Add RenderTooltipEvent (#3034)

src/main/java/net/minecraftforge/client/event/RenderTooltipEvent.java

@@ -0,0 +1,225 @@
+package net.minecraftforge.client.event;
+
+import java.util.Collections;
+import java.util.List;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import net.minecraft.client.gui.FontRenderer;
+import net.minecraft.item.ItemStack;
+import net.minecraftforge.event.entity.player.ItemTooltipEvent;
+import net.minecraftforge.fml.common.eventhandler.Cancelable;
+import net.minecraftforge.fml.common.eventhandler.Event;
+
+/**
+ * A set of events which are fired at various points during tooltip rendering.
+ * <p>
+ * Can be used to change the rendering parameters, draw something extra, etc.
+ * <p>
+ * Do not use this event directly, use one of the subclasses:
+ * <ul>
+ * <li>{@link RenderTooltipEvent.Pre}</li>
+ * <li>{@link RenderTooltipEvent.PostBackground}</li>
+ * <li>{@link RenderTooltipEvent.PostText}</li>
+ * </ul>
+ */
+public abstract class RenderTooltipEvent extends Event
+{
+    protected final ItemStack stack;
+    protected final List<String> lines;
+    protected int x;
+    protected int y;
+    protected FontRenderer fr;
+
+    public RenderTooltipEvent(@Nullable ItemStack stack, @Nonnull List<String> lines, int x, int y, @Nonnull FontRenderer fr)
+    {
+        this.stack = stack;
+        this.lines = Collections.unmodifiableList(lines); // Leave editing to ItemTooltipEvent
+        this.x = x;
+        this.y = y;
+        this.fr = fr;
+    }
+
+    /**
+     * @return The stack which the tooltip is being rendered for. As tooltips can be drawn without itemstacks, this return is {@link Nullable}. 
+     */
+    @Nullable
+    public ItemStack getStack()
+    {
+        return stack;
+    }
+    
+    /**
+     * The lines to be drawn. May change between {@link RenderTooltipEvent.Pre} and {@link RenderTooltipEvent.Post}.
+     * 
+     * @return An <i>unmodifiable</i> list of strings. Use {@link ItemTooltipEvent} to modify tooltip text.
+     */
+    @Nonnull
+    public List<String> getLines()
+    {
+        return lines;
+    }
+
+    /**
+     * @return The X position of the tooltip box. By default, the mouse X position.
+     */
+    public int getX()
+    {
+        return x;
+    }
+
+    /**
+     * @return The Y position of the tooltip box. By default, the mouse Y position.
+     */
+    public int getY()
+    {
+        return y;
+    }
+    
+    /**
+     * @return The {@link FontRenderer} instance the current render is using.
+     */
+    @Nonnull
+    public FontRenderer getFontRenderer()
+    {
+        return fr;
+    }
+
+    /**
+     * This event is fired before any tooltip calculations are done. It provides setters for all aspects of the tooltip, so the final render can be modified.
+     * <p>
+     * This event is {@link Cancelable}.
+     */
+    @Cancelable
+    public static class Pre extends RenderTooltipEvent
+    {
+        private int screenWidth;
+        private int screenHeight;
+        private int maxWidth;
+
+        public Pre(@Nullable ItemStack stack, @Nonnull List<String> lines, int x, int y, int screenWidth, int screenHeight, int maxWidth, @Nonnull FontRenderer fr)
+        {
+            super(stack, lines, x, y, fr);
+            this.screenWidth = screenWidth;
+            this.screenHeight = screenHeight;
+            this.maxWidth = maxWidth;
+        }
+
+        public int getScreenWidth()
+        {
+            return screenWidth;
+        }
+
+        public void setScreenWidth(int screenWidth)
+        {
+            this.screenWidth = screenWidth;
+        }
+
+        public int getScreenHeight()
+        {
+            return screenHeight;
+        }
+
+        public void setScreenHeight(int screenHeight)
+        {
+            this.screenHeight = screenHeight;
+        }
+
+        /**
+         * @return The max width the tooltip can be. Defaults to -1 (unlimited).
+         */
+        public int getMaxWidth()
+        {
+            return maxWidth;
+        }
+
+        /**
+         * Sets the max width of the tooltip. Use -1 for unlimited.
+         */
+        public void setMaxWidth(int maxWidth)
+        {
+            this.maxWidth = maxWidth;
+        }
+        
+        /**
+         * Sets the {@link FontRenderer} to be used to render text.
+         */
+        public void setFontRenderer(@Nonnull FontRenderer fr)
+        {
+            this.fr = fr;
+        }
+
+        /**
+         * Set the X origin of the tooltip.
+         */
+        public void setX(int x)
+        {
+            this.x = x;
+        }
+
+        /**
+         * Set the Y origin of the tooltip.
+         */
+        public void setY(int y)
+        {
+            this.y = y;
+        }
+    }
+
+    /**
+     * Events inheriting from this class are fired at different stages during the tooltip rendering.
+     * <p>
+     * Do not use this event directly, use one of its subclasses:
+     * <ul>
+     * <li>{@link RenderTooltipEvent.PostBackground}</li>
+     * <li>{@link RenderTooltipEvent.PostText}</li>
+     * </ul>
+     */
+    protected static abstract class Post extends RenderTooltipEvent
+    {
+        private final int width;
+        private final int height;
+        
+        public Post(@Nullable ItemStack stack, @Nonnull List<String> textLines, int x, int y, @Nonnull FontRenderer fr, int width, int height)
+        {
+            super(stack, textLines, x, y, fr);
+            this.width = width;
+            this.height = height;
+        }
+
+        /**
+         * @return The width of the tooltip box. This is the width of the <i>inner</i> box, not including the border.
+         */
+        public int getWidth()
+        {
+            return width;
+        }
+
+        /**
+         * @return The height of the tooltip box. This is the height of the <i>inner</i> box, not including the border.
+         */
+        public int getHeight()
+        {
+            return height;
+        }
+    }
+    
+    /**
+     * This event is fired directly after the tooltip background is drawn, but before any text is drawn.
+     */
+    public static class PostBackground extends Post 
+    {
+        public PostBackground(@Nullable ItemStack stack, @Nonnull List<String> textLines, int x, int y, @Nonnull FontRenderer fr, int width, int height)
+            { super(stack, textLines, x, y, fr, width, height); }
+    }
+
+    /**
+     * This event is fired directly after the tooltip text is drawn, but before the GL state is reset.
+     */
+    public static class PostText extends Post
+    {
+        public PostText(@Nullable ItemStack stack, @Nonnull List<String> textLines, int x, int y, @Nonnull FontRenderer fr, int width, int height)
+            { super(stack, textLines, x, y, fr, width, height); }
+    }
+}

