1 files changed, 91 insertions, 0 deletions
diff --git a/src/main/java/me/shedaniel/rei/impl/DisplayHelperImpl.java b/src/main/java/me/shedaniel/rei/impl/DisplayHelperImpl.java
new file mode 100644
index 000000000..470d5a2c1
--- /dev/null
+++ b/src/main/java/me/shedaniel/rei/impl/DisplayHelperImpl.java
@@ -0,0 +1,91 @@
+/*
+ * Roughly Enough Items by Danielshe.
+ * Licensed under the MIT License.
+ */
+
+package me.shedaniel.rei.impl;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import me.shedaniel.rei.api.BaseBoundsHandler;
+import me.shedaniel.rei.api.DisplayHelper;
+
+import java.awt.*;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+public class DisplayHelperImpl implements DisplayHelper {
+    
+    private static final Comparator<DisplayBoundsHandler<?>> BOUNDS_HANDLER_COMPARATOR;
+    private static final DisplayBoundsHandler<Object> EMPTY = new DisplayBoundsHandler() {
+        @Override
+        public Class getBaseSupportedClass() {
+            return null;
+        }
+        
+        @Override
+        public Rectangle getLeftBounds(Object screen) {
+            return new Rectangle();
+        }
+        
+        @Override
+        public Rectangle getRightBounds(Object screen) {
+            return new Rectangle();
+        }
+        
+        @Override
+        public float getPriority() {
+            return -10f;
+        }
+    };
+    
+    static {
+        Comparator<DisplayBoundsHandler<?>> comparator = Comparator.comparingDouble(DisplayBoundsHandler::getPriority);
+        BOUNDS_HANDLER_COMPARATOR = comparator.reversed();
+    }
+    
+    private List<DisplayBoundsHandler<?>> screenDisplayBoundsHandlers = Lists.newArrayList();
+    private Map<Class<?>, DisplayBoundsHandler<?>> handlerCache = Maps.newHashMap();
+    private BaseBoundsHandler baseBoundsHandler;
+    
+    @Override
+    public List<DisplayBoundsHandler<?>> getSortedBoundsHandlers(Class<?> screenClass) {
+        return screenDisplayBoundsHandlers.stream().filter(handler -> handler.getBaseSupportedClass().isAssignableFrom(screenClass)).sorted(BOUNDS_HANDLER_COMPARATOR).collect(Collectors.toList());
+    }
+    
+    @Override
+    public List<DisplayBoundsHandler<?>> getAllBoundsHandlers() {
+        return screenDisplayBoundsHandlers;
+    }
+    
+    @Override
+    public DisplayBoundsHandler<?> getResponsibleBoundsHandler(Class<?> screenClass) {
+        Optional<? extends DisplayBoundsHandler<?>> any = handlerCache.entrySet().stream().filter(entry -> entry.getKey().equals(screenClass)).map(Map.Entry::getValue).findAny();
+        if (any.isPresent())
+            return any.get();
+        handlerCache.put(screenClass, screenDisplayBoundsHandlers.stream().filter(handler -> handler.getBaseSupportedClass().isAssignableFrom(screenClass)).sorted(BOUNDS_HANDLER_COMPARATOR).findAny().orElse(EMPTY));
+        return handlerCache.get(screenClass);
+    }
+    
+    @Override
+    public void registerBoundsHandler(DisplayBoundsHandler<?> handler) {
+        screenDisplayBoundsHandlers.add(handler);
+    }
+    
+    @Override
+    public BaseBoundsHandler getBaseBoundsHandler() {
+        return baseBoundsHandler;
+    }
+    
+    public void setBaseBoundsHandler(BaseBoundsHandler baseBoundsHandler) {
+        this.baseBoundsHandler = baseBoundsHandler;
+    }
+    
+    public void resetCache() {
+        handlerCache.clear();
+    }
+    
+}