com.sun.electric.tool.SwingExamineTask Maven / Gradle / Ivy
/* -*- tab-width: 4 -*-
*
* Electric(tm) VLSI Design System
*
* File: SwingExamineTask.java
*
* Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
*
* Electric(tm) is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* Electric(tm) is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Electric(tm); see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, Mass 02111-1307, USA.
*/
/**
* User: gainsley
* Date: Oct 7, 2004
* Time: 2:15:59 PM
*/
package com.sun.electric.tool;
/**
* Allows the GUI thread to attempt to examine the database immediately. If that
* fails, then the GUI can pass this object to the Job queue via Job.invokeExamineLater()
* to have it run at a later time in the GUI thread. A standard usage is as follows:
*
*
* SwingExamineTask task = new SwingExamineTask() {
* protected boolean doIt() {
* // do something that requires database examine and GUI modification
* }
* }
* // try to run the task immediately, if not possible, run at a later time
* if (!task.runImmediately()) {
* Job.invokeExamineLater(task, null);
* }
*
*
* Note: it is not necessary to acquire an examine lock in doIt(),
* as the SwingExamineTask ensures that an examine lock already held
* in all cases.
*
*/
public abstract class SwingExamineTask implements Runnable {
private boolean immediate = true;
/**
* This should only be called by the Job class.
* It asserts that the Job class has created an active examine
* Job which guarantees that this will be able to get
* an examine lock from the GUI thread.
*/
public final void run() {
immediate = false;
boolean b = runImmediately();
assert(b);
immediate = true;
}
/**
* This tries to execute doIt() immediately by trying to
* acquire an examine lock for the database. Returns false
* if could not get lock.
* @return true if lock acquired and doIt() run, false if
* lock not acquired and nothing done.
*/
public final boolean runImmediately() {
/*
if (Job.acquireExamineLock(false)) {
try {
doIt(immediate);
Job.releaseExamineLock();
} catch (Error e) {
Job.releaseExamineLock();
throw e;
}
return true;
}
return false;
*/
// locking not working right now, just run it
doIt(immediate);
return true;
}
/**
* This should contain the code that needs to examine the database
* while in the GUI thread
* @param immediate true if run immediately using runImmediate(),
* false if run through callback to run().
* @return true if successful, false otherwise
*/
protected abstract boolean doIt(boolean immediate);
}