Android Text: The good 😎, the bad 😳, the ugly 🥴 (droidcon NYC 2018)

Learn about internals of Android Text stack, starting with TextView and EditText. The talk focuses on how to effectively use various features of text stack in order to improve functionality and performance of your applications.

See related resources at https://github.com/siyamed/droidcon-nyc-18

Transcript

1. @siyamed Android Text The good , the bad , the ugly Siyamed Sinir Android Text @ Google
2. • Performance • Editable Text
3. Performance Performance • Scrolling screen • With some text
4. Performance • No measurement, no improvement
5. Performance • No measurement, no improvement • Results differ with environment setup, input
6. Performance • No measurement, no improvement • Results differ with environment setup, input • Tradeoffs, performance vs ◦ Effort ◦ Design ◦ Maintainability/Extensibility ◦ CPU/Memory ◦ ….
7. Turn off default hyphenation 2.5x text layout performance improvement Very cheap to implement
8. Turn off default hyphenation 2.5x text layout performance improvement Very cheap to implement Introduced on M 66% of devices* * https://developer.android.com/about/dashboards/
9. How to turn off default hyphenation res/values/styles.xml <style name="AppTheme" parent="Theme.AppCompat.Light"> <item name="android:textViewStyle">@style/MyTextViewStyle</item> </style>
10. How to turn off default hyphenation res/values/styles.xml <style name="BaseTextViewStyle" parent="android:Widget.TextView"/> <style name="MyTextViewStyle" parent="BaseTextViewStyle"> <item name="android:hyphenationFrequency">none</item> </style>
11. How to turn off default hyphenation res/values/styles.xml <style name="BaseTextViewStyle" parent="android:Widget.TextView"/> <style name="MyTextViewStyle" parent="BaseTextViewStyle"> <item name="android:hyphenationFrequency">none</item> </style> // res/values-21/styles.xml <style name="BaseTextViewStyle" parent="android:Widget.Material.TextView"/>
12. Prefetch & Precomputed Text up to 10x text layout performance improvement Very cheap to implement androidx:1.0.0-rc01
13. Prefetch RecyclerView & PrecomputedText override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) { viewHolder.txtContent.text = dataSet[index] }
14. Prefetch RecyclerView & PrecomputedText override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) { // viewHolder.txtContent.text = dataSet[index] viewHolder.txtContent.setTextFuture( PrecomputedTextCompat.getTextFuture( dataSet[index], viewHolder.txtContent.textMetricsParamsCompat, null/* executor */ ) ) }
15. Prefetch RecyclerView & PrecomputedText override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) { // viewHolder.txtContent.text = dataSet[index] viewHolder.txtContent.setTextFuture( // run when idle PrecomputedTextCompat.getTextFuture( // pre measure text dataSet[index], // with this CharSequence viewHolder.txtContent.textMetricsParamsCompat,// and display config null/* executor */ ) ) }
16. View UI Thread text setText onMeasure
17. View UI Thread text setText measure text onMeasure
