Introduce System Favorites

8 files changed, 224 insertions, 16 deletions

diff --git a/runtime/src/main/java/me/shedaniel/rei/impl/client/favorites/FavoriteEntryTypeRegistryImpl.java b/runtime/src/main/java/me/shedaniel/rei/impl/client/favorites/FavoriteEntryTypeRegistryImpl.java
index fb5787276..99886055d 100644
--- a/runtime/src/main/java/me/shedaniel/rei/impl/client/favorites/FavoriteEntryTypeRegistryImpl.java
+++ b/runtime/src/main/java/me/shedaniel/rei/impl/client/favorites/FavoriteEntryTypeRegistryImpl.java
@@ -25,15 +25,20 @@ package me.shedaniel.rei.impl.client.favorites;
 
 import com.google.common.collect.BiMap;
 import com.google.common.collect.HashBiMap;
+import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import me.shedaniel.rei.api.client.config.ConfigManager;
 import me.shedaniel.rei.api.client.config.ConfigObject;
 import me.shedaniel.rei.api.client.favorites.FavoriteEntry;
 import me.shedaniel.rei.api.client.favorites.FavoriteEntryType;
+import me.shedaniel.rei.api.client.favorites.SystemFavoriteEntryProvider;
 import me.shedaniel.rei.api.client.plugins.REIClientPlugin;
 import me.shedaniel.rei.api.common.registry.ReloadStage;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
+import org.apache.commons.lang3.mutable.MutableLong;
+import org.apache.commons.lang3.tuple.Pair;
+import org.apache.commons.lang3.tuple.Triple;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
@@ -45,6 +50,7 @@ import java.util.Map;
 @ApiStatus.Internal
 public class FavoriteEntryTypeRegistryImpl implements FavoriteEntryType.Registry {
     private final BiMap<ResourceLocation, FavoriteEntryType<?>> registry = HashBiMap.create();
+    private final List<Triple<SystemFavoriteEntryProvider<?>, MutableLong, List<FavoriteEntry>>> systemFavorites = Lists.newArrayList();
     private final Map<Component, FavoriteEntryType.Section> sections = Maps.newLinkedHashMap();
     
     @Override
@@ -84,8 +90,18 @@ public class FavoriteEntryTypeRegistryImpl implements FavoriteEntryType.Registry
     }
     
     @Override
+    public <A extends FavoriteEntry> void registerSystemFavorites(SystemFavoriteEntryProvider<A> provider) {
+        this.systemFavorites.add(Triple.of(provider, new MutableLong(-1), new ArrayList<>()));
+    }
+    
+    public List<Triple<SystemFavoriteEntryProvider<?>, MutableLong, List<FavoriteEntry>>> getSystemProviders() {
+        return this.systemFavorites;
+    }
+    
+    @Override
     public void startReload() {
         this.registry.clear();
+        this.systemFavorites.clear();
         this.sections.clear();
     }
     
diff --git a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/EntryListWidget.java b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/EntryListWidget.java
index f992145bc..5cf28663e 100644
--- a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/EntryListWidget.java
+++ b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/EntryListWidget.java
@@ -420,6 +420,7 @@ public class EntryListWidget extends WidgetWithBounds implements OverlayListWidg
         }
         FavoritesListWidget favoritesListWidget = ScreenOverlayImpl.getFavoritesListWidget();
         if (favoritesListWidget != null) {
+            favoritesListWidget.getSystemRegion().updateEntriesPosition(entry -> true);
             favoritesListWidget.getRegion().updateEntriesPosition(entry -> true);
         }
     }
diff --git a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/EntryStacksRegionWidget.java b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/EntryStacksRegionWidget.java
index f403ef6fe..bf7bbc97a 100644
--- a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/EntryStacksRegionWidget.java
+++ b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/EntryStacksRegionWidget.java
@@ -39,6 +39,7 @@ import me.shedaniel.rei.api.client.REIRuntime;
 import me.shedaniel.rei.api.client.config.ConfigObject;
 import me.shedaniel.rei.api.client.entry.region.RegionEntry;
 import me.shedaniel.rei.api.client.gui.drag.DraggableStack;
+import me.shedaniel.rei.api.client.gui.drag.DraggableStackProviderWidget;
 import me.shedaniel.rei.api.client.gui.drag.DraggableStackVisitorWidget;
 import me.shedaniel.rei.api.client.gui.drag.DraggingContext;
 import me.shedaniel.rei.api.client.gui.widgets.Widget;
@@ -56,6 +57,7 @@ import net.minecraft.util.Tuple;
 import net.minecraft.util.Unit;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Optional;
@@ -67,8 +69,8 @@ import java.util.stream.Stream;
 import static me.shedaniel.rei.impl.client.gui.widget.EntryListWidget.entrySize;
 import static me.shedaniel.rei.impl.client.gui.widget.EntryListWidget.notSteppingOnExclusionZones;
 
