Jetpack Compose: How it works?

Transcript

1. Jetpack Compose: How it works? ✨
   ૑ࢿ࠼

2. How it works? ↟$PNQJMFS
   ↟ 3VOUJNF

3. None

4. /** * Composable য֢ప੉࣌਷ ஹನૉ ೣࣻীࢲ ೙ࣻ੸ਵ۽ ࢎਊغݴ ௼ѱ 3о૑੄

   ৉ೡਸ ыणפ׮. * * 1. ݵ١ࢿ੄ ࠁ੢ * 2. ਤ஖ ݫݽ੉ઁ੉࣌ ഝࢿച * 3. ؘ੉ఠ ઁҕ ژח ஹನ੷࠶ ߑ୹ */ @MustBeDocumented @Retention(AnnotationRetention.BINARY) @Target( AnnotationTarget.FUNCTION, AnnotationTarget.TYPE, AnnotationTarget.TYPE_PARAMETER, AnnotationTarget.PROPERTY_GETTER ) annotation class Composable

5. // э਷ inputਸ ߉਷ ஹನ੷࠶ਸ ݵ١ࢿ੄ ࠁ੢ਵ۽ ೦࢚ ੤प೯ਸ Ѥցګ׮.

   // ݵ١ࢿ: э਷ ো࢑੄ Ѿҗח ೦࢚ زੌೞ׮ח ࢿ૕ @Composable fun Idempotent() { // ݅ড UI јन੉ ೙ਃೞ׮ݶ... Text(text = "ࢿ࠼ے٘") // ੉ ஹನ੷࠶਷ ೠ ߣ݅ प೯ػ׮. Text(text = System.currentTimeMillis().toString()) // ੉ ஹನ੷࠶਷ ೦࢚ ੤प೯ػ׮. }

6. // ஹನ੷࠶਷ ۠ఋ੐ীࢲ Ѿ੿ػ ਋ࢶࣽਤী ݏѱ ߽۳۽ प೯ؽਵ۽ ஹನ੷࠶੄ प೯

   ࣽࢲী ੄ઓೞח Ѥ ০૑ ঋ׮. // ٮۄࢲ ݵ١ࢿਸ ࠁ੢ೞח Ѫ੉ ઺ਃೞ׮. lateinit var text: String @Composable @Composable fun PureFunction() { fun LoadText() { LoadText() text = "Bye, world!" ShowText() Text(text = "Load Text...") } } @Composable fun ShowText() { Text(text = text) // text is not initialized properly оמࢿ ੓਺ }

7. // ஹನ੷࠶ ೣࣻ੄ दӒפ୊৬ call-site, ӒܻҊ प೯ػ ࣽࢲܳ ӝળਵ۽ Ҋਬೠ

   keyо ࢤࢿغҊ, // ஹನૉח ೧׼ keyܳ ӝળਵ۽ ݽٚ ؘ੉ఠܳ ੷੢ೞҊ ҙܻೠ׮. // э਷ keyܳ о૓ ஹನ੷࠶੉ э਷ inputਵ۽ ੤प೯ ػ׮ݶ ӝઓী प೯ػ Ѿҗܳ Ӓ؀۽ ੤ࢎਊೠ׮. // -> ݵ١ࢿҗ ਤ஖ ݫݽ੉ઁ੉࣌੄ Ѿҗ // ਤ஖ ݫݽ੉ઁ੉࣌: э਷ ਤ஖ীࢲ э਷ inputਵ۽ प೯غݶ ೦࢚ э਷ output੉ աৢ Ѫ੉ۄҊ о੿ೞҊ, // чਸ நयೞҊ ੤ࢎਊ ೞח ӝࣿ @Composable fun PositionMemoization() { repeat(5) { Text(text = "Bye, world!") // э਷ call-site ੉૑݅, ஹನ੷࠶ ؘ੉ఠо ׮ ׮ܲ ҕрী ੷੢ؽ } }

