Weakly observe properties

Author: NichtStudioCode

gradle/libs.versions.toml

@@ -3,7 +3,7 @@ kotlin = "2.1.0"
 paper = "1.21.5-R0.1-SNAPSHOT"
 
 [libraries]
-commons-provider = { module = "xyz.xenondevs.commons:commons-provider", version = "1.25" }
+commons-provider = { module = "xyz.xenondevs.commons:commons-provider", version = "1.29" }
 jetbrains-annotations = { module = "org.jetbrains:annotations", version = "26.0.1" }
 jspecify = { module = "org.jspecify:jspecify", version = "1.0.0" }
 junit-bom = { module = "org.junit:junit-bom", version = "5.11.4" }

invui-kotlin/src/main/kotlin/xyz/xenondevs/invui/PropertyWrappers.kt

@@ -4,21 +4,25 @@ import xyz.xenondevs.commons.provider.MutableProvider
 import xyz.xenondevs.commons.provider.Provider
 import xyz.xenondevs.invui.state.MutableProperty
 import xyz.xenondevs.invui.state.Property
+import java.util.function.Consumer
 
 internal class PropertyAdapter<T : Any>(private val provider: Provider<T>) : Property<T> {
 
     override fun get(): T {
         return provider.get()
     }
 
-    override fun observe(observer: Runnable) {
-        provider.observe(observer::run)
+    override fun <O : Any> observeWeak(owner: O, observer: Consumer<in O>) {
+        provider.observeWeak(owner, observer::accept)
     }
 
-    override fun unobserve(observer: Runnable) {
-        provider.unobserve(observer::run)
+    override fun <O : Any> unobserveWeak(owner: O, observer: Consumer<in O>) {
+        provider.unobserveWeak(owner, observer::accept)
     }
 
+    override fun unobserveWeak(owner: Any) {
+        provider.unobserveWeak(owner)
+    }
 
 }
 
@@ -32,12 +36,16 @@ internal class MutablePropertyAdapter<T : Any>(private val provider: MutableProv
         provider.set(value)
     }
 
-    override fun observe(observer: Runnable) {
-        provider.observe(observer::run)
+    override fun <O : Any> observeWeak(owner: O, observer: Consumer<in O>) {
+        provider.observeWeak(owner, observer::accept)
+    }
+    
+    override fun <O : Any> unobserveWeak(owner: O, observer: Consumer<in O>) {
+        provider.unobserveWeak(owner, observer::accept)
     }
 
-    override fun unobserve(observer: Runnable) {
-        provider.unobserve(observer::run)
+    override fun unobserveWeak(owner: Any) {
+        provider.unobserveWeak(owner)
     }
 
 }

invui/src/main/java/xyz/xenondevs/invui/gui/AbstractPagedGui.java

@@ -12,6 +12,7 @@
 import java.util.List;
 import java.util.SequencedSet;
 import java.util.function.BiConsumer;
+import java.util.function.Consumer;
 
 sealed abstract class AbstractPagedGui<C>
     extends AbstractGui
@@ -21,9 +22,7 @@ sealed abstract class AbstractPagedGui<C>
 
     protected int[] contentListSlots;
 
-    private final Runnable bakeFn = this::bake;
-    
-    private MutableProperty<Integer> page;
+    private final MutableProperty<Integer> page;
     private Property<? extends List<? extends C>> content;
     private final List<BiConsumer<? super Integer, ? super Integer>> pageChangeHandlers = new ArrayList<>(0);
     private final List<BiConsumer<? super Integer, ? super Integer>> pageCountChangeHandlers = new ArrayList<>(0);
@@ -36,9 +35,9 @@ public AbstractPagedGui(
     ) {
         super(width, height);
         this.page = MutableProperty.of(0);
-        page.observe(this::update);
+        page.observeWeak(this, AbstractPagedGui::update);
         this.content = content;
-        content.observe(bakeFn);
+        content.observeWeak(this, AbstractPagedGui::bake);
         this.contentListSlots = SlotUtils.toSlotIndices(contentListSlots, getWidth());
     }
 