-public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWithBounds implements DraggableStackVisitorWidget {
-    private final RegionListener<T> listener;
+public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWithBounds implements DraggableStackProviderWidget, DraggableStackVisitorWidget {
+    public final RegionListener<T> listener;
     protected int blockedCount;
     private Rectangle bounds = new Rectangle(), innerBounds;
     protected final ScrollingContainer scrolling = new ScrollingContainer() {
@@ -79,6 +81,7 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
         
         @Override
         public int getMaxScrollHeight() {
+            if (innerBounds.width == 0) return 0;
             return Mth.ceil((entries.size() + blockedCount) / (innerBounds.width / (float) entrySize())) * entrySize();
         }
         
@@ -187,11 +190,12 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
         return false;
     }
     
+    @Override
     @Nullable
     public DraggableStack getHoveredStack(DraggingContext<Screen> context, double mouseX, double mouseY) {
         if (innerBounds.contains(mouseX, mouseY)) {
             for (RealRegionEntry<T> entry : entries.values()) {
-                if (entry.getWidget().containsMouse(mouseX, mouseY)) {
+                if (entry.getWidget().containsMouse(mouseX, mouseY) && listener.canBeDragged(entry)) {
                     return new RegionDraggableStack<>(entry, null);
                 }
             }
@@ -222,9 +226,11 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
     public boolean acceptDraggedStack(DraggingContext<Screen> context, DraggableStack stack) {
         return checkDraggedStacks(context, stack)
                 .filter(entry -> innerBounds.contains(context.getCurrentPosition()))
-                .map(entry -> {
-                    drop(entry);
-                    return Unit.INSTANCE;
+                .flatMap(entry -> {
+                    if (!drop(entry)) {
+                        return Optional.empty();
+                    }
+                    return Optional.of(Unit.INSTANCE);
                 }).isPresent();
     }
     
@@ -258,6 +264,7 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
             this.removedEntries.put(removedEntry.hashIgnoreAmount(), removedEntry);
         }
         
+        List<RealRegionEntry<T>> addedEntries = new ArrayList<>();
         Int2ObjectMap<RealRegionEntry<T>> prevEntries = new Int2ObjectOpenHashMap<>(entries);
         this.entries.clear();
         
@@ -266,6 +273,7 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
             
             if (realEntry == null) {
                 realEntry = new RealRegionEntry<>(this, regionEntry, entrySize);
+                addedEntries.add(realEntry);
             }
             
             if (!ConfigObject.getInstance().isFavoritesAnimated()) realEntry.size.setAs(entrySize * 100);
@@ -275,6 +283,20 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
         
         applyNewEntriesList();
         updateEntriesPosition(entry -> prevEntries.containsKey(entry.hashIgnoreAmount()));
+    
+        for (RealRegionEntry<T> removedEntry : removedEntries) {
+            this.listener.onRemove(removedEntry);
+        }
+    
+        for (RealRegionEntry<T> addedEntry : addedEntries) {
+            this.listener.onAdd(addedEntry);
+        }
+        
+        this.listener.onSetNewEntries(entriesList);
+    }
+    
+    public boolean isEmpty() {
+        return entries.isEmpty();
     }
     
     public void applyNewEntriesList() {
@@ -390,7 +412,11 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
         return new Rectangle((int) (bounds.getCenterX() - width * (entrySize / 2f) - 3), bounds.y, width * entrySize, bounds.height);
     }
     