8. /** * @Composable (input) -> output * ੉ ೣࣻ੄ ҃਋

   input਷ ܻࣗझ ই੉٣, output਷ ܻࣗझ чܳ աఋշפ׮. * * ੉ ೣࣻ੄ @Composable਷ ؘ੉ఠܳ ઁҕೞח ৉ೡਸ ೤פ׮. */ @Composable fun stringResource(@StringRes id: Int): String { val resources = resources() return resources.getString(id) }

9. /** * @Composable (input) -> Unit * ੉ ೣࣻ੄ ҃਋

   inputҗ output੉ হणפ׮. * * ੉ ೣࣻ੄ @Composable਷ ஹನ੷࠶ਸ ߑ୹ೞח ৉ೡਸ ೤פ׮. */ @Composable fun ByeWorld() { Text(text = "Bye, world!") }

10. /** * ஹನૉ੄ ݽٚ ؘ੉ఠܳ ੷੢ೞҊ ҙܻೞח ௿ېझੑפ׮. * Gap

    Buffer ੗ܐҳઑ৬ ےؒ ঘࣁझ۽ ҳഅعҊ, ղࠗ ؘ੉ఠח Array<Any?>ী ੷੢ؾפ׮. */ internal class SlotTable : CompositionData, Iterable<CompositionGroup>

11. Gap Buffer: ࢎਊೡ ҕрٜਸ ޷ܻ ഛࠁ೧ فҊ, ೧׼ ҕрীࢲ ੘সਸ

    ૓೯ೞח ੗ܐ ҳઑ. ਤఃೖ٣ইীࢲח زੌೠ ਤ஖ Ӕ୊ী ௿۞झఠ݂ػ ബਯ੸ੋ ࢗੑ ߂ ࢏ઁ ੘সਸ ೲਊೞח ز੸ ߓৌ ੉ۄҊ ੿੄ೞҊ ੓णפ׮.

12. Gap Buffer: زੌೠ ਤ஖ Ӕ୊ী ௿۞झఠ݂ػ ബਯ੸ੋ ࢗੑ ߂ ࢏ઁ

    ੘সਸ ೲਊೞח ز੸ ߓৌ 1, ୡӝ Gap ࢤࢿ: O(N) [(v)_, _, _, _, _, _, _, _, _, _] // _ח Gap, (v)ח അ੤ cursorܳ աఋն

13. Gap Buffer: زੌೠ ਤ஖ Ӕ୊ী ௿۞झఠ݂ػ ബਯ੸ੋ ࢗੑ ߂ ࢏ઁ

    ੘সਸ ೲਊೞח ز੸ ߓৌ 1, ୡӝ Gap ࢤࢿ: O(N) [(v)_, _, _, _, _, _, _, _, _, _] // _ח Gap, (v)ח അ੤ cursorܳ աఋն 2. 0ߣ૩ ੋؙझী Hi ࢗੑ [(v)H, i, _, _, _, _, _, _, _, _] // ݽف Gapী ࢗੑغ޲۽ ୶о Gap ࢤࢿ੉ ೙ਃೞ૑ ঋই O(1)ী ৮ܐؽ

14. Gap Buffer: زੌೠ ਤ஖ Ӕ୊ী ௿۞झఠ݂ػ ബਯ੸ੋ ࢗੑ ߂ ࢏ઁ

    ੘সਸ ೲਊೞח ز੸ ߓৌ 1, ୡӝ Gap ࢤࢿ: O(N) [(v)_, _, _, _, _, _, _, _, _, _] // _ח Gap, (v)ח അ੤ cursorܳ աఋն 2. 0ߣ૩ ੋؙझী Hi ࢗੑ [(v)H, i, _, _, _, _, _, _, _, _] // ݽف Gapী ࢗੑغ޲۽ ୶о Gap ࢤࢿ੉ ೙ਃೞ૑ ঋই O(1)ী ৮ܐؽ 3. 1ߣ૩ ੋؙझ੄ i ઁѢ [H, (v)_, _, _, _, _, _, _, _, _] // cursorܳ iо ੓ח ਤ஖۽ ৤ӝӝ ਤ೧ O(N)੉ ѦܻҊ // ੉റ Gapীࢲ ч ઁѢо ૓೯غ޲۽ O(1)݅ী ৮ܐؽ (ч ઁѢח ೧׼ чਸ Gapਵ۽ ߸҃ೞח Ѫਵ۽ ҳഅؾפ׮)

