|

font := CompoundFont basedOn:(Font family:'courier' size:18).
font2 := Font family:'times' size:24.

#($a $e $i $o $u $j) do:[:char |
    font glyphAt:char putFont:font2.
    font glyphAt:char asUppercase putFont:font2.
].
top := ScrollableView forView:(list := EditTextView new).
list font:font.
list list:#('hello' 'abcdefghijklmnopqrstuvwxyz' 'xyz'
            'HELLO' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'XYZ').
top extent:200@200.
top open.

a mixed font; the dollar character is replaced by the european EURO symbol; the rest is helvetica (this is a hack - we really need a resizable font for this):

|font baseFont euroGlyph glyphs euroFont top list|

baseFont := Font family:'helvetica' size:12.
baseFont := baseFont onDevice:Display.
glyphs := Array new:256.
euroGlyph := Form 
                width:12 
                height:16 
                fromArray:#( 
                            2r00000000 2r00000000
                            2r00000000 2r00000000
                            2r00000000 2r00000000
                            2r00000111 2r11000000
                            2r00001000 2r00100000
                            2r00010000 2r00000000
                            2r01111111 2r10000000
                            2r00010000 2r00000000
                            2r01111111 2r10000000
                            2r00010000 2r00000000
                            2r00001000 2r00100000
                            2r00000111 2r11000000
                            2r00000000 2r00000000
                            2r00000000 2r00000000
                            2r00000000 2r00000000
                            2r00000000 2r00000000
                           ).
glyphs at:($$ asciiValue+1) put:euroGlyph.

euroFont := BitmapFont new glyphs:glyphs.
euroFont setAscent:(baseFont ascent).
euroFont setDescent:(baseFont descent).

font := CompoundFont basedOn:baseFont.
font glyphAt:$$ putFont:euroFont.

top := ScrollableView forView:(list := EditTextView new).
list font:font.
list list:#('100 $' '193 DM').
top extent:200@200.
top open.

mix courier with a font which has emojis

|baseFont emojiFont mixedFont mixedFont2 top list|

baseFont := Font family:'courier' size:14.
baseFont := baseFont onDevice:Display.

emojiFont := Font family:'symbola' size:14.

mixedFont := CompoundFont basedOn:baseFont.
mixedFont glyphsFrom:0x1F600 to:0x1F6FF putFont:emojiFont.

top := ScrollableView forView:(list := EditTextView new).
list font:mixedFont.
list list:{ 'Hello Emoji',#(0x1f600) asUnicodeString}.
top extent:200@200.
top open.

mixedFont2 := mixedFont asSize:20.

top := ScrollableView forView:(list := EditTextView new).
list font:mixedFont2.
list list:{ 'Hello Emoji',#(0x1f600) asUnicodeString}.
top extent:200@200.
top open.

ST/X 7.7.0.0; WebServer 1.702 at 20f6060372b9.unknown:8081; Sat, 27 Jul 2024 08:33:09 GMT