Expose a method to purge caches used for TextLayout, useful for low
memory conditions.

Change-Id: I92f41afe987b7be4af5ca0a0c50fb51be35a2758

This patch includes an implementation of grapheme cluster breaking,
which is especially useful for repositioning the cursor for left and
right arrow key presses. The implementation is closely based on Unicode
TR29, and uses the ICU grapheme cluster break property, but is tailored
to more closely match the existing implementation and expected behavior.

Part of a fix for b/15653110 Improve behavior of arrow keys in EditText

Change-Id: I8eb742f77039c9ab7b2838285018cf8a8fc88343

Fixes b/15734816 In the text "Wi-Fi", "-Fi" appears bolder than "Wi"

The problem was caused by "stickiness" in choosing fonts, where layout
would prefer using a font used for preceding characters as long as it
mapped the following characters in a run, in favor of the "best match"
rules. This patch adds a whitelist for making the stickiness more
conservative, only applying it for characters necessary for correct
shaping (ZWJ and ZWNJ in particular) and basic punctuation, where it is
desirable to match the style of the preceding text.

Change-Id: I1cf116879f074a5a71c351846707bfdd07b0d320

* commit 'e68467e9':
  Tighten requirements for fake bold

* commit '15651697':
  Support for fake bold and italics

* commit 'b1eae5ea':
  Add baseFont method to FontCollection

The simple predicate for fake bold (2 or more grades darker than
requested) was applying it to thin (100 weight) when normal was
requested. This patch tightens the predicate to also require that
the requested weight be in the bold range.

Fix for bug 15588352 "sans-serif-thin doesn't work on lockscreen"

Change-Id: Id9988bd149a9c8a7c943e3b221f7fb4b37fb6ddb
(cherry picked from commit 9f9f3b1e)

The simple predicate for fake bold (2 or more grades darker than
requested) was applying it to thin (100 weight) when normal was
requested. This patch tightens the predicate to also require that
the requested weight be in the bold range.

Fix for bug 15588352 "sans-serif-thin doesn't work on lockscreen"

Change-Id: Id9988bd149a9c8a7c943e3b221f7fb4b37fb6ddb

Fix for bug 15570313 "Missing text on nonexistent font file"

This patch makes sure that the lastChar and mInstances arrays are in
sync with each other even when a FontFamily being added has no valid
fonts in it. Previously, when they got out of sync, unicode coverage
calculation would be wrong, resulting in missing text.

Change-Id: I69c727ef69e2c61e2b2d6b81d5a28c806327f865

This patch adds support for computing when fake bold and fake italics
are needed (because the styles are requested but not provided by the
matching FontFamily), and providing them as part of the layout result.

Part of the fix for bug 15436379 Fake bold doesn't fully work (Minikin)

Change-Id: I180c034b559837943673b5c272c8e890178dff0d

This patch adds a method to retrieve the base font from a
FontCollection, which is useful when querying global font metrics.

Part of the fix for bug 15467288 "Inconsistent line heights on
Minikin builds"

Change-Id: I268ae5128d0852a020d746bc22af81fc1a623228

This patch adds support for computing when fake bold and fake italics
are needed (because the styles are requested but not provided by the
matching FontFamily), and providing them as part of the layout result.

Part of the fix for bug 15436379 Fake bold doesn't fully work (Minikin)

Change-Id: I180c034b559837943673b5c272c8e890178dff0d

We want to test configurations where the Noto Japanese font will have
its "palt" feature (to select tighter spacing in kana) will be enabled
for framework but not WebView or Chrome rendering of Japanese text. This
patch simply hardcodes this feature on.

This is also a first step towards more general setting of OpenType
features. The hardcoded feature list will grow into one set by
parameters which will eventually be plumbed up to Java.

Change-Id: Ie284e0487a1434155c8ac1cb68ddc4fc4b3c018a

This patch adds a method to retrieve the base font from a
FontCollection, which is useful when querying global font metrics.

Part of the fix for bug 15467288 "Inconsistent line heights on
Minikin builds"

Change-Id: I268ae5128d0852a020d746bc22af81fc1a623228

* commit '89339973':
  Fix unmatching type

* commit '448b0fd7':
  Support for scaleX and skewX

This patch completes support for adding context for complex script
layout, for example when a string with joins straddles two spans.

Part of the fix for 15431028: "Properly support context for joining
scripts (Minikin)"

Change-Id: I65b0833be92eb477aa531bbef0ac6eddeb3a962a

Change internal plumbing of paint flags (including CssParse) to uint32_t
consistently, to match the type used in the client. This will probably
prevent compiler warnings. Also renames "float" to "double" to avoid
confusion about precision.

Change-Id: I80374712c4067ca9e7711cc2d4ec33c440ab9c7c

Missed a slightly mismatched type (int vs int32_t) from a previous code
review.

