/** This applet combines the code in Simple Applet 7 ** and Animator Applet 3 in an interesting way. It ** begins with user interaction that switches over ** to an animation. ** ** Written by John Pais, February 1998. **/ /** USE EXISTING JAVA CLASSES **/ import java.awt.*; import java.applet.Applet; /** EXTEND THE JAVA APPLET CLASS AND IMPLEMENT THE RUNNABLE INTERFACE **/ public class AnimatorApplet8 extends Applet implements Runnable {final int maxnumlines = 10; // Define max number of lines, final int maxsize = maxnumlines + 5; // max array size, Point startpoint[] = new Point[maxsize]; // the array of start points, Point endpoint[] = new Point[maxsize]; // the array of end points, Point anchorpoint, connectpoint; // the current anchor point and int entrynum = 0; // connection point, and the // current array entry number, // starting with 0 (instead of 1). Font permitfont = new Font("TimesRoman",Font.BOLD+Font.ITALIC,18); FontMetrics permitfontm = getFontMetrics(permitfont); String permitText[] = new String[maxsize+1]; int xpermitText[] = new int[maxsize+1]; String punish = "Now I must punish you"; String forbidbegin = "I real"; String forbidend = "y forbid you from drawing any more lines."; int tempentrynum = 0; String exclamation = "!"; int fontPoint = 12; Font resistfont = new Font("TimesRoman",Font.BOLD,fontPoint); FontMetrics resistfontm = getFontMetrics(resistfont); int xresistfont; int yresistfont; String resist = "RESISTANCE"; int frameNumber = -1; int delay; Thread animatorThread; boolean frozen = true; String framestr = ""; boolean eraser = false; int linesleft = maxnumlines; Dimension preImageDim; // Define preImage variables needed to Image preImage; // create the offscreen copy of the image Graphics preImageGraphics; // we want to paint on the screen. /** INITIALIZE THE APPLET **/ public void init() {setBackground(Color.blue); String str; int fps = 2; // Define the default fps (frames per second). str = getParameter("fps"); // Possibly, get HTML string specifying the try // fps. {if (str != null) {fps = Integer.parseInt(str);} // If possible, convert HTML fps to an } // integer. catch (Exception e) {} // In case the try caused something strange. delay = (fps > 0) ? (1000/fps): 100; // Convert fps to the milisecond delay } // time between frames. /** HANDLE THE MOUSEDOWN EVENT **/ public boolean mouseDown(Event e, int x, int y) {if (entrynum < maxsize) {anchorpoint = new Point(x,y); // Initialize both points to connectpoint = anchorpoint; // the current mouse position. return true;} // Note that this will give us a else // way to prevent painting a single {return false;} // point (see the mouseUp method). } /** HANDLE THE MOUSEDRAG EVENT **/ public boolean mouseDrag(Event e, int x, int y) {if (entrynum < maxsize) // A mouseDrag event occurs only {connectpoint = new Point(x,y); // when the mouse is moved. So, repaint(); // we must have connectpoint != return true;} // anchorpoint, which ensures that else // a temporary (red) line will be {return false;} // painted (see the paint method). } /** HANDLE THE MOUSEUP EVENT **/ public boolean mouseUp(Event e, int x, int y) {if (entrynum < maxsize && connectpoint != anchorpoint) // Don't add a single point. {addline(); // Add new points to the arrays. if (!eraser) {repaint();} // Repaint everything, including else // the new line (all yellow). {frozen = false; start(); } return true; } else {return false;} } /** THE ADDLINE METHOD **/ void addline() {startpoint[entrynum] = anchorpoint; // Record the startpoint and endpoint endpoint[entrynum] = connectpoint; // of the new line. entrynum++; // Add 1 to the current entry number. anchorpoint = null; // Nullifying these points prevents the connectpoint = null; // line from being painted twice (see } // the paint method). /** GENERATE AND/OR START THE ANIMATION THREAD **/ public void start() {if (frozen) { } // The animation is supposed to stay frozen. else // Otherwise, generate and/or start the {if (animatorThread == null) // animation thread. Apparently, if run {animatorThread = new Thread(this);} // breaks after catching an exception, animatorThread.start(); // the animatorThread though not null } // will still need to be restarted. } /** CREATE AND DISPLAY FRAMES OF THE ANIMATION THREAD **/ public void run() {Thread.currentThread().setPriority(Thread.MIN_PRIORITY); // Set the priority low. long startTime = System.currentTimeMillis(); // Remember start time. while (Thread.currentThread() == animatorThread) // The animation