15. Gap Buffer: زੌೠ ਤ஖ Ӕ୊ী ௿۞झఠ݂ػ ബਯ੸ੋ ࢗੑ ߂ ࢏ઁ

    ੘সਸ ೲਊೞח ز੸ ߓৌ 1, ୡӝ Gap ࢤࢿ: O(N) [(v)_, _, _, _, _, _, _, _, _, _] // _ח Gap, (v)ח അ੤ cursorܳ աఋն 2. 0ߣ૩ ੋؙझী Hi ࢗੑ [(v)H, i, _, _, _, _, _, _, _, _] // ݽف Gapী ࢗੑغ޲۽ ୶о Gap ࢤࢿ੉ ೙ਃೞ૑ ঋই O(1)ী ৮ܐؽ 3. 1ߣ૩ ੋؙझ੄ i ઁѢ [H, (v)_, _, _, _, _, _, _, _, _] // cursorܳ iо ੓ח ਤ஖۽ ৤ӝӝ ਤ೧ O(N)੉ ѦܻҊ // ੉റ Gapীࢲ ч ઁѢо ૓೯غ޲۽ O(1)݅ী ৮ܐؽ (ч ઁѢח ೧׼ чਸ Gapਵ۽ ߸҃ೞח Ѫਵ۽ ҳഅؾפ׮) 4. 0ߣ૩ ੋؙझ੄ H ܳ Bye ۽ ߸҃ [(v)B, y, e, _, _, _, _, _, _, _] // cursorܳ Hо ੓ח ਤ஖۽ ৤ӝӝ ਤ೧ O(N)੉ ѦܻҊ // ੉റ ݽف Gapীࢲ ч সؘ੉౟о ૓೯غ޲۽ O(1)݅ী ৮ܐؽ

16. var isLoading = false @Composable fun Main() { Column {

    // 1ߣ૩ ਤ஖ (അ੤ cursor) Text(text = "Column Data") if (isLoading) { Text(text = "Loading...") } } } Column Text “Column Data” Gap Gap Gap Gap Gap Gap ߣ૩
    
    ਤ஖

17. var isLoading = true @Composable fun Main() { Column {

    // 1ߣ૩ ਤ஖ (੉੹ cursor) Text(text = "Column Data") if (isLoading) { // 2ߣ૩ ਤ஖ (അ੤ cursor) Text(text = "Loading...") } } } Column Text “Column Data” Gap Gap Gap Gap Text “Loading…” ߣ૩
    
    ਤ஖ ߣ૩
    
    ਤ஖

18. /** * Gapਸ ޖदೞҊ ౠ੿ ਤ஖੄ ੺؀੸ੋ ੋؙझܳ оܰఃח ېಌੑפ׮.

    (ےؒ ঘࣁझ ഝࢿച) * * ےؒ ঘࣁझ: ؘ੉ఠܳ ੷੢ೞח ࠶۾ਸ ೠߣী ৈ۞ ѐ ঘࣁझೞח Ѫ੉ ইפۄ * ౠ੿ ਤ஖۽ ߄۽ ੽Ӕೞৈ ೠ ߣী ೞա੄ ࠶۾ਸ ঘࣁझೞח ߑध */ internal class Anchor(loc: Int) { internal var location = loc val valid get() = location != Int.MIN_VALUE fun toIndexFor(slots: SlotTable) = slots.anchorIndex(this) fun toIndexFor(writer: SlotWriter) = writer.anchorIndex(this) }

19. var isLoading = true @Composable fun Main() { Column {

    Text(text = "Column Data") if (isLoading) { // Anchor۽ ߄۽ ੽Ӕ Text(text = "Loading...") } } } Column “Column Data” Gap Gap Gap Gap Text “Loading…” "ODIPS۽
    ߄۽
    ੽Ӕ Text

20. var isColumn = true @Composable fun Main() { if (isColumn)

    { Column { Text(text = "Column Data") } } else { Row { repeat(10) { index -> Text(text = "Row Data - $index") } } } } Column Text “Column Data” Gap Gap Gap Gap Gap Gap