-    public void drop(RealRegionEntry<T> entry) {
+    public boolean drop(RealRegionEntry<T> entry) {
+        if (!listener.canAcceptDrop(entry)) {
+            return false;
+        }
+        
         DraggingContext<?> context = DraggingContext.getInstance();
         double x = context.getCurrentPosition().x;
         double y = context.getCurrentPosition().y + scrolling.scrollAmount;
@@ -402,7 +428,7 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
         boolean contains = bounds.contains(PointHelper.ofMouse());
         int newIndex = contains ? getReleaseIndex() : Math.max(0, Iterables.indexOf(entries.values(), e -> e == entry));
         
-        if (entries.size() - 1 <= newIndex) {
+        if (entries.size() <= newIndex) {
             RealRegionEntry<T> remove = this.entries.remove(entry.hashIgnoreAmount());
             if (remove != null) {
                 remove.remove();
@@ -433,6 +459,7 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
         setEntries(this.entries.values().stream()
                 .map(RealRegionEntry::getEntry)
                 .collect(Collectors.toList()));
+        return true;
     }
     
     public void remove(RealRegionEntry<T> entry) {
@@ -445,7 +472,15 @@ public class EntryStacksRegionWidget<T extends RegionEntry<T>> extends WidgetWit
     }
     
     public boolean has(RealRegionEntry<T> entry) {
-        int hash = entry.hashIgnoreAmount();
+        return has(entry.getEntry());
+    }
+    
+    public boolean has(T entry) {
+        int hash = entry.hashCode();
         return entries.containsKey(hash) && !removedEntries.containsKey(hash);
     }
+    
+    public Rectangle getInnerBounds() {
+        return innerBounds;
+    }
 }
diff --git a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/FavoritesListWidget.java b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/FavoritesListWidget.java
index c98d689b3..771708dfb 100644
--- a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/FavoritesListWidget.java
+++ b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/FavoritesListWidget.java
@@ -38,6 +38,7 @@ import me.shedaniel.rei.api.client.config.ConfigManager;
 import me.shedaniel.rei.api.client.config.ConfigObject;
 import me.shedaniel.rei.api.client.favorites.FavoriteEntry;
 import me.shedaniel.rei.api.client.favorites.FavoriteEntryType;
+import me.shedaniel.rei.api.client.favorites.SystemFavoriteEntryProvider;
 import me.shedaniel.rei.api.client.gui.AbstractContainerEventHandler;
 import me.shedaniel.rei.api.client.gui.drag.DraggableStack;
 import me.shedaniel.rei.api.client.gui.drag.DraggableStackProviderWidget;
@@ -54,8 +55,10 @@ import me.shedaniel.rei.api.common.util.CollectionUtils;
 import me.shedaniel.rei.api.common.util.ImmutableTextComponent;
 import me.shedaniel.rei.impl.client.config.ConfigManagerImpl;
 import me.shedaniel.rei.impl.client.config.ConfigObjectImpl;
+import me.shedaniel.rei.impl.client.favorites.FavoriteEntryTypeRegistryImpl;
 import me.shedaniel.rei.impl.client.gui.widget.region.RealRegionEntry;
 import me.shedaniel.rei.impl.client.gui.widget.region.RegionDraggableStack;
+import me.shedaniel.rei.impl.client.gui.widget.region.RegionEntryListEntry;
 import me.shedaniel.rei.impl.client.gui.widget.region.RegionListener;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.components.events.GuiEventListener;
@@ -64,12 +67,15 @@ import net.minecraft.client.renderer.MultiBufferSource;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.chat.TranslatableComponent;
 import net.minecraft.util.Mth;
+import org.apache.commons.lang3.mutable.MutableLong;
+import org.apache.commons.lang3.tuple.Triple;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 import java.util.function.Predicate;
 import java.util.stream.Stream;
 