Change-Id: Ib56775a3a1a6ec3763da7f7432186954251cc048

Adds pseudo-css properties for scaleX and skewX, as well as paint flags,
and plumb them through to the MinikinPaint abstraction and to Harfbuzz,
to support nontrivial scale and stretch of text.

This is the Minikin part of the fix for bug 15186705 "Usability of the
suggestion strip in recent OTA's is severely reduced"

Change-Id: Ifa60355e086e4691ff92c5d50d84eb7cea0fea95

* commit '066e8575':
  Fix ZWJ not working for Indic fonts

* commit '7b221d97':
  Language and variant selection

This is a fix for bug 15185229 ZWJ not working in Sinhala and Kannada.

Indic fonts (unlike Arabic) require the entire string, including ZWJ,
to be passed to Harfbuzz; it's not enough for the ZWJ to be present in
the context. The solution is to be "sticky" in font itemization,
continuing to use the same font as long as it has Unicode coverage.

Change-Id: I7673bc56fbda09f1e1a4582e8d88342343b706f1

This patch adds a "lang" pseudo-CSS property and uses it both to select
an appropriate font and control the "locl" OpenType feature to get the
most appropriate rendering for the langauge and script.  In addition,
the "-minikin-variant" property selects between "compact" and "elegant"
variants of a font, as the former is needed for vertically cramped
spaces.

This is part of the fix for bug 15179652 "Japanese font isn't shown on
LMP".

Change-Id: I7fab23c12d4c797a6d339a16e497b79a3afe9df1

* commit '0297ee98':
  Fix for Minikin native crash

The context start offset wasn't being taken into account for
accumulating the advance values, leading in some cases to array index
overflow.

This is a fix for bug 15327918 "SIGSEGV in
android::MinikinFontSkia::GetSkTypeface()"

Change-Id: I9b646785724c9b72d862b822cd84661c106fbe52

* commit '7c382381':
  Fix for bug 15252902 native crash in Minikin

* commit '4d4e6bc8':
  Caching for layouts and harfbuzz faces

* commit 'd973b392':
  Do BiDi algorithm for text layout

This is a fix for bug 15252902 "Crash observed on keep launch or
existing youtube app after playing video". It was doing the test for a
null font after trying to resolve the font in a cache, which caused a
crash when there was no font for the run. This patch just tests before
cache lookup.

Change-Id: Iee41f7ce6b69cb09438462b6aaa916f242da7b77

This patch adds caching for both layouts and for HarfBuzz face objects.
The granularity of the cache for layouts is words, so it splits the
input string at word boundaries (using a heuristic). There are is also
some refactoring to reduce the amount of allocation and copying, and
movement towards properly supporting contexts.

The size of the caches is a fixed number of entries; thus, it is
possible to consume a large amount of memory by filling the cache with
lots of large strings. This should be refined towards a scheme that
bounds the total memory used by the cache.

This patch fixes bug 15237293 "Regression: Measure performance is
significantly slower with minikin".

Change-Id: Ie8176857e2d78656ce5479a7c04969819ef2718d

This is a fix for bug 15130102 "Language name for Hebrew displayed the
wrong way around on keyboard".

This patch extends the previous BiDi support (when the direction for the
entire string was given by the caller) to run the BiDi algorithm
(provided by ICU) over the string to break it into BiDi runs. Thus, it
handles mixed LTR and RTL strings in a single layout, and also respects
heuristics for inferring the paragraph direction from the string.

Change-Id: Ia4b869de3c139c5a7d16b8ce7766870b98a815ea
(cherry picked from commit 4b3a9411)

* commit '72fe9422':
  Fix native crash in Latin-1 typefaces

am b43357ad: merge in master-release history after reset to c31e3883

* commit 'b43357ad':
  Fix incomplete refcounting and locking

This is a fix for bug 15171911 Timely crashes (native crash in
libminikin) when I go to add a new alarm

This patch fixes an off-by-one error that caused typefaces with only one
page of Unicode coverage (ASCII or Latin-1) to have nPages = 0 instead
of the correct value of 1 in the corresponding FontCollection.

Change-Id: Id8be0c9e5713b8af22d863992921ee6382416a34

This patch adds caching for both layouts and for HarfBuzz face objects.
The granularity of the cache for layouts is words, so it splits the
input string at word boundaries (using a heuristic). There are is also
some refactoring to reduce the amount of allocation and copying, and
movement towards properly supporting contexts.

The size of the caches is a fixed number of entries; thus, it is
possible to consume a large amount of memory by filling the cache with
lots of large strings. This should be refined towards a scheme that
bounds the total memory used by the cache.

Change-Id: Ie8176857e2d78656ce5479a7c04969819ef2718d