@@ -49,9 +48,9 @@ public AbstractPagedGui(
     ) {
         super(structure.getWidth(), structure.getHeight());
         this.page = page;
-        page.observe(this::update);
+        page.observeWeak(this, AbstractPagedGui::update);
         this.content = content;
-        content.observe(bakeFn);
+        content.observeWeak(this, AbstractPagedGui::bake);
         this.contentListSlots = structure.getIngredientMatrix().findContentListSlots();
         super.applyStructure(structure); // super call to avoid bake() through applyStructure override
     }
@@ -116,7 +115,7 @@ private void updatePageContent() {
 
     @Override
     public void setContent(List<? extends C> content) {
-        this.content.unobserve(bakeFn);
+        this.content.unobserveWeak(this);
         this.content = Property.of(content);
         bake();
     }

invui/src/main/java/xyz/xenondevs/invui/gui/AbstractScrollGui.java

@@ -23,8 +23,6 @@ sealed abstract class AbstractScrollGui<C>
     private int lineLength;
     private int[] contentListSlots = new int[0];
 
-    private final Runnable bakeFn = this::bake;
-    
     private final MutableProperty<Integer> line;
     private Property<? extends List<? extends C>> content;
     private final List<BiConsumer<? super Integer, ? super Integer>> scrollHandlers = new ArrayList<>(0);
@@ -39,9 +37,9 @@ public AbstractScrollGui(
     ) {
         super(width, height);
         this.line = MutableProperty.of(0);
-        line.observe(this::update);
+        line.observeWeak(this, AbstractScrollGui::update);
         this.content = content;
-        content.observe(bakeFn);
+        content.observeWeak(this, AbstractScrollGui::bake);
         setContentListSlots(SlotUtils.toSlotIndicesSet(contentListSlots, getWidth()), horizontalLines);
     }
 
@@ -52,9 +50,9 @@ public AbstractScrollGui(
     ) {
         super(structure.getWidth(), structure.getHeight());
         this.line = line;
-        line.observe(this::update);
+        line.observeWeak(this, AbstractScrollGui::update);
         this.content = content;
-        content.observe(bakeFn);
+        content.observeWeak(this, AbstractScrollGui::bake);
         super.applyStructure(structure); // super call to avoid bake() through applyStructure override
         setContentListSlotsFromStructure(structure);
     }
@@ -158,7 +156,7 @@ public int getMaxLine() {
 
     @Override
     public void setContent(List<? extends C> content) {
-        this.content.unobserve(bakeFn);
+        this.content.unobserveWeak(this);
         this.content = Property.of(content);
         bake();
     }

invui/src/main/java/xyz/xenondevs/invui/gui/TabGuiImpl.java

@@ -17,8 +17,6 @@ final class TabGuiImpl extends AbstractGui implements TabGui {
 
     private int[] contentListSlots;
 
-    private final Runnable bakeFn = this::bake;
-    
     private final MutableProperty<Integer> tab;
     private Property<? extends List<? extends @Nullable Gui>> tabs;
     private final List<BiConsumer<? super Integer, ? super Integer>> tabChangeHandlers = new ArrayList<>(0);
@@ -33,9 +31,9 @@ public TabGuiImpl(
         if (contentListSlots.isEmpty())
             throw new IllegalArgumentException("Content list slots must not be empty");
         this.tab = MutableProperty.of(0);
-        tab.observe(this::update);
+        tab.observeWeak(this, TabGuiImpl::update);
         this.tabs = tabs;
-        tabs.observe(bakeFn);
+        tabs.observeWeak(this, TabGuiImpl::bake);
         this.contentListSlots = SlotUtils.toSlotIndices(contentListSlots, getWidth());
         bake();
     }
@@ -47,9 +45,9 @@ public TabGuiImpl(
     ) {
         super(structure.getWidth(), structure.getHeight());
         this.tab = tab;
-        tab.observe(this::update);
+        tab.observeWeak(this, TabGuiImpl::update);
         this.tabs = tabs;
-        tabs.observe(bakeFn);
+        tabs.observeWeak(this, TabGuiImpl::bake);
         super.applyStructure(structure); // super call to avoid bake() through applyStructure override
         this.contentListSlots = structure.getIngredientMatrix().findContentListSlots();
         bake();
@@ -117,7 +115,7 @@ private void updateContent() {
 
     @Override
     public void setTabs(List<? extends @Nullable Gui> tabs) {
-        this.tabs.unobserve(bakeFn);
+        this.tabs.unobserveWeak(this);
         this.tabs = Property.of(tabs);
         bake();
     }

invui/src/main/java/xyz/xenondevs/invui/state/MutableProperty.java

@@ -2,8 +2,7 @@
 
 import org.jetbrains.annotations.ApiStatus;
 
-import java.util.HashSet;
-import java.util.Set;
+import java.util.*;
 import java.util.function.Consumer;
 
 @ApiStatus.Experimental
@@ -24,7 +23,7 @@ default void accept(T value) {
 
 class MutablePropertyImpl<T> implements MutableProperty<T> {
 
-    private final Set<Runnable> observers = new HashSet<>();
+    private final Map<Object, List<Consumer<Object>>> weakObservers = new WeakHashMap<>();
     private T value;
 
     public MutablePropertyImpl(T value) {
@@ -34,22 +33,35 @@ public MutablePropertyImpl(T value) {
     @Override
     public void set(T value) {
         this.value = value;
-        observers.forEach(Runnable::run);
+        weakObservers.forEach((owner, observers) -> observers.forEach(observer -> observer.accept(owner)));
     }
 
     @Override
     public T get() {
         return value;
     }
 
+    @SuppressWarnings("unchecked")
     @Override
-    public void observe(Runnable observer) {
-        observers.add(observer);
+    public <O> void observeWeak(O owner, Consumer<? super O> observer) {
+        weakObservers.computeIfAbsent(owner, k -> new ArrayList<>())
+            .add((Consumer<Object>)observer);
     }
 
     @Override
-    public void unobserve(Runnable observer) {
-        observers.remove(observer);
+    public <O> void unobserveWeak(O owner, Consumer<? super O> observer) {
+        List<Consumer<Object>> observers = weakObservers.get(owner);
+        if (observers != null) {
+            observers.remove(observer);
+            if (observers.isEmpty()) {
+                weakObservers.remove(owner);
+            }
+        }
+    }
+    
+    @Override
+    public void unobserveWeak(Object owner) {
+        weakObservers.remove(owner);
     }
 
 }

invui/src/main/java/xyz/xenondevs/invui/state/Property.java

@@ -2,6 +2,7 @@
 
 import org.jetbrains.annotations.ApiStatus;
 
+import java.util.function.Consumer;
 import java.util.function.Supplier;
 
 @ApiStatus.Experimental
@@ -13,9 +14,11 @@ static <T> Property<T> of(T value) {
 
     T get();
 
-    void observe(Runnable observer);
+    <O> void observeWeak(O owner, Consumer<? super O> observer);
 
-    void unobserve(Runnable observer);
+    <O> void unobserveWeak(O owner, Consumer<? super O> observer);
+    
+    void unobserveWeak(Object owner);
 
 }
 
@@ -33,12 +36,17 @@ public T get() {
     }
 
     @Override
-    public void observe(Runnable observer) {
+    public <O> void observeWeak(O owner, Consumer<? super O> observer) {
+        // empty
+    }
+    
+    @Override
+    public <O> void unobserveWeak(O owner, Consumer<? super O> observer) {
         // empty
     }
 
     @Override
-    public void unobserve(Runnable observer) {
+    public void unobserveWeak(Object owner) {
         // empty
     }