Highly incomplete code. First work on porting to 1.12. Still need to rework a LOT of things.

src/main/java/appeng/client/gui/AEBaseGui.java

@@ -36,6 +36,8 @@ import com.google.common.base.Stopwatch;
 import com.google.common.collect.Lists;
 
 import mezz.jei.api.IRecipesGui;
+import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.vertex.VertexBuffer;
 import net.minecraftforge.client.event.GuiOpenEvent;
 import net.minecraftforge.common.MinecraftForge;
 import org.lwjgl.input.Keyboard;
@@ -48,7 +50,6 @@ import net.minecraft.client.gui.inventory.GuiContainer;
 import net.minecraft.client.renderer.GlStateManager;
 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.entity.player.EntityPlayer;
 import net.minecraft.inventory.ClickType;
@@ -766,7 +767,7 @@ public abstract class AEBaseGui extends GuiContainer
 							final float par4 = uv_y * 16;
 
 							final Tessellator tessellator = Tessellator.getInstance();
-							final VertexBuffer vb = tessellator.getBuffer();
+							final BufferBuilder vb = tessellator.getBuffer();
 
 							vb.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_TEX_COLOR );
 

src/main/java/appeng/client/gui/AEBaseMEGui.java

@@ -23,6 +23,7 @@ import java.text.NumberFormat;
 import java.util.List;
 import java.util.Locale;
 
+import net.minecraft.client.util.ITooltipFlag;
 import net.minecraft.inventory.Container;
 import net.minecraft.inventory.Slot;
 import net.minecraft.item.ItemStack;
@@ -116,10 +117,11 @@ public abstract class AEBaseMEGui extends AEBaseGui
 			{
 			}
 
+			ITooltipFlag.TooltipFlags tooltipFlag = this.mc.gameSettings.advancedItemTooltips ? ITooltipFlag.TooltipFlags.ADVANCED : ITooltipFlag.TooltipFlags.NORMAL;
 			if( myStack != null )
 			{
 				@SuppressWarnings( "unchecked" )
-				final List<String> currentToolTip = stack.getTooltip( this.mc.player, this.mc.gameSettings.advancedItemTooltips );
+				final List<String> currentToolTip = stack.getTooltip( this.mc.player, tooltipFlag );
 
 				if( myStack.getStackSize() > BigNumber || ( myStack.getStackSize() > 1 && stack.isItemDamaged() ) )
 				{
@@ -136,7 +138,7 @@ public abstract class AEBaseMEGui extends AEBaseGui
 			}
 			else if( stack.getCount() > BigNumber )
 			{
-				List<String> var4 = stack.getTooltip( this.mc.player, this.mc.gameSettings.advancedItemTooltips );
+				List<String> var4 = stack.getTooltip( this.mc.player, tooltipFlag );
 				var4.add( "Items Stored: " + NumberFormat.getNumberInstance( Locale.US ).format( stack.getCount() ) );
 				this.drawTooltip( x, y, var4 );
 				return;

src/main/java/appeng/client/gui/Size1Slot.java

@@ -1,6 +1,7 @@
 package appeng.client.gui;
 
 
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 import net.minecraft.client.renderer.texture.TextureAtlasSprite;
@@ -28,8 +29,8 @@ class Size1Slot extends Slot
 		this.delegate = delegate;
 	}
 
-	@Nullable
 	@Override
+	@Nonnull
 	public ItemStack getStack()
 	{
 		ItemStack orgStack = delegate.getStack();

src/main/java/appeng/client/gui/config/AEConfigGuiFactory.java

@@ -67,13 +67,7 @@ public class AEConfigGuiFactory implements IModGuiFactory
 	 */
 	@Override
 	public GuiScreen createConfigGui(GuiScreen parentScreen) {
-		return null;
-	}
-
-	@Override
-	public Class<? extends GuiScreen> mainConfigGuiClass()
-	{
-		return AEConfigGui.class;
+		return new AEConfigGui(parentScreen);
 	}
 
 	@Override
@@ -82,9 +76,4 @@ public class AEConfigGuiFactory implements IModGuiFactory
 		return null;
 	}
 
-	@Override
-	public RuntimeOptionGuiHandler getHandlerFor( final RuntimeOptionCategoryElement element )
-	{
-		return null;
-	}
 }

src/main/java/appeng/client/gui/implementations/GuiNetworkStatus.java

@@ -22,6 +22,8 @@ package appeng.client.gui.implementations;
 import java.io.IOException;
 import java.util.List;
 
+import net.minecraft.client.util.ITooltipFlag;
+import net.minecraftforge.fml.client.FMLClientHandler;
 import org.lwjgl.input.Mouse;
 
 import net.minecraft.client.gui.GuiButton;
@@ -253,7 +255,8 @@ public class GuiNetworkStatus extends AEBaseGui implements ISortSource
 
 			if( myStack != null )
 			{
-				List<String> currentToolTip = stack.getTooltip( this.mc.player, this.mc.gameSettings.advancedItemTooltips );
+				ITooltipFlag.TooltipFlags tooltipFlag = this.mc.gameSettings.advancedItemTooltips ? ITooltipFlag.TooltipFlags.ADVANCED : ITooltipFlag.TooltipFlags.NORMAL;
+				List<String> currentToolTip = stack.getTooltip( this.mc.player, tooltipFlag );
 
 				while( currentToolTip.size() > 1 )
 				{

src/main/java/appeng/client/gui/widgets/GuiImgButton.java

@@ -181,7 +181,7 @@ public class GuiImgButton extends GuiButton implements ITooltip
 	}
 
 	@Override
-	public void drawButton( final Minecraft par1Minecraft, final int par2, final int par3 )
+	public void drawButton( final Minecraft par1Minecraft, final int par2, final int par3, float partial )
 	{
 		if( this.visible )
 		{

src/main/java/appeng/client/gui/widgets/GuiProgressBar.java

@@ -59,7 +59,7 @@ public class GuiProgressBar extends GuiButton implements ITooltip
 	}
 
 	@Override
-	public void drawButton( final Minecraft par1Minecraft, final int par2, final int par3 )
+	public void drawButton( final Minecraft par1Minecraft, final int par2, final int par3, final float partial )
 	{
 		if( this.visible )
 		{

src/main/java/appeng/client/gui/widgets/GuiTabButton.java

@@ -71,7 +71,7 @@ public class GuiTabButton extends GuiButton implements ITooltip
 	}
 
 	@Override
-	public void drawButton( final Minecraft minecraft, final int x, final int y )
+	public void drawButton( final Minecraft minecraft, final int x, final int y, float partial )
 	{
 		if( this.visible )
 		{

src/main/java/appeng/client/gui/widgets/GuiToggleButton.java

@@ -58,7 +58,7 @@ public class GuiToggleButton extends GuiButton implements ITooltip
 	}
 
 	@Override
-	public void drawButton( final Minecraft par1Minecraft, final int par2, final int par3 )
+	public void drawButton( final Minecraft par1Minecraft, final int par2, final int par3, final float partial )
 	{
 		if( this.visible )
 		{

src/main/java/appeng/client/gui/widgets/MEGuiTextField.java

@@ -61,13 +61,14 @@ public class MEGuiTextField extends GuiTextField
 	}
 
 	@Override
-	public void mouseClicked( final int xPos, final int yPos, final int button )
+	public boolean mouseClicked( final int xPos, final int yPos, final int button )
 	{
 		super.mouseClicked( xPos, yPos, button );
 
 		final boolean requiresFocus = this.isMouseIn( xPos, yPos );
 
 		this.setFocused( requiresFocus );
+		return true;
 	}
 
 	/**