It turned out that hb_font_t creation is not a lightweight operation.
Especially, Paint.hasGlyph creates hb_font_t for all existing fonts
every time. To improve the performance, cache hb_font_t instead
of hb_face_t.

Note that to calculate horizontal advance, MinikinPaint needs to be
associated with hb_font_t by calling hb_font_set_funcs. With this patch,
hb_font_set_funcs may be called multiple times for the same hb_font_t
object. However this is not an issue since MinikinPaint is unique
during layout.

Bug: 26784699

Change-Id: I516498ae9f0127d700fc9829327e9789845a1416

Bug: http://b/26781196
Bug: http://b/25884483
Bug: http://b/26432628

Although this issue was first only manifesting on Fugu, it now affects
N9 and N6p as well. This change disables unsigned overflow sanitization
on all platforms. The real fix for libc++ (r257368) can't be committed
until we have updated Clang at least one more time.

Change-Id: I71e9c50d25ae4566d4c06f348183c4b22a4bb60a

The intruduced method measureText can be used instead of
doLayout for text measurement purpose.

Bug: 24505153
Change-Id: Ic29bbb347daf18d1f6c13f86970dcdd11dd6a2bd

The motivation of this CL is enhance the font fallback score design
to support multiple language font fallback.

This CL contains following changes:
- Break language based font score into two: script-based score and
  primary-language-based score.
- The primary-language-based score is 0 if the script-based score is 0.
  If the script-based score is not 0 and the primary language is the
  as same as the requested one, the font gets an extra score of 1.
- The language score gets a higher multiplier for languages higher in
  the locale list.

Bug: 25122318
Bug: 26168983
Change-Id: Ib999997a88e6977e341f4c325e2a1b41a59db2d5

Make it so it's not possible to position the cursor inside an emoji
formed by a sequence including zero-width joiners.

Bug: 25368653
Change-Id: I67ec0874cd1505f3c82ab91492ffc3d39a52fae6

Make it so it's not possible to position the cursor inside an emoji
formed by a sequence including zero-width joiners.

Bug: 25368653
Change-Id: I67ec0874cd1505f3c82ab91492ffc3d39a52fae6

A corrupt or malicious font may have a negative size in its cmap
range, which in turn could lead to memory corruption. This patch
detects the case and rejects the font, and also includes an assertion
in the sparse bit set implementation if we missed any such case.

External issue:
https://code.google.com/p/android/issues/detail?id=192618

Bug: 26413177
Change-Id: Icc0c80e4ef389abba0964495b89aa0fae3e9f4b2

A corrupt or malicious font may have a negative size in its cmap
range, which in turn could lead to memory corruption. This patch
detects the case and rejects the font, and also includes an assertion
in the sparse bit set implementation if we missed any such case.

External issue:
https://code.google.com/p/android/issues/detail?id=192618

Bug: 26413177
Change-Id: Icc0c80e4ef389abba0964495b89aa0fae3e9f4b2

Disable unsigned-integer-overflow sanitizer on x86, as it crashes.

Bug: 25884483
Bug: 26432628
Change-Id: Ia658ed56a6c81660a36edf71f7116118056aa917

Enable signed and unsigned integer sanitization in libminikin.

Bug: 25884483
Change-Id: I98905827174d16138d20bb443fe2e1d7228ea1a3

This reverts commit 9c13a3dc.

Change-Id: Iecd1f61a5fdf5955d871a920cb243553857d46ff

The caller of FontFamily::hasVariationSelector needs to acquire the
lock before calling it, but FontCollection::hasVariationSelector
didn't acquire the lock. This caused a race condition.
This CL fixes this race condition.

Also, it turned out that assertMinikinLocked didn't assert even on
eng or userdebug device. This CL enables assertion on eng and userdebug
device since this assertion must be treated as bug.

BUG: 26323806

Change-Id: I9c4b1e1f09c6793e387fbdb8bb654cc0a13c65d5

Enable signed and unsigned integer sanitization in libminikin.

Bug: 25884483
Change-Id: I53abf6affea8e2bb3a5abd381a9f19003a306b36

The emoji variant script "Zsye" is registered in ISO 15924.

Bug: 26226285
Change-Id: Ibc2bc740d57c48f99b6f66b1ad7595bfa8c3cff4

This is 2nd attempt of I8df992a6851021903478972601a9a5c9424b100c.

The main purpose of this CL is expanding FontLanguage to be able to
save full script tag. Previously, FontLangauge kept only limited script
tags. With this CL, FontLanguage keeps all script tags.

