Previously, in greedy line breaking, when a line overflowed, we found
the best line breaking candidate before it and broke the line there.
But we didn't check to see if the remaining part now fits in a line.

With this change, we now repeat checking for overflows, and break
again until we have no breaking opportunity or the remaining text now
fits in a line.

Also found an issue with greedy line breaking and keeping the
hyphenation edit for the next line which is now fixed.

Test: Manual. The issue reported in the bug is now fixed.
Bug: 34185255
Bug: https://code.google.com/p/android/issues/detail?id=231437
Bug: 33560754
Change-Id: I93bdd341e4f8e1257710e453e4938f224cb2a1ff

LayoutCache only keeps result of layout and can live after
FontCollection is destructed by GC.

This kind of failure will be captured by minikin_stress_tests in the
subsequent CL (I1bf4ba43e6e97cd04e7d6dd42d388dd17ce64c7b)

Test: ran minikin_tests
Bug: 36223724
Change-Id: I639b73c0f1041549158c43212a901c82df4b02db

Previously, we stayed on the conservative side and disallowed any
grapheme breaks (and thus cursoring) where a virama was followed by a
letter, since we did not know if the virama would be forming a
cluster with the letter or not. This created problems with Indic
languages with infrequent conjuncts, such as Tamil.

Now we use the information in calculated advances to find if a
cluster is formed. If there is no cluster, we break the grapheme and
allow cursoring after the virama.

Test: Unit tests added to GraphemeBreakTests and MeasurementTests.
Test: Also manually tested Tamil sequences.
Bug: 35721792
Change-Id: Ib159edb94b3ad6f693f0d3dad016b332b2cef447

This reverts commit 62ad5653.

Bug: 36208043
Test: N/A

Change-Id: I165ab7a0718ea50a8034adb6277809e271fd762c

To share the calculated coverage information across the processes, make
SparseBitSet serializable.

Bug: 34042446
Test: minikin_tests passes
Change-Id: I0463138adcf234739bb3ce1cdadf382021921f3e

This CL includes:
- Stop using utils/Mutex and use std::mutex instead.
- Stop using utils/Singleton.

Test: minikin_tests passed
Change-Id: Ib3f75b83397a546472bb5f91e066e44506e78263

This is 2nd attempt at I9e01d237c9adcb05e200932401cb1a4780049f86.

The previous CL was reverted because 8-bit integers were too small to
store the indices of mFamilyVec. This CL changes it to 16-bit integers
since size_t is still unnecessary large.

Theoretically, 32-bit integers are necessary for the indices of
mFamilyVec since the size of mFamilyVec can be 0x10EE01. However, in
practice, 16-bit integers are enough for the indices of mFamilyVec.
The length of mFamilyVec for the system fonts is 2084. Even if the
developers load their own very large fonts, it can only increase the
number of elements in mFamilyVec to at most 0x10FF.

As the result, memory usage of the FontCollections for the system fonts
decreases as follows.
64-bit process: before: 398,264 bytes, after: 282,568 bytes (-115,696 bytes)
32-bit process: before: 199,132 bytes, after: 149,548 bytes (-49,584 bytes)

Bug: 33562608
Test: Verified Emoji and CJK characters are present.
Test: android.text.cts.EmojiTest passed
Test: Minikin unit tests passed
Change-Id: I6796fd55ac30fe30528a212ebf6097b1d672e2f8

With this change, different languages can have a different minimum
length for suffix and prefixes when hyphenating. Previously, the
defaults used for English, 2 and 3, were used for every language.

Bug: 35712376
Test: Minikin unit tests were updated and the pass
Change-Id: Iffaf11c6b208c57d28d45b17246e177572dc1210

This adds better support for Arabic script languages, Armenian,
Catalan, Hebrew, Kannada, Malayalam, Polish, Tamil, and Telugu by
adding various hyphenation types and edits appropriate for the
locales.

For Arabic script languages, soft hyphens act transparently with
regard to joining: If a line is broken at a soft hyphen where the two
characters around the soft hyphen were joining each other before,
they will continue to appear joining if the line is broken at the
soft hyphen and a hyphen glyph is inserted.  This is needed for
Central Asian languages such as Uighur.

For Armenian, U+058A ARMENIAN HYPHEN is used for line breaks caused
by either automatic hyphenation or soft hyphens.

For Catalan, nonstandard line breaks are implemented for "l·l", which
hyphenates as "l-/l".

For Polish, when there is a line break at a hyphen, the hyphen is
repeated at the next line.

For the South Indic languages, when breaks happen due to soft breaks
or automatic hyphenation, no visible hyphen is inserted, although a
penalty is added.