21. var isColumn = false @Composable fun Main() { if (isColumn)

    { Column { Text(text = "Column Data") } } else { Row { repeat(10) { index -> Text(text = "Row Data - $index") } } } } Row Text “Row Data - 0” Text “Row Data - 1” Text Text Text “Row Data - 2” “Row Data - 3”

22. var isLoading = false @Composable fun Main() { Column {

    Text(text = "Column Data") if (isLoading) { Text(text = "Loading...") } } } Column Text “Column Data” Gap Gap Gap Gap Gap Gap Composition

23. var isLoading = true @Composable fun Main() { Column {

    Text(text = "Column Data") if (isLoading) { Text(text = "Loading...") } } } Column Text “Column Data” Gap Gap Gap Gap Text “Loading…” Recomposition

24. var isLoading = true @Composable fun Main() { Column {

    Text(text = "Column Data") if (isLoading) { Text(text = "Loading...") } } } Emit Column Text Text

25. var isLoading = true @Composable fun Main() { Column {

    Text(text = "Column Data") if (isLoading) { Text(text = "Loading...") } } } Materializing

26. var isLoading = true @Composable fun Main() { Column {

    Text(text = "Column Data") if (isLoading) { Text(text = "Loading...") } } } Column Text “Column Data” Gap Gap Gap Gap Text “Loading…”

27. val isLoading = mutableStateOf(false) // Snapshot System isLoading.value = true

    @Composable fun Main() { Column { Text(text = "Column Data") if (isLoading) { Text(text = "Loading...") } } } Column Text “Column Data” Gap Gap Gap Gap Text “Loading…”

28. How it works? ↟$PNQJMFS
    ↟ 3VOUJNF

29. @Composable fun TextWrapper() { Text(text = "SungbinLand") } dependencies {

    // annotation processor XXX implementation "androidx.compose.foundation:foundation:1.3.0-alpha01" }

30. @Composable fun TextWrapper() { Text(text = "SungbinLand") } buildFeatures {

    compose true // ஹನૉ ௏ౣܽ ஹ౵ੌ۞ ഝࢿച /* * ஹನૉ ஹ౵ੌ җ੿ਸ ௏ౣܽ ঱য੄ ஹ౵ੌ җ੿ਵ۽ ੐ߓ٘ೞৈ ୊ܻ ࣘبܳ ֫੉Ҋ, * য֢ప੉࣌ ೐۽ࣁࢲח ೡ ࣻ হח ֫ਸ ࣻળ੄ ௏٘ ੽Ӕਸ ೞৈ ஹ౵ੌؾפ׮. * ৘ܳ ٜয, ௏ౣܽҗ ஹನૉח ݣ౭೒ۖಬਸ ؀࢚ਵ۽ ೞ޲۽ ஹ౵ੌ җ੿ীࢲ ࢤࢿغח IRਸ * അ੤ ೒ۖಬী ݏח ജ҃ਵ۽ ࣻ੿ೞҊ loweringਸ ૓೯೤פ׮. */ } // or… dependencies { "kotlinCompilerPluginClasspath"("org.jetbrains.compose.compiler:compiler:$version") }

31. ௏ౣܽ
    ஹ౵ੌ۞
    ߡ੹
    ୓௼ ௏٘
    ੿੸
    ࠙ࢳ
    ߂
    ӝઓ
    ҃Ҋ
    রઁ ஹನૉ
    ۠ఋ੐
    ߡ੹
    ୓௼ *3
    ࢤࢿ ௿ېझ
    উ੿ࢿ
    ୶ۿ -JWF-JUFSBM
    ഝࢿച ۈ׮
    ୭੸ച $PNQPTFS
    ઱ੑ ࠺Ү
    ੹౵
    ഝࢿച %FGBVMU
    "SHVNFOUT
    ੤ҳഅ

