I am creating an audio player application, i need to enable the user to fast forward and backward a song by holding a button(seperately for each). I've done for playing, stopping, skip to next and previous song. But i got stuck with this section. I dont know the method to implement this. pls help.
Iphone – fast forwarding a song using AVAudioPlayer
avaudioplayeriphone
Related Solutions
It's certainly possible to develop on a Windows machine, in fact, my first application was exclusively developed on the old Dell Precision I had at the time :)
There are three routes;
- Install OSx86 (aka iATKOS / Kalyway) on a second partition/disk and dual boot.
- Run Mac OS X Server under VMWare (Mac OS X 10.7 (Lion) onwards, read the update below).
- Use Delphi XE4 and the macincloud service. This is a commercial toolset, but the component and lib support is growing.
The first route requires modifying (or using a pre-modified) image of Leopard that can be installed on a regular PC. This is not as hard as you would think, although your success/effort ratio will depend upon how closely the hardware in your PC matches that in Mac hardware - e.g. if you're running a Core 2 Duo on an Intel Motherboard, with an NVidia graphics card you are laughing. If you're running an AMD machine or something without SSE3 it gets a little more involved.
If you purchase (or already own) a version of Leopard then this is a gray area since the Leopard EULA states you may only run it on an "Apple Labeled" machine. As many point out if you stick an Apple sticker on your PC you're probably covered.
The second option is more costly. The EULA for the workstation version of Leopard prevents it from being run under emulation and as a result, there's no support in VMWare for this. Leopard server, however, CAN be run under emulation and can be used for desktop purposes. Leopard server and VMWare are expensive, however.
If you're interested in option 1) I would suggest starting at Insanelymac and reading the OSx86 sections.
I do think you should consider whether the time you will invest is going to be worth the money you will save though. It was for me because I enjoy tinkering with this type of stuff and I started during the early iPhone betas, months before their App Store became available.
Alternatively, you could pick up a low-spec Mac Mini from eBay. You don't need much horsepower to run the SDK and you can always sell it on later if you decide to stop development or buy a better Mac.
Update: You cannot create a Mac OS X Client virtual machine for OS X 10.6 and earlier. Apple does not allow these Client OSes to be virtualized. With Mac OS X 10.7 (Lion) onwards, Apple has changed its licensing agreement in regards to virtualization. Source: VMWare KnowledgeBase
Personally I'd just track the button's state with an integer on your view controller or within a button subclass. If you track what the button is doing you can control what each of the actions do. In your .h file put in some stuff like this:
enum {
MyButtonScanning,
MyButtonStalling,
MyButtonIdle
};
@interface YourClass : UIViewController {
NSInteger buttonModeAt;
}
@property (nonatomic) NSInteger buttonModeAt;
-(IBAction)buttonPushedDown:(id)sender;
-(void)tryScanForward:(id)sender;
-(IBAction)buttonReleasedOutside:(id)sender;
-(IBAction)buttonReleasedInside:(id)sender;
@end
And then in your .m file throw in some of this stuff:
@implementation YourClass
///in your .m file
@synthesize buttonModeAt;
///link this to your button's touch down
-(IBAction)buttonPushedDown:(id)sender {
buttonModeAt = MyButtonStalling;
[self performSelector:@selector(tryScanForward:) withObject:nil afterDelay:1.0];
}
-(void)tryScanForward:(id)sender {
if (buttonModeAt == MyButtonStalling) {
///the button was not released so let's start scanning
buttonModeAt = MyButtonScanning;
////your actual scanning code or a call to it can go here
[self startScanForward];
}
}
////you will link this to the button's touch up outside
-(IBAction)buttonReleasedOutside:(id)sender {
if (buttonModeAt == MyButtonScanning) {
///they released the button and stopped scanning forward
[self stopScanForward];
} else if (buttonModeAt == MyButtonStalling) {
///they released the button before the delay period finished
///but it was outside, so we do nothing
}
self.buttonModeAt = MyButtonIdle;
}
////you will link this to the button's touch up inside
-(IBAction)buttonReleasedInside:(id)sender {
if (buttonModeAt == MyButtonScanning) {
///they released the button and stopped scanning forward
[self stopScanForward];
} else if (buttonModeAt == MyButtonStalling) {
///they released the button before the delay period finished so we skip forward
[self skipForward];
}
self.buttonModeAt = MyButtonIdle;
}
After that just link the button's actions to what I've noted in the comments before the IBactions. I haven't tested this but it should work.
Best Answer
Use the
currentTime
andduration
properties.i.e. to skip forward
Similar for going backwards, only compare
currentTime
against0
, instead ofduration