We changed the signature of the MinikinFont::GetTable method. This
patch updates the sample code, and fixes the build.

Change-Id: I1977be868bf7636986fc802915f3dd54c418a73a

The hb_font_t object holds on to tables of font data, acquired through
the MinikinFont::GetTable interface, which is based on copying data
into caller-owned buffers. Now that we're caching lots of hb_font_t's,
the cost of these buffers is significant.

This patch moves to a different interface, inspired by HarfBuzz's
hb_reference_table API, where the font can provide a pointer to the
actual font data (which will often be mmap'ed, so it doesn't even
consume physical RAM).

Bug: 27860101
Change-Id: Id766ab16a8d342bf7322a90e076e801271d527d4

This patch eagerly purges the corresponding hb_font_t object from
the HbFontCache when the underlying MinikinFont is destroyed. After
that, the key will no longer be accessed, so having the entry is
wastes memory.

Bug: 27251075
Bug: 27860101
Change-Id: I1b98016133fe3baf6525ac37d970a65ddccadb4f

Some fonts support multiple scripts, for example, some fonts for
Korean supports not only "Kore" but also "Jamo".

To select fonts based on their multiple languages, this CL introduces
the following changes:
- Compares all languages of the font family and use the maximum score
  for font selection.
- Even if each language of the font family doesn't support the requested
  language, the font get score of 2 if the requested font is covered by
  all of the languages of the font family. For example, the font for
  "ko-Hang,ko-Hani" gets score of 2 for the requested language "ko-Kore".

Bug: 26687969

Change-Id: I7f13b51464c9b01982bb573251d77052b9ddbd70

Indic combining marks, when combined with a common character such as
a hyphen or a dotted circle, used to get rendered in a different font
due to the greedy algorithm used in determining runs, which resulted
in the base character and the combining mark getting rendered in
separate font runs, resulting in a dotted circle appearing in phrases
such as "100-ാം" (0031 0030 0030 002D 0D3E 0D02).

This change makes combining marks change the font run of the base
character if the base character is supported in the same font as the
combining mark, similar to the support for emoji modifiers and the
combining keycap.

Bug: 25036888
Bug: 24535344
Change-Id: I8e2798e8ecb8efaf723a0fd02c05c6fbdef8b365

Implement the change proposed in UTC document L2/16-043R
(http://www.unicode.org/L2/L2016/16043r-line-break-pr-po.txt) to make
sure we do not break between letters and currency symbols.

Bug: 24959657
Change-Id: Ia29d0e5625f84870bd910d0c6e19036d17206704

Bug: 26808815
Change-Id: I2a5a52f2c441d27c7ef270342b4ef93c3de9e56e

Bug: 23288449
Change-Id: If1419ff9e44e8e640616979bae88311f414b42a1

I computed ranges using low <= c || c <= high, should be &&.

Bug: 26829153
Change-Id: Ic1002d90b6a408a0b415f2d117d0e57adcbc2fa9

An emoji base with an emoji modifier renders as a single glyph and
thus should not be a line break. Current (Unicode 8) logic does
indicate a line break, so we override the results of the ICU line
break iterator. The code references a proposal to improve Unicode
behavior; when that is adopted and we upgrade ICU accordingly, the
special-case code should be deleted, but the tests can remain.

Bug: 27343378
Change-Id: I5de9c53e9a34c503816f9131e3d894e6f7a57d13

If skin tone is specified, the base emoji should be emoji style even
if it is text presentation default emoji.

This patch also removes wrong test case which expects default emoji
presentation but it is controlled by family order in /etc/fonts.xml
and there is no special logic for default presentation in minikin.
Thus the default presentation unit test should not be in minikin.

Bug: 27342346

Change-Id: I74a2b2feab4d559535049e368cfd833063cce81c

An emoji with a modifier should be treated as a single grapheme, i.e.
it should not be possible to place the cursor between the base and
modifier.  This patch implements the proposed Rule GB9c from Mark
Davis's proposal entitled "Fixing breaking properties for emoji",
L2/16-011R3.

The patch also skips over variation sequences attached the to the
preceding character, for computing grapheme cluster boundaries.

Bug: 26829153
Change-Id: Iff5bc2bb8e5246223a017c7cf33acfbf63817f16

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.

