Creating a Linked Typeface

Example code

The following code example shows how to create, specify and then register a linked typeface.

// Create a typeface specification
CLinkedTypefaceSpecification *typefaceSpec;
    
// This is the name of the new linked typeface.
_LIT(KLinkedTypeface, "LinkedTypefaceTT") ;  
            
typefaceSpec = CLinkedTypefaceSpecification::NewLC( KLinkedTypeface );
    
// Create at least one linked typeface group.
// Each typeface in the linked font must be assigned to a group.
// The group specifies font characteristics.
const TUint KGroup1Id = 1 ; // group ID
CLinkedTypefaceGroup* group1 = CLinkedTypefaceGroup::NewLC( KGroup1Id ); 
     
// Italic angle is specified as a percentage. 
group1->SetItalicAngle( 30 ); 
group1->SetBaselineShift( ENoBaselineShift ); 
    
// Add the group to the typeface specification
typefaceSpec->AddLinkedTypefaceGroupL( *group1 );
CleanupStack::Pop(); // group1.
    
// Add additional groups...
const TUint KGroup2Id = 2; 
    
...
    
// Add first typeface by creating an element specification. 
// This must be the name of a font in the font store.
_LIT( KLinkedTypeface1, "LinkedFont1TT" );  
    
CLinkedTypefaceElementSpec *elementSpec1;
elementSpec1 = CLinkedTypefaceElementSpec::NewLC( KLinkedTypeface1, KGroup1Id );
    
// One typeface (not necessarily the first) must be set as the canonical typeface.
elementSpec1->SetCanonical( ETrue );
    
// Add the element to the typeface.
typefaceSpec->AddTypefaceAtBackL( *elementSpec1 );
CleanupStack::Pop() ;  // elementSpec1.
    
// Create and add additional element specifications.
    
...
    
elementSpecX = CLinkedTypefaceElementSpec::NewLC( KLinkedTypefaceX, KGroupNId );
    
...
    
typefaceSpec->AddTypefaceAtBackL( *elementSpecX );
    
...
    
// Register the linked typeface with the Typeface store.
// iDev is a previously created CFbsDevice.
CFbsTypefaceStore* typefaceStore = CFbsTypefaceStore::NewL( iDev ); 
CleanupStack::PushL( typefaceStore );
    
typefaceSpec->RegisterLinkedTypefaceL( *typefaceStore  );
CleanupStack::PopAndDestroy( 2, store );

The following code example shows one way of getting the nearest font to a specified font specification.

TFontSpec fontSpec;
fontSpec.iTypeface.iName = KRequiredTypeface;
fontSpec.iHeight = 20;
fontSpec.iFontStyle.SetBitmapType(EAntiAliasedGlyphBitmap);
    
// CFbsTypefaceStore
CFont* myFont;
tfstore->GetNearestFontToMaxHeightInPixelsL(myFont, fontSpec);
    
// CFbsBitGc
gc->UseFont(myFont);
...

Multiple linked typefaces

You can create any number of linked typefaces (subject to device resource limitations) as long as they all have different names. You can:

• use the same typeface as a component typeface in multiple linked typefaces

• create the same linked font multiple times in multiple clients

• create multiple linked fonts, with different specifications, from the same linked typeface

• create multiple linked fonts from different linked typefaces

• create linked typefaces that can contain nested linked typefaces, if supported by the font rasterizer.

The following constraints apply:

• The typefaces composing a linked typeface must be open typefaces. Bitmaps fonts are not supported.

• The linked typeface name must be unique.

• The typefaces in a linked typeface must be present when the linked typeface is registered.

• Linked typefaces cannot be deleted.