ScrollingListElement.java

package com.multi.microZ.gui.elements;

import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.FontRenderer;
import net.minecraft.client.gui.Gui;
import org.lwjgl.input.Mouse;

import java.util.List;

/**
 * Created by multimote on 12.07.14.
 */
public class ScrollingListElement extends Gui {

    private FontRenderer fontRenderer;
    public List<String> strings;
    public int indexSelected;

    public int xPos;
    public int yPos;
    public int width;
    public int height;
    public int sliderPos;

    private int elementsDisplayed;
    private int firstIndex;


    public ScrollingListElement(FontRenderer fr, int x, int y, int width, int height, List<String> list) {
        this.fontRenderer = fr;
        this.xPos = x;
        this.yPos = y;
        this.width = width;
        this.height = height;
        this.strings = list;
    }

    public boolean isMouseIn(int x, int y){
        return x >= this.xPos && x < this.xPos + this.width && y >= this.yPos && y < this.yPos + this.height;
    }

    public boolean isMouseInSliderZone(int x, int y){
        return isMouseIn(x, y) && x>xPos+width-8 && x<xPos+width-1;
    }

    public void drawSlider(int x, int y){
        drawRect(x, y+1, x+5, y+getSliderHeight()-3, 0xFFFFFFFF);
    }

    public int getSliderHeight(){
        return  strings.size() == 0 ? 5 : this.height / Math.max((strings.size())/8, 8);
    }

    public float getRelativeSliderPos(){

        return height==0 ? 0 : (float)sliderPos/(float)(height-getSliderHeight());
    }

    public void mouseClicked(int x, int y){
        if(isMouseIn(x,y) && x<xPos+width-10){
         int yIn = Math.round((float)((y - yPos)+2)/8)-1;
         if(yIn<elementsDisplayed) indexSelected=yIn+firstIndex < 0 ? 0 : yIn+firstIndex;
        }
    }

    public void drawList(int x, int y, float f) {

        drawRect(xPos, yPos, xPos+width, yPos+height, 0xFFFFFFFF);
        drawRect(xPos+1, yPos+1, xPos+width-1, yPos+height-1, 0xFF000000);


        drawRect(xPos+width-9, yPos, xPos+width-8, yPos+height, 0xFFFFFFFF);
        drawSlider(xPos+width-7, yPos+sliderPos+1);

        firstIndex = (int)((float)strings.size() * getRelativeSliderPos());

        int p = 0;
        for(int i=firstIndex; i<strings.size(); i++){

            int yString = yPos + 2 + p * 8;
            if(yString+8 < yPos+height){
                String toDisplay = fontRenderer.getStringWidth(strings.get(i)) > this.width-10 ? fontRenderer.trimStringToWidth(strings.get(i), this.width-15)+"..." : strings.get(i);
                if(i==indexSelected)drawRect(xPos+1, yString, xPos+width-10, yString+8, 0xFF555555);
                fontRenderer.drawString(toDisplay, xPos+2, yString, 0xFFFFFFFF);
                p++;
            }
        }
        elementsDisplayed = p;

        if(indexSelected>strings.size()-1)indexSelected=strings.size()-1;
        if(indexSelected<0)indexSelected=0;

        if(Mouse.isButtonDown(0) && isMouseInSliderZone(x, y))
        {
            sliderPos=y-getSliderHeight()/2-yPos;
            if(yPos+sliderPos < yPos)sliderPos = 0;
            if(yPos+sliderPos+getSliderHeight() > yPos+height)sliderPos = height-getSliderHeight();
        }

    }

}