@@ -79,11 +85,40 @@ import static me.shedaniel.rei.impl.client.gui.widget.EntryListWidget.notSteppin
 @ApiStatus.Internal
 public class FavoritesListWidget extends WidgetWithBounds implements DraggableStackProviderWidget, OverlayListWidget, RegionListener<FavoriteEntry> {
     private Rectangle fullBounds;
+    private EntryStacksRegionWidget<FavoriteEntry> systemRegion = new EntryStacksRegionWidget<>(new RegionListener<FavoriteEntry>() {
+        @Override
+        @Nullable
+        public FavoriteEntry convertDraggableStack(DraggingContext<Screen> context, DraggableStack stack) {
+            return FavoriteEntry.fromEntryStack(stack.getStack().copy());
+        }
+        
+        @Override
+        public boolean canAcceptDrop(RealRegionEntry<FavoriteEntry> entry) {
+            return false;
+        }
+        
+        @Override
+        @Nullable
+        public FavoriteEntry asFavorite(RealRegionEntry<FavoriteEntry> entry) {
+            return null;
+        }
+        
+        @Override
+        public boolean canBeDragged(RealRegionEntry<FavoriteEntry> entry) {
+            return RegionListener.super.canBeDragged(entry);
+        }
+        
+        @Override
+        public boolean removeOnDrag() {
+            return false;
+        }
+    });
     private EntryStacksRegionWidget<FavoriteEntry> region = new EntryStacksRegionWidget<>(this);
+    private List<FavoriteEntry> lastSystemEntries = new ArrayList<>();
     
     public final AddFavoritePanel favoritePanel = new AddFavoritePanel(this);
     public final ToggleAddFavoritePanelButton favoritePanelButton = new ToggleAddFavoritePanelButton(this);
-    private List<Widget> children = ImmutableList.of(favoritePanel, favoritePanelButton, region);
+    private List<Widget> children = ImmutableList.of(favoritePanel, favoritePanelButton, systemRegion, region);
     
     @Override
     public boolean mouseScrolled(double mouseX, double mouseY, double amount) {
@@ -111,6 +146,10 @@ public class FavoritesListWidget extends WidgetWithBounds implements DraggableSt
         return region;
     }
     
+    public EntryStacksRegionWidget<FavoriteEntry> getSystemRegion() {
+        return systemRegion;
+    }
+    
     @Override
     public void onDrop(Stream<FavoriteEntry> entries) {
         if (ConfigObject.getInstance().isFavoritesEnabled()) {
@@ -135,6 +174,8 @@ public class FavoritesListWidget extends WidgetWithBounds implements DraggableSt
     public DraggableStack getHoveredStack(DraggingContext<Screen> context, double mouseX, double mouseY) {
         DraggableStack stack = region.getHoveredStack(context, mouseX, mouseY);
         if (stack != null) return stack;
+        stack = systemRegion.getHoveredStack(context, mouseX, mouseY);
+        if (stack != null) return stack;
         if (favoritePanel.bounds.contains(mouseX, mouseY)) {
             for (AddFavoritePanel.Row row : favoritePanel.rows.get()) {
                 if (row instanceof AddFavoritePanel.SectionEntriesRow entriesRow) {
@@ -156,6 +197,8 @@ public class FavoritesListWidget extends WidgetWithBounds implements DraggableSt
         Point mouse = PointHelper.ofMouse();
         EntryStack<?> stack = region.getFocusedStack();
         if (stack != null && !stack.isEmpty()) return stack;
+        stack = systemRegion.getFocusedStack();
+        if (stack != null && !stack.isEmpty()) return stack;
         if (favoritePanel.bounds.contains(mouse)) {
             for (AddFavoritePanel.Row row : favoritePanel.rows.get()) {
                 if (row instanceof AddFavoritePanel.SectionEntriesRow entriesRow) {
@@ -180,13 +223,74 @@ public class FavoritesListWidget extends WidgetWithBounds implements DraggableSt
         if (fullBounds.isEmpty())
             return;
         