For Hebrew, support for using U+05BE HEBREW PUNCTUATION MAQAF has
been implemented, but it's turned off pending confirmation of
desirability.

Also, hard hyphens, which previously had no penalty added for
breaking the line after them, now have the same penalty as an
automatic or soft break, with the difference that no hyphen is
inserted when they break.

Finally, some bugs have been fixed with hyphenating multiscript and
multi-font words.

Bug: 19950445
Bug: 19955011
Bug: 25623243
Bug: 26154469
Bug: 26154471
Bug: 33387871
Bug: 33560754
Bug: 33752592
Bug: 33754204
Test: Unit tests added, plus thorough manual testing
Change-Id: Iaccf776ce8d1d434ee8b1c534ff3659d80fdc338

Let's use shared_ptr since manual ref counting can be a bug-prone and
using the global mutex inside destructor is not useful for some time.

To remove raw pointer manipulation, needed to change Layout
constructors. Layout is no longer copyable and need to pass
FontCollection to constructor.

Bug: 28119474
Test: minikin_tests passed
Test: hwui_unit_tests passed
Test: No performance regression in minikin_perftest.
Change-Id: I8824593206ecba74cbc9731e298f045e1ae442a3

Test: None
Change-Id: I203d9ba7e1a1fcfdb10cd6a711d9a35136cbddd6

This is 2nd attempt of I08e9b74192f8af1d045f1276498fa4e60d73863e.
The original CL was reverted due to conflicting with another CL submitted
before.

Here is the original commit message of reverted change.

This lays the groundwork for variation settings support.
Since we should regard different variations of a font as different fonts, we
need to create new typefaces. To reuse the same instance of MinikinFont, as
much as possible, FontFamily::createFamilyWithVariation now reuses an
existence instance, while incrementing the reference count.

Test: minikin_tests
Bug: 33062398
Change-Id: Ib25bf1bb5a5191e15a6523954146521464c91906

This is 2nd attempt of 41e02e96
The difference is adding clearElementsEithLock to Font class which
is necessary to delete Fonts object outside of minikin. This method
should be removed once http://b/28119474 is fixed.

Here is original commit message of reverted change.

This lays the groundwork for making SparseBitSet serializable.
FontFamily.addFont is only used when the FontFamily is constructed.
Thus, instead of calling FontFamily.addFont multiple time, passes
Font list to the constructor. By this change, FontFamily can be
immutable now.

By making FontFamily immutable, We can create FontFamily with
pre-calculated SparseBitSet.

Bug: 34042446
Bug: 28119474
Bug: 34378805
Test: minikin_tests has passed
Change-Id: Ice433931196f5ae79a1a7ee0c98020f914aeb5f2

This reverts commit 41e02e96.

Bug: 34378805
Change-Id: I8f1ee00b365c8b17c6140e9e286fbea082e31364

This reverts commit 90e6b188.

Bug: 34378805
Change-Id: I22b683f774813724f220b1b8584ab188f3cf4fa7

This reverts commit c4b989fc.

Test: Manually tested
Bug: 34247671
Change-Id: I0510009b2deac784770f26059681b1980800abc8

This lays the groundwork for variation settings support.
Since we should regard different variations of a font as different fonts, we
need to create new typefaces. To reuse the same instance of MinikinFont, as
much as possible, FontFamily::createFamilyWithVariation now reuses an
existence instance, while incrementing the reference count.

Test: minikin_tests
Bug: 33062398
Change-Id: I08e9b74192f8af1d045f1276498fa4e60d73863e

This lays the groundwork for making SparseBitSet serializable.
FontFamily.addFont is only used when the FontFamily is constructed.
Thus, instead of calling FontFamily.addFont multiple time, passes
Font list to the constructor. By this change, FontFamily can be
immutable now.

By making FontFamily immutable, We can create FontFamily with
pre-calculated SparseBitSet.

Bug: 34042446
Test: minikin_tests has passed
Change-Id: I2576789fba6cb27687e920e2488e8bedbcf7d36f

Since switching to 64-bit devices, size_t is now a 64-bit integer.
FontCollection::Range uses two size_t integers but they just point to an index
in mFamilies. To reduce the memory usage, this CL changes the size_t integers to
uint8_t.

The maximum size of each integer in Range is the size of FontCollection::mFamilies.
The largest this can go is the system font list plus a user defined family, which
has 91 families. So an 8-bit integer should be enough.

With this change, about 84 KiB of memory will be saved per font collection. Since
eight font collections are created during bootstrap, about 670 KiB of memory will
be saved with this CL.

Bug: 33562608
Test: Ran FontCollection.collectionAllocationSizeTest on a 64-bit device.
      On my Nexus 5X, it changed from 327358 to 241342.

