clipcontrol.java

一个按钮控制程序

// Copyright (c) 1996 Stephen B Kinzler.  All rights reserved.
//
// THIS PROGRAM IS FURNISHED UNDER A LICENSE AND MAY BE USED AND COPIES OR
// MODIFICATIONS MADE ONLY IN ACCORDANCE WITH THE TERMS OF THAT LICENSE AND
// WITH THE INCLUSION OF THIS COPYRIGHT NOTICE.  NO TITLE TO OR OWNERSHIP
// OF THE PROGRAM IS HEREBY TRANSFERRED.
//
// LICENSE: This program may be freely used and distributed provided the
// following conditions are met:
// (1) This license and the following disclaimer must remain with this
//     program however distributed or published.
// (2) All advertising materials mentioning features or use of this software
//     must display the following acknowledgement:
//       This product includes software developed by the Stephen B Kinzler.
// (3) Any commercial use or distribution of this program, or its use or
//     distribution by any commercial entity, must first have the express
//     permission of Stephen B Kinzler.  A modest fee may be requested to
//     help fund this program's support and development.
//
// THIS SOFTWARE IS PROVIDED BY STEPHEN B KINZLER ``AS IS'' AND ANY EXPRESS
// OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL STEPHEN B KINZLER BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
// IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

import java.applet.*;
import java.awt.*;
import java.net.*;

///////////////////////////////////////////////////////////////////////////////
// ClipControl // Declaration /////////////////////////////////////////////////

public class ClipControl extends Applet implements Runnable {

	int width  = 260, height = 40;
	String url = "http://www.cs.indiana.edu/hyplan/kinzler/fun/"
		   + "shr_sounds/index.html";

	public String getAppletInfo() {
		return
"ClipControl - an AudioClip control applet with play/loop/stop/load buttons\n"
+ "Steve Kinzler, [e-mail], May 96/Sep 96\n" + url
+ "\nVersion 2.0.2, see source code for license\n"
+ "Copyright (c) 1996 Stephen B Kinzler.  All rights reserved.\n\n"
+ "color  := hexadecimal number prefixed with '#'\n"
+ "action := load = reload the clip\n"
+ "          play = play the clip, loading it first if needed\n"
+ "          loop = loop the clip, loading it first if needed\n"
+ "          quit = quit loading the clip\n"
+ "          stop = stop the clip";
	}

	String pinfo[][] = {
	    {"clip",      "URL",     "audio clip"},
	    {"bgcolor",   "color",   "background color"},
	    {"fgcolor",   "color",   "foreground color"},
	    {"bgstatus",  "string",  "background status string"},
	    {"noplay",    "boolean", "don't show play button [false]"},
	    {"noloop",    "boolean", "don't show loop button [false]"},
	    {"nostop",    "boolean", "don't show stop button [false]"},
	    {"noload",    "boolean", "don't show load button [false]"},
	    {"boxplay",   "boolean", "use a checkbox for play button [false]"},
	    {"boxloop",   "boolean", "use a checkbox for loop button [false]"},
	    {"boxstop",   "boolean", "use a checkbox for stop button [false]"},
	    {"playlabel", "string",  "play button label [Play]"},
	    {"looplabel", "string",  "loop button label [Loop]"},
	    {"stoplabel", "string",  "stop button label [Stop]"},
	    {"loadlabel", "string",  "load button label [Load]"},
	    {"nextlabel", "string",  "next load button label [Reload]"},
	    {"nextload",  "boolean", "keep load button for reloads [false]"},
	    {"oninit",    "actions", "actions on applet initialization []"},
	    {"onstart",   "actions", "actions on applet start []"},
	    {"onstop",    "actions", "actions on applet stop [quitstop]"},
	    {"ondestroy", "actions", "actions on applet destruction [stop]"},
	};

	public String[][] getParameterInfo() {
		return pinfo;
	}

	String	  clipname, status, nextlabel;
	URL	  clipurl;
	boolean	  nextload = false;
	String	  oninit, onstart, onstop, ondestroy;

	AudioClip clip = null;
	Component play = null, loop = null, stop = null, load = null;
	Event	  pend = null;
	Thread	  thrd = null;
	boolean	  looping = false, loading = false;

// ClipControl // Initialization //////////////////////////////////////////////

	public synchronized void init() {
		Dimension d = size();
		if (d.width  > 0) width  = d.width;
		if (d.height > 0) height = d.height;
		resize(width, height);

		String s = getParameter("BGCOLOR");
		if (s != null && s.startsWith("#")) {
			int i = Integer.parseInt(s.substring(1), 16);
			setBackground(new Color(i));
		}
		s = getParameter("FGCOLOR");
		if (s != null && s.startsWith("#")) {
			int i = Integer.parseInt(s.substring(1), 16);
			setForeground(new Color(i));
		}

		s = getParameter("BGSTATUS");
		status = (s != null) ? s : "ClipControl: click, type 'h' " +
					   "for home page or '?' for keys";

		s = clipname = getParameter("CLIP");
		try { clipurl = (s != null) ? new URL(getDocumentBase(), s)
					    : null; }
		catch (MalformedURLException e) { clipurl = null; }
		if (clipurl == null) return;

		s = getParameter("NEXTLABEL");
		nextlabel = (s != null) ? s : "Reload";
		s = getParameter("NEXTLOAD");
		nextload  = (s != null) ? s.equals("true") : false;

		play = makeButton(play, "PLAY", "Play");
		loop = makeButton(loop, "LOOP", "Loop");
		stop = makeButton(stop, "STOP", "Stop");
		load = makeButton(load, "LOAD", "Load");

