www.pudn.com > src.rar > AssignReferencesCanvas.java
/*
* Copyright (c) 1996, 1997 Bill Venners. All Rights Reserved.
*
* This Java source file is part of the Interactive Illustrations Web
* Site, which is delivered in the applets directory of the CD-ROM
* that accompanies the book "Inside the Java Virtual Machine" by Bill
* Venners, published by McGraw-Hill, 1997,ISBN: 0-07-913248-0. This
* source file is provided for evaluation purposes only, but you can
* redistribute it under certain conditions, described in the full
* copyright notice below.
*
* Full Copyright Notice:
*
* All the web pages and Java applets delivered in the applets
* directory of the CD-ROM, consisting of ".html," ".gif," ".class,"
* and ".java" files, are copyrighted (c) 1996, 1997 by Bill
* Venners, and all rights are reserved. This material may be copied
* and placed on any commercial or non-commercial web server on any
* network (including the internet) provided that the following
* guidelines are followed:
*
* a. All the web pages and Java Applets (".html," ".gif," ".class,"
* and ".java" files), including the source code, that are delivered
* in the applets directory of the CD-ROM that
* accompanies the book must be published together on the same web
* site.
*
* b. All the web pages and Java Applets (".html," ".gif," ".class,"
* and ".java" files) must be published "as is" and may not be altered
* in any way.
*
* c. All use and access to this web site must be free, and no fees
* can be charged to view these materials, unless express written
* permission is obtained from Bill Venners.
*
* d. The web pages and Java Applets may not be distributed on any
* media, other than a web server on a network, and may not accompany
* any book or publication.
*
* BILL VENNERS MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE
* SUITABILITY OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING
* BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR PARTICULAR PURPOSE, OR NON-INFRINGEMENT. BILL VENNERS
* SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY A LICENSEE AS A
* RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES.
*/
import java.awt.*;
/**
* This class is the panel on which is drawn the local variable rectangles, all
* the allocated fish, and the lines showing their connections. All this drawing
* is done by the paint() method of this class.
*
* @author Bill Venners
*/
public class AssignReferencesCanvas extends Canvas {
protected GCHeap gcHeap;
protected LocalVariables localVars;
protected HeapOfFishTextArea controlPanelTextArea;
protected final int poolImageInsets = 5;
protected final int localVarStringMargin = 5;
protected int localVarRectWidth;
protected int localVarRectHeight;
protected int xLocalVarRectStart;
protected int yYellowFishLocalVarStart;
protected int yBlueFishLocalVarStart;
protected int yRedFishLocalVarStart;
// Fish area is just to the left of the local variables.
protected int xFishAreaStart;
public Dimension minimumSize() {
return new Dimension(500, 240);
}
public Dimension preferredSize() {
return new Dimension(500, 240);
}
public void paint(Graphics g) {
Font font = g.getFont();
FontMetrics fm = getFontMetrics(font);
int localVarsStringWidth = fm.stringWidth(HeapOfFishStrings.localVariables);
int redFishStringWidth = fm.stringWidth(HeapOfFishStrings.redFishLocalVar);
int blueFishStringWidth = fm.stringWidth(HeapOfFishStrings.blueFishLocalVar);
int yellowFishStringWidth = fm.stringWidth(HeapOfFishStrings.yellowFishLocalVar);
localVarRectWidth = localVarsStringWidth;
if (redFishStringWidth > localVarRectWidth) {
localVarRectWidth = redFishStringWidth;
}
if (blueFishStringWidth > localVarRectWidth) {
localVarRectWidth = blueFishStringWidth;
}
if (yellowFishStringWidth > localVarRectWidth) {
localVarRectWidth = yellowFishStringWidth;
}
localVarRectWidth += 2 * localVarStringMargin;
xFishAreaStart = localVarRectWidth + (2 * localVarStringMargin);
localVarRectHeight = fm.getAscent() + fm.getDescent() + 2 * localVarStringMargin;
Dimension dim = size();