    ஹನ੷࠶
    Ӓܛ
    ࢤࢿ ,MJC
    EFDPZ
    ࢤࢿ

32. ௏ౣܽ
    ஹ౵ੌ۞
    ߡ੹
    ୓௼ ௏٘
    ੿੸
    ࠙ࢳ
    ߂
    ӝઓ
    ҃Ҋ
    রઁ ஹನૉ
    ۠ఋ੐
    ߡ੹
    ୓௼ *3
    ࢤࢿ ௿ېझ
    উ੿ࢿ
    ୶ۿ -JWF-JUFSBM
    ഝࢿച ۈ׮
    ୭੸ച $PNQPTFS
    ઱ੑ ࠺Ү
    ੹౵
    ഝࢿച %FGBVMU
    "SHVNFOUT
    ੤ҳഅ

    ஹನ੷࠶
    Ӓܛ
    ࢤࢿ ,MJC
    EFDPZ
    ࢤࢿ

33. ௏٘
    ੿੸
    ࠙ࢳ
    ߂
    ӝઓ
    ҃Ҋ
    রઁ j j

34. ௏٘
    ੿੸
    ࠙ࢳ
    ߂
    ӝઓ
    ҃Ҋ
    রઁ j j

35. ௏٘
    ੿੸
    ࠙ࢳ
    ߂
    ӝઓ
    ҃Ҋ
    রઁ j j

36. None

37. $PNQPTFS
    ઱ੑ j j // ஹ౵ੌ ੹ @Composable fun TextWrapper() {

    Text(text = "SungbinLand") } // ஹ౵ੌ റ, Composer: ஹನૉ ۠ఋ੐੉ ஹನ੷࠶җ ࢚ഐ ੘ਊ ೡ ࣻ ੓ѱ ب৬઱ח ੋఠಕ੉झ @Composable fun TextWrapper(composer: Composer, changed: Int) { composer.startRestartGroup(-137853230) composer.sourceInformation("C(TextWrapper)22@513L26:MainActivity.kt#dmu2em") if (changed == 0 && composer.skipping) { composer.skipToGroupEnd() } else { Text(text = "SungbinLand") } composer.endRestartGroup()?.updateScope { composer, _ -> TextWrapper(composer, changed or 1) } }

38. @Composable fun TextWrapper(composer: Composer, changed: Int) { composer.startRestartGroup(-137853230) composer.sourceInformation("C(TextWrapper)22@513L26:MainActivity.kt#dmu2em") if

    (changed == 0 && composer.skipping) { composer.skipToGroupEnd() } else { Text(text = "SungbinLand") } composer.endRestartGroup()?.updateScope { composer, _ -> TextWrapper(composer, changed or 1) } } Group ஹನ੷࠶
    Ӓܛ
    ࢤࢿ j j

39. @Composable fun Main() { Column { Text(text = "Column Data")

    } } Column Text “Column Data” Gap Gap Gap Gap Gap Gap

40. @Composable fun Main() { Column { Text(text = "Column Data")

    } } “Column Data” Gap Gap Gap Gap Gap Gap Group Group

41. // RestartableGroup: ܻஹನ૑࣌੉ ੌযզ ࣻ ੓ח ஹನ੷࠶ // ઱ਤ۽ ࢤࢿػ׮.

    ߹ب੄ ২࣌੉ হ׮ݶ ݽٚ ஹನ੷࠶ী // ࢤࢿغח Ӓܛ੉Ҋ, ܻஹನ૑࣌ ೞח ߑߨਸ оܰ஘׮. // ݽٚ RestartableGroup਷ ೧׼ ߧਤ ݅ఀ // ੗୓੄ ܻஹನ૑࣌ झ௏೐(RecomposeScope)ܳ ഋࢿೠ׮. @Composable fun RestartableContainer() { Text(text = "SungbinLand") } RestartableGroup “SungbinLand” Gap Gap Gap Gap Gap Gap RestartableGroup 3FTUBSUBCMF$POUBJOFS
    3FDPNQPTF4DPQF 5FYU
    3FDPNQPTF4DPQF

