Watmean - a small mod to tell you how stuff works.

Watmean.java

package vazkii.watmean;

import java.awt.Desktop;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.net.URI;
import java.util.LinkedHashMap;
import java.util.Map;

import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.GuiChat;
import net.minecraft.client.gui.GuiScreen;
import net.minecraft.client.gui.GuiTextField;
import net.minecraft.client.gui.ScaledResolution;
import net.minecraft.util.MathHelper;

import org.lwjgl.input.Mouse;
import org.lwjgl.opengl.GL11;

import cpw.mods.fml.common.FMLCommonHandler;
import cpw.mods.fml.common.Mod;
import cpw.mods.fml.common.Mod.EventHandler;
import cpw.mods.fml.common.event.FMLInitializationEvent;
import cpw.mods.fml.common.eventhandler.SubscribeEvent;
import cpw.mods.fml.common.gameevent.TickEvent.Phase;
import cpw.mods.fml.common.gameevent.TickEvent.RenderTickEvent;
import cpw.mods.fml.relauncher.ReflectionHelper;

@Mod(modid = "watmean", name = "watmean", version = "1.0")
public final class Watmean {

	private static final String[] OBF_TEXT_FIELD = {
		"inputField", "field_146415_a", "a" 
	};

	private static final String DEFAULT_PROPS = "# Watmean config, add websites here. Format: (name)>(url).\n"
			+ "# Set %text% to be the text you put in.\n"
			+ "# Do NOT include http:// in the URL, that is added automatically.\n"
			+ "Wikipedia>wikipedia.org/wiki/%text%\n"
			+ "Minecraft Wiki>minecraftwiki.net/%text%\n"
			+ "Dictionary.com>dictionary.com/browse/%text%\n"
			+ "Thesaurus>thesaurus.com/browse/%text%\n"
			+ "LMGTFY>lmgtfy.com/?q=%text%\n"
			+ "Urban Dictionary>urbandictionary.com/define.php?term=%text%\n"
			+ "MCSkinSearch>mcskinsearch.com/skin/%text%"; 

	Map<String, String> websites = new LinkedHashMap(); 

	boolean leftDown = false;
	boolean rightDown = false;

	@EventHandler
	public void init(FMLInitializationEvent event) {
		try {
			File file = new File(".", "config/watmean.properties");
			if(!file.exists()) {
				file.createNewFile();
				BufferedWriter writer = new BufferedWriter(new FileWriter(file));
				writer.write(DEFAULT_PROPS);
				writer.close();
			}

			BufferedReader reader = new BufferedReader(new FileReader(file));
			String line;
			while((line = reader.readLine()) != null) {
				if(line.startsWith("#"))
					continue;

				line = line.trim();
				String[] tokens = line.split(">");
				if(tokens.length == 2)
					websites.put(tokens[0], tokens[1]);
			}
			reader.close();
		} catch(IOException e) {
			e.printStackTrace();
		}

		FMLCommonHandler.instance().bus().register(this);
	}

	@SubscribeEvent
	public void renderTick(RenderTickEvent event) {
		if(event.phase == Phase.END) {
			Minecraft mc = Minecraft.getMinecraft();
			GuiScreen gui = mc.currentScreen;
			boolean isChat = gui instanceof GuiChat;
			if(isChat) {
				ScaledResolution res = new ScaledResolution(mc.gameSettings, mc.displayWidth, mc.displayHeight);
				int mouseX = Mouse.getX() * res.getScaledWidth() / mc.displayWidth;
				int mouseY = res.getScaledHeight() - Mouse.getY() * res.getScaledHeight() / mc.displayHeight;

				boolean leftDown = Mouse.isButtonDown(0);
				boolean rightDown = Mouse.isButtonDown(1);

				final int start = 300;
				final float tweenPixels = 200F;

				int i = 0;

				GL11.glEnable(GL11.GL_BLEND);
				GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
				for(String website : websites.keySet()) {
					int width = mc.fontRenderer.getStringWidth(website);
					int x = gui.width - width - 5;
					int y = gui.height - 30 - (websites.size() * 15) + i * 15;
					int relPos = gui.width - mouseX;

					if(relPos > start)
						break;

					boolean in = mouseX >= x && mouseX - x < width && mouseY >= y && mouseY - y < 10;

					if(in) {
						GuiTextField field = ReflectionHelper.getPrivateValue(GuiChat.class, (GuiChat) gui, OBF_TEXT_FIELD);
						String text = getFormattedText(field, websites.get(website));

						if(!MathHelper.stringNullOrLengthZero(text)) {
							if(!this.rightDown && rightDown)
								field.setText(text);
							else if(!this.leftDown && leftDown)
								try {
									Desktop.getDesktop().browse(new URI("http://" + text));
								} catch(Exception e) {
									e.printStackTrace();
								}
						}
					}

					float alpha = Math.max(0.02F, Math.min(1F, (float) (start - relPos) / tweenPixels));
					mc.fontRenderer.drawStringWithShadow(website, x, y, (in ? 0x66FF66 : 0xFFFFFF) | ((int) (alpha * 0xFF)) << 24);
					i++;
				}
				GL11.glDisable(GL11.GL_BLEND);

				this.leftDown = leftDown;
				this.rightDown = rightDown;
			}
		}
	}

	private String getFormattedText(GuiTextField field, String format) {
		return format.replaceAll("%text%", field.getText().replaceAll(" ", "%20"));
	}

}