Keyframe Animation - Core Animation - page 53

LISTING 4-4 Set Up the Animation and Create Timers to Monitor Animation Progress

- ( IBAction )startAnimation:( id )sender;
{

if ( starPath )
{

// Reset our starPath CGMutablePathRef if
// it has already run before
CFRelease (starPath);
[ self createPath];
[[[window contentView ] layer ] setNeedsDisplay ];

}

// Define a path for the star shape.
CGMutablePathRef path = CGPathCreateMutable ();

CGPathMoveToPoint (path, NULL ,240.0, 280.0);

CGPathAddLineToPoint (path, NULL , 181.0, 99.0);
CGPathAddLineToPoint (path, NULL , 335.0, 210.0);
CGPathAddLineToPoint (path, NULL , 144.0, 210.0);
CGPathAddLineToPoint (path, NULL , 298.0, 99.0);
CGPathCloseSubpath (path);

CAKeyframeAnimation *animation =
[ CAKeyframeAnimation
animationWithKeyPath : @”position” ];
[animation setDuration :10.0f];
[animation setDelegate : self ];

// Set the animation's path
[animation setPath :path];
// Release the path
CFRelease (path);

[dotLayer addAnimation :animation forKey : @”position” ];

[ NSTimer scheduledTimerWithTimeInterval :2.0
target : self
selector : @selector (legOne:)
userInfo : nil
repeats : NO ];

[ NSTimer scheduledTimerWithTimeInterval :4.0