This is an adaptation of I225ebebc0f4186e4b8f48fee399c4a62b3f0218a
into the nyc-dev branch.

Bug: 25433289
Change-Id: I84b50b1e6ef13d436965eab389659d02a30d100f

With this CL, measureText is used for getRunAdvance,
getOffsetForAdvance and line breaking.

Bug: 24505153
Change-Id: Ib699f6b1391b46537736fc274cdb41686586b550

In cases when a word (as defined by the ICU break iterator) overlaps a
style boundary, the returned wordStart can be extend before the range
currently being measured for layout. When we try to hyphenate the
resulting substrings, we get a negative range, which crashes. This
patch disables hyphenation in this case.

Bug: 27237112
Change-Id: I76d04b39dd3b4d6d267aaaf4bebc9ab361891646

Hanb is a union of Han and Bopomofo.

Bug: 26687969
Change-Id: Ic696bcbbc9607f3842fd0115668b8e7bd917e62b

Add error logging on invalid cmap - DO NOT MERGE am: 48e53074 am: d60a48cc  -s ours am: 4741030f am: c2792665  -s ours am: c2f0c7a8 am: cb14adf0
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* commit '00e9a7cd':
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am: c2792665  -s ours

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Recent changes have added special cases for line breaks within URLs
and email addresses. Such breaks are undesirable when they can be
avoided, but at other times are needed to avoid huge gaps, or indeed
to make the line fit at all.

This patch assigns a penalty for such breaks, equal to the hyphenation
penalty. The mechanism is currently very simple, but would be easy to
fine-tune based on more detailed information about break quality.

Bug: 20126487
Bug: 20566159
Change-Id: I0d3323897737a2850f1e734fa17b96b065eabd9c

This change adds accceptable line breaks according to sections 7.42
(Dividing URLs and e-mail addresses) and 14.12 (URLs or DOIs and line
breaks) of the Chicago Manual of Style (16th ed.). In general, these
place breaks before punctuation symbols, and suppresses them after
hyphens.

Bug: 20126487
Bug: 20566159
Change-Id: I2d07d516b920a506a2f718c38fb435c5eb1ee1f8

Detect URLs and email addresses, and suppress both line breaking and
hyphenation within them.

Bug: 20126487
Bug: 20566159

Change-Id: I43629347a063dcf579e355e5b678d7195f453ad9

Before this patch, the font fallback chain iterated all installed font
families if a variation selector was specified.

This CL narrows down the range of iteration.
To decide the font family for the variation sequence, we need to search
for both the variation sequence and its base code point.
The new range of the iteration is a union of them.

With this change, the running time of Paint.hasGlyph for the variation
sequence improves 50% and the running time of Paint.measureText for the
variation sequence improves 40% for the large text case on Nexus 6
userdebug.

Bug: 26784699
Bug: 11750374

Change-Id: Iced1349e3ca750821d8882c551551f65bb569794

Implement a WordBreaker that defines our concept of valid word
boundaries, customizing the ICU behavior. Currently, we suppress line
breaks at soft hyphens (these are handled specially). Also, the
new WordBreaker class has methods that determine the start and end
of the word (punctuation stripped) for the purpose of hyphenation.

This patch, in its current form, doesn't handle email addresses and
URLs specially, but the WordBreaker class is the correct place to do
so. Also, special case handling of hyphens and dashes is still done
in LineBreaker, but all of that should be moved to WordBreaker.

Bug: 20126487
Bug: 20566159
Change-Id: I492cbad963f9b74a2915f010dad46bb91f97b2fe

This patch logs instances of fonts with invalid cmap tables.

Bug: 25645298
Bug: 26413177
Change-Id: I183985e9784a97a2b4307a22e036382b1fc90e5e

This patch logs instances of fonts with invalid cmap tables.

Bug: 25645298
Bug: 26413177
Change-Id: I183985e9784a97a2b4307a22e036382b1fc90e5e

Removing variables in main function of sample/example.cpp as
they are not used.

Bug: 26936282
Change-Id: I64ae0a455b413df333ddd4810a9e090d52322041

Bug: 24505153
Change-Id: If61c063c175086dec88cda187eafd9ce923e4cb1

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