com.lion328.thaifixes.coremod.patcher.GuiChatBytecodePatcher.java Source code

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Here is the source code for com.lion328.thaifixes.coremod.patcher.GuiChatBytecodePatcher.java

Source

/*
 * Copyright (c) 2014 Waritnan Sookbuntherng
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package com.lion328.thaifixes.coremod.patcher;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.FieldInsnNode;
import org.objectweb.asm.tree.IntInsnNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.VarInsnNode;

import com.lion328.thaifixes.nmod.ClassMap;
import com.lion328.thaifixes.nmod.ThaiFixesConfiguration;
import com.lion328.thaifixes.nmod.ThaiFixesFontRenderer;
import com.lion328.thaifixes.nmod.ThaiFixesFontStyle;

public class GuiChatBytecodePatcher implements IBytecodePatcher {

    public static final ClassMap CLASSMAP = ClassMap.getClassMap("net.minecraft.client.gui.GuiChat");

    @Override
    public byte[] patchClass(byte[] source) {
        if (ThaiFixesConfiguration.getFontStyle() != ThaiFixesFontStyle.MCPX)
            return source;

        ClassReader classReader = new ClassReader(source);
        ClassNode classNode = new ClassNode();
        classReader.accept(classNode, 0);

        for (MethodNode method : classNode.methods) {
            boolean drawScreenFlag;
            if ((drawScreenFlag = (method.name.equals(CLASSMAP.getMethod("drawScreen"))
                    && method.desc.equals("(IIF)V")))
                    || (method.name.equals(CLASSMAP.getMethod("initGui")) && method.desc.equals("()V"))) {
                for (int i = 0; i < method.instructions.size(); i++) {
                    if ((method.instructions.get(i).getOpcode() == Opcodes.BIPUSH)
                            && (method.instructions.get(i + 1).getOpcode() == Opcodes.ISUB)) {
                        IntInsnNode node = (IntInsnNode) method.instructions.get(i);
                        if (node.operand == (drawScreenFlag ? 14 : 12))
                            method.instructions.set(node,
                                    new VarInsnNode(Opcodes.BIPUSH,
                                            (drawScreenFlag ? ThaiFixesFontRenderer.MCPX_CHATBLOCK_HEIGHT + 2
                                                    : ThaiFixesFontRenderer.MCPX_CHATBLOCK_TEXT_YPOS + 2)));
                    }
                }
            }
        }

        ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);
        classNode.accept(writer);
        return writer.toByteArray();
    }

    @Override
    public ClassMap getClassMap() {
        return CLASSMAP;
    }

}