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Ko#n Android Extensionsͷதͱ͜Ε͔Β
@RyotaMurohoshi
2017/11/09 ୈ7ճ Kotlinษڧձ @SanSan
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Kotlin Android Extensions
͍ͬͯΔਓʁ
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ͬͺΓDataBindingͰ͔͢ʁ
ͦΕͱankoͰ͔͢ʁ
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Kotlin Android Extensions
ɺ͖Ͱ͢
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ɹࣗݾհ
@RyotaMurohoshi
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࠷ۙձࣾͰɺKotlinຊಡॻձΛ࢝Ί·ͨ͠
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Tools > Kotlin > Show Kotlin Bytecode > Decompile
͜ΕΛԿΑΓઌʹڭ͑ͯ͋͛Δͱ͍͍ͱࢥ͏ʂ
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ʮKo#n Android Extensionsͷ
தͱ͜Ε͔Βʯ
ʹ͍ͭͯ͠·͢
Kotlin 1.1.51ʹͯ
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Kotlin Android Extensions
ʹ͍͓ͭͯ͞Β͍
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ViewͷΠϯελϯεʹ؆୯ʹ
ΞΫηεͰ͖Δͭ
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gadleͷதͰ͜͏ॻ͘
(͍ͯ͏͔σϑΥϧτͰೖ͍ͬͯΔ)
apply plugin: 'kotlin-android-extensions'
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ίʔυͰtextViewͱ͍͏໊લͰ
TextViewܕͱͯ͠ΞΫηεͰ͖Δ
class MainActivity : Activity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// TextViewܕͷtextView͕ʂ
textView.text = "Hello Activity"
}
}
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// TextViewܕͷtextView͕ʂ
textView.text = "Hello Activity"
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؆୯Ͱ͠ΐʂ
ศརͰ͠ΐʂ
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தΈͯΈ·͠ΐ͏
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Tools > Kotlin > Show Kotlin Bytecode > Decompile
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class MainActivity : Activity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// TextViewܕͷtextView͕ʂ
textView.text = "Hello Activity"
}
}
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/* ུ */
public final class MainActivity extends AppCompatActivity {
private HashMap _$_findViewCache;
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(2131296283);
((TextView)this._$_findCachedViewById(id.textView)).setText((CharSequence)"Hello Activity");
}
public View _$_findCachedViewById(int var1) {
if(this._$_findViewCache == null) {
this._$_findViewCache = new HashMap();
}
View var2 = (View)this._$_findViewCache.get(Integer.valueOf(var1));
if(var2 == null) {
var2 = this.findViewById(var1);
this._$_findViewCache.put(Integer.valueOf(var1), var2);
}
return var2;
}
public void _$_clearFindViewByIdCache() {
if(this._$_findViewCache != null) {
this._$_findViewCache.clear();
}
}
}
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/* ུ */
public final class MainActivity extends AppCompatActivity {
private HashMap _$_findViewCache;
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(2131296283);
((TextView)this._$_findCachedViewById(id.textView))
.setText((CharSequence)"Hello Activity");
}
public View _$_findCachedViewById(int var1) {
if(this._$_findViewCache == null) {
this._$_findViewCache = new HashMap();
}
View var2 = (View)this._$_findViewCache.get(Integer.valueOf(var1));
if(var2 == null) {
var2 = this.findViewById(var1);
this._$_findViewCache.put(Integer.valueOf(var1), var2);
}
return var2;
}
/* ུ */
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σίϯύΠϧͯ͠ΈΔͱ
• _$_findViewCacheͱ͍͏HashMapΛϑΟʔϧυͱͯ࣋ͭ͠
• _$_findCachedViewByIdϝιουɺ