This CL contains the following changes:
- FontLanguage changes:
-- Moved to private directory not to be instantiated outside of Minikin.
-- Removed bool(), bits(), FontLanguage(uint32_t) methods which are no
   longer used.
-- Change the FontLanguage internal data structure.
-- Introduces script match logic.

- FontLanguages changes:
-- Moved to private directory not to be instantiated outside of Minikin.
-- This is now std::vector<FontLanguage>

- FontLanguageListCache changes:
-- Now FontLanguageListCache::getId through
   FontStyle::registerLanguageList is the only way to instantiate the
   FontLanguage.
-- Normalize input to be BCP47 compliant identifier by ICU.

Bug: 26168983
Change-Id: I431b3f361a7635497c05b85e8ecbeb48d9aef63e

This reverts commit 5e995fb8.

Change-Id: I761e0e41906742fbe3d3ac34170af3101e18042a

The main purpose of this CL is expanding FontLanguage to be able to
save full script tag. Previously, FontLangauge kept only limited script
tags. With this CL, FontLanguage keeps all script tags.

This CL contains the following changes:
- FontLanguage changes:
-- Moved to private directory not to be instantiated outside of Minikin.
-- Removed bool(), bits(), FontLanguage(uint32_t) methods which are no
   longer used.
-- Change the FontLanguage internal data structure.
-- Introduces script match logic.

- FontLanguages changes:
-- Moved to private directory not to be instantiated outside of Minikin.
-- This is now std::vector<FontLanguage>

- FontLanguageListCache changes:
-- Now FontLanguageListCache::getId through
   FontStyle::registerLanguageList is the only way to instantiate the
   FontLanguage.
-- Normalize input to be BCP47 compliant identifier by ICU.

Bug: 26168983
Change-Id: I8df992a6851021903478972601a9a5c9424b100c

Replaced two instances of negating an unsigned long, which was
resulting in aborts from unsigned integer sanitization with the
equivalent logical not-add 1.

Bug: 25884483
Change-Id: Ic7498e0af638dcd438ce69803021d3cdc3acd4f6

Removing the extra score of 2 for the script matching from the font
fallback score calculation.  If the two langauges have different
scripts, we should treat them as different languages.

Change-Id: Ie0d6f27bd1086248895935a7bd01b5d404044ad0

FontLanguageListCache is an intentionally leaky singleton and its
internal cache won't be purged.

BUG: 25122318

Change-Id: I272097e979fe44b83fd86822235350e12eda8f51

If U+FE0E is appended to the emoji code point, the glyph should have a
text presentation.
On the other hand, if U+FE0F is appended to the emoji code point, the
glyph should have an emoji presentation.

Bug: 11256006
Change-Id: I5187d44500b13a138e7ffbcf2c72e2da06374c8c

A malformed TTF can cause size calculations to overflow. This patch
checks the maximum reasonable value so that the total size fits in 32
bits. It also adds some explicit casting to avoid possible technical
undefined behavior when parsing sized unsigned values.

Bug: 25645298
Change-Id: Id4716132041a6f4f1fbb73ec4e445391cf7d9616
(cherry picked from commit 183c9ec2)

A malformed TTF can cause size calculations to overflow. This patch
checks the maximum reasonable value so that the total size fits in 32
bits. It also adds some explicit casting to avoid possible technical
undefined behavior when parsing sized unsigned values.

Bug: 25645298
Change-Id: Id4716132041a6f4f1fbb73ec4e445391cf7d9616

To optimize the font family search, mRanges is used for narrowing down
the search range. However, mRanges is constructed from format 4 or
format 12 entries. So, if the font supports a variation sequence but doesn't
support the base character of the sequence, the font may not be listed in
mRanges.

The proper way to fix this issue is using format 14 subtable information
for mRanges construction. However, this is not a trivial work since currently
we rely on HarfBuzz for variation sequence lookup and it doesn't provide any
API for retrieving coverage information.

Thus, as the quick fix, iterate all font families in font fallback chain if
the variation sequence is specified.

Change-Id: I278da84be8fb8f553590e2e42ed450b7e4a34eca

To implement Paint.hasGlyph(), we need a new method to ask the
FontCollection if it has a glyph for the code point and variation
selector pair.

Bug: 11256006
Change-Id: Ie4185c91bcaa4d01aee6beb97784b1f9d2a88f12

Due to the way emoji ZWJ sequences are defined, the ICU line breaking
algorithm determines that there are valid line breaks inside the
sequence. This patch suppresses these line breaks.

Bug: 25433289
Change-Id: I225ebebc0f4186e4b8f48fee399c4a62b3f0218a

This patch basically ignores variation selectors for the purpose of
itemization into font runs. This allows GSUB to be applied when input
sequences contain variation selectors.