18. View UI Thread Bg Thread text measure text Precomputed Text 1 setText onMeasure
19. View UI Thread setText onMeasure Bg Thread text measure text Precomputed Text 1 2
20. PrecomputedText added in Android P PrecomputedTextCompat in androidX
21. Native Text measurement Hel + + + + H e l o Font H 65 e 48 l 6C l 6C o 6F Word Layout LRU Cache Native 5K items (since Android L)
22. GoogleSans-Regular.ttf GoogleSans-Italic.ttf GoogleSans-Medium.ttf GoogleSans-MediumItalic.ttf GoogleSans-Bold.ttf GoogleSans-BoldItalic.ttf Roboto-Thin.ttf Roboto-ThinItalic.ttf Roboto-Light.ttf Roboto-LightItalic.ttf Roboto-Regular.ttf Roboto-Italic.ttf Roboto-Medium.ttf Roboto-MediumItalic.ttf Roboto-Black.ttf Roboto-BlackItalic.ttf Roboto-Bold.ttf Roboto-BoldItalic.ttf RobotoCondensed-Light.ttf RobotoCondensed-LightItalic.ttf RobotoCondensed-Regular.ttf RobotoCondensed-Italic.ttf RobotoCondensed-Medium.ttf RobotoCondensed-MediumItalic.ttf RobotoCondensed-Bold.ttf RobotoCondensed-BoldItalic.ttf NotoSerif-Regular.ttf NotoSerif-Bold.ttf NotoSerif-Italic.ttf NotoSerif-BoldItalic.ttf DroidSansMono.ttf CutiveMono.ttf ComingSoon.ttf DancingScript-Regular.ttf DancingScript-Bold.ttf CarroisGothicSC-Regular.ttf NotoNaskhArabic-Regular.ttf NotoNaskhArabic-Bold.ttf NotoNaskhArabicUI-Regular.ttf NotoNaskhArabicUI-Bold.ttf NotoSansEthiopic-Regular.ttf NotoSansEthiopic-Bold.ttf NotoSerifEthiopic-Regular.otf NotoSerifEthiopic-Bold.otf NotoSansHebrew-Regular.ttf NotoSansHebrew-Bold.ttf NotoSerifHebrew-Regular.ttf NotoSerifHebrew-Bold.ttf NotoSansThai-Regular.ttf NotoSansThai-Bold.ttf NotoSerifThai-Regular.ttf NotoSerifThai-Bold.ttf NotoSansThaiUI-Regular.ttf NotoSansThaiUI-Bold.ttf NotoSansArmenian-Regular.otf NotoSansArmenian-Medium.otf NotoSansArmenian-Bold.otf NotoSerifArmenian-Regular.otf NotoSerifArmenian-Bold.otf NotoSansGeorgian-Regular.otf NotoSansGeorgian-Medium.otf NotoSansGeorgian-Bold.otf NotoSerifGeorgian-Regular.otf NotoSerifGeorgian-Bold.otf NotoSansDevanagari-Regular.otf NotoSansDevanagari-Medium.otf NotoSansDevanagari-Bold.otf NotoSerifDevanagari-Regular.ttf NotoSerifDevanagari-Bold.ttf NotoSansDevanagariUI-Regular.otf NotoSansDevanagariUI-Medium.otf NotoSansDevanagariUI-Bold.otf NotoSansGujarati-Regular.ttf NotoSansGujarati-Bold.ttf NotoSerifGujarati-Regular.ttf NotoSerifGujarati-Bold.ttf NotoSansGujaratiUI-Regular.ttf NotoSansGujaratiUI-Bold.ttf NotoSansGurmukhi-Regular.ttf NotoSansGurmukhi-Bold.ttf NotoSerifGurmukhi-Regular.otf NotoSerifGurmukhi-Bold.otf NotoSansGurmukhiUI-Regular.ttf NotoSansGurmukhiUI-Bold.ttf NotoSansTamil-Regular.otf NotoSansTamil-Medium.otf NotoSansTamil-Bold.otf NotoSerifTamil-Regular.otf NotoSerifTamil-Bold.otf NotoSansTamilUI-Regular.otf NotoSansTamilUI-Medium.otf NotoSansTamilUI-Bold.otf NotoSansMalayalam-Regular.otf NotoSansMalayalam-Medium.otf NotoSansMalayalam-Bold.otf NotoSerifMalayalam-Regular.ttf NotoSerifMalayalam-Bold.ttf NotoSansMalayalamUI-Regular.otf NotoSansMalayalamUI-Medium.otf NotoSansMalayalamUI-Bold.otf NotoSansBengali-Regular.otf