www.pudn.com > java_chat.rar > ChatUtil.java
package at.ac.uni_linz.tk.vchat;
import java.awt.*;
import java.util.*;
import java.text.*;
import java.net.*;
import java.applet.*;
/**
* Provides frequently needed utility methods.
*
* @author Arno Huetter
* (C)opyright by the Institute for Computer Science, Telecooperation Department, University of Linz
*/
public class ChatUtil extends Object {
/**
* Returns the distance between two Points.
*
* @param point1 the first point
* @param point2 the second point
*/
public static int getDistance(Point point1, Point point2) {
return (int)Math.sqrt(Math.pow(point1.x - point2.x, 2) + Math.pow(point1.y - point2.y, 2));
}
/**
* Brightens up a given color.
*
* @param color the color to be brightened
*/
public static Color brighten(Color color) {
return new Color((255 + color.getRed()) / 2, (255 + color.getGreen()) / 2, (255 + color.getBlue()) / 2);
}
/**
* Adds up two angles.
*
* @param angle1 the first angle
* @param angle2 the second angle
*/
public static int addAngle(int angle1, int angle2) {
return (angle1 + angle2) % 360;
}
/**
* Substracts one angle from another angle.
*
* @param angle1 the angle to substract from
* @param angle2 the angle to be substracted
*/
public static int subAngle(int angle1, int angle2) {
int angle;
return Math.abs(angle1 - angle2 + 360) % 360;
}
/**
* Returns the mean value of two angles.
*
* @param angle1 the first angle
* @param angle2 the second angle
*/
public static int getMiddleAngle(int angle1, int angle2) {
int angle;
angle = (angle1 + angle2) / 2 % 360;
return Math.abs(angle1 - angle2) > 180 ? (angle + 180) % 360 : angle;
}
/**
* Returns the angle bewteen two Points (< 180 degrees).
*
* @param point1 the first Point
* @param point2 the second Point
*/
public static int getAngle(Point point1, Point point2) {
return ((int)(Math.atan2((double)(point1.y - point2.y), (double)(point2.x - point1.x)) / Math.PI * 180.0) + 360) % 360;
}
/**
* Returns true if one angle lies in bewteen two given angles.
*
* @param angle the angle to be checked
* @param angleStart the minimum angle
* @param angleStop the maximum angle
*/
public static boolean inAngleRange(int angle, int angleStart, int angleStop) {
if (angleStart > angleStop)
return (!inAngleRange(angle, angleStop, angleStart));
else
return (angle >= angleStart && angle <= angleStop);
}
/**
* Paints a pattern onto a given Graphics conext.
*
* @param g the Graphics context
* @param clipRect the clipping area
* @param colorParam the color in which to paint
*/
public static void paintPattern(Graphics g, Rectangle clipRect, Color colorParam) {
Rectangle previousClipRect;
Color previousColor;
previousClipRect = (Rectangle)(g.getClip());
previousColor = g.getColor();
g.setClip(clipRect);
g.setColor(colorParam);
for (int i = - clipRect.height; i <= clipRect.width; i += 2) {
g.drawLine(clipRect.x + i, clipRect.y, clipRect.x + i - clipRect.height, clipRect.y + clipRect.height);
g.drawLine(clipRect.x + i, clipRect.y, clipRect.x + i + clipRect.height, clipRect.y + clipRect.height);
}
g.setClip(previousClipRect);
g.setColor(previousColor);
}
/**
* Adds a Component to a Container's GridBagLayout.
*
* @param containerParam the Container to add to
* @param componentParam the Comnponent to be added
* @param constraintsParam the GridBagConstraints to use for adding
*/
public static void addWithConstraints(Container containerParam, Component componentParam, GridBagConstraints constraintsParam) {
if (!(containerParam.getLayout() instanceof GridBagLayout))
containerParam.setLayout(new GridBagLayout());
((GridBagLayout)containerParam.getLayout()).setConstraints(componentParam, constraintsParam);
containerParam.add(componentParam);
}
/**
* Adds a Component to the beginning of a new row in a Container's GridBagLayout.
*
* @param containerParam the Container to add to
* @param componentParam the Comnponent to be added
*/
public static void addWithBeginningConstraints(Container containerParam, Component componentParam, Insets insetsParam) {
GridBagConstraints constraints;
constraints = new GridBagConstraints();
constraints.anchor = GridBagConstraints.NORTHWEST;
constraints.insets = new Insets(insetsParam.top / 2, insetsParam.left / 2, insetsParam.bottom / 2, insetsParam.right / 2);
constraints.fill = GridBagConstraints.BOTH;
addWithConstraints(containerParam, componentParam, constraints);
}
/**
* Adds a Component to the beginning of a new row in a Container's GridBagLayout.
