me.themallard.bitmmo.impl.plugin.inputactiontracker.InputActionTrackerPlugin.java Source code

Introduction

Here is the source code for me.themallard.bitmmo.impl.plugin.inputactiontracker.InputActionTrackerPlugin.java

Source

/* Copyright (C) 2015 maaatts
    
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
    
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>. */

package me.themallard.bitmmo.impl.plugin.inputactiontracker;

import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.FieldInsnNode;
import org.objectweb.asm.tree.FieldNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.InsnNode;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.TypeInsnNode;
import org.objectweb.asm.tree.VarInsnNode;

import me.themallard.bitmmo.api.util.Filter;
import me.themallard.bitmmo.impl.plugin.Plugin;
import me.themallard.bitmmo.impl.plugin.SimplePlugin;

@Plugin
public class InputActionTrackerPlugin extends SimplePlugin implements Opcodes {
    public InputActionTrackerPlugin() {
        super("InputActionTracker");
        registerDependency(IInputActionTracker.class);
        addFilter(new Filter<ClassNode>() {
            @Override
            public boolean accept(ClassNode cn) {
                return cn.name.equals("HTMud/InputActionTracker");
            }
        });
    }

    private void createIsKeyDown(ClassNode cn) {
        // again too lazy to make actual work
        // steal it from original code and hope that it works ;)

        for (MethodNode mn : cn.methods) {
            if (mn.desc.equals("(LHTMud/InputActionTracker$ActionType;)Z")) {
                InsnList method = mn.instructions;

                MethodVisitor mv = cn.visitMethod(ACC_PUBLIC, "isKeyDown", mn.desc, null, null);
                method.accept(mv);
                mv.visitEnd();
                break;
            }
        }
    }

    private void createSetKeyDown(ClassNode cn) {
        InsnList insn = new InsnList();

        MethodNode mn = new MethodNode(cn, ACC_PUBLIC, "setKeyDown", "(LHTMud/InputActionTracker$ActionType;Z)V",
                null, null);

        // ((Key) this.enumMap.get(actionType)).setKeyPressed(value);

        // aload0
        // getfield this.enumMap Ljava/util/EnumMap;
        // aload1
        // invokevirtual \
        // java/util/EnumMap.get((Ljava/lang/Object;)Ljava/lang/Object;);
        // checkcast Key
        // aload2
        // invokevirtual Key.setKeyPressed((Z)V);
        // return

        mn.visitMaxs(3, 3);

        insn.add(new VarInsnNode(ALOAD, 0));

        FieldNode enumMap = cn.getField(null, "Ljava/util/EnumMap;");
        insn.add(new FieldInsnNode(GETFIELD, cn.name, enumMap.name, enumMap.desc));

        insn.add(new VarInsnNode(ALOAD, 1));

        insn.add(new MethodInsnNode(INVOKEVIRTUAL, "java/util/EnumMap", "get",
                "(Ljava/lang/Object;)Ljava/lang/Object;", false));

        insn.add(new TypeInsnNode(CHECKCAST, "Key"));

        insn.add(new VarInsnNode(ILOAD, 2));

        insn.add(new MethodInsnNode(INVOKEVIRTUAL, "Key", "setKeyPressed", "(Z)V", false));

        insn.add(new InsnNode(RETURN));

        mn.instructions.insert(insn);

        cn.methods.add(mn);
    }

    @Override
    public void run(ClassNode cn) {
        addInterface(cn, "me/themallard/bitmmo/impl/plugin/inputactiontracker/IInputActionTracker");

        createIsKeyDown(cn);
        createSetKeyDown(cn);
    }
}