More work on hovering and observables

9 files changed, 102 insertions, 26 deletions

diff --git a/src/main/java/io/github/cottonmc/cotton/gui/impl/client/MouseInputHandler.java b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/MouseInputHandler.java
index 4791c39..055df75 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/impl/client/MouseInputHandler.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/MouseInputHandler.java
@@ -4,6 +4,7 @@ import net.minecraft.client.gui.screen.Screen;
 
 import io.github.cottonmc.cotton.gui.widget.WWidget;
 import io.github.cottonmc.cotton.gui.widget.data.InputResult;
+import io.github.cottonmc.cotton.gui.widget.data.ObservableProperty;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.function.Function;
@@ -13,10 +14,14 @@ import java.util.function.Function;
  */
 public final class MouseInputHandler<S extends Screen & CottonScreenImpl> {
 	private final S screen;
-	private @Nullable WWidget hovered;
+	private final ObservableProperty<WWidget> hovered = ObservableProperty.of(null);
 
 	public MouseInputHandler(S screen) {
 		this.screen = screen;
+		hovered.addListener((property, from, to) -> {
+			if (from != null) from.setHovered(false);
+			if (to != null) to.setHovered(true);
+		});
 	}
 
 	public void onMouseDown(int containerX, int containerY, int mouseButton) {
@@ -89,16 +94,7 @@ public final class MouseInputHandler<S extends Screen & CottonScreenImpl> {
 
 	public void onMouseMove(int containerX, int containerY) {
 		WWidget hit = screen.getDescription().getRootPanel().hit(containerX, containerY);
-
-		// TODO: Some sort of canHover?
-		if (hit != hovered) {
-			if (hovered != null) {
-				hovered.getHovered().set(false);
-			}
-
-			hovered = hit;
-			hit.getHovered().set(true);
-		}
+		hovered.set(hit);
 
 		runTree(
 				hit,
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/impl/client/NarrationHelper.java b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/NarrationHelper.java
index 9b44210..55095a3 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/impl/client/NarrationHelper.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/NarrationHelper.java
@@ -18,7 +18,7 @@ public final class NarrationHelper {
 	public static void addNarrations(WPanel rootPanel, NarrationMessageBuilder builder) {
 		List<WWidget> narratableWidgets = getAllWidgets(rootPanel)
 			.filter(WWidget::isNarratable)
-			.filter(WWidget::isFocused) // TODO: || isHovered
+			.filter(widget -> widget.isFocused() || widget.isHovered())
 			.collect(Collectors.toList());
 
 		for (int i = 0, childCount = narratableWidgets.size(); i < childCount; i++) {
@@ -28,7 +28,7 @@ public final class NarrationHelper {
 			if (narratableWidgets.size() > 1) {
 				builder.put(NarrationPart.POSITION, new TranslatableText(NarrationMessages.Vanilla.SCREEN_POSITION_KEY, i + 1, childCount));
 
-				if (child.isFocused()) { // TODO: this check is currently useless but will be used with hovering
+				if (child.isFocused()) {
 					builder.put(NarrationPart.USAGE, NarrationMessages.Vanilla.COMPONENT_LIST_USAGE);
 				}
 			}
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WButton.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WButton.java
index c6fdfc2..533e436 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WButton.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WButton.java
@@ -230,8 +230,7 @@ public class WButton extends WWidget {
 		if (isEnabled()) {
 			if (isFocused()) {
 				builder.put(NarrationPart.USAGE, NarrationMessages.Vanilla.BUTTON_USAGE_FOCUSED);
-			} else {
-				// TODO: hovering, again
+			} else if (isHovered()) {
 				builder.put(NarrationPart.USAGE, NarrationMessages.Vanilla.BUTTON_USAGE_HOVERED);
 			}
 		}
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WItemSlot.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WItemSlot.java
index 18c812d..a4788a7 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WItemSlot.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WItemSlot.java
@@ -450,6 +450,8 @@ public class WItemSlot extends WWidget {
 			parts.add(new TranslatableText(NarrationMessages.ITEM_SLOT_TITLE_KEY, focusedSlot + 1, slotsWide * slotsHigh));
 			builder.put(NarrationPart.TITLE, parts.toArray(new Text[0]));
 		}
+
+		// TODO: hovered slot
 	}
 