• Ҿʹͱͬͨid͕HashMapʹ͋ΕͦΕΛฦ͠
• ͳ͚Ε୳ࡧɺHashMapʹೖΕͨޙɺͦΕΛฦ͢
_$_findViewCache_findCachedViewByIdɺKotlinͰίʔυͰ͔͚ͳ͍ɻཁʮ``ʯ
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/* ུ */
public final class MainActivity extends AppCompatActivity {
private HashMap _$_findViewCache;
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(2131296283);
((TextView)this._$_findCachedViewById(id.textView))
.setText((CharSequence)"Hello Activity");
}
public View _$_findCachedViewById(int var1) {
if(this._$_findViewCache == null) {
this._$_findViewCache = new HashMap();
}
View var2 = (View)this._$_findViewCache.get(Integer.valueOf(var1));
if(var2 == null) {
var2 = this.findViewById(var1);
this._$_findViewCache.put(Integer.valueOf(var1), var2);
}
return var2;
}
/* ུ */
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͜Μͳײ͡ͷ֦ுϓϩύςΟ͕ੜ͑ΔΘ͚Ͱͳ͍ʂ
// ͜Μͳײ͡͡Όͳ͍ʂ
// Ωϟογϡػߏ͋ΔΑ
val MainActivity.textView : TextView
get() = findViewById(R.id.textView)
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FragmentͰKotlin Android Extensions͑·͢
FragmentͰಉ͡Α͏ʹHashMapͰͷΩϟογϡػߏʂ
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֦ுؔͷதͰʂ
package com.teammurosta
import kotlinx.android.synthetic.main.activity_main.*
fun MainActivity.updateText(text: String) {
this.textView.text = text
}
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import android.os.Bundle
import android.support.v7.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
updateText("Hello")
}
}
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// ֦ுؔͷσίϯύΠϧ݁Ռ
public final class MainActivityExtensionsKt {
public static final void updateText(@NotNull MainActivity $receiver, @NotNull String text) {
Intrinsics.checkParameterIsNotNull($receiver, "$receiver");
Intrinsics.checkParameterIsNotNull(text, "text");
((TextView)$receiver._$_findCachedViewById(id.textView)).setText((CharSequence)text);
}
}
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// MainActivityͷσίϯύΠϧ݁Ռ
public final class MainActivity extends AppCompatActivity {
private HashMap _$_findViewCache;
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(2131296283);
MainActivityExtensionsKt.updateText(this, "Hello");
}
public View _$_findCachedViewById(int var1) {
if(this._$_findViewCache == null) {
this._$_findViewCache = new HashMap();
}
View var2 = (View)this._$_findViewCache.get(Integer.valueOf(var1));
if(var2 == null) {
var2 = this.findViewById(var1);
this._$_findViewCache.put(Integer.valueOf(var1), var2);
}
return var2;
}
public void _$_clearFindViewByIdCache() {
if(this._$_findViewCache != null) {
this._$_findViewCache.clear();
}
}
}
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Կ͕ԿͰΩϟογϡ͢ΔΘ͚͡Όͳ͍
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֦ுؔͷதͰʂMainAc'vity -> Ac'vityʹมߋʂ
package com.teammurosta
import kotlinx.android.synthetic.main.activity_main.*
fun Activity.updateText(text: String) {
this.textView.text = text
}
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// ֦ுؔͷσίϯύΠϧ݁Ռ
public final class MainActivityExtensionsKt {
public static final void updateText(@NotNull Activity $receiver, @NotNull String text) {
Intrinsics.checkParameterIsNotNull($receiver, "$receiver");
Intrinsics.checkParameterIsNotNull(text, "text");
((TextView)$receiver.findViewById(id.textView)).setText((CharSequence)text);
}
}
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android.app.Ac+vityΫϥε
