概述
还记得这张图吗？
本节将介绍这张图中的⑤部分。
此外，本节将在之间的章节中制作的熔炉添加一个GUI，也就是说将TileEntity中的数据应用到GUI中。
准备工作
我们先准备一张GUI的贴图，并将其起名为gui_metal_furnace.png，放入assets.fmltutor.textures.gui.container目录下：
src/main/resources/assets/fmltutor/textures/gui/container/gui_metal_furnace.png:
（好像没有燃料槽？不要在意这些细节）
实际上，用于熔炉的GUI的代码和之间使用的示例GUI的代码是十分相近的。我们先在包com.github.ustc_zzzz.fmltutor.inventory下新建类ContainerMetalFurnace：
src/main/java/com/github/ustc_zzzz/fmltutor/inventory/ContainerMetalFurnace.java:
package com.github.ustc_zzzz.fmltutor.inventory;
import com.github.ustc_zzzz.fmltutor.tileentity.TileEntityMetalFurnace;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.inventory.Container;
import net.minecraft.inventory.Slot;
import net.minecraft.item.ItemStack;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.util.EnumFacing;
import net.minecraftforge.items.CapabilityItemHandler;
import net.minecraftforge.items.IItemHandler;
import net.minecraftforge.items.SlotItemHandler;
public class ContainerMetalFurnace extends Container
{
private IItemHandler upItems;
private IItemHandler downItems;
protected TileEntityMetalFurnace tileEntity;
protected int burnTime = 0;
public ContainerMetalFurnace(EntityPlayer player, TileEntity tileEntity)
{
super();
this.upItems = tileEntity.getCapability(CapabilityItemHandler.ITEM_HANDLER_CAPABILITY, EnumFacing.UP);
this.downItems = tileEntity.getCapability(CapabilityItemHandler.ITEM_HANDLER_CAPABILITY, EnumFacing.DOWN);
this.addSlotToContainer(new SlotItemHandler(this.upItems, 0, 56, 30));
this.addSlotToContainer(new SlotItemHandler(this.downItems, 0, 110, 30)
{
@Override
public boolean isItemValid(ItemStack stack)
{
return false;
}
});
for (int i = 0; i < 3; ++i)
{
for (int j = 0; j < 9; ++j)
{
this.addSlotToContainer(new Slot(player.inventory, j + i * 9 + 9, 8 + j * 18, 74 + i * 18));
}
}
for (int i = 0; i < 9; ++i)
{
this.addSlotToContainer(new Slot(player.inventory, i, 8 + i * 18, 132));
}
this.tileEntity = (TileEntityMetalFurnace) tileEntity;
}
@Override
public ItemStack transferStackInSlot(EntityPlayer playerIn, int index)
{
Slot slot = inventorySlots.get(index);
if (slot == null || !slot.getHasStack())
{
return null;
}
ItemStack newStack = slot.getStack(), oldStack = newStack.copy();
boolean isMerged = false;
if (index == 0 || index == 1)
{
isMerged = mergeItemStack(newStack, 2, 38, true);
}
else if (index >= 2 && index < 29)
{
isMerged = mergeItemStack(newStack, 0, 1, false) || mergeItemStack(newStack, 29, 38, false);
}
else if (index >= 29 && index < 38)
{
isMerged = mergeItemStack(newStack, 0, 1, false) || mergeItemStack(newStack, 2, 29, false);
}
if (!isMerged)
{
return null;
}
if (newStack.stackSize == 0)
{
slot.putStack(null);
}
else
{
slot.onSlotChanged();
}
slot.onPickupFromSlot(playerIn, newStack);
return oldStack;
}
@Override
public boolean canInteractWith(EntityPlayer playerIn)
{
return playerIn.getDistanceSq(this.tileEntity.getPos()) <= 64;
}
}
- 第一点区别，是我们在这个类的构造方法中加入了一个
TileEntityMetalFurnace的参数，用于传入我们之前写的金属熔炉的TileEntity - 第二点区别，就是这里的
IItemHandler，是直接通过TileEntity获取，而不是新创建的 - 第三点区别，就是