src/main/java/net/minecraftforge/fml/client/config/GuiUtils.java

@@ -26,13 +26,18 @@ import net.minecraft.client.renderer.RenderHelper;
 import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.client.renderer.VertexBuffer;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.item.ItemStack;
 import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.client.event.RenderTooltipEvent;
+import net.minecraftforge.common.MinecraftForge;
 
 import org.lwjgl.opengl.GL11;
 
 import java.util.ArrayList;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 /**
  * This class provides several methods and constants used by the Config GUI classes.
  *
@@ -205,6 +210,26 @@ public class GuiUtils
         tessellator.draw();
     }
 
+    private static ItemStack cachedTooltipStack;
+
+    /**
+     * Must be called from {@code GuiScreen.renderToolTip} before {@code GuiScreen.drawHoveringText} is called.
+     * 
+     * @param stack The stack for which a tooltip is about to be drawn.
+     */
+    public static void preItemToolTip(ItemStack stack)
+    {
+        cachedTooltipStack = stack;
+    }
+    
+    /**
+     * Must be called from {@code GuiScreen.renderToolTip} after {@code GuiScreen.drawHoveringText} is called.
+     */
+    public static void postItemToolTip()
+    {
+        cachedTooltipStack = null;
+    }
+
     /**
      *  Draws a tooltip box on the screen with text in it.
      *  Automatically positions the box relative to the mouse to match Mojang's implementation.
@@ -220,10 +245,32 @@ public class GuiUtils
      *                     Set to a negative number to have no max width.
      * @param font the font for drawing the text in the tooltip box
      */
-    public static void drawHoveringText(List<String> textLines, final int mouseX, final int mouseY, final int screenWidth, final int screenHeight, final int maxTextWidth, FontRenderer font)
+    public static void drawHoveringText(List<String> textLines, int mouseX, int mouseY, int screenWidth, int screenHeight, int maxTextWidth, FontRenderer font)
+    {
+        drawHoveringText(cachedTooltipStack, textLines, mouseX, mouseY, screenWidth, screenHeight, maxTextWidth, font);
+    }
+    
+    /**
+     * Use this version if calling from somewhere where ItemStack context is available.
+     * 
+     * @see #drawHoveringText(List, int, int, int, int, int, FontRenderer)
+     */
+    public static void drawHoveringText(@Nullable final ItemStack stack, List<String> textLines, int mouseX, int mouseY, int screenWidth, int screenHeight,
+            int maxTextWidth, FontRenderer font)
     {
         if (!textLines.isEmpty())
         {
+            RenderTooltipEvent.Pre event = new RenderTooltipEvent.Pre(stack, textLines, mouseX, mouseY, screenWidth, screenHeight, maxTextWidth, font);
+            if (MinecraftForge.EVENT_BUS.post(event)) {
+                return;
+            }
+            mouseX = event.getX();
+            mouseY = event.getY();
+            screenWidth = event.getScreenWidth();
+            screenHeight = event.getScreenHeight();
+            maxTextWidth = event.getMaxWidth();
+            font = event.getFontRenderer();
+            
             GlStateManager.disableRescaleNormal();
             RenderHelper.disableStandardItemLighting();
             GlStateManager.disableLighting();
@@ -333,6 +380,9 @@ public class GuiUtils
             drawGradientRect(zLevel, tooltipX - 3, tooltipY - 3, tooltipX + tooltipTextWidth + 3, tooltipY - 3 + 1, borderColorStart, borderColorStart);
             drawGradientRect(zLevel, tooltipX - 3, tooltipY + tooltipHeight + 2, tooltipX + tooltipTextWidth + 3, tooltipY + tooltipHeight + 3, borderColorEnd, borderColorEnd);
 
+            MinecraftForge.EVENT_BUS.post(new RenderTooltipEvent.PostBackground(stack, textLines, tooltipX, tooltipY, font, tooltipTextWidth, tooltipHeight));
+            int tooltipTop = tooltipY;
+            
             for (int lineNumber = 0; lineNumber < textLines.size(); ++lineNumber)
             {
                 String line = textLines.get(lineNumber);
@@ -346,6 +396,8 @@ public class GuiUtils
                 tooltipY += 10;
             }
 
+            MinecraftForge.EVENT_BUS.post(new RenderTooltipEvent.PostText(stack, textLines, tooltipX, tooltipTop, font, tooltipTextWidth, tooltipHeight));
+
             GlStateManager.enableLighting();
             GlStateManager.enableDepth();
             RenderHelper.enableStandardItemLighting();