+        updateSystemRegion();
+//        systemRegion.getBounds().setBounds(this.fullBounds.x + 1, this.fullBounds.y - 1 + 14, this.fullBounds.width - 1, Math.max(1, systemRegion.scrolling.getMaxScrollHeight()));
+        systemRegion.getBounds().setBounds(this.fullBounds.x, this.fullBounds.y + 1, this.fullBounds.width, Math.max(1, systemRegion.scrolling.getMaxScrollHeight()));
+        int systemHeight = systemRegion.getBounds().getHeight();
+        if (systemHeight > 1 && !region.isEmpty()) {
+            Rectangle innerBounds = systemRegion.getInnerBounds();
+//            font.draw(matrices, new TranslatableComponent("System Favorites").withStyle(ChatFormatting.UNDERLINE), innerBounds.x - 1 + 4, fullBounds.y - 1 + 4, 0xFFFFFFFF);
+            fillGradient(matrices, innerBounds.x + 1, this.fullBounds.y + systemHeight + 2, innerBounds.getMaxX() - 1, this.fullBounds.y + systemHeight + 3, 0xFF777777, 0xFF777777);
+//            fillGradient(matrices, innerBounds.x - 2, this.fullBounds.y - 1, innerBounds.getMaxX() + 2, this.fullBounds.y + systemHeight + 1 + 14, 0x34FFFFFF, 0x34FFFFFF);
+//            systemHeight += 4 + 14;
+            systemHeight += 4;
+        }
         if (favoritePanel.getBounds().height > 20)
-            region.getBounds().setBounds(this.fullBounds.x, this.fullBounds.y, this.fullBounds.width, this.fullBounds.height - (this.fullBounds.getMaxY() - this.favoritePanel.bounds.y) - 4);
-        else region.getBounds().setBounds(this.fullBounds);
+            region.getBounds().setBounds(this.fullBounds.x, this.fullBounds.y + systemHeight, this.fullBounds.width, this.fullBounds.height - systemHeight - (this.fullBounds.getMaxY() - this.favoritePanel.bounds.y) - 4);
+        else region.getBounds().setBounds(this.fullBounds.x, this.fullBounds.y + systemHeight, this.fullBounds.width, this.fullBounds.height - systemHeight);
+        systemRegion.render(matrices, mouseX, mouseY, delta);
         region.render(matrices, mouseX, mouseY, delta);
         renderAddFavorite(matrices, mouseX, mouseY, delta);
     }
     