Change-Id: I9e01d237c9adcb05e200932401cb1a4780049f86

Add an "mJustified" for justification, and tune the line breaking to
produce good results. Major differences for fully justified text include:
- Space can be shrunk in justified text.
- Hyphenation should be more aggressive in justified text.

Also adds a penalty for the last line being very short. This is tuned
to be more aggressive for ragged right than for justified text.

This is based on a patch by Raph Levien (raph@google.com).

Bug: 31707212
Test: Manually tested with Icbfab2faa11a6a0b52e6f0a77a9c9b5ef6e191da
Change-Id: If366f82800831ccc247ec07b7bc28ca4c6ae0ed6

This is 2nd attempt of Ifcd7a348d7fb5af081192899dbcdfc7fb4eebbf9

After Id766ab16a8d342bf7322a90e076e801271d527d4, GetTable is no longer
used in production due to poor performance and it is now only used in
tests. This CL removes GetTable interface from MinikinFont and update
tests code to use new interfaces, GetFontData, GetFontSize and
GetFontIndex.

Bug: 27860101
Test: Manually done
Change-Id: Ib48973ff25cdc61a4c666d28128266df0aaea83e

Add a wordSpacing paint parameter, which will be used for
justification.

Bug: 31707212
Test: ran minikin_tests
Change-Id: I91224ab8ef882ac0c87425c28ab731fead283612

This reverts commit 1d525df4.

This causes a crash on Android Auto.

Bug: 32374752
Change-Id: Ia2ff77bf9a12351c6949f79ef6fa2d8016e3022d

After Id766ab16a8d342bf7322a90e076e801271d527d4, GetTable is no longer
used in production due to poor performance and it is now only used in
tests. This CL removes GetTable interface from MinikinFont and update
tests code to use new interfaces, GetFontData, GetFontSize and
GetFontIndex.

Bug: 27860101
Test: Manually done

Change-Id: Ifcd7a348d7fb5af081192899dbcdfc7fb4eebbf9

Bug: http://b/22403888
Change-Id: I9e18496fcc38ad2e6b922455daa9f2a46778ec55

* Add explicit keyword to conversion constructors,
  or add NOLINT(implicit) for implicit converters.
Bug: 28341362
Test: build with WITH_TIDY=1

Change-Id: I0c7b90f9bb953a9f2e4f0fb2032fa65ac604b9ca
Merged-In: I0c7b90f9bb953a9f2e4f0fb2032fa65ac604b9ca

* Add explicit keyword to conversion constructors,
  or add NOLINT(implicit) for implicit converters.
Bug: 28341362
Test: build with WITH_TIDY=1

Change-Id: I0c7b90f9bb953a9f2e4f0fb2032fa65ac604b9ca

Here is a new policy of the namespace of minikin.
- All components should be in minikin namespace.
- All tests are also in minikin namespace and no anonymous namespace.

Bug: 29233740
Change-Id: I71a8a35049bb8d624f7a78797231e90fed1e2b8c

Minikin has a special font fallback for VS15/VS16, so
hasVariationSelector for emojis with VS15/VS16 should always return
true.

Bug: 27531970
Change-Id: Ieebd58f48b135b6ec50d999df68dcc09b1284606

There was the possibility of stale indents from previous invocations
persisting in the mLineWidths across multiple invocations. This patch
clears them.

Bug: 28090810
Change-Id: I3621dfbe983512046289373711709aeade52eab4

This CL fixes following test cases in minikin_tests
- FontFamilyTest.hasVariationSelectorTest
- HbFontCacheTest.getHbFontLockedTest
- HbFontCacheTest.purgeCacheTest

For the fix of FontFamilyTest.hasVariationSelectorTest, removing virtual
from GetUniqueId() in MinikinFont.  After [1], MinikinFont's destructor
started calling purgeHbCache() which calls virtual method,
MinikinFont::GetUniqueId().  Fortunately, the SkTypeface::uniqueID()
returns just internal value, so we can store it at the construction time
and use it instead of calling SkTypeface::uniqueID() every time.

This patch also changes purgeHbFont to purgeHbFontLocked, as all uses of
it were already under global mutex. This change avoids deadlock on
explicit unref, as when invoked by a Java finalizer from the Java object
that holds a reference to the font.

Some of the tests needed to change to using the ref counting protocol
rather than explicitly destructing font objects, as well.

[1] 9afcc6e2

Bug: 28105730
Bug: 28105688
Change-Id: Ie5983c4869147dacabdca81af1605066cd680b3f

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

Bug: 26808815
Change-Id: I2a5a52f2c441d27c7ef270342b4ef93c3de9e56e

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

Bug: 24505153
Change-Id: Ib699f6b1391b46537736fc274cdb41686586b550

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