42. // ReplaceableGroup: ࠙ӝী ٮۄ ੤ߓ஖ ؼ ࣻ ੓ח // ஹನ੷࠶

    ઱ਤ۽ ࢤࢿػ׮. // Ӓܛਸ Ү୓೧ঠ ೡ ٸ ੘ࢿػ ؘ੉ఠܳ ੿ܻೞח ߑߨਸ оܰ஘׮. @Composable fun ReplaceableContainer(isColumn: Boolean = true) { when (isColumn) { true -> Text(text = "Column") else -> Text(text = "Row") } } RestartableGroup “Column” Gap Gap Gap Gap Gap ReplaceableGroup 3FQMBDFBCMF$POUBJOFS XIFO RestartableGroup 5FYU

43. /** * ஹನ੷࠶੉ ߓ஖ػ ਤ஖о ׳ۄ૑ݶ ਤ஖ ݫݽ੉ઁ੉࣌੄ keyо ׳ۄઉࢲ

    ؘ੉ఠо ୡӝചؾפ׮. * ؘ੉ఠܳ ਬ૑ೠ ࢚క۽ ਤ஖ܳ ৤ӝӝ ਤ೧ࢶ key ஹನ੷࠶ਸ ੉ਊ೧ * ਤ஖ ݫݽ੉ઁ੉࣌ীࢲ ଵҊೡ keyܳ ૒੽ ੿੄೧ঠ ೤פ׮. * * key ஹನ੷࠶ਸ ੉ਊ೧ ߓ஖ػ ஹನ੷࠶਷ ઱ਤ۽ MovableGroup੉ ࢤࢿؾפ׮. * MovableGroup਷ ஹನ੷࠶੉ ਤ஖ ݫݽ੉ઁ੉࣌ key৬ ؘ੉ఠܳ ೦࢚ ࠁઓೞݴ * ੉زೞח ߑߨਸ оܰ஝פ׮. */ @Composable inline fun <T> key( vararg keys: Any?, block: @Composable () -> T ) @Composable fun MovableContainer() { key(Any()) { Text(text = "Key") } } RestartableGroup “Key” Gap Gap Gap Gap Gap MovableGroup .PWBCMF$POUBJOFS LFZ RestartableGroup 5FYU

44. ↟3FTUBSUBCMF(SPVQ
    ↟3FQMBDFBCMF(SPVQ
    ↟.PWBCMF(SPVQ ஹನ੷࠶
    Ӓܛ
    ࢤࢿ j j

45. How it works? ↟$PNQJMFS
    ↟3VOUJNF

46. 🎨 🖼️ 🖌️ 🧰 Material ݠఠܻ঴
    ٣੗ੋ
    दझమ 5FYU
    #VUUPO
    #PUUPN4IFFU
    $IJQ

    
    "MFSU%JBMPH
    *DPOT
    4VSGBDF Foundation о੢
    ӝୡ੸ੋ
    ٣੗ੋ -B[Z-JTU
    $PMVNO
    $BOWBT
    4IBQF
    (FTUVSFT
    0WFSTDSPMM&GGFDU UI ஹನૉ
    6*
    5PPMLJU੄
    ӝࠄ
    ࢸ҅ -BZPVU
    %JBMPH
    $PNQPTF7JFX"EBQUFS
    1SFWJFX"DUJWJUJZ Runtime ஹನૉউ٘۽੉٘
    োѾ *OWBMJEBUJPO
    4OBQTIPU
    4ZTUFN
    4MPU5BCMF
    -JWF-JUFSBM

47. Runtime Process (full)

48. Runtime Process (simply)

49. class MainActivity : ComponentActivity() { override fun onCreate(savedInstanceState: Bundle?) {

    super.onCreate(savedInstanceState) setContent { Text(text = "SungbinLand") } } }

50. // ஹನૉ ۠ఋ੐җ UI੄ োѾ fun ComponentActivity.setContent( parent: CompositionContext? =

    null, content: @Composable () -> Unit ) { ComposeView(this).apply { setParentCompositionContext(parent) setContent(content) setOwners() setContentView(this, DefaultActivityContentLayoutParams) } }

51. // ComposeView#setContent۽ ੉ ೣࣻо प೯ؽ private fun ensureCompositionCreated() { setContent(/*