int yLocalVarsAreaStart = (dim.height - (4 * localVarRectHeight)) / 2;
if (yLocalVarsAreaStart < 0) {
yLocalVarsAreaStart = 0;
}
// draw "Local Variables"
int xStart = ((localVarRectWidth - localVarsStringWidth) / 2) + localVarStringMargin;
int yStart = yLocalVarsAreaStart + localVarStringMargin + fm.getAscent();
g.setColor(Color.white);
g.drawString(HeapOfFishStrings.localVariables, xStart, yStart);
// draw "YellowFish yf" on a yellow rectangle
xStart = localVarStringMargin;
yStart = yLocalVarsAreaStart + localVarRectHeight;
g.setColor(Color.yellow);
g.fillRect(xStart, yStart, localVarRectWidth, localVarRectHeight);
xLocalVarRectStart = xStart;
yYellowFishLocalVarStart = yStart;
xStart = ((localVarRectWidth - yellowFishStringWidth) / 2) + localVarStringMargin;
yStart += localVarStringMargin + fm.getAscent();
g.setColor(Color.black);
g.drawString(HeapOfFishStrings.yellowFishLocalVar, xStart, yStart);
// draw "BlueFish bf" on a cyan rectangle
xStart = localVarStringMargin;
yStart = yLocalVarsAreaStart + (2 * localVarRectHeight);
g.setColor(Color.cyan);
g.fillRect(xStart, yStart, localVarRectWidth, localVarRectHeight);
yBlueFishLocalVarStart = yStart;
xStart = ((localVarRectWidth - blueFishStringWidth) / 2) + localVarStringMargin;
yStart += localVarStringMargin + fm.getAscent();
g.setColor(Color.black);
g.drawString(HeapOfFishStrings.blueFishLocalVar, xStart, yStart);
// draw "RedFish rf" on a red rectangle
xStart = localVarStringMargin;
yStart = yLocalVarsAreaStart + (3 * localVarRectHeight);
g.setColor(Color.red);
g.fillRect(xStart, yStart, localVarRectWidth, localVarRectHeight);
yRedFishLocalVarStart = yStart;
xStart = ((localVarRectWidth - redFishStringWidth) / 2) + localVarStringMargin;
yStart += localVarStringMargin + fm.getAscent();
g.setColor(Color.black);
g.drawString(HeapOfFishStrings.redFishLocalVar, xStart, yStart);
if (localVars.yellowFish != 0) {
g.setColor(Color.blue);
g.setXORMode(Color.yellow);
ObjectHandle yf = gcHeap.getObjectHandle(localVars.yellowFish);
int xLineStart = xLocalVarRectStart + localVarRectWidth;
int yLineStart = yYellowFishLocalVarStart + (localVarRectHeight / 2);
g.drawLine(xLineStart, yLineStart, yf.fish.getFishPosition().x, yf.fish.getFishPosition().y);
if (localVars.yellowLineStart == null) {
localVars.yellowLineStart = new Point(0, 0);
localVars.yellowLineEnd = new Point(0, 0);
}
localVars.yellowLineStart.x = xLineStart;
localVars.yellowLineStart.y = yLineStart;
localVars.yellowLineEnd.x = yf.fish.getFishPosition().x;
localVars.yellowLineEnd.y = yf.fish.getFishPosition().y;
g.setPaintMode();
}
if (localVars.blueFish != 0) {
g.setColor(Color.blue);
g.setXORMode(Color.cyan);
ObjectHandle bf = gcHeap.getObjectHandle(localVars.blueFish);
int xLineStart = xLocalVarRectStart + localVarRectWidth;
int yLineStart = yBlueFishLocalVarStart + (localVarRectHeight / 2);
g.drawLine(xLineStart, yLineStart, bf.fish.getFishPosition().x, bf.fish.getFishPosition().y);
if (localVars.blueLineStart == null) {
localVars.blueLineStart = new Point(0, 0);
localVars.blueLineEnd = new Point(0, 0);
}
localVars.blueLineStart.x = xLineStart;
localVars.blueLineStart.y = yLineStart;
localVars.blueLineEnd.x = bf.fish.getFishPosition().x;
localVars.blueLineEnd.y = bf.fish.getFishPosition().y;
g.setPaintMode();
}
if (localVars.redFish != 0) {
g.setColor(Color.blue);
g.setXORMode(Color.red);
ObjectHandle rf = gcHeap.getObjectHandle(localVars.redFish);
int xLineStart = xLocalVarRectStart + localVarRectWidth;
int yLineStart = yRedFishLocalVarStart + (localVarRectHeight / 2);
g.drawLine(xLineStart, yLineStart, rf.fish.getFishPosition().x, rf.fish.getFishPosition().y);
if (localVars.redLineStart == null) {
localVars.redLineStart = new Point(0, 0);
localVars.redLineEnd = new Point(0, 0);
}
localVars.redLineStart.x = xLineStart;
localVars.redLineStart.y = yLineStart;
localVars.redLineEnd.x = rf.fish.getFishPosition().x;
localVars.redLineEnd.y = rf.fish.getFishPosition().y;
g.setPaintMode();
}
// Figure out how many slots will be in each of three columns of slots where
// new fish are put.