+    private void updateSystemRegion() {
+        boolean updated = false;
+        List<Triple<SystemFavoriteEntryProvider<?>, MutableLong, List<FavoriteEntry>>> providers = ((FavoriteEntryTypeRegistryImpl) FavoriteEntryType.registry()).getSystemProviders();
+        
+        for (Triple<SystemFavoriteEntryProvider<?>, MutableLong, List<FavoriteEntry>> pair : providers) {
+            SystemFavoriteEntryProvider<?> provider = pair.getLeft();
+            MutableLong mutableLong = pair.getMiddle();
+            List<FavoriteEntry> entries = pair.getRight();
+            
+            if (mutableLong.getValue() == -1 || mutableLong.getValue() < System.currentTimeMillis()) {
+                mutableLong.setValue(System.currentTimeMillis() + provider.updateInterval());
+                List<FavoriteEntry> provide = (List<FavoriteEntry>) provider.provide();
+                if (!provide.equals(entries)) {
+                    entries.clear();
+                    entries.addAll(provide);
+                    updated = true;
+                }
+            }
+        }
+        
+        if (updated) {
+            lastSystemEntries = CollectionUtils.flatMap(providers, Triple::getRight);
+            setSystemRegionEntries();
+        }
+    }
+    
+    private void setSystemRegionEntries() {
+        systemRegion.setEntries(CollectionUtils.filterToList(lastSystemEntries, entry -> {
+            if (region.has(entry)) return false;
+            if (DraggingContext.getInstance().isDraggingStack()) {
+                DraggableStack currentStack = DraggingContext.getInstance().getCurrentStack();
+                if (currentStack instanceof RegionDraggableStack) {
+                    RegionDraggableStack<?> stack = (RegionDraggableStack<?>) currentStack;
+                    
+                    if (stack.getEntry().region == region && Objects.equals(stack.getEntry().getEntry(), entry)) {
+                        return false;
+                    }
+                }
+            }
+            return true;
+        }));
+    }
+    
+    @Override
+    public void onSetNewEntries(List<RegionEntryListEntry<FavoriteEntry>> regionEntryListEntries) {
+        setSystemRegionEntries();
+    }
+    
     private void renderAddFavorite(PoseStack matrices, int mouseX, int mouseY, float delta) {
         this.favoritePanel.render(matrices, mouseX, mouseY, delta);
         this.favoritePanelButton.render(matrices, mouseX, mouseY, delta);
@@ -218,7 +322,7 @@ public class FavoritesListWidget extends WidgetWithBounds implements DraggableSt
     
     @Override
     public boolean mouseClicked(double mouseX, double mouseY, int button) {
-        if (region.mouseClicked(mouseX, mouseY, button))
+        if (systemRegion.mouseClicked(mouseX, mouseY, button) || region.mouseClicked(mouseX, mouseY, button))
             return true;
         for (Widget widget : children())
             if (widget.mouseClicked(mouseX, mouseY, button))
diff --git a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionDraggableStack.java b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionDraggableStack.java
index 06c3543c0..33238c38e 100644
--- a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionDraggableStack.java
+++ b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionDraggableStack.java
@@ -48,7 +48,7 @@ public class RegionDraggableStack<T extends RegionEntry<T>> implements Draggable
     
     @Override
     public void drag() {
-        if (showcaseWidget == null) {
+        if (showcaseWidget == null && entry.region.listener.removeOnDrag()) {
             entry.region.remove(entry);
         }
     }
@@ -60,7 +60,10 @@ public class RegionDraggableStack<T extends RegionEntry<T>> implements Draggable
     @Override
     public void release(boolean accepted) {
         if (!accepted) {
-            if (showcaseWidget != null) {
+            if (!entry.region.listener.removeOnDrag()) {
+                DraggingContext.getInstance().renderBackToPosition(this, DraggingContext.getInstance().getCurrentPosition(),
+                        () -> new Point(entry.x.doubleValue(), entry.y.doubleValue()));
+            } else if (showcaseWidget != null) {
                 DraggingContext.getInstance().renderBackToPosition(this, DraggingContext.getInstance().getCurrentPosition(),
                         () -> new Point(showcaseWidget.getBounds().x, showcaseWidget.getBounds().y));
             } else {
diff --git a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionEntryListEntry.java b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionEntryListEntry.java
index 2ebcc49ae..6cc5a3d01 100644
--- a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionEntryListEntry.java
+++ b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionEntryListEntry.java
@@ -53,7 +53,7 @@ public class RegionEntryListEntry<T extends RegionEntry<T>> extends EntryListEnt
     
     @Override
     protected FavoriteEntry asFavoriteEntry() {
-        return entry.getEntry().asFavorite();
+        return entry.region.listener.asFavorite(entry);
     }
     
