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Commit a553477d authored by Seigo Nonaka's avatar Seigo Nonaka
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Make PrecomputedText Spannable for supporting selection

This is 2nd attempt of I072dfd70b9a687d9c47e310d8cdb34f988fbb32e

The root cause of crashing is unexpected copying of NoCopySpan by
SpannableString constructor. To prevent crashing, stop copying
NoCopySpan by passing ignoreNoCopySpan=true to SpannableString
copy constructor.

The original commit message is following:

To support selectable TextView, make PrecomputedText spannable.
By this change, TextView start using DynamicLayout instead of
StaticLayout. DynamicLayout requires boundary rectangle of the
text, so this CL also adds getBounds method to PrecomputedText
which retrieves measured boundary box from native.

By this change, the selectable TextView performance for the
precomputed text 10x faster. On the other hand, the performacne
for the non-selectable text gets 2.5x slower. However, we concluded
that we accept this performance regression since it still 10 times
faster than non precomputed text.

Here is a precomputed text performance result of TextView.
android.widget.TextViewPrecomputedTextPerfTest:
  newLayout_PrecomputedText           :    736,130 ->  1,648,694: (+124.0%)
  newLayout_PrecomputedText_Selectable: 17,379,765 ->  1,700,146: (-90.2%)
  onDraw_PrecomputedText              :  1,274,921 ->  1,848,076: (+45.0%)
  onDraw_PrecomputedText_Selectable   : 17,367,238 ->  1,399,169: (-91.9%)
  onMeasure_PrecomputedText           :    752,875 ->  1,766,606: (+134.6%)
  onMeasure_PrecomputedText_Selectable: 17,647,842 ->  1,810,704: (-89.7%)
  setText_PrecomputedText             :     92,894 ->    135,471: (+45.8%)
  setText_PrecomputedText_Selectable  :    145,134 ->    215,757: (+48.7%)

Bug: 72998298
Test: atest CtsWidgetTestCases:EditTextTest
    CtsWidgetTestCases:TextViewFadingEdgeTest
    FrameworksCoreTests:TextViewFallbackLineSpacingTest
    FrameworksCoreTests:TextViewTest FrameworksCoreTests:TypefaceTest
    CtsGraphicsTestCases:TypefaceTest CtsWidgetTestCases:TextViewTest
    CtsTextTestCases FrameworksCoreTests:android.text
    CtsWidgetTestCases:TextViewPrecomputedTextTest

Change-Id: Ie98c75d8b4ba962eaf0a544357b2ff1ade891118
parent 6a505e2d
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