loop. {frameNumber++; // Advance the frame number. framestr = "Frame " + frameNumber; // Create the frame string. repaint(); // Display the frame. try // Sleep for the delay period. {startTime += delay; Thread.sleep(Math.max(0, startTime-System.currentTimeMillis())); } catch (InterruptedException e) {break;} // In case the try caused } // something strange, exit } // the while loop. /** CREATE THE CURRENT FRAME OF THE ANIMATION THREAD **/ public void paint(Graphics g) // This technique of painting by calling {update(g);} // update, prevents the default (and hidden) // behavior of update, and instead allows public void update(Graphics g) // the creation of an offscreen preImage {Dimension d = size(); // preImage before painting the screen. if ((preImageGraphics == null) || (d.width != preImageDim.width) || // Compare the current applet (d.height != preImageDim.height)) // viewing size to our preImage, {preImageDim = d; // and if different, resize our preImage = createImage(d.width,d.height); // next preImage. preImageGraphics = preImage.getGraphics(); } preImageGraphics.setColor(getBackground()); // Clear the previous preImage preImageGraphics.fillRect(0,0,d.width,d.height); // by filling with the current // background color (blue), // and then create the next // offscreen preImage. if (entrynum == 0) {permitText[entrynum] = "I will permit you to draw "+ maxnumlines + " lines.";} else if (entrynum < maxnumlines) {permitText[entrynum] = "I will permit you to draw "+ (maxnumlines-entrynum) + " more lines.";} else if (entrynum == maxnumlines) {permitText[entrynum] = "I forbid you from drawing any more lines.";} else if (entrynum < maxsize) {if (entrynum != tempentrynum) {forbidbegin += "l"; permitText[entrynum] = forbidbegin + forbidend; tempentrynum = entrynum; } } else {if (frameNumber < 30) // {punish += entrynum;} {punish += exclamation;} permitText[entrynum] = punish; } xpermitText[entrynum] = (size().width - permitfontm.stringWidth(permitText[entrynum]))/2; preImageGraphics.setFont(permitfont); preImageGraphics.setColor(Color.red); preImageGraphics.drawString(permitText[entrynum],xpermitText[entrynum],15); preImageGraphics.setColor(Color.black); preImageGraphics.fillRect(0,20,500,10); if (frameNumber > maxnumlines) {Font resistfont=new Font("TimesRoman",Font.BOLD,fontPoint); FontMetrics resistfontm = getFontMetrics(resistfont); xresistfont = (size().width - resistfontm.stringWidth(resist))/2; yresistfont = (size().height - 30)/2 + 30; preImageGraphics.setFont(resistfont); preImageGraphics.setColor(Color.magenta); preImageGraphics.drawString(resist,xresistfont,yresistfont); fontPoint += 10; fontPoint %= 70; //if (resist != "FUTILE") // {fontPoint %= 70;} //else // {fontPoint %= 100;} fontPoint = Math.max(fontPoint,12); if (resist == "RESISTANCE" && fontPoint == 12) {resist = "IS";} else if (resist == "IS" && fontPoint == 12) {resist = "FUTILE";} else if (resist == "FUTILE" && fontPoint == 12) {resist = "RESISTANCE";} } if (entrynum < maxsize) {preImageGraphics.setColor(Color.yellow); for (int i = 0; i < entrynum; i++) // Note that nothing happens here, {if (i < maxnumlines) // until a mouseDown event occurs. {preImageGraphics.drawLine(startpoint[i].x, startpoint[i].y, // Repaint all lines from endpoint[i].x, endpoint[i].y);} // 0 to maxnumlines-1. } if (connectpoint != anchorpoint) // Paint a temporary red line in {preImageGraphics.setColor(Color.red); // response to a mouseDrag event. preImageGraphics.drawLine(anchorpoint.x, anchorpoint.y, connectpoint.x, connectpoint.y);} if (entrynum == maxsize-1) {eraser = true;} } else if (entrynum == maxsize) {preImageGraphics.setColor(Color.yellow); if (linesleft == maxnumlines) {for (int i = 0; i < maxnumlines; i++) preImageGraphics.drawLine(startpoint[i].x, startpoint[i].y, endpoint[i].x, endpoint[i].y); linesleft -= 1; } else //Font font=new Font("TimesRoman",Font.BOLD,fontPoint); //g.setFont(font); //g.setColor(Color.red); //g.drawString(framestr,120,110); {for (int i = 0; i < linesleft+1; i++) {preImageGraphics.drawLine(startpoint[i].x, startpoint[i].y, endpoint[i].x, endpoint[i].y); } if (linesleft >= 0) {preImageGraphics.setColor(Color.red); preImageGraphics.drawLine(startpoint[linesleft].x, startpoint[linesleft].y, endpoint[linesleft].x, endpoint[linesleft].y); linesleft -= 1; } } } g.drawImage(preImage,0,0,this); } /** STOP THE ANIMATION THREAD **/ public void stop() {animatorThread = null;} // The user either clicked to stop or left the page, } // so wipe out the current thread.