 	@Nullable
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WLabel.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WLabel.java
index 5c6b2da..83f0700 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WLabel.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WLabel.java
@@ -5,6 +5,8 @@ import net.fabricmc.api.Environment;
 import net.minecraft.client.MinecraftClient;
 import net.minecraft.client.font.TextRenderer;
 import net.minecraft.client.gui.screen.Screen;
+import net.minecraft.client.gui.screen.narration.NarrationMessageBuilder;
+import net.minecraft.client.gui.screen.narration.NarrationPart;
 import net.minecraft.client.util.math.MatrixStack;
 import net.minecraft.text.LiteralText;
 import net.minecraft.text.Style;
@@ -261,4 +263,10 @@ public class WLabel extends WWidget {
 		this.verticalAlignment = align;
 		return this;
 	}
+
+	@Environment(EnvType.CLIENT)
+	@Override
+	public void addNarrations(NarrationMessageBuilder builder) {
+		builder.put(NarrationPart.TITLE, text);
+	}
 }
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WText.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WText.java
index 96f78ed..8a4f03e 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WText.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WText.java
@@ -4,6 +4,8 @@ import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
 import net.minecraft.client.MinecraftClient;
 import net.minecraft.client.font.TextRenderer;
+import net.minecraft.client.gui.screen.narration.NarrationMessageBuilder;
+import net.minecraft.client.gui.screen.narration.NarrationPart;
 import net.minecraft.client.util.math.MatrixStack;
 import net.minecraft.text.OrderedText;
 import net.minecraft.text.Style;
@@ -253,4 +255,10 @@ public class WText extends WWidget {
 		this.verticalAlignment = verticalAlignment;
 		return this;
 	}
+
+	@Environment(EnvType.CLIENT)
+	@Override
+	public void addNarrations(NarrationMessageBuilder builder) {
+		builder.put(NarrationPart.TITLE, text);
+	}
 }
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WToggleButton.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WToggleButton.java
index d4fb728..ca0285f 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WToggleButton.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WToggleButton.java
@@ -223,8 +223,7 @@ public class WToggleButton extends WWidget {
 
 		if (isFocused()) {
 			builder.put(NarrationPart.USAGE, NarrationMessages.Vanilla.BUTTON_USAGE_FOCUSED);
-		} else {
-			// TODO: hovering, again
+		} else if (isHovered()) {
 			builder.put(NarrationPart.USAGE, NarrationMessages.Vanilla.BUTTON_USAGE_HOVERED);
 		}
 	}
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WWidget.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WWidget.java
index 3beacee..ac08ae6 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WWidget.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WWidget.java
@@ -44,7 +44,7 @@ public class WWidget {
 	@Nullable
 	protected GuiDescription host;
 
-	private final ObservableProperty<Boolean> hovered = ObservableProperty.of(false).nonnullValues();
+	private final ObservableProperty<Boolean> hovered = ObservableProperty.of(false).nonnullValues().setName("WWidget.hovered");
 
 	/**
 	 * Sets the location of this widget relative to its parent.
@@ -461,11 +461,39 @@ public class WWidget {
 	public void addPainters() {
 	}
 
-	public ObservableProperty<Boolean> getHovered() {
+	/**
+	 * Returns whether the user is hovering over this widget.
+	 * The result is an <i>observable property</i> that can be modified and listened to.
+	 *
+	 * @return the {@code hovered} property
+	 * @since 4.2.0
+	 */
+	public ObservableProperty<Boolean> hoveredProperty() {
 		return hovered;
 	}
 