		oninit	  = getParameter("ONINIT");
		onstart   = getParameter("ONSTART");
		s	  = getParameter("ONSTOP");
		onstop	  = (s != null) ? s : "quitstop";
		s	  = getParameter("ONDESTROY");
		ondestroy = (s != null) ? s : "stop";

		doAction(oninit);
	}

	synchronized Component makeButton(Component button,
					  String param, String label) {
		if (button != null) remove(button);
		String l = getParameter(param + "LABEL");
		if (l == null) l = label;

		if (param.equalsIgnoreCase("LOAD")) {
			button = new Checkbox((clip == null) ? l : nextlabel);
			setButton(button, loading);
			String s = getParameter("NO" + param);
			if ((s == null || ! s.equals("true")) &&
			    (nextload || clip == null)) add(button);
			return(button);
		}

		String s = getParameter("BOX" + param);
		if (s != null && s.equals("true"))
			button = new Checkbox(l);
		else
			button = new Button(l);
		setButton(button, (param.equalsIgnoreCase("LOOP")) ? looping
								   : false);
		s = getParameter("NO" + param);
		if (s == null || ! s.equals("true")) add(button);
		return(button);
	}

	void setButton(Component button, boolean state) {
		if (button instanceof Checkbox)
			((Checkbox) button).setState(state);
	}

	public void start() {
		doAction(onstart);
	}

// ClipControl // Actions /////////////////////////////////////////////////////

	void doAction(String action) {
		if (action == null) return;
		String a = action.toLowerCase();
		if (a.indexOf("load") >= 0) {
			quitLoad();
			pressButton(load);
		}
		if (a.indexOf("play") >= 0) pressButton(play);
		if (a.indexOf("loop") >= 0) {
			if (loop instanceof Checkbox && looping)
				pressButton(loop);
			pressButton(loop);
		}
		if (a.indexOf("quit") >= 0) quitLoad();
		if (a.indexOf("stop") >= 0) pressButton(stop);
	}

	void pressButton(Component button) {
		action(new Event(button, Event.ACTION_EVENT, this), this);
	}

// ClipControl // Events //////////////////////////////////////////////////////

	public boolean mouseEnter(Event evt, int x, int y) {
		requestFocus();
		showStatus(status);
		return true;
	}

	public boolean mouseExit(Event evt, int x, int y) {
		showStatus(null);
		return true;
	}

	public boolean keyDown(Event evt, int key) {
		switch (key) {
		case 'h':
                case 'H':	toHome();	  break;
		case 'p':
                case 'P':	doAction("play"); break;
		case 'l':
                case 'L':	doAction("loop"); break;
		case 's':
                case 'S':	doAction("stop"); break;
		case 'r':
                case 'R':	doAction("load"); break;
		case 'q':
                case 'Q':	doAction("quit"); break;
		case '?':
		default:	showStatus("(h)ome (p)lay (l)oop (s)top " +
					   "(r)eload (q)uit loading");
		}
		return true;
	}

	void toHome() {
		try { getAppletContext().showDocument(new URL(url)); }
		catch (MalformedURLException e) {
			showStatus("Ignoring Malformed Home URL");
		}
	}

	public synchronized boolean action(Event e, Object o) {
		if (e.target == null) return true;

		if (e.target.equals(play)) {
			setButton(play, true);
			if (! getClip(e)) {
				showStatus("Playing " + clipname);
				clip.play();
			}
			setButton(play, false);

		} else if (e.target.equals(loop)) {
			if (loop instanceof Checkbox && looping) {
				showStatus("Stopping " + clipname);
				clip.stop();
				looping = false;
				setButton(loop, false);
				return true;
			}
			setButton(loop, true);
			if (! getClip(e)) {
				looping = true;
				showStatus("Looping " + clipname);
				clip.loop();
			} else
				setButton(loop, false);

		} else if (e.target.equals(stop)) {
			setButton(stop, true);
			if (clip != null) {
				showStatus("Stopping " + clipname);
				clip.stop();
				if (looping) setButton(loop, false);
			}
			pend    = null;
			looping = false;
			setButton(stop, false);

		} else if (e.target.equals(load)) {
			if (loading) { quitLoad(); } else { getClip(null); }
		}

		return true;
	}

// ClipControl // Loading /////////////////////////////////////////////////////

	synchronized boolean getClip(Event e) {
		if (e != null && clip != null) return false;
		if (e == null) quitLoad();
		if (loading) {
			pend = e;
			showStatus("Still loading " + clipname);
			return true;
		}

		loading = true;
		setButton(load, true);
		showStatus("Loading " + clipname);
		if (e != null) pend = e;
		thrd = new Thread(this);
		thrd.start();
		return true;
	}

	public void run() {
		AudioClip c = getAudioClip(clipurl);
		synchronized (this) {
			if (clip != null) doAction("stop");
			clip = c; c = null;
			loading = false;
			showStatus("Loaded " + clipname);
			if (! nextload) remove(load);
			((Checkbox) load).setLabel(nextlabel);
			setButton(load, false);
			if (pend != null) action(pend, this);
			pend = null; thrd = null;
		}
	}

	synchronized void quitLoad() {
		if (thrd != null) {
			thrd.stop();
			showStatus("Quit loading " + clipname);
		}
		loading = false; pend = null; thrd = null;
		setButton(load, false);
	}

// ClipControl // Destruction /////////////////////////////////////////////////

	public void stop() {
		doAction(onstop);
	}

	public void destroy() {
		doAction(ondestroy);
		quitLoad();
	}
}