Bug: 25368653
Change-Id: I9c1d325ae0cd322c21b7e850d0ec4d73551b2372

This issue was introduced by I22ce0e9eadc941f84e3a9b23462f194e51dd7180.
Need to decrement the two utf16 chars in KEYCAP handling.

To add unit tests, this CL also addresses the Bug: 24184208 by
introducing self built fonts since there is no good example in system
installed fonts.

Bug: 24184208
Change-Id: I23fa008adbaced78a3cb96442a6bc8892ab84ce8

Due to the way emoji ZWJ sequences are defined, the ICU line breaking
algorithm determines that there are valid line breaks inside the
sequence. This patch suppresses these line breaks.

Bug: 25433289
Change-Id: I225ebebc0f4186e4b8f48fee399c4a62b3f0218a

This patch basically ignores variation selectors for the purpose of
itemization into font runs. This allows GSUB to be applied when input
sequences contain variation selectors.

Bug: 25368653
Change-Id: I9c1d325ae0cd322c21b7e850d0ec4d73551b2372

This is 2nd trial of I30a0914a4633bd93eb60957cdf378770f04d8428

- To suppress noisy unused parameter warnings, comment out unused
  arguments.
- Add -Werror for suppressing further warning.
- Add -Wall -Wextra for safety.
- Use "z" prefix for format string of size_t.

Verified that compile succeeded on all arm,arm64,mips,x86,x86_64.

Change-Id: I7ad208464486b8a35da53929cb1cfe541ed0052f

This reverts commit 63635cff.

Change-Id: I2b4b10e8afedc85dbe2d07f3e47315652b65cd14

- To suppress noisy unused parameter warnings, comment out unused
  arguments.
- Add -Werror for suppressing further warning.
- Add -Wall -Wextra for safety.

Change-Id: I30a0914a4633bd93eb60957cdf378770f04d8428

The behavior hasn't changed much yet: all languages are ignored for
rendering text, except the very first supported language.

Change-Id: I1695fb985927ae5e28e4f59c1b531e4993af8688

This CL contains the following changes:
- Add a variation selector argument into getFamilyForChar to be able to
  select fonts which support variation selector.
- In case no fonts support the codepoint and variation selector pair,
  add a fallback rule which selects font family with ignoring variation
  selector.
- Change FontCollection::itemize to not change the font family
  immediately preceding a variation selector.
- Introduce unit tests for variation selectors.

With this CL, TextView can render the variation selectors correctly.

Bug: 11256006
Change-Id: I22ce0e9eadc941f84e3a9b23462f194e51dd7180

MinikinFont:GetGlyph is no longer used.
No behavior chnages are expected with this CL.

Change-Id: I13398503841ac06f930b04815017d4b33338efa1

The previous commit, 6e2cccdc, was
incompletely cherry-picked. This adds the missing parts.

Bug: 24570591
Change-Id: I1097c60587fb8a88cfe6b8ffed5b1689d9bdd429

In the current state, hyphenation in all languages than Sanskrit seems
to work (case-folding edge cases). Thus, we just disable Sanskrit.
Packed tries are implemented, but not the finite state machine
(space/speed tradeoff).

This commit contains a throw-away test app, which runs on the host.
I think I want to replace it with unit tests, but I'm including it in
the CL because it's useful during development.

Bug: 21562869
Bug: 21826930
Bug: 23317038
Bug: 23317904
Bug: 24570591
Change-Id: I7479a565a4a062fa319651c2c14c0fa18c5ceaea
(cherry picked from commit f0be43de)

This CL introduces new method hasVariationSelector into FontFamily but it
is not used in production code. So no behavior changes are expected.

This CL contains the following changes:
- Introduce hasVariationSelector which returns true if the corresponding
  font has a glyph for a code point and variation selector pair.
- Introduce purgeHbFontCache since hb_face_t won't be released by
  keeping hb_font_t.
- Introduce unit tests with self-built font.

Change-Id: I659a6d03d9ec446b409e1fba2758452abb9f44fa

In the current state, hyphenation in all languages than Sanskrit seems
to work (case-folding edge cases). Thus, we just disable Sanskrit.
Packed tries are implemented, but not the finite state machine
(space/speed tradeoff).

This commit contains a throw-away test app, which runs on the host.
I think I want to replace it with unit tests, but I'm including it in
the CL because it's useful during development.

Bug: 21562869
Bug: 21826930
Bug: 23317038
Bug: 23317904

Change-Id: I7479a565a4a062fa319651c2c14c0fa18c5ceaea