Can one get a list of fonts available for text annotations in DM scripting? - dm-script

Question

One can create text annotations on image displays via the function NewTextAnnotation and then change the font via the method ComponentSetFontFaceName. However to do so successfully, one must provide the full name of the desired font as a string and one must already know that it is available on the current system. If one specifies an unavailable font, some default font seems to be chosen and no exception or error message is posted.
Is there any way to get a list of available fonts within a DM script or to determine whether a specific named font is actually available?

Answer 1

Interesting task!
There is no actual script command to do this, and the list of installed font-names is populated by the OS.
However, using Powershell and the script command LaunchExternal() one can construct a workaround.
After some trial and error, I think I got it working by the following script:
void WriteFontListToDisk( string fileName )
{
String PSscript
PSscript += "[System.Reflection.Assembly]::LoadWithPartialName('System.Drawing');"
PSscript += "(New-Object System.Drawing.Text.InstalledFontCollection).Families "
PSscript += " | out-file -encoding ASCII " + fileName // Need to specify ASCII here!
String callString
callString += "powershell"
//callString += " -NoExit" // Keep Powershell open
callString += " -Command &{ "
callString += PSscript
callString += " }"
LaunchExternalProcess( callString, 5 )
}
TagGroup ReadFontListFromFile( string fileName )
{
TagGroup tg = NewTagList()
if ( !DoesFileExist( fileName ) ) Throw( "Font list file not found:\n" + fileName )
number fileID = OpenFileForReading( fileName )
object fileStream = NewStreamFromFileReference( fileID, 1 )
result("\n SIZE:" + fileStream.StreamGetSize() )
// Output format is
// #1:(empty)
// #2: Name
// #3: ----
// #4+: FontNames
string line
for( number i=0;i<3;i++) fileStream.StreamReadTextLine( 0, line )
number inc = 0
while( fileStream.StreamGetPos() != fileStream.StreamGetSize() )
{
if ( !fileStream.StreamReadTextLine( 0, line ) ) break;
tg.TagGroupInsertTagAsString( Infinity(), line )
if ( ShiftDown() ) exit(0)
}
return tg
}
TagGroup GetFontList()
{
TagGroup tg = NewTagGroup()
string fileName = "C:\\FontNamesList.txt"
if ( DoesFileExist( fileName ) ) DeleteFile( fileName )
WriteFontListToDisk( fileName )
tg = ReadFontListFromFile( fileName )
if ( DoesFileExist( fileName ) ) DeleteFile( fileName )
return tg
}
GetFontList().TagGroupOpenBrowserWindow( "Fonts" , 0 )
It is worthwhile to note that PowerShell by default streams text output as UNICODE and that does not work well with text-import in DM. However, this question was helpful, and the script above sets the output to ASCII. One issue though is, that in doing so some characters might be lost and it might be needed to carefully check the output font-list.