appcontroller.m

基于Quicktime的mp3播放器源代码,可以播放MP3 ,wav等格式

// AppController.m -- application controller, handler of all the buttons.

// Copyright (C) 2003 Borkware
// We use the BSD License.  Check out http://borkware.com/license

#import "AppController.h"
#import <Quicktime/Quicktime.h>

@implementation AppController


// initialize our controller object

- (id) init
{
    if (self = [super init]) {

	// apple docs say to call EnterMovies before using the C API
	// from Cocoa-land, so here it is
	OSErr result;
	result = EnterMovies ();
	if (result != noErr) {
	    NSLog (@"could not enterMovies: error code %d", result);
	}
    }

    return (self);

} // init



// clean up our mess

- (void) dealloc
{
    [qtmovie release];
    [super dealloc];
} // dealloc



// button action handler.  Slurp in the mp3 file as a quicktime movie

- (IBAction) loadMp3File: (id) sender
{
    // use an open panel file chooser modal sheeting thingie

    NSOpenPanel *fileChooser;
    fileChooser = [NSOpenPanel openPanel];

    // just load one file at a time.  and no directories!

    [fileChooser setAllowsMultipleSelection: NO];
    [fileChooser setCanChooseDirectories: NO];

    // kick off the sheet

    [fileChooser beginSheetForDirectory: @""
		 file: @""
		 types: [NSArray arrayWithObject: @"mp3"] // only mp3 files
		 modalForWindow: window
		 modalDelegate: self
		 didEndSelector: @selector(openPanelDidEnd:returnCode:context:)
		 contextInfo: nil];

} // loadMP3FIle



// sheet delegate handler.  This gets invoked by the file chooser open file
// thingie when the user selects an item, or cancels it

- (void) openPanelDidEnd: (NSOpenPanel *) chooser
	      returnCode: (int) returnCode
		 context: (id) context
{
    // only look at stuff on an OK click

    if (returnCode == NSOKButton) {

	// get the item selected
	NSString *filename;
	filename = [[chooser filenames] objectAtIndex: 0];

	// get rid of any currently loaded sound
	[qtmovie release];

	// get the new movie
	qtmovie = [[NSMovie alloc]
		      initWithURL: [NSURL fileURLWithPath: filename]
		      byReference: NO];
	// (the by reference is really only used when using
	// encodeWithCoder: on the sound)

	if (qtmovie != nil) {
	    [titleField setStringValue: [filename lastPathComponent]];
	} else {
	    [titleField setStringValue: @""];
	}

	// enable/disable the button based on success of loading
	[playButton setEnabled: (qtmovie != nil)];
    }

} // openPanelDidEnd



// button action handler.  Start the movie playing

- (IBAction) play: (id) sender
{
    // this is kind of gross.
    // It looks like The Way to play movies is a loop like
    // while (!IsMovieDone(movie)) moviesTask (movie, 0);
    // so schedule a timer so we can poll when the movie (our mp3)
    // has stopped playing
    
    pollTimer = [NSTimer scheduledTimerWithTimeInterval: 0.25 // 4x second
			 target: self
			 selector: @selector(pollMovie:)
			 userInfo: nil
			 repeats: YES];

    // update the UI accordingly

    [stopButton setEnabled: YES];
    [playButton setEnabled: NO];

    // set our progress indicator to show how far we've gone through the
    // movie

    [progressIndicator setMinValue: 0.0];
    [progressIndicator setMaxValue: GetMovieDuration([qtmovie QTMovie])];

    // start the movie from the very beginning

    GoToBeginningOfMovie ([qtmovie QTMovie]);
    StartMovie ([qtmovie QTMovie]);

} // play



// timer handler.  We poll to see when the movie has stopped
// also update the progress indicator with how far we've gotten

- (void) pollMovie: (NSTimer *) timer
{
    if (IsMovieDone([qtmovie QTMovie])) {
	[stopButton setEnabled: NO];
	[playButton setEnabled: YES];
	[timer invalidate];
	timer = nil;
    }

    [progressIndicator 
	setDoubleValue: GetMovieTime ([qtmovie QTMovie], NULL)];

} // pollMovie



// button action handler.  stop the sound

- (IBAction) stop: (id) sender
{
    StopMovie ([qtmovie QTMovie]);
    [playButton setEnabled: YES];

} // stop


@end // AppController