1457103 - Implement missing variation-font query APIs in the Android (FT2Fonts) backend

Status: RESOLVED FIXED

(Core :: Graphics: Text, enhancement)

Description

[Jonathan Kew [:jfkthame]]

The FT2Fonts backend doesn't provide overrides for the (empty) default implementations of gfxFontEntry::HasVariations(), GetVariationAxes(), and GetVariationInstances(). This will (I believe) prevent the font inspector working fully for variation fonts when targetting Firefox on Android, even though the fonts work OK for rendering.

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: patch 1 - Make gfxFontEntry::HasVariations a pure-virtual method, and fill in missing subclass implementations, particularly in FT2FontEntry

Comment 2

[Jonathan Kew [:jfkthame]]

Attachment: patch 2 - Refactor logic from gfxFontconfigFontEntry implementations of GetVariationAxes and GetVariationInstances to gfxFT2Utils, where it can be shared by the gfxFT2Fonts backend

Comment 3

[Jonathan Kew [:jfkthame]]

Attachment: patch 3 - Make gfxFontEntry::GetVariationAxes and GetVariationInstances pure virtual, and provide missing subclass implementations

Comment 4

[Jonathan Watt [:jwatt]]

Comment on attachment 8971290 [details] [diff] [review]
patch 3 - Make gfxFontEntry::GetVariationAxes and GetVariationInstances pure virtual, and provide missing subclass implementations

Review of attachment 8971290 [details] [diff] [review]:
-----------------------------------------------------------------

::: gfx/thebes/gfxFontEntry.h
@@ +365,5 @@
>  
>      bool SupportsScriptInGSUB(const hb_tag_t* aScriptTags);
>  
> +    // For variation font support; font backends that don't support variations
> +    // should provide empty implementations.

Doxygen style while you're here, please.

@@ +370,2 @@
>      virtual bool HasVariations() = 0;
> +    

Remove white space on empty line.

@@ +370,5 @@
>      virtual bool HasVariations() = 0;
> +    
> +    virtual void
> +    GetVariationAxes(nsTArray<gfxFontVariationAxis>& aVariationAxes) = 0;
> +    

Remove white space on empty line.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/46864f33859e
patch 1 - Make gfxFontEntry::HasVariations a pure-virtual method, and fill in missing subclass implementations, particularly in FT2FontEntry. r=jwatt
https://hg.mozilla.org/integration/mozilla-inbound/rev/c4e1dc66dae2
patch 2 - Refactor logic from gfxFontconfigFontEntry implementations of GetVariationAxes and GetVariationInstances to gfxFT2Utils, where it can be shared by the gfxFT2Fonts backend. r=jwatt
https://hg.mozilla.org/integration/mozilla-inbound/rev/f1c7ad9294b3
patch 3 - Make gfxFontEntry::GetVariationAxes and GetVariationInstances pure virtual, and provide missing subclass implementations. r=jwatt

Comment 6

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/46864f33859e
https://hg.mozilla.org/mozilla-central/rev/c4e1dc66dae2
https://hg.mozilla.org/mozilla-central/rev/f1c7ad9294b3