/* Copyright (c) 2010, Carl Burch. License information is located in the
* com.cburch.logisim.Main source code and at www.cburch.com/logisim/. */
package com.cburch.logisim.prefs;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.prefs.PreferenceChangeEvent;
import java.util.prefs.PreferenceChangeListener;
import java.util.prefs.Preferences;
class RecentProjects implements PreferenceChangeListener {
private static final String BASE_PROPERTY = "recent";
private static final int NUM_RECENT = 10;
private static class FileTime {
private long time;
private File file;
public FileTime(File file, long time) {
this.time = time;
this.file = file;
}
@Override
public int hashCode() {
return ((int)time % 25);
}
@Override
public boolean equals(Object other) {
if (other instanceof FileTime) {
FileTime o = (FileTime) other;
return this.time == o.time && isSame(this.file, o.file);
} else {
return false;
}
}
}
private File[] recentFiles;
private long[] recentTimes;
RecentProjects() {
recentFiles = new File[NUM_RECENT];
recentTimes = new long[NUM_RECENT];
Arrays.fill(recentTimes, System.currentTimeMillis());
Preferences prefs = AppPreferences.getPrefs();
prefs.addPreferenceChangeListener(this);
for (int index = 0; index < NUM_RECENT; index++) {
getAndDecode(prefs, index);
}
}
public List<File> getRecentFiles() {
long now = System.currentTimeMillis();
long[] ages = new long[NUM_RECENT];
long[] toSort = new long[NUM_RECENT];
for (int i = 0; i < NUM_RECENT; i++) {
if (recentFiles[i] == null) {
ages[i] = -1;
} else {
ages[i] = now - recentTimes[i];
}
toSort[i] = ages[i];
}
Arrays.sort(toSort);
List<File> ret = new ArrayList<File>();
for (long age : toSort) {
if (age >= 0) {
int index = -1;
for (int i = 0; i < NUM_RECENT; i++) {
if (ages[i] == age) {
index = i;
ages[i] = -1;
break;
}
}
if (index >= 0) {
ret.add(recentFiles[index]);
}
}
}
return ret;
}
public void updateRecent(File file) {
File fileToSave = file;
try {
fileToSave = file.getCanonicalFile();
} catch (IOException e) { }
long now = System.currentTimeMillis();
int index = getReplacementIndex(now, fileToSave);
updateInto(index, now, fileToSave);
}
private int getReplacementIndex(long now, File f) {
long oldestAge = -1;
int oldestIndex = 0;
int nullIndex = -1;
for (int i = 0; i < NUM_RECENT; i++) {
if (f.equals(recentFiles[i])) {
return i;
}
if (recentFiles[i] == null) {
nullIndex = i;
}
long age = now - recentTimes[i];
if (age > oldestAge) {
oldestIndex = i;
oldestAge = age;
}
}
if (nullIndex != -1) {
return nullIndex;
} else {
return oldestIndex;
}
}
@Override
public void preferenceChange(PreferenceChangeEvent event) {
Preferences prefs = event.getNode();
String prop = event.getKey();
if (prop.startsWith(BASE_PROPERTY)) {
String rest = prop.substring(BASE_PROPERTY.length());
int index = -1;
try {
index = Integer.parseInt(rest);
if (index < 0 || index >= NUM_RECENT) {
index = -1;
}
} catch (NumberFormatException e) { }
if (index >= 0) {
File oldValue = recentFiles[index];
long oldTime = recentTimes[index];
getAndDecode(prefs, index);
File newValue = recentFiles[index];
long newTime = recentTimes[index];
if (!isSame(oldValue, newValue) || oldTime != newTime) {
AppPreferences.firePropertyChange(AppPreferences.RECENT_PROJECTS,
new FileTime(oldValue, oldTime),
new FileTime(newValue, newTime));
}
}
}
}
private void updateInto(int index, long time, File file) {
File oldFile = recentFiles[index];
long oldTime = recentTimes[index];
if (!isSame(oldFile, file) || oldTime != time) {
recentFiles[index] = file;
recentTimes[index] = time;
try {
AppPreferences.getPrefs().put(BASE_PROPERTY + index,
"" + time + ";" + file.getCanonicalPath());
AppPreferences.firePropertyChange(AppPreferences.RECENT_PROJECTS,
new FileTime(oldFile, oldTime),
new FileTime(file, time));
} catch (IOException e) {
recentFiles[index] = oldFile;
recentTimes[index] = oldTime;
}
}
}
private void getAndDecode(Preferences prefs, int index) {
String encoding = prefs.get(BASE_PROPERTY + index, null);
if (encoding == null) {
return;
}
int semi = encoding.indexOf(';');
if (semi < 0) {
return;
}
try {
long time = Long.parseLong(encoding.substring(0, semi));
File file = new File(encoding.substring(semi + 1));
updateInto(index, time, file);
} catch (NumberFormatException e) { }
}
private static boolean isSame(Object a, Object b) {
return a == null ? b == null : a.equals(b);
}
}