android.support.v7.app.AppCompatAc2vityΫϥεɺ
android.support.v4.app.FragmentΫϥεΛ֦ுͨ͠߹ɺ
ී௨ʹfindViewByIdΛݺͿ
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ViewHolderͰͷ׆༻ྫ
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Kotlin Android Extensions ΛͬͯBind
import kotlinx.android.synthetic.main.listitem_product.view.*
class ProductViewHolder(containerView: View)
: RecyclerView.ViewHolder(containerView) {
fun bind(product: Product) {
itemView.nameTextView.text = product.name
itemView.idTextView.text = product.id
}
}
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σίϯύΠϧ݁ՌΛΈΔͱΩϟογϡ͍ͯ͠ͳ͍
public final class ProductViewHolder extends ViewHolder {
public final void bind(@NotNull Product product) {
Intrinsics.checkParameterIsNotNull(product, "product");
((TextView)this.itemView.findViewById(id.nameTextView)).setText((CharSequence)product.getName());
((TextView)this.itemView.findViewById(id.idTextView)).setText((CharSequence)product.getId());
}
public ProductViewHolder(@NotNull View containerView) {
Intrinsics.checkParameterIsNotNull(containerView, "containerView");
super(containerView);
}
}
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͔͜͜Βઌɺ͜Ε͔Βͷ
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Kotlin 1.1.4ͰύϫʔΞοϓ
experimental͚ͩͲ
androidExtensions {
experimental = true
}
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1. Ωϟογϡઓུ
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@ContainerOp,ons
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ࠓ·ͰΩϟογϡHashMapͷΈ
ʮSparseArrayʯͱʮΩϟογϡ͠ͳ͍ʯ
ΛબΔΑ͏ʹͳͬͨʂ
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// ↓Ξϊςʔγϣϯ
@ContainerOptions(CacheImplementation.SPARSE_ARRAY)
class MainActivity : Activity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
textView.text = "Hello"
}
}
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public final class MainActivity extends Activity {
private SparseArray _$_findViewCache;
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
((TextView)this._$_findCachedViewById(id.textView)).setText((CharSequence)"Hello");
}
public View _$_findCachedViewById(int var1) {
if(this._$_findViewCache == null) {
this._$_findViewCache = new SparseArray();
}
View var2 = (View)this._$_findViewCache.get(var1);
if(var2 == null) {
var2 = this.findViewById(var1);
this._$_findViewCache.put(var1, var2);
}
return var2;
}
public void _$_clearFindViewByIdCache() {
if(this._$_findViewCache != null) {
this._$_findViewCache.clear();
}
}
}
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// ↓Ξϊςʔγϣϯ
@ContainerOptions(CacheImplementation.NO_CACHE)
class MainActivity : Activity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
textView.text = "Hello"
}
}
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public final class MainActivity extends Activity {
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
((TextView)this.findViewById(id.textView)).setText((CharSequence)"Hello");
}
}
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ҰׅมߋͰ͖Δ
ະυΩϡϝϯτԽͰ༷มߋ͢Δ͔͠Εͳ͍͚Ͳ
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app/build.gradleͰઃఆ
androidExtensions {
experimental = true
defaultCacheImplementation = "sparse_array"
// hash_map or none
}
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ΩϟογϡʹSparseArrayɺͬͨ΄͏͕͍͍ͷʁ
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Do we need to change the default cache implementa3on to SparseArray?