canInteractWith方法被设计为了玩家距离熔炉不超过64格，这往往也是用于方块的GUI的惯例
剩下的代码和之前的GUI类似，这里也就不过多解释了。这里还添加了一个burnTime变量，用于存储同步的数据。
然后我们着手写GuiContainer。在包com.github.ustc_zzzz.fmltutor.client.gui，并在其中新建类GuiMetalFurnace：
src/main/java/com/github/ustc_zzzz/fmltutor/client/gui/GuiMetalFurnace.java:
package com.github.ustc_zzzz.fmltutor.client.gui;
import com.github.ustc_zzzz.fmltutor.FMLTutor;
import com.github.ustc_zzzz.fmltutor.inventory.ContainerMetalFurnace;
import net.minecraft.client.gui.inventory.GuiContainer;
import net.minecraft.client.renderer.GlStateManager;
import net.minecraft.util.ResourceLocation;
import net.minecraftforge.fml.relauncher.Side;
import net.minecraftforge.fml.relauncher.SideOnly;
@SideOnly(Side.CLIENT)
public class GuiMetalFurnace extends GuiContainer
{
private static final String TEXTURE_PATH = FMLTutor.MODID + ":" + "textures/gui/container/gui_metal_furnace.png";
private static final ResourceLocation TEXTURE = new ResourceLocation(TEXTURE_PATH);
protected ContainerMetalFurnace inventory;
public GuiMetalFurnace(ContainerMetalFurnace inventorySlotsIn)
{
super(inventorySlotsIn);
this.xSize = 176;
this.ySize = 156;
this.inventory = inventorySlotsIn;
}
@Override
protected void drawGuiContainerBackgroundLayer(float partialTicks, int mouseX, int mouseY)
{
GlStateManager.color(1.0F, 1.0F, 1.0F);
this.mc.getTextureManager().bindTexture(TEXTURE);
int offsetX = (this.width - this.xSize) / 2, offsetY = (this.height - this.ySize) / 2;
this.drawTexturedModalRect(offsetX, offsetY, 0, 0, this.xSize, this.ySize);
// TODO: draw progress bar
}
}
这里还有一点，就是绘制进度条尚未完成，不过不要着急，进度条数据的处理也是本部分的重点。
最后我们调整GuiElementLoader类：
src/main/java/com/github/ustc_zzzz/fmltutor/inventory/GuiElementLoader.java（部分）:
public static final int GUI_DEMO = 1;
public static final int GUI_METAL_FURNACE = 2;
public GuiElementLoader()
{
NetworkRegistry.INSTANCE.registerGuiHandler(FMLTutor.instance, this);
}
@Override
public Object getServerGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z)
{
switch (ID)
{
case GUI_DEMO:
return new ContainerDemo(player);
case GUI_METAL_FURNACE:
return new ContainerMetalFurnace(player, world.getTileEntity(new BlockPos(x, y, z)));
default:
return null;
}
}
@Override
public Object getClientGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z)
{
switch (ID)
{
case GUI_DEMO:
return new GuiContainerDemo(new ContainerDemo(player));
case GUI_METAL_FURNACE:
return new GuiMetalFurnace(new ContainerMetalFurnace(player, world.getTileEntity(new BlockPos(x, y, z))));
default:
return null;
}
}
然后我们重新覆写对应方块的onBlockActivated方法：
src/main/java/com/github/ustc_zzzz/fmltutor/block/BlockMetalFurnace.java（部分）:
@Override
public boolean onBlockActivated(World worldIn, BlockPos pos, IBlockState state, EntityPlayer playerIn,
EnumFacing side, float hitX, float hitY, float hitZ)
{
if (!worldIn.isRemote)
{
int id = GuiElementLoader.GUI_METAL_FURNACE;
playerIn.openGui(FMLTutor.instance, id, worldIn, pos.getX(), pos.getY(), pos.getZ());
}
return true;
}
现在除了进度条，一切都已经就绪了。
数据同步
本节的重点也就在于此，即自定义数据从服务端传输至客户端的同步。
每一个gametick服务端都会试图找到数据变化，并将其更新到客户端，而找到并更新的方法，就是Container类的detectAndSendChanges方法。