     @Override
diff --git a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionListener.java b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionListener.java
index 9009560c3..caff430b9 100644
--- a/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionListener.java
+++ b/runtime/src/main/java/me/shedaniel/rei/impl/client/gui/widget/region/RegionListener.java
@@ -24,11 +24,13 @@
 package me.shedaniel.rei.impl.client.gui.widget.region;
 
 import me.shedaniel.rei.api.client.entry.region.RegionEntry;
+import me.shedaniel.rei.api.client.favorites.FavoriteEntry;
 import me.shedaniel.rei.api.client.gui.drag.DraggableStack;
 import me.shedaniel.rei.api.client.gui.drag.DraggingContext;
 import net.minecraft.client.gui.screens.Screen;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.List;
 import java.util.stream.Stream;
 
 public interface RegionListener<T extends RegionEntry<T>> {
@@ -38,4 +40,27 @@ public interface RegionListener<T extends RegionEntry<T>> {
     default T convertDraggableStack(DraggingContext<Screen> context, DraggableStack stack) {
         return null;
     }
+    
+    default boolean canAcceptDrop(RealRegionEntry<T> entry) {
+        return true;
+    }
+    
+    @Nullable
+    default FavoriteEntry asFavorite(RealRegionEntry<T> entry) {
+        return entry.getEntry().asFavorite();
+    }
+    
+    default boolean canBeDragged(RealRegionEntry<T> entry) {
+        return true;
+    }
+    
+    default boolean removeOnDrag() {
+        return true;
+    }
+    
+    default void onRemove(RealRegionEntry<T> entry) {}
+    
+    default void onAdd(RealRegionEntry<T> entry) {}
+    
+    default void onSetNewEntries(List<RegionEntryListEntry<T>> entries) {}
 }
diff --git a/runtime/src/main/java/me/shedaniel/rei/plugin/test/REITestPlugin.java b/runtime/src/main/java/me/shedaniel/rei/plugin/test/REITestPlugin.java
index f9eedfdce..28bbe66ca 100644
--- a/runtime/src/main/java/me/shedaniel/rei/plugin/test/REITestPlugin.java
+++ b/runtime/src/main/java/me/shedaniel/rei/plugin/test/REITestPlugin.java
@@ -23,6 +23,9 @@
 
 package me.shedaniel.rei.plugin.test;
 
+import com.google.common.collect.ImmutableList;
+import me.shedaniel.rei.api.client.favorites.FavoriteEntry;
+import me.shedaniel.rei.api.client.favorites.FavoriteEntryType;
 import me.shedaniel.rei.api.client.plugins.REIClientPlugin;
 import me.shedaniel.rei.api.client.registry.entry.EntryRegistry;
 import me.shedaniel.rei.api.common.entry.EntryStack;
@@ -30,10 +33,13 @@ import me.shedaniel.rei.api.common.entry.comparison.ItemComparatorRegistry;
 import me.shedaniel.rei.api.common.util.EntryStacks;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
+import net.minecraft.client.Minecraft;
 import net.minecraft.core.Registry;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.level.GameType;
 import org.apache.logging.log4j.LogManager;
 import org.jetbrains.annotations.TestOnly;
 
@@ -76,4 +82,22 @@ public class REITestPlugin implements REIClientPlugin {
         tag.putInt("Whatever", random.nextInt(Integer.MAX_VALUE));
         return stack;
     }
+    
+    @Override
+    public void registerFavorites(FavoriteEntryType.Registry registry) {
+        registry.registerSystemFavorites(() -> {
+            GameType mode = Minecraft.getInstance().gameMode.getPlayerMode();
+            switch (mode) {
+                case SURVIVAL:
+                    return ImmutableList.of(FavoriteEntry.fromEntryStack(EntryStacks.of(Items.STONE)));
+                case CREATIVE:
+                    return ImmutableList.of(FavoriteEntry.fromEntryStack(EntryStacks.of(Items.PACKED_ICE)));
+                case ADVENTURE:
+                    return ImmutableList.of(FavoriteEntry.fromEntryStack(EntryStacks.of(Items.ANVIL)));
+                case SPECTATOR:
+                default:
+                    return ImmutableList.of();
+            }
+        });
+    }
 }