NotoSansBengali-Medium.otf NotoSansBengali-Bold.otf NotoSerifBengali-Regular.ttf NotoSerifBengali-Bold.ttf NotoSansBengaliUI-Regular.otf NotoSansBengaliUI-Medium.otf NotoSansBengaliUI-Bold.otf NotoSansTelugu-Regular.ttf NotoSansTelugu-Bold.ttf NotoSerifTelugu-Regular.ttf NotoSerifTelugu-Bold.ttf NotoSansTeluguUI-Regular.ttf NotoSansTeluguUI-Bold.ttf NotoSansKannada-Regular.ttf NotoSansKannada-Bold.ttf NotoSerifKannada-Regular.ttf NotoSerifKannada-Bold.ttf NotoSansKannadaUI-Regular.ttf NotoSansKannadaUI-Bold.ttf NotoSansOriya-Regular.ttf NotoSansOriya-Bold.ttf NotoSansOriyaUI-Regular.ttf NotoSansOriyaUI-Bold.ttf NotoSansSinhala-Regular.otf NotoSansSinhala-Medium.otf NotoSansSinhala-Bold.otf NotoSerifSinhala-Regular.otf NotoSerifSinhala-Bold.otf NotoSansSinhalaUI-Regular.otf NotoSansSinhalaUI-Medium.otf NotoSansSinhalaUI-Bold.otf NotoSansKhmer-VF.ttf NotoSansKhmer-VF.ttf NotoSansKhmer-VF.ttf NotoSansKhmer-VF.ttf NotoSansKhmer-VF.ttf NotoSansKhmer-VF.ttf NotoSansKhmer-VF.ttf NotoSansKhmer-VF.ttf NotoSansKhmer-VF.ttf NotoSerifKhmer-Regular.otf NotoSerifKhmer-Bold.otf NotoSansKhmerUI-Regular.ttf NotoSansKhmerUI-Bold.ttf NotoSansLao-Regular.ttf NotoSansLao-Bold.ttf NotoSerifLao-Regular.ttf NotoSerifLao-Bold.ttf NotoSansLaoUI-Regular.ttf NotoSansLaoUI-Bold.ttf NotoSansMyanmar-Regular.otf NotoSansMyanmar-Medium.otf NotoSansMyanmar-Bold.otf NotoSerifMyanmar-Regular.otf NotoSerifMyanmar-Bold.otf NotoSansMyanmarUI-Regular.otf NotoSansMyanmarUI-Medium.otf NotoSansMyanmarUI-Bold.otf NotoSansThaana-Regular.ttf NotoSansThaana-Bold.ttf NotoSansCham-Regular.ttf NotoSansCham-Bold.ttf NotoSansAhom-Regular.otf NotoSansAdlam-Regular.ttf NotoSansAvestan-Regular.ttf NotoSansBalinese-Regular.ttf NotoSansBamum-Regular.ttf NotoSansBatak-Regular.ttf NotoSansBrahmi-Regular.ttf NotoSansBuginese-Regular.ttf NotoSansBuhid-Regular.ttf NotoSansCanadianAboriginal-Regular.ttf NotoSansCarian-Regular.ttf NotoSansChakma-Regular.ttf NotoSansCherokee-Regular.ttf NotoSansCoptic-Regular.ttf NotoSansCuneiform-Regular.ttf NotoSansCypriot-Regular.ttf NotoSansDeseret-Regular.ttf NotoSansEgyptianHieroglyphs-Regular.ttf NotoSansElbasan-Regular.otf NotoSansGlagolitic-Regular.ttf NotoSansGothic-Regular.ttf NotoSansHanunoo-Regular.ttf NotoSansImperialAramaic-Regular.ttf NotoSansInscriptionalPahlavi-Regular.ttf NotoSansInscriptionalParthian-Regular.ttf NotoSansJavanese-Regular.ttf NotoSansKaithi-Regular.ttf NotoSansKayahLi-Regular.ttf NotoSansKharoshthi-Regular.ttf NotoSansLepcha-Regular.ttf NotoSansLimbu-Regular.ttf NotoSansLinearB-Regular.ttf NotoSansLisu-Regular.ttf NotoSansLycian-Regular.ttf NotoSansLydian-Regular.ttf NotoSansMandaic-Regular.ttf NotoSansMeeteiMayek-Regular.ttf NotoSansNewTaiLue-Regular.ttf NotoSansNKo-Regular.ttf NotoSansOgham-Regular.ttf NotoSansOlChiki-Regular.ttf NotoSansOldItalic-Regular.ttf NotoSansOldPersian-Regular.ttf NotoSansOldSouthArabian-Regular.ttf NotoSansOldTurkic-Regular.ttf NotoSansOsage-Regular.ttf NotoSansOsmanya-Regular.ttf NotoSansPhoenician-Regular.ttf NotoSansRejang-Regular.ttf NotoSansRunic-Regular.ttf