    Recomposerо ٜ݅য૑Ҋ ઱ੑؾפ׮ */) { content() } }

52. /** * ܻஹನ૑࣌ਸ ࣻ೯ೞҊ ೞա ੉࢚੄ ஹನ੷࠶ী সؘ੉౟ܳ ੸ਊೞӝ ਤೠ

    झா઴۞ ੑפ׮. */ class Recomposer( effectCoroutineContext: CoroutineContext ) : CompositionContext() /** * Handler ௒ߔ ژח Choreographer੄ গפݫ੉࣌ ೐ۨ੐ ױ҅ ઺ * ݢ੷ بېೞח ױ҅ীࢲ ٣झಁ஖ܳ ࣻ೯ೞח CoroutineDispatcher ੑפ׮. */ class AndroidUiDispatcher private constructor( val choreographer: Choreographer, private val handler: Handler ) : CoroutineDispatcher()

53. /** * ܻஹನ૑࣌ਸ ࣻ೯ೞҊ ೞա ੉࢚੄ ஹನ੷࠶ী সؘ੉౟ܳ ੸ਊೞӝ ਤೠ

    झா઴۞ ੑפ׮. */ class Recomposer( effectCoroutineContext: CoroutineContext ) : CompositionContext() /** * Handler ௒ߔ ژח Choreographer੄ গפݫ੉࣌ ೐ۨ੐ ױ҅ ઺ * ݢ੷ بېೞח ױ҅ীࢲ ٣झಁ஖ܳ ࣻ೯ೞח CoroutineDispatcher ੑפ׮. */ class AndroidUiDispatcher private constructor( val choreographer: Choreographer, private val handler: Handler ) : CoroutineDispatcher()

54. suspend fun runRecomposeAndApplyChanges() = recompositionRunner { parentFrameClock -> val toRecompose

    = mutableListOf<RecomposeScope>() while (shouldKeepRecomposing) { awaitWorkAvailable() parentFrameClock.withFrameNanos { frameTime -> try { toRecompose.fastForEach { composition -> performRecompose(composition) } } finally { toRecompose.clear() } } } }

55. private suspend fun recompositionRunner( block: suspend CoroutineScope.(parentFrameClock: MonotonicFrameClock) -> Unit

    ) { // Recomposerীࢲ ߉਷ Choreographer੄ ېಌੋ MonotonicFrameClockਸ оઉৡ׮. val parentFrameClock: MonotonicFrameClock = coroutineContext.monotonicFrameClock // broadcastFrameClock: ஹನૉ ۠ఋ੐ীࢲ ҟ৉ਵ۽ ࢎਊغח MonotonicFrameClock੄ ېಌ withContext(broadcastFrameClock) { Snapshot.registerApplyObserver { _, _ -> // State੄ write ੉߮౟ܳ ߉ח׮. deriveStateLocked()?.resume(Unit) } coroutineScope { block(parentFrameClock) } } }

56. private suspend fun recompositionRunner( block: suspend CoroutineScope.(parentFrameClock: MonotonicFrameClock) -> Unit

    ) { // Recomposerীࢲ ߉਷ Choreographer੄ ېಌੋ MonotonicFrameClockਸ оઉৡ׮. val parentFrameClock: MonotonicFrameClock = coroutineContext.monotonicFrameClock // broadcastFrameClock: ஹನૉ ۠ఋ੐ীࢲ ҟ৉ਵ۽ ࢎਊغח MonotonicFrameClock੄ ېಌ withContext(broadcastFrameClock) { Snapshot.registerApplyObserver { _, _ -> // State੄ write ੉߮౟ܳ ߉ח׮. deriveStateLocked()?.resume(Unit) } coroutineScope { block(parentFrameClock) } } }

57. suspend fun runRecomposeAndApplyChanges() = recompositionRunner { parentFrameClock -> // ܻஹನ૑࣌੉

