ドットの上をなぞるとその周辺が強調されるiPhoneアプリのサンプルコードを描いてみます。
#import “ViewController.h”
@interface ViewController ()
@end
@implementation ViewController
– (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor purpleColor];
[self createDot];
}
– (void)createDot
{
for (int i=0; i<30*30; i++) {
float x = (i % 30) * 10 + 10;
float y = (i / 30) * 10 + 30;
UIView *dot = [[UIView alloc] initWithFrame:CGRectMake(x, y, 4, 4)];
dot.tag = 1;
dot.layer.cornerRadius = 2;
dot.backgroundColor = [UIColor whiteColor];
[self.view addSubview:dot];
}
}
– (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint p = [[touches anyObject] locationInView:self.view];
[self transformDots:p];
}
– (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint p = [[touches anyObject] locationInView:self.view];
[self transformDots:p];
}
– (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
for (UIView *v in self.view.subviews) {
if (v.tag == 1) {
v.transform = CGAffineTransformIdentity;
}
}
}
– (void)transformDots:(CGPoint)p
{
for (UIView *v in self.view.subviews) {
if (v.tag == 1) {
float dr = hypotf(p.x – v.center.x, p.y – v.center.y);
float scale = MAX(1, (160.0 – dr) / 80.0);
v.transform = CGAffineTransformMakeScale(scale, scale);
}
}
