Creating +a Linked Typeface

Once a linked typeface has been created any client may get a linked font +back in response to a request for the nearest font. When the Font Store searches +for the best match to the requested font specification, linked fonts are considered +alongside normal bitmap and open fonts. If a linked font represents the best +match, it is returned. As far as the client is concerned, the fact that it +is a linked font is invisible.

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.