*
* @param containerParam the Container to add to
* @param componentParam the Comnponent to be added
*/
public static void addWithBeginningConstraints(Container containerParam, Component componentParam) {
addWithBeginningConstraints(containerParam, componentParam, ChatRepository.INSETS);
}
/**
* Adds a Component to the remainings of a row in a Container's GridBagLayout.
*
* @param containerParam the Container to add to
* @param componentParam the Comnponent to be added
*/
public static void addWithRemainingConstraints(Container containerParam, Component componentParam, Insets insetsParam) {
GridBagConstraints constraints;
constraints = new GridBagConstraints();
constraints.anchor = GridBagConstraints.NORTHWEST;
constraints.insets = new Insets(insetsParam.top / 2, insetsParam.left / 2, insetsParam.bottom / 2, insetsParam.right / 2);
constraints.weightx = 1.0;
constraints.fill = GridBagConstraints.BOTH;
constraints.gridwidth = GridBagConstraints.REMAINDER;
addWithConstraints(containerParam, componentParam, constraints);
}
/**
* Adds a Component to the remainings of a row in a Container's GridBagLayout.
*
* @param containerParam the Container to add to
* @param componentParam the Comnponent to be added
*/
public static void addWithRemainingConstraints(Container containerParam, Component componentParam) {
addWithRemainingConstraints(containerParam, componentParam, ChatRepository.INSETS);
}
/**
* Returns a formated Date value (short format).
*
* @param dateParam the Date to be formatted
*/
public static String dateToTimeString(Date dateParam) {
return DateFormat.getTimeInstance(DateFormat.SHORT).format(dateParam);
}
/**
* Rotates a point around another point by a given angle.
*
* @param centerPoint the center Point of the rotation
* @param rotatePoint the Point to be rotated
* @param rotateAngle the angle of the rotation
*/
public static Point rotatePoint(Point centerPoint, Point rotatePoint, int rotateAngle) {
int angle, distance;
distance = getDistance(centerPoint, rotatePoint);
angle = addAngle(getAngle(centerPoint, rotatePoint), rotateAngle);
rotatePoint.x = centerPoint.x + (int)(Math.cos(angle * Math.PI / 180.0) * distance);
rotatePoint.y = centerPoint.y + (int)(Math.sin(angle * Math.PI / 180.0) * distance);
return rotatePoint;
}
/**
* Returns the signum of a given double value.
*
* @param x the double value to calculate the signum of
*/
public static double sgn(double x) {
return (x != 0.0) ? Math.abs(x) / x : 0.0;
}
/**
* Converts an array of bytes to an array of ints.
*
* @param byteArray the byte array to be converted
*/
public static int[] byteArrayToIntArray(byte[] byteArray) {
int[] intArray = new int[byteArray.length];
for (int i = 0; i < byteArray.length; i++) {
intArray[i] = (int)byteArray[i];
}
return intArray;
}
/**
* Converts an array of ints to an array of bytes.
*
* @param intArray the int array to be converted
*/
public static byte[] intArrayToByteArray(int[] intArray) {
byte[] byteArray = new byte[intArray.length];
for (int i = 0; i < intArray.length; i++) {
byteArray[i] = (byte)intArray[i];
}
return byteArray;
}
/**
* Loads an image from a given URL.
*
* @param url the image's URL
*/
public static Image getImage (URL url) {
Image image;
Applet applet;
applet = new Applet();
MediaTracker tracker = new MediaTracker(applet);
image = applet.getToolkit().getImage(url);
tracker.addImage(image, 0);
try {
tracker.waitForAll();
}
catch (InterruptedException e)
{ }
return image;
}
/**
* Loads an image with a given filename from the server.
*
* @param name the image's filename
*/
public static Image getImage (String name) {
Image image;
Applet applet;
applet = new Applet();
MediaTracker tracker = new MediaTracker(applet);
image = applet.getToolkit().getImage(name);
tracker.addImage(image, 0);
try {
tracker.waitForAll();
}
catch (InterruptedException e)
{ }
return image;
}
/**
* Fills up a String to a certain length.
*
* @param sourceString the original String
* @param fillChar the char to use for filling up the String
* @param length the length of the String to be returned
*/
public static String pad(String sourceString, char fillChar, int length) {
return pad (sourceString, fillChar, length, true);
}
/**
* Fills up a String to a certain length.
*
* @param sourceString the original String
* @param fillChar the char to use for filling up the String
* @param length the length of the String to be returned
* @param orientatedLeft true if the orginal String should be placed at the end
*/
public static String pad(String sourceString, char fillChar, int length, boolean orientatedLeft) {
String workString;
workString = sourceString;
if (workString.length() >= length)
return workString.substring(0, length);
else {
while(workString.length() < length) {
if (orientatedLeft)
workString += fillChar;
else
workString = fillChar + workString;
}
return workString;
}
}
public static int getInt(String string) {
try {
return new Integer(string).intValue();
}
catch (Exception excpt) {
return 0;
}
}
}