Looks like no, because "It is generally slower than a tradi8onal
HashMap, since lookups require a binary search and adds and
removes require inser8ng and dele8ng entries in the array"
Kotlin KEEPΑΓ
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2. ViewHolderରԠ
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Kotlin Android Extensions ΛͬͯBind
import kotlinx.android.synthetic.main.listitem_product.view.*
class ProductViewHolder(containerView: View)
: RecyclerView.ViewHolder(containerView) {
fun bind(product: Product) {
itemView.nameTextView.text = product.name
itemView.idTextView.text = product.id
}
}
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σίϯύΠϧ݁ՌΛΈΔͱΩϟογϡ͍ͯ͠ͳ͍
public final class ProductViewHolder extends ViewHolder {
public final void bind(@NotNull Product product) {
Intrinsics.checkParameterIsNotNull(product, "product");
((TextView)this.itemView.findViewById(id.nameTextView)).setText((CharSequence)product.getName());
((TextView)this.itemView.findViewById(id.idTextView)).setText((CharSequence)product.getId());
}
public ProductViewHolder(@NotNull View containerView) {
Intrinsics.checkParameterIsNotNull(containerView, "containerView");
super(containerView);
}
}
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Ac#vityFragmentͷαϒΫϥεΈ͍ͨʹ
Ωϟογϡ͢Δʹʁ
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LayoutContainer
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LayoutContainerΛ࣮͢Δ
import kotlinx.android.synthetic.main.listitem_product.*
class ProductViewHolder(override val containerView: View /*<= */)
: RecyclerView.ViewHolder(containerView), LayoutContainer /*<= */ {
fun bind(product: Product) {
//
nameTextView.text = product.name
idTextView.text = product.id
}
}
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Ωϟογϡ͢ΔΑ͏ʹʂ
public final class ProductViewHolder extends ViewHolder implements LayoutContainer {
@NotNull
private final View containerView;
private HashMap _$_findViewCache;
public final void bind(@NotNull Product product) {
Intrinsics.checkParameterIsNotNull(product, "product");
((TextView)this._$_findCachedViewById(id.nameTextView)).setText((CharSequence)product.getName());
((TextView)this._$_findCachedViewById(id.idTextView)).setText((CharSequence)product.getId());
}
@NotNull
public View getContainerView() {
return this.containerView;
}
public ProductViewHolder(@NotNull View containerView) {
Intrinsics.checkParameterIsNotNull(containerView, "containerView");
super(containerView);
this.containerView = containerView;
}
public View _$_findCachedViewById(int var1) {
if(this._$_findViewCache == null) {
this._$_findViewCache = new SparseArray();
}
View var2 = (View)this._$_findViewCache.get(var1);
if(var2 == null) {
View var10000 = this.getContainerView();
if(var10000 == null) {
return null;
}
var2 = var10000.findViewById(var1);
this._$_findViewCache.put(var1, var2);
}
return var2;
}
public void _$_clearFindViewByIdCache() {
if(this._$_findViewCache != null) {
this._$_findViewCache.clear();
}
}
}
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3. ParcelableରԠ
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@Parcelize
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@SuppressLint("ParcelCreator")
@Parcelize
data class Product(val name: String, val id: String) : Parcelable
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public final int describeContents() {
return 0;
}
public final void writeToParcel(@NotNull Parcel parcel, int flags) {
Intrinsics.checkParameterIsNotNull(parcel, "parcel");
parcel.writeString(this.name);
parcel.writeString(this.id);
}
public static class Creator implements android.os.Parcelable.Creator {
@NotNull
public final Product[] newArray(int size) {
return new Product[size];
}
@NotNull
public final Object createFromParcel(@NotNull Parcel in) {
Intrinsics.checkParameterIsNotNull(in, "in");
return new Product(in.readString(), in.readString());
}
}
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ͨͩɺAndroid 4ܥͷҰ෦ͷͰ
Πϯετʔϧʹࣦഊ͢ΔΈ͍ͨ
͜Ε͔Βʹظʂ
4.1ͷEmulatorͰࣦഊΛ֬ೝࡁΈ
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KEEPʹɺʮSealdΫϥεʹରԠΛݕ౼ʯͬͯॻ͍ͯ͋Δ
࣮ࡍ·ͩͰ͖ͳ͍Έ͍ͨʁͲ͏ͳΔͩΖ͏ʁ
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ࠓޙʹظʂ
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ͶɺKotlin Android Extensions
͍͍Ͱ͠ΐʂ
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·ͱΊ
• DataBinding͍͍͚ͲɺKotlin Android ExtensionsͶ
• Parcelizeɺࠓޙʹظʂ
• KEEPΈΔͷָ͍͠Αʂ
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όάʁ
Kotlin Android Extensions͕༗ޮʹͳͬͯͳ͍
ϓϩδΣΫͰAc#vityFragmentʹ
_$_findCachedViewByIdͱ͔͕Ͱ͖͍ͯΔʁ
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Ko#n Android Extensionsͷதͱ͜Ε͔Β
@RyotaMurohoshi
2017/11/09 ୈ7ճ Kotlinษڧձ @SanSan