int columnCount = 3;
int slotsPerColumn = gcHeap.getHandlePoolSize() / columnCount;
if (gcHeap.getHandlePoolSize() % columnCount > 0) {
++slotsPerColumn;
}
int fishAreaWidth = dim.width - xFishAreaStart;
int slotWidth = fishAreaWidth / columnCount;
int slotHeight = dim.height / slotsPerColumn;
for (int i = 0; i < gcHeap.getHandlePoolSize(); ++i) {
ObjectHandle oh = gcHeap.getObjectHandle(i + 1);
if (!oh.free) {
FishIcon fishIcon = oh.fish;
if (!fishIcon.getFishHasBeenInitiallyPositioned()) {
int column = i / slotsPerColumn;
int row = i % slotsPerColumn;
int xFishPosition = (int) ((double) (slotWidth - fishIcon.getFishWidth()) * Math.random());
if (xFishPosition < 0) {
xFishPosition = 0;
}
xFishPosition += xFishAreaStart + (column * slotWidth);
int yFishPosition = (slotHeight - fishIcon.getFishHeight()) / 2;
if (yFishPosition < 0) {
yFishPosition = 0;
}
yFishPosition += row * slotHeight;
fishIcon.moveFish(xFishPosition, yFishPosition);
}
fishIcon.paint(g);
// Draw any lines connecting fish.
g.setColor(Color.blue);
g.setXORMode(fishIcon.getFishColor());
Point fishNose = fishIcon.getFishNosePosition();
oh.gotFriend = false;
oh.myFriendLineStart = null;
oh.myFriendLineEnd = null;
oh.gotLunch = false;
oh.myLunchLineStart = null;
oh.myLunchLineEnd = null;
oh.gotSnack = false;
oh.mySnackLineStart = null;
oh.mySnackLineEnd = null;
int myFriendIndex = gcHeap.getObjectPool(oh.objectPos);
if (myFriendIndex != 0) {
ObjectHandle myFriend = gcHeap.getObjectHandle(myFriendIndex);
g.drawLine(fishNose.x, fishNose.y, myFriend.fish.getFishPosition().x, myFriend.fish.getFishPosition().y);
oh.gotFriend = true;
oh.myFriendLineStart = new Point(fishNose.x, fishNose.y);
oh.myFriendLineEnd = new Point(myFriend.fish.getFishPosition().x, myFriend.fish.getFishPosition().y);
}
if (fishIcon.getFishColor() == Color.yellow) {
g.setPaintMode();
continue;
}
int myLunchIndex = gcHeap.getObjectPool(oh.objectPos + 1);
if (myLunchIndex != 0) {
ObjectHandle myLunch = gcHeap.getObjectHandle(myLunchIndex);
g.drawLine(fishNose.x, fishNose.y, myLunch.fish.getFishPosition().x, myLunch.fish.getFishPosition().y);
oh.gotLunch = true;
oh.myLunchLineStart = new Point(fishNose.x, fishNose.y);
oh.myLunchLineEnd = new Point(myLunch.fish.getFishPosition().x, myLunch.fish.getFishPosition().y);
}
if (fishIcon.getFishColor() == Color.cyan) {
g.setPaintMode();
continue;
}
int mySnackIndex = gcHeap.getObjectPool(oh.objectPos + 2);
if (mySnackIndex != 0) {
ObjectHandle mySnack = gcHeap.getObjectHandle(mySnackIndex);
g.drawLine(fishNose.x, fishNose.y, mySnack.fish.getFishPosition().x, mySnack.fish.getFishPosition().y);
oh.gotSnack = true;
oh.mySnackLineStart = new Point(fishNose.x, fishNose.y);
oh.mySnackLineEnd = new Point(mySnack.fish.getFishPosition().x, mySnack.fish.getFishPosition().y);
}
g.setPaintMode();
}
}
}
}