NotoSansSamaritan-Regular.ttf NotoSansSaurashtra-Regular.ttf NotoSansShavian-Regular.ttf NotoSansSundanese-Regular.ttf NotoSansSylotiNagri-Regular.ttf NotoSansSyriacEstrangela-Regular.ttf NotoSansSyriacEastern-Regular.ttf NotoSansSyriacWestern-Regular.ttf NotoSansTagalog-Regular.ttf NotoSansTagbanwa-Regular.ttf NotoSansTaiTham-Regular.ttf NotoSansTaiViet-Regular.ttf NotoSansTibetan-Regular.ttf NotoSansTibetan-Bold.ttf NotoSansTifinagh-Regular.ttf NotoSansUgaritic-Regular.ttf NotoSansVai-Regular.ttf NotoSansSymbols-Regular-Subsetted.ttf NotoSansCJK-Regular.ttc NotoSerifCJK-Regular.ttc NotoSansCJK-Regular.ttc NotoSerifCJK-Regular.ttc NotoSansCJK-Regular.ttc NotoSerifCJK-Regular.ttc NotoSansCJK-Regular.ttc NotoSerifCJK-Regular.ttc NotoColorEmoji.ttf NotoSansSymbols-Regular-....ttf NotoSansTaiLe-Regular.ttf NotoSansYi-Regular.ttf NotoSansMongolian-Regular.ttf NotoSansPhagsPa-Regular.ttf NotoSansAnatolianHieroglyphs-....otf NotoSansBassaVah-Regular.otf NotoSansBhaiksuki-Regular.otf NotoSansHatran-Regular.otf NotoSansLinearA-Regular.otf NotoSansManichaean-Regular.otf NotoSansMarchen-Regular.otf NotoSansMeroitic-Regular.otf NotoSansMiao-Regular.otf NotoSansMro-Regular.otf NotoSansMultani-Regular.otf NotoSansNabataean-Regular.otf NotoSansNewa-Regular.otf NotoSansOldNorthArabian-Regular.otf NotoSansOldPermic-Regular.otf NotoSansPahawhHmong-Regular.otf NotoSansPalmyrene-Regular.otf NotoSansPauCinHau-Regular.otf NotoSansSharada-Regular.otf NotoSansSoraSompeng-Regular.otf
23. (Text)Layout is a blueprint for text This is an example text Native measurement / line breaking This is an example text top: x1 descent: y1 top: x2 descent: y2 top padding bottom padding start index LTR 2 lines end index
24. PrecomputedText Hel + + + + = PrecomputedText.create(“Hello”, params) text Native reference word layout result tradeoff: uses memory (20K for 500 chars)
25. PrecomputedText. Params Parameters that would change text measurement Requires a TextPaint but not a TextView
26. Utility functions you don’t necessarily need TextView to create PrecomputedText TextView.getTextMetricsParams AppCompatTextView.getTextMetricsParamsCompat
27. PrecomputedTextCompat
28. measure text measure TextView onMeasure() draw text draw TextView onDraw() Word Layout LRU Cache So What? draw needs word layout objects
29. Performance cont’d
30. Inflation cost ...creating the necessary TextViews (around 40 for more) is responsible for a significant part of the overall view inflation cost (about 30 ms on a Pixel) “ ” An Android Developer
31. To improve inflation Create less TextViews maybe?
32. <CardView ...> <TextView android:id="@+id/username" android:textAppearance="@style/Username" .../> <TextView android:id="@+id/title" android:textAppearance="@style/Title" ..../> Inflation
33. <CardView ...> <TextView android:id="@+id/username_title" .../> Inflation val spannable = SpannableString(username_and_title); spannable.setSpan( TextAppearanceSpan(cxt, R.style.Username)... spannable.setSpan( TextAppearanceSpan(cxt, R.style.Title)...