为方便起见，我们先为TileEntity加两个方法：
src/main/java/com/github/ustc_zzzz/fmltutor/tileentity/TileEntityMetalFurnace.java（部分）:
public int getBurnTime()
{
return this.burnTime;
}
public int getTotalBurnTime()
{
IBlockState state = this.worldObj.getBlockState(this.pos);
switch (state.getValue(BlockMetalFurnace.MATERIAL))
{
case GOLD:
return 100;
case IRON:
return 150;
default:
return 200;
}
}
然后我们覆写ContainerMetalFurnace类的detectAndSendChanges方法：
src/main/java/com/github/ustc_zzzz/fmltutor/inventory/ContainerMetalFurnace.java（部分）:
@Override
public void detectAndSendChanges()
{
super.detectAndSendChanges();
this.burnTime = tileEntity.getBurnTime();
for (ICrafting i : this.crafters)
{
i.sendProgressBarUpdate(this, 0, this.burnTime);
}
}
Container类提供了一个名为crafters的列表，用于表示监听该Container的所有对象，如玩家等。我们遍历这一列表，并调用其sendProgressBarUpdate方法发送数据。
sendProgressBarUpdate方法的第一个参数用于指定同步数据的Container，这里传入this就可以了sendProgressBarUpdate方法的第二个参数用于指定数据的标识符，一般情况下硬编码sendProgressBarUpdate方法的第三个参数用于指定一个整数数据
一个典型的同步数据的代码如下：
int data1;
int data2;
int data3;
// ...
for (ICrafting i : this.crafters)
{
i.sendProgressBarUpdate(this, 0, data1);
i.sendProgressBarUpdate(this, 1, data2);
i.sendProgressBarUpdate(this, 2, data3);
// ...
}
然后客户端的Container类会在每次接收到服务端发送的数据后，调用updateProgressBar方法接收数据（记得加上@SideOnly(Side.CLIENT)注解，因为其只作用于客户端）：
一个典型的接收数据的代码如下：
@SideOnly(Side.CLIENT)
@Override
public void updateProgressBar(int id, int data)
{
super.updateProgressBar(id, data);
int data1;
int data2;
int data3;
// ...
switch (id)
{
case 0:
data1 = data;
break;
case 1:
data2 = data;
break;
case 2:
data3 = data;
break;
// ...
default:
break;
}
}
这是我们的示例中的代码：
src/main/java/com/github/ustc_zzzz/fmltutor/inventory/ContainerMetalFurnace.java（部分）:
@SideOnly(Side.CLIENT)
@Override
public void updateProgressBar(int id, int data)
{
super.updateProgressBar(id, data);
switch (id)
{
case 0:
this.burnTime = data;
break;
default:
break;
}
}
然后我们提供两个方法用于GuiMetalFurnace获取数据，以确定进度条如何绘制：
src/main/java/com/github/ustc_zzzz/fmltutor/inventory/ContainerMetalFurnace.java（部分）:
public int getBurnTime()
{
return this.burnTime;
}
public int getTotalBurnTime()
{
return this.tileEntity.getTotalBurnTime();
}
然后我们就可以绘制进度条了：
src/main/java/com/github/ustc_zzzz/fmltutor/client/gui/GuiMetalFurnace.java（部分）:
private int totalBurnTime;
public GuiMetalFurnace(ContainerMetalFurnace inventorySlotsIn)
{
super(inventorySlotsIn);
this.xSize = 176;
this.ySize = 156;
this.inventory = inventorySlotsIn;
this.totalBurnTime = inventorySlotsIn.getTotalBurnTime();
}
@Override
protected void drawGuiContainerBackgroundLayer(float partialTicks, int mouseX, int mouseY)
{
GlStateManager.color(1.0F, 1.0F, 1.0F);
this.mc.getTextureManager().bindTexture(TEXTURE);
int offsetX = (this.width - this.xSize) / 2, offsetY = (this.height - this.ySize) / 2;
this.drawTexturedModalRect(offsetX, offsetY, 0, 0, this.xSize, this.ySize);
int burnTime = this.inventory.getBurnTime();
int textureWidth = 1 + (int) Math.ceil(22.0 * burnTime / this.totalBurnTime);
this.drawTexturedModalRect(offsetX + 79, offsetY + 30, 0, 156, textureWidth, 17);
}
大功告成！可以打开游戏试试了。