GuiReactiveList.java

package blusunrize.immersiveengineering.client.gui.elements;

import blusunrize.immersiveengineering.api.Lib;
import blusunrize.immersiveengineering.client.ClientUtils;
import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.FontRenderer;
import net.minecraft.client.gui.GuiButton;
import net.minecraft.client.gui.GuiScreen;
import net.minecraft.client.renderer.GlStateManager;
import org.lwjgl.input.Mouse;

import java.util.function.Function;

public class GuiReactiveList extends GuiButton
{
	private final GuiScreen gui;
	private String[] entries;
	private int[] padding = {0,0,0,0};
	private boolean needsSlider = false;
	private int perPage;
	private Function<String, String> translationFunction;
	private int scrollMode = 0;
	private float textScale = 1;
	private boolean unicode = false;

	private int offset;
	private int maxOffset;

	private long prevWheelNano = 0;
	private int targetEntry = -1;
	private int hoverTimer = 0;

	public GuiReactiveList(GuiScreen gui, int id, int x, int y, int w, int h, String... entries)
	{
		super(id, x, y, w, h, "");
		this.gui = gui;
		this.entries = entries;
		recalculateEntries();
	}
	private void recalculateEntries()
	{
		perPage = (int)((this.height-padding[0]-padding[1])/(ClientUtils.mc().fontRendererObj.FONT_HEIGHT*textScale));
		if(perPage<entries.length)
		{
			needsSlider = true;
			maxOffset = entries.length-perPage;
		}
		else
			needsSlider = false;
	}
	public GuiReactiveList setPadding(int up, int down, int left, int right)
	{
		this.padding[0] = up;
		this.padding[1] = down;
		this.padding[2] = left;
		this.padding[3] = right;
		recalculateEntries();
		return this;
	}
	public GuiReactiveList setTranslationFunc(Function<String,String> func)
	{
		this.translationFunction = func;
		return this;
	}
	/** @param mode 0: No scrolling<br>1: Scroll when hovered<br>2: Scroll all */
	public GuiReactiveList setScrollMode(int mode)
	{
		this.scrollMode = mode;
		return this;
	}
	public GuiReactiveList setFormatting(float textScale, boolean unicode)
	{
		this.textScale = textScale;
		this.unicode = unicode;
		this.recalculateEntries();
		return this;
	}

	public int getOffset()
	{
		return this.offset;
	}
	public void setOffset(int offset)
	{
		this.offset = offset;
	}
	public int getMaxOffset()
	{
		return this.maxOffset;
	}

	@Override
	public void drawButton(Minecraft mc, int mx, int my)
	{
		FontRenderer fr = ClientUtils.mc().fontRendererObj;
		boolean uni = fr.getUnicodeFlag();
		fr.setUnicodeFlag(unicode);

		int mmY = my-this.yPosition;
		int strWidth = width-padding[2]-padding[3]-(needsSlider?6:0);
		GlStateManager.color(1, 1, 1);
		if(needsSlider)
		{
			ClientUtils.bindTexture("immersiveengineering:textures/gui/hudElements.png");
			this.drawTexturedModalRect(xPosition+width-6,yPosition, 16,136, 6,4);
			this.drawTexturedModalRect(xPosition+width-6,yPosition+height-4, 16,144, 6,4);
			for(int i=0;i<height-8; i+=2)
				this.drawTexturedModalRect(xPosition+width-6,yPosition+4+i, 16,141, 6,2);

			int sliderSize = Math.max(6,height-maxOffset*fr.FONT_HEIGHT);
			float silderShift = (height-sliderSize)/(float)maxOffset * offset;

			this.drawTexturedModalRect(xPosition+width-5,yPosition+silderShift+1, 20,129, 4,2);
			this.drawTexturedModalRect(xPosition+width-5,yPosition+silderShift+sliderSize-4, 20,132, 4,3);
			for(int i=0;i<sliderSize-7; i++)
				this.drawTexturedModalRect(xPosition+width-5,yPosition+silderShift+3+i, 20,131, 4,1);
		}

		GlStateManager.scale(textScale,textScale,1);
		this.hovered = mx>=xPosition&&mx<xPosition+width && my>=yPosition&&my<yPosition+height;
		boolean hasTarget = false;
		for(int i=0; i<Math.min(perPage, entries.length); i++)
		{
			int j = offset+i;
			int col = 0xE0E0E0;
			boolean selectionHover = hovered && mmY>=i*fr.FONT_HEIGHT && mmY<(i+1)*fr.FONT_HEIGHT;
			if(selectionHover)
			{
				hasTarget = true;
				if(targetEntry!=j)
				{
					targetEntry = j;
					hoverTimer = 0;
				}
				else
					hoverTimer++;
				col = Lib.COLOUR_I_ImmersiveOrange;
			}
			if(j>entries.length-1)
				j=entries.length-1;
			String s = translationFunction!=null?translationFunction.apply(entries[j]):entries[j];
			int overLength = s.length()-fr.sizeStringToWidth(s, strWidth);
			if(overLength>0)//String is too long
			{
				if(selectionHover && hoverTimer>20)
				{
					int textOffset = (hoverTimer/10)%(s.length());
					s = s.substring(textOffset)+" "+s.substring(0,textOffset);
				}
				s = fr.trimStringToWidth(s, strWidth);
			}
			float tx = ((xPosition+padding[2])/textScale);
			float ty = ((yPosition+padding[0]+(fr.FONT_HEIGHT*i))/textScale);
			GlStateManager.translate(tx, ty, 0);
			fr.drawString(s, 0,0, col, false);
			GlStateManager.translate(-tx, -ty, 0);
		}
		GlStateManager.scale(1/textScale,1/textScale,1);
		if(!hasTarget)
		{
			targetEntry = -1;
			hoverTimer = 0;
		}

		fr.setUnicodeFlag(uni);

		//Handle DWheel
		int mouseWheel = Mouse.getEventDWheel();
		if(mouseWheel!=0 && maxOffset>0 && Mouse.getEventNanoseconds()!=prevWheelNano)
		{
			prevWheelNano = Mouse.getEventNanoseconds();
			if(mouseWheel<0 && offset<maxOffset)
				offset++;
			if(mouseWheel>0 && offset>0)
				offset--;
		}
	}

	public int selectedOption=-1;
	@Override
	public boolean mousePressed(Minecraft mc, int mx, int my)
	{
		boolean b = super.mousePressed(mc, mx, my);
		FontRenderer fr = ClientUtils.mc().fontRendererObj;
		selectedOption=-1;
		if(b)
		{
			int mmY = my-this.yPosition;
			for(int i=0; i<Math.min(perPage, entries.length); i++)
				if(mmY>=i*fr.FONT_HEIGHT && mmY<(i+1)*fr.FONT_HEIGHT)
					selectedOption=offset+i;
		}
		return selectedOption!=-1;
	}
}