34. <CardView ...> <TextView android:id="@+id/username_title" .../> Inflation val spannable = SpannableString(username_and_title); spannable.setSpan( TextAppearanceSpan(cxt, R.style.Username)... spannable.setSpan( TextAppearanceSpan(cxt, R.style.Title)... tradeoff
35. TextView.setText might copy CharSequences and dereference causing CPU & GC cost
36. Why Important Data Views setText() RecycleView copy CharSequence throw away old one
37. class InputFilter changes input TextView setText(CharSequence s) filter() mText = result InputFilter
38. class InputFilter ex: EmojiCompat Emoji InputFilter String( Some emoji here ) Spannned( Some here )
39. CharSequence type TextView guards against external changes if (type == BufferType.EDITABLE ...) { Editable t = mEditableFactory.newEditable(text); .... } else if (precomputed != null) { ... } else if (type == BufferType.SPANNABLE ...) { text = mSpannableFactory.newSpannable(text); } else if (!(text instanceof CharWrapper)) { text = TextUtils.stringOrSpannedString(text); } if mutable then copy copy copy copy
40. class TransformationMethod change displayed text setText(CharSequence s) getTransformation() TextView mText = s mTransformed = TransformationMethod
41. class TransformationMethod ex: All Caps AllCapsTransformationMethod String( “username” ) String( “USERNAME”) mText =”username” mTransformed = “USERNAME” <TextView android:text="username" android:textAllCaps="true" .../>
42. Keep an eye on TextView copying your CharSequence
43. Checking for spans / Iterating fun hasUrlSpan(spanned: Spanned): Boolean { val spans: Array<out T> = spanned.getSpans(0, spanned.length, URLSpan.class) return spans.isNotEmpty() }
44. nextSpanTransition good for iterating, and checking for existence fun hasUrlSpan(spanned: Spanned): Boolean { val limit = spanned.length return spanned.nextSpanTransition(0, limit, URLSpan.class) < limit }
45. override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) { val mySpannable = SpannableStringBuilder(string); mySpannable.setSpan(...) // ... viewHolder.textView.text = mySpannable } Spannables
46. val mySpannable = SpannableString(string); mySpannable.setSpan(...) Create spannables before using during adapter creation or data load
47. configure SpannableFactory class MySpannableFactory : Spannable.Factory() { override fun newSpannable(source: CharSequence): Spannable { return source as? Spannable ?: super.newSpannable(source) } } textView.spannableFactory = spannableFactory
48. override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) { viewHolder.textView.text = mySpannable } Set text and relax
49. Don’t use autoLink in RecyclerView expensive operation runs on UI Thread <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:autoLink="web"/>
50. Instead extract links when preparing the UI data, on a background thread val spannable = SpannableString(string) LinkifyCompat.addLinks(spannable, Linkify.WEB_URLS) override fun onBindViewHolder(holder: ViewHolder, position: Int) { holder.textView.setText(spannable, BufferType.SPANNABLE) // ... }
51. Editable Text
52. Editable Text components EditText DynamicLayout SpannableStringBuilder StaticLayout update text layout text buffer
53. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris velit sapien, ultrices nec pellentesque eget, viverra nec felis. Proin ante est, malesuada sit amet est a, posuere molestie ipsum. Etiam efficitur orci non elit laoreet pharetra. Mauris tristique maximus pharetra. Etiam faucibus, odio non dictum euismod, eros sapien hendrerit eros, vitae molestie lectus eros nec tortor. Integer luctus in erat eget pulvinar. DynamicLayout
54. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris velit sapien, ultrices nec pellentesque eget, viverra nec felis. Proin ante est, malesuada sit amet est a, posuere molestie ipsum. Etiam efficitur orci non elit laoreet pharetra. Mauris tristique maximus pharetra. Etiam faucibus, odio non dictum euismod, eros sapien hendrerit eros, vitae molestie lectus eros nec tortor. Integer luctus in erat eget pulvinar. DynamicLayout
55. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris velit sapien, ultrices nec pellentesque eget, viverra nec felis. Proin ante est, malesuada sit amet est a, posuere molestie ipsum. Etiam efficitur orci non elit laoreet pharetra. Mauris tristique maximus pharetra. Etiam faucibus, odio non dictum euismod, eros sapien hendrerit eros, vitae molestie lectus eros nec tortor. Integer luctus in erat eget pulvinar. DynamicLayout
56. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris velit sapien, ultrices nec pellentesque eget, viverra nec felis. Proin ante est, malesuada sit amet est a, posuere molestie ipsum. Etiam efficitur orci non elit laoreet pharetra. Mauris tristique maximus pharetra. Etiam faucibus, odio non dictum euismod, eros sapien hendrerit eros, vitae molestie lectus eros nec tortor. Integer luctus in erat eget pulvinar. DynamicLayout StaticLayout StaticLayout
57. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris velit sapien, ultrices nec pellentesque eget, viverra nec felis. Proin ante est, malesuada sit amet est a, posuere molestie ipsum. Etiam efficitur orci non elit laoreet pharetra. Mauris tristique maximus pharetra. Etiam faucibus, odio non dictum euismod, eros sapien hendrerit eros, vitae molestie lectus eros nec tortor. Integer luctus in erat eget pulvinar. DynamicLayout
58. Editable Text events EditText DynamicLayout SpannableStringBuilder StaticLayout InputFilter TextWatcher KeyListener change events before change (control over change) hardware keyboard events (mostly) SpanWatcher changes to spans
59. glide typing auto suggest hand writing voice translate Input Method, not keyboard :) different world than hardware keyboard
60. H He Hel Hell Hello Hello␣ Hello␣W Hello␣Wo Hello␣Wor Hello␣Worl Hello␣World
61. H He Hel Hell Hello Hello␣ Hello␣W Hello␣Wo Hello␣Wor Hello␣Wor Hello␣World delete 3 letters add this 5
62. “Replace” test different input methods test different languages
63. InputFilter TextView.setText() SpannableStringBuilder.replace()
64. InputFilter “replace” CharSequence filter ( CharSequence source, int sourceStart, int sourceEnd, Spanned dest, int destStart, int destEnd) source destination sourceStart sourceEnd destStart destEnd (result)
65. InputFilter length limit editText.filters = arrayOf(InputFilter.LengthFilter(5)) 12345 Label Label u+1F469 u+1F3FD u+200D u+1F3A4 u+1F468 u+200D u+1F469 u+200D u+1F467 u+200D u+1F466 4 7 ZWJ ZWJ ZWJ ZWJ
66. InputFilter BreakIterator fun countCharacterBreaks(string: String): Int { val breakIterator = BreakIterator.getCharacterInstance() breakIterator.setText(string) var count = 0 while (breakIterator.next() != BreakIterator.DONE) count++ return count }
67. InputFilter handle emoji editText.filters = arrayOf(InputFilter { source, sStart, sEnd, dest, dStart, dEnd -> val destCount = countCharacterBreaks(dest.toString()) val removedCount = countCharacterBreaks(dest.substring(dStart, dEnd)) val addedCount = countCharacterBreaks(source.substring(sStart, sEnd)) })
68. InputFilter handle emoji editText.filters = arrayOf(InputFilter { source, sStart, sEnd, dest, dStart, dEnd -> val destCount = countCharacterBreaks(dest.toString()) val removedCount = countCharacterBreaks(dest.substring(dStart, dEnd)) val addedCount = countCharacterBreaks(source.substring(sStart, sEnd)) var remaining = 5 - (destCount - removedCount) if (remaining <= 0) { return@InputFilter "" //reject } else if (remaining >= addedCount) { return@InputFilter null //apply } })
69. InputFilter handle emoji editText.filters = arrayOf(InputFilter { source, sStart, sEnd, dest, dStart, dEnd -> val destCount = countCharacterBreaks(dest.toString()) val removedCount = countCharacterBreaks(dest.substring(dStart, dEnd)) val addedCount = countCharacterBreaks(source.substring(sStart, sEnd)) var remaining = 5 - (destCount - removedCount) if (remaining <= 0) { return@InputFilter "" //reject } else if (remaining >= addedCount) { return@InputFilter null //apply } else { return@InputFilter trimSource(source, sStart, sEnd, remaining) } })
70. InputFilter trimSource fun trimSource(source: CharSequence, start: Int, end: Int, max: Int): CharSequence { val breakIterator = BreakIterator.getCharacterInstance() breakIterator.setText(source.subSequence(start, end).toString()) var endIndex = start; var remaining = max while(remaining > 0 && breakIterator.next() != BreakIterator.DONE) { remaining-- endIndex = breakIterator.current() } return source.subSequence(start, endIndex) }
71. Editable Text input EditText DynamicLayout SpannableStringBuilder StaticLayout InputConnection Input Method Engine get (soft keyboard) events
72. InputConnection EditText EditableInputConnection BaseInputConnection InputConnection
73. final class EmojiInputConnection extends InputConnectionWrapper { //... @Override public boolean deleteSurroundingText(final int beforeLength, final int afterLength) { final boolean result = EmojiCompat.handleDeleteSurroundingText(this, getEditable(), beforeLength, afterLength, false /*inCodePoints*/); return result || super.deleteSurroundingText(beforeLength, afterLength); } @Override public boolean deleteSurroundingTextInCodePoints(final int beforeLength, final int afterLength) { final boolean result = EmojiCompat.handleDeleteSurroundingText(this, getEditable(), beforeLength, afterLength, true /*inCodePoints*/); return result || super.deleteSurroundingTextInCodePoints(beforeLength, afterLength); } //... }
74. Resources https://github.com/siyamed/droidcon-nyc-18 @siyamed