    ೙ਃೠ RecomposeScopeо ׸ӟ׮. (׸ח җ੿ ࢤۚ) val toRecompose = mutableListOf<RecomposeScope>() // shouldKeepRecomposing: Recomposerо ܻஹನ૑࣌ ਃ୒ਸ х૑೧ঠ ೞח૑ܳ աఋմ׮. while (shouldKeepRecomposing) { awaitWorkAvailable() // ࢜۽਍ ܻஹನ૑࣌ ਃ୒੉ ੓ਸ ٸ ө૑ suspend ࢚క۽ ӝ׮ܽ׮. parentFrameClock.withFrameNanos { frameTime -> // Choreographer#postFrameCallbackਸ ഐ୹ೠ׮. try { toRecompose.fastForEach { composition -> // RecomposeScopeܳ ࣽഥೞݴ performRecompose(composition) // ܻஹನ૑࣌ ૓೯! } } finally { toRecompose.clear() } } } }

58. private suspend fun awaitWorkAvailable() { suspendCancellableCoroutine { co -> if

    (hasSchedulingWork) { // ؀ӝ઺ੋ ܻஹನ૑࣌ ਃ୒੉ ੓׮ݶ ߄۽ resume ೞҊ co.resume(Unit) } else { // ؀ӝ઺ੋ ܻஹನ૑࣌ ਃ୒੉ হ׮ݶ // workContinuationਵ۽ CancellableContinuation ੷੢ റ suspend ਬ૑ workContinuation = co } } }

59. private fun deriveStateLocked(): CancellableContinuation<Unit>? { // ࠁܨ ઺ੋ ੘স: ܻஹನ૑࣌

    ਃ୒ ١١ ஹನૉ ۠ఋ੐ ղࠗীࢲ ૓೯غח ৈ۞ ੘স ਃ୒ val newState = when { /* അ੤ ࠁܨ ઺ੋ ੘স ৈࠗী ٮۄ ࢜۽਍ ࢚క ҅࢑ */ } return if (newState == State.PendingWork) { // ࠁܨ ઺ੋ ੘স੉ ੓׮ݶ workContinuation.also { // workContinuation ߈ജ ߂ workContinuation ୡӝച workContinuation = null } } else null }

60. private suspend fun recompositionRunner( block: suspend CoroutineScope.(parentFrameClock: MonotonicFrameClock) -> Unit

    ) { val parentFrameClock = coroutineContext.monotonicFrameClock withContext(broadcastFrameClock) { Snapshot.registerApplyObserver { _, _ -> deriveStateLocked()?.resume(Unit) } coroutineScope { block(parentFrameClock) } } }

61. suspend fun runRecomposeAndApplyChanges() = recompositionRunner { parentFrameClock -> val toRecompose

    = mutableListOf<RecomposeScope>() while (shouldKeepRecomposing) { awaitWorkAvailable() // ܻஹನ૑࣌ ਃ୒੉ ੓ਸ ٸ ө૑ suspend parentFrameClock.withFrameNanos { frameTime -> // ׮਺ ೐ۨ੐ীࢲ try { toRecompose.fastForEach { composition -> performRecompose(composition) } // Recomposition! } finally { toRecompose.clear() } } } } private suspend fun recompositionRunner(block: suspend CoroutineScope.(MonotonicFrameClock) -> Unit) { val parentFrameClock = coroutineContext.monotonicFrameClock withContext(broadcastFrameClock) { Snapshot.registerApplyObserver { _, _ -> deriveStateLocked()?.resume(Unit) } // State ч ߸҃੉ ੓ਸ ٸ resume coroutineScope { block(parentFrameClock) } } }

62. // ComposeView#setContent۽ ੉ ೣࣻо प೯ؽ private fun ensureCompositionCreated() { setContent(/*

    Recomposerо ٜ݅য૑Ҋ ઱ੑؾפ׮ */) { content() } }

63. // this: Composer private fun doCompose(content: @Composable () -> Unit)

    { startRoot() // ठܶ ప੉࠶ ୡӝച startGroup() // ஹನ੷࠶੉ ٜযт Ӓܛ ࢤࢿ invokeComposable(this, content) endGroup() endRoot() } // performRecomposeب ѾҴ ੉ ೣࣻܳ प೯ೠ׮. internal actual fun invokeComposable( composer: Composer, composable: @Composable () -> Unit ) { val realFn = composable as Function2<Composer, Int, Unit> realFn(composer, 1) } Root Group Composable Gap Gap Gap Gap Gap Gap

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    షझಕ੉झо ੸ਊغয ੓णפ׮. QnA
    
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