java - How can I prevent the Ball from moving off of the edge of the screen? simple KeyListenerDemo example -


I have limited experience, especially when it comes to graphics, I have got very good help on this problem so far And I am sure to be more familiar with this site as well as to contribute more. The starter code (below) that works fine as I had tested it in the eclipse. I am using it from a classroom to teach a high school student, according to the instructions given below, will an easy way to extend the simple program in advance so that I can get the ball out of the window edge Preventable from being able to? The ball runs fine with the arrow keys, but I can still move the scene completely out of the window / any easy ways to extend this demo program greatly appreciate. Thank you. 

  Import java.awt. *; Import java.awt.event. *; // # 1 import javax.swing. *; / *************************************************************************************************** **************** KeyListenerDemo.java * Provides keyboard input for using the KeyListener interface * * Program 18: Adding some more keystroke commands to this program Increase: * z (VK_Z) - The cause of the ball to jump at a random new place. * S (VCSI) - Make the ball small - its diameter is 1/2 times. * B (VKB) - Make the ball bigger - increase its diameter by 2. times (vk) - Change the color (by any means you want). * * * Also, modify the program to ensure the following: * - The ball goes all the way to the edge of the screen but remains perfectly on the screen *. * - If the double diameter is not fit, then make it as big as possible. * - Make sure the ball never disappears altogether. * *************************************************************************************************** **************************************************************************************************** ************************************* KeyListenerDemo extends JFrame KeyListener // # 2 {// Class Scope Final Personal Stable Final Integer SCREEN_WIDTH = 1000; Personal Static FINAL END SCREEN_HEIGHT = 800; Personal static ending ending START_RADIUS = 25; Personal fixed ending end START_X = 100; Private static final end START_Y = 100; Private stable final IT STEP_SIZE = 10; // class scope variables personal static x = START_X; // Private stationary in the center of the ball = = yY; // y in the center of the ball, the private constant int radius = START_RADIUS; // Line of radius // Method / ** * Create a window and register it as a kernelist * * Ultimate Arguments * / Public Static Wide Men (string [] ARGs) {// Set GeFame window. KeyListenerDemo GP = New KeyListenerDemo (); Gp.setSize (SCREEN_WIDTH, SCREEN_HEIGHT); Gp.setVisible (true); gp.addKeyListener (GP); // # 3 // If this class was a constructor and you created this line in // then this constructor can not refer to this GP because the variable // is local for this method. Instead you will write: // addKeyListener (this); } / ** * is called when a key is pressed first * required for any keyListener * * @param e pressed * / public zero keypressed (KeyEvent e) key // # 4a {int keycode = e.getKeyCode Information about (included); If (keycode == KeyEvent.VK_LEFT) {x = x - STEP_SIZE; } And if (keycode == KeyEvent.VK_RIGHT) {x = x + STEP_SIZE; } And if (keycode == KeyEvent.VK_UP) {y = y - STEP_SIZE; } And if (keycode == KeyEvent.VK_DOWN) {y = y + STEP_SIZE; } Color (); } / ** * When a key typing is completed * * Key * required for any KeyListener * typed * @param * / Public Zero keyTyped (KeyEvent e) key # 4b {} / ** * When the information is included, it is called the key is issued * Required key releases for any Keygenist * * @ Ultimate E contains information about public release / key vacuum (KAVEEDE) // # 4 C {} / ** * Paint - Drag Draw * * @ Ultimate G Graphics * / Sub Nick void paint (Graphics g) object to draw in {g.setColor (Color.white); g.fillRect (0, 0, SCREEN_WIDTH, SCREEN_HEIGHT); G.setColor (Color.blue); Gifil (x - radius, y - radius, 2 * radius, 2 * radius); }}    
 
 
 Just set a max before reprint:  
  Public Zero Key Pressed (keyEvent e) // # 4A {int keyCode = e.getKeyCode (); If (keycode == KeyEvent.VK_LEFT) {x = x - STEP_SIZE; } And if (keycode == KeyEvent.VK_RIGHT) {x = x + STEP_SIZE; } And if (keycode == KeyEvent.VK_UP) {y = y - STEP_SIZE; } And if (keycode == KeyEvent.VK_DOWN) {y = y + STEP_SIZE; } X = mathematics.max (0, x); X = Math (SCREEN_WIDTH, x + radius); Y = Math.Max ​​(0, Y + radius); Y = Math (SCREEN_HEIGHT, Y); Repaint (); }

Comments

Post a Comment

Popular posts from this blog

Verilog Error: output or inout port "Q" must be connected to a structural net expression -

I get the error every time, I try to compile. I'm not sure why anyone can help is? I'm new to verilog. Module D_FF (clerk, d, reset_n, q); Input D, Clack, reset_en; Output Q; reg Q; lab4_gdl f1 (.lk (~ clk), d (d), .q.m (qm)); lab4_GDL f2 (.Clk (Clk), D (QM), .Q (Q)); Always start at @ (posedge clk, neggeous reset_n) (Reset_n == 0) Q & lt; = 0; Other questions & lt; = D; Edit End: The problem is what we are asking to do: In this section, you apply the memory / registration circuit on the AlterEdie 2 board. will do. The circuit has the following specifications: The present value of swift SW15-0 on the D2 board should be shown in four hexadecimal four sections of HEX3-0. This part of the circuit will be combination logic. To use an active-less asynchronous reset and KEY1 to use KEY0 as the clock input, you must store SW15-0in in a 16-bit register in the value The register should be enabled to have a 16-bit positive edge, which uses the embedded D flip-flo
Read more

jasper reports - How to center align barcode using jasperreports and barcode4j -

I use iReport 5.5.0 . How to align a barcode component to the center The relevant piece of my jrxml is below & Lt; JR: Code 128 xmlns: JR = "http://jasperreports.sourceforge.net/jasperreports/components" xsi: schemaLocation = "http://jasperreports.sourceforge.net/jasperreports/components http: //jasperreports.sourceforge Purge / xsd / components.xsd "textPosition =" bottom "& gt; & Lt; Jr: codeExpression & gt; & Lt; [CDATA [$ F {number}]] & gt; & Lt; / Jr: codeExpression & gt; & Lt; / Jr: Code 128 & gt; & Lt; / componentElement & gt; "Text" itemprop = "text"> Create a style after this, it is called "barcode", like: & lt; Style name = "barcode" fontName = "Helvetica" fONTSIZE = "10" hAlign = "center" valign = "center" /> and set the property of your barcode element to "barcode".
Read more

c# - ASP.NET MVC - Attaching an entity of type 'MODELNAME' failed because another entity of the same type already has the same primary key value -

In brief, the wrapper module is inserted during posting and the status of an entry is changed to 'modified' . Before changing the state, the state is set to 'separate', but calling attachments () causes the same error to be thrown away. I am using EF 6. Model / wrapper class public class avi model {public A is a {get; Set; } Public listing & lt; B & gt; B {received; Set; } Public cc {receipt; Set; }} Administrator edit public functioning (int? id) {if (id == null) {new HttpStatusCodeResult (HttpStatusCode.BadRequest); } If (! Conveyor Access (id.Value)) new HTTPTitus code result (HTTP status code. Forbidden); Var aViewModel = new AViewModel (); aViewModel.A = db.As.Find (id); If (aViewModel.Receipt == zero) {return HttpNotFound (); } aViewModel.b = db.Bs.Where (x => x.aid == id.Value) .Oolist (); AViewModel.Vendor = db.Cs.Where (x => x.cid == aViewModel.a.cID) .FirstOrDefault (); See Return (aViewModel); } [HTPFost] [Valid AntitiferousTeacon
Read more