import java.awt.*;

class MyCanvas extends Canvas {
	String numstring, sortType;
	int x, j;
	public float barwid, barhei, space;
	public float[] heights;
	public boolean[] arraycolor;
	SortClass sorter;

	MyCanvas (SortClass temp) {
		sorter = temp;
	}

	public void drawArrow(Graphics g,int x1,int y1,int x2,int y2) {
                int r=15;
                g.drawLine(x1,y1,x2,y2);
                int[] x=new int[3];
                int[] y=new int[3];
                x[0]=x2;
                y[0]=y2;
                double angle1=Math.atan2(y2-y1,x1-x2);
                x[1]=(int)Math.floor(r*Math.cos(angle1+Math.PI/6))+x2;
                y[1]=-(int)Math.floor(r*Math.sin(angle1+Math.PI/6))+y2;
                x[2]=(int)Math.floor(r*Math.cos(angle1-Math.PI/6))+x2;
                y[2]=-(int)Math.floor(r*Math.sin(angle1-Math.PI/6))+y2;
                g.fillPolygon(x,y,3);
        }

	public void paint(Graphics g) {
		int w=size().width;
		int h=size().height;
		int i;

		if (sorter.currsort.equals("select") || sorter.currsort.equals("bubble") || sorter.currsort.equals("insert") || sorter.currsort.equals("quick ") || sorter.currsort.equals("merge ") || sorter.currsort.equals("shell ")) {
			g.setColor(sorter.blockcolor);
			numstring = sorter.blockField.getText();
			try {
				x = Integer.parseInt(numstring);
			} catch (NumberFormatException e) {
				x = 20;
			}
			sortType = sorter.orderChoices.getSelectedItem();
			space = (float)x/(float)10;
			barwid = (float)w/((float)x+space); 
			barhei = (float)h/(float)(x+1);
			if(sorter.newpaint == false) {
				for(i=0;i<x;i++) {
					if (arraycolor[i]) {
						g.setColor(sorter.blockcolor);
					} else {
						g.setColor(sorter.sortedcolor);
					}
       		                        g.fillRect(Math.round(i*(barwid+(barwid*space/(x-1)))),Math.round(h-heights[i]-5),Math.round(barwid),Math.round(heights[i]));
				}
			} else {
				heights = new float[x];
				arraycolor = new boolean[x];
				for (j=0;j<x;j++) {
					arraycolor[j] = true;
				}
				if(sorter.currsort.equals("quick ") || sorter.currsort.equals("merge ")) {
					if(sortType.equals("Random")) {
						for(i=0;i<x;i++) {
							heights[i]=Math.round(Math.random()*(h-10)*0.75+5);
							g.fillRect(Math.round(i*(barwid+(barwid*space/(x-1)))),Math.round(h-heights[i]-5),Math.round(barwid),Math.round(heights[i]));
						}
					} else if (sortType.equals("Ascending")) {
						for(i=0;i<x;i++) {
							heights[i]=Math.round(barhei*(i+1)*0.75-5);
							g.fillRect(Math.round(i*(barwid+(barwid*space/(x-1)))),Math.round(h-heights[i]-5),Math.round(barwid),Math.round(heights[i]));
						}
					} else {
						for(i=0;i<x;i++) {
							heights[i]=Math.round((x-i+1)*barhei*0.75-5);
							g.fillRect(Math.round(i*(barwid+(barwid*space/(x-1)))),Math.round(h-heights[i]-5),Math.round(barwid),Math.round(heights[i]));
						}
					}	
				} else {
					if(sortType.equals("Random")) {
                                                for(i=0;i<x;i++) {
                                                        heights[i]=Math.round(Math.random()*(h-10)+5);
                                                        g.fillRect(Math.round(i*(barwid+(barwid*space/(x-1)))),Math.round(h-heights[i]-5),Math.round(barwid),Math.round(heights[i]));
                                                }
                                        } else if (sortType.equals("Ascending")) {                          
                                                for(i=0;i<x;i++) {
                                                        heights[i]=barhei*(i+1)-5;                          
                                                        g.fillRect(Math.round(i*(barwid+(barwid*space/(x-1)))),Math.round(h-heights[i]-5),Math.round(barwid),Math.round(heights[i]));
                                                }
                                        } else {
                                                for(i=0;i<x;i++) {
                                                        heights[i]=(x-i+1)*barhei-5;                        
                                                        g.fillRect(Math.round(i*(barwid+(barwid*space/(x-1)))),Math.round(h-heights[i]-5),Math.round(barwid),Math.round(heights[i]));
                                                }
                                        }
				}
			}
    		} else if(sorter.currsort.equals("ilist") || sorter.currsort.equals("dlist") || sorter.currsort.equals("flist")) {
			ListNode node;
		
			g.setColor(sorter.blockcolor);
			g.fillRect(50,50,50,50);
			g.fillRect(w-100,50,50,50);
			g.setColor(Color.black);
			g.drawRect(51,51,47,47);
			g.drawLine(51,75,98,75);
			g.drawString("HEAD",58,70);	
			g.drawRect(w-99,51,47,47);
			g.drawLine(w-99,75,w-52,75);
			g.drawString("TAIL",w-88,70);
			node = ListNode.getHead();
			i = 0;
			while (node != null) {
				if(i == 0) {
					g.setColor(sorter.blockcolor);
					drawArrow(g,75,100,37,h/2-25);
				} else {
					g.setColor(sorter.blockcolor);
					drawArrow(g,75*i,h/2,75*i+25,h/2);	
				}
				g.setColor(sorter.blockcolor);
				g.fillRect(75*i+25,h/2-25,50,50);
				g.setColor(Color.black);
				g.drawRect(75*i+26,h/2-24,47,47);
				g.drawLine(75*i+50,h/2-24,75*i+50,h/2+23);
				g.drawString(Integer.toString(node.getData()),75*i+30,h/2+5);
				i++;
				node = node.getNext();
			}
			i--;
			g.setColor(sorter.blockcolor);
			if(node.getHead() == null) {
				g.setColor(Color.black);
				g.drawString("null",62,95);
				g.drawString("null",w-88,95);
			} else {
				drawArrow(g,w-75,100,75*i+37,h/2-25);
				g.setColor(Color.black);
                       		g.drawString("n",75*i+52,h/2-10);
                        	g.drawString("u",75*i+57,h/2);
                        	g.drawString("l",75*i+64,h/2+10);
                        	g.drawString("l",75*i+67,h/2+20);
			}
		}
	}

	public void resetcolor() {
		int n,i;
		String numstring;

		numstring = sorter.blockField.getText();
		try {
			i = Integer.parseInt(numstring);
		} catch (NumberFormatException e) {
			i = 20;
		}
		for(n=0;n<i;n++) {
			arraycolor[n] = true;
		}
		sorter.newpaint = false;
		repaint();
	}

    //If we don't specify this, the canvas might not show up at all
    //(depending on the layout manager).
    public Dimension minimumSize() {
        return new Dimension(600,400);
    }

    //If we don't specify this, the canvas might not show up at all
    //(depending on the layout manager).
    public Dimension preferredSize() {
        return minimumSize();
    }
}