 	/**
+	 * Returns whether the user is hovering over this widget.
+	 * This is equivalent to calling <code>{@link #hoveredProperty()}.get()</code>.
+	 *
+	 * @return true if this widget is hovered, false otherwise
+	 * @since 4.2.0
+	 */
+	public final boolean isHovered() {
+		return hoveredProperty().get();
+	}
+
+	/**
+	 * Sets the {@link ##hoveredProperty()} hovered} property.
+	 *
+	 * @param hovered the new value; true if hovered, false otherwise
+	 * @since 4.2.0
+	 */
+	public final void setHovered(boolean hovered) {
+		hoveredProperty().set(hovered);
+	}
+
+	/**
 	 * {@return whether this widget can be narrated}
 	 *
 	 * @see #addNarrations(NarrationMessageBuilder)
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/data/ObservableProperty.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/data/ObservableProperty.java
index 723cf60..3b0205e 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/data/ObservableProperty.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/data/ObservableProperty.java
@@ -7,10 +7,22 @@ import java.util.List;
 import java.util.Objects;
 import java.util.function.Supplier;
 
-public final class ObservableProperty<T> {
+/**
+ * An observable mutable property. Observable properties are containers for values
+ * that can be modified, listened to and bound to other suppliers.
+ *
+ * <p>The naming convention for {@code ObservableProperty} getters follows the convention
+ * {@code <property name>Property}. For example, the {@code WWidget.hovered} property can be retrieved with
+ * {@link io.github.cottonmc.cotton.gui.widget.WWidget#hoveredProperty() hoveredProperty()}.
+ *
+ * @param <T> the contained value type
+ * @since 4.2.0
+ */
+public final class ObservableProperty<T> implements Supplier<T> {
 	private Supplier<? extends T> value;
 	private final List<ChangeListener<? super T>> listeners = new ArrayList<>();
 	private boolean allowNull = true;
+	private String name = "<unnamed>";
 
 	private ObservableProperty() {
 	}
@@ -36,13 +48,14 @@ public final class ObservableProperty<T> {
 	 * @throws IllegalStateException if not initialized
 	 * @throws NullPointerException if the value is null and null values aren't allowed
 	 */
+	@Override
 	public T get() {
 		if (value == null) {
-			throw new IllegalStateException("Property not initialized!");
+			throw new IllegalStateException("Property " + name + " not initialized!");
 		}
 
 		T ret = value.get();
-		if (ret == null && !allowNull) throw new NullPointerException("Null value for nonnull property!");
+		if (ret == null && !allowNull) throw new NullPointerException("Null value for nonnull property " + name + "!");
 		return ret;
 	}
 
@@ -66,9 +79,12 @@ public final class ObservableProperty<T> {
 		Objects.requireNonNull(value, "value");
 		T oldValue = this.value != null ? this.value.get() : null;
 		this.value = value;
+		T newValue = value.get();
 
-		for (ChangeListener<? super T> listener : listeners) {
-			listener.onPropertyChange(this, oldValue, value.get());
+		if (oldValue != newValue) {
+			for (ChangeListener<? super T> listener : listeners) {
+				listener.onPropertyChange(this, oldValue, newValue);
+			}
 		}
 	}
 
@@ -79,8 +95,10 @@ public final class ObservableProperty<T> {
 		T oldValue = this.value != null ? this.value.get() : null;
 		value = null;
 
-		for (ChangeListener<? super T> listener : listeners) {
-			listener.onPropertyChange(this, oldValue, null);
+		if (oldValue != null) {
+			for (ChangeListener<? super T> listener : listeners) {
+				listener.onPropertyChange(this, oldValue, null);
+			}
 		}
 	}
 
@@ -94,6 +112,24 @@ public final class ObservableProperty<T> {
 		return this;
 	}
 
+	/**
+	 * {@return the name of this property}
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * Sets the name of this property, which is used in debug messages.
+	 *
+	 * @param name the new name
+	 * @return this property
+	 */
+	public ObservableProperty<T> setName(String name) {
+		this.name = Objects.requireNonNull(name, "name");
+		return this;
+	}
+
 	public void addListener(ChangeListener<? super T> listener) {
 		listeners.add(listener);
 	}