graphcanvas.java

dijkstra algorithm, need complile and building to jar file and run it.

	}

	public boolean mouseDown(Event evt, int x, int y) {
		// System.out.println("****** mouseDown******");
		clicked = true;

		if (evt.shiftDown()) {

			// move a node

			if (nodehit(x, y, NODESIZE)) {

				prevPoint = graph.node[hitnode];

				node1 = hitnode;

				movenode = true;

			}

		}

		else if (evt.controlDown()) {

			// delete a node

			if (nodehit(x, y, NODESIZE)) {

				node1 = hitnode;

				if (graph.startgraph == node1) {

					movestart = true;

					currPoint = new Point(x, y);

					graph.colorNode[graph.startgraph] = Color.gray;

				}
			}

		}

		else if (arrowhit(x, y, 5)) {

			// change weight of an edge

			movearrow = true;

		}

		else if (nodehit(x, y, NODESIZE)) {

			// draw a new arrow

			if (!newarrow) {

				newarrow = true;

				currPoint = new Point(x, y);

				node1 = hitnode;

			}

		}

		else if (!nodehit(x, y, 50) && !arrowhit(x, y, 50)) {

			// draw new node

			// take the next available spot in the array

			if (numOfNodes < MAXNODES)

				graph.node[numOfNodes++] = new Point(x, y);

		}

		return true;

	}

	public boolean mouseDrag(Event evt, int x, int y) {

		if (clicked) {

			if (movenode) {

				// move node and adjust arrows coming into/outof the node

				graph.adjustArrow(node1, numOfNodes, x, y);

				repaint();

			}

			else if (movestart || newarrow) {

				currPoint = new Point(x, y);

				repaint();

			}

			else if (movearrow) {

				graph.changeWeight(x, y, node1, node2);

				repaint();

			}

		}

		return true;

	}

	public boolean mouseUp(Event evt, int x, int y) {
		// System.out.println("****** mouseUp******");
		if (clicked) {

			if (movenode) {

				// move the node if the new position is not to close to

				// another node or outside of the panel

				graph.node[node1] = new Point(0, 0);

				if (nodehit(x, y, 50) || (x < 0) || (x > this.getSize().width)
						||

						(y < 0) || (y > this.getSize().height)) {

					graph.node[node1] = prevPoint;
				}

				else
					graph.node[node1] = new Point(x, y);

				for (int i = 0; i < numOfNodes; i++) {

					if (graph.weight[i][node1] > 0)

						graph.arrowUpdate(i, node1, graph.weight[i][node1]);

					if (graph.weight[node1][i] > 0)

						graph.arrowUpdate(node1, i, graph.weight[node1][i]);

				}

				movenode = false;

			}

			else if (newarrow) {

				newarrow = false;

				if (nodehit(x, y, NODESIZE)) {

					node2 = hitnode;

					if (node1 != node2) {

						graph.arrowUpdate(node1, node2, 50);

						if (graph.weight[node2][node1] > 0) {
							graph.arrowUpdate(node2, node1,
									graph.weight[node2][node1]);
						}
					}

				}

			}

			else if (movearrow) {

				movearrow = false;

				if (graph.weight[node1][node2] > 0)

					graph.changeWeight(x, y, node1, node2);

			}

			else if (movestart) {

				// if new position is a node, this node becomes the startnode

				if (nodehit(x, y, NODESIZE))

					graph.startgraph = hitnode;

				graph.colorNode[graph.startgraph] = Color.blue;

				movestart = false;

			}
			repaint();
		}

		return true;

	}

	public boolean nodehit(int x, int y, int dist) {

		// checks if you hit a node with your mouseclick

		for (int i = 0; i < numOfNodes; i++) {

			if ((x - graph.node[i].x) * (x - graph.node[i].x) +

			(y - graph.node[i].y) * (y - graph.node[i].y) < dist * dist) {

				hitnode = i;

				return true;

			}
		}

		return false;

	}

	public boolean arrowhit(int x, int y, int dist) {

		// checks if you hit an arrow with your mouseclick

		for (int i = 0; i < numOfNodes; i++) {

			for (int j = 0; j < numOfNodes; j++) {

				if ((graph.weight[i][j] > 0) &&

				(Math.pow(x - graph.arrow[i][j].x, 2) +

				Math.pow(y - graph.arrow[i][j].y, 2) < Math.pow(dist, 2))) {

					node1 = i;

					node2 = j;

					return true;

				}

			}
		}

		return false;

	}

	public void paint(Graphics g) {
		inPrint = true;
		update();
		inPrint = false;
	}

	private void drawAllArrows(Graphics g) {
		for (int i = 0; i < numOfNodes; i++) {
			for (int j = 0; j < numOfNodes; j++) {
				if (graph.weight[i][j] > 0) {
					// if algorithm is running then perform next step for this
					// arrow

					if (performalg) {
						applyAlgorithm(g, i, j);
					}

					graph.drawArrow(g, i, j, fmetrics);

				}
			}
		}
	}

	private void drawAllNodes(Graphics g) {
		for (int i = 0; i < numOfNodes; i++) {
			if (graph.node[i].x > 0) {
				g.setColor(graph.colorNode[i]);
				g.fillOval(graph.node[i].x - NODERADIX, graph.node[i].y
						- NODERADIX, NODESIZE, NODESIZE);
			}
		}
	}

	/**
	 * draw black circles around nodes, write their names to the screen
	 * 
	 */
	private void drawCircledNode(Graphics g) {
		g.setFont(helvetica);

		for (int i = 0; i < numOfNodes; i++) {

			if (graph.node[i].x > 0) {

				g.setColor(Color.black);

				g.drawOval(graph.node[i].x - NODERADIX, graph.node[i].y
						- NODERADIX,

				NODESIZE, NODESIZE);

				g.setColor(Color.blue);

				g.drawString(findNodeName(i), graph.node[i].x - 14,
						graph.node[i].y - 14);

			}
		}
	}

	/**
	 * draw a new arrow to current mouse position if needed.
	 * 
	 * @param g
	 */
	public void drawNewLine(Graphics g) {
		if (newarrow) {
			g.drawLine(graph.node[node1].x, graph.node[node1].y, currPoint.x,
					currPoint.y);
		}
	}

	public void update() {
		Graphics g = getGraphics();
		minDistance = 0;

		minNode = MAXNODES;

		minStart = MAXNODES;

		minEnd = MAXNODES;

		g.setFont(roman);

		g.setColor(Color.black);

		drawNewLine(g);

		// draw all arrows
		drawAllArrows(g);

		// if arrowhead has been dragged to 0, draw it anyway, so the user

		// will have the option to make it positive again

		if (movearrow && graph.weight[node1][node2] == 0) {

			graph.drawArrow(g, node1, node2, fmetrics);

			g.drawLine(graph.startPoint[node1][node2].x,
					graph.startPoint[node1][node2].y,

					graph.endPoint[node1][node2].x,
					graph.endPoint[node1][node2].y);

		}

		// draw the nodes
		drawAllNodes(g);

		g.setColor(Color.black);

		// finish this step of the algorithm

		if (performalg) {
			endStepAlgorithm(g);
		}

		// draw black circles around nodes, write their names to the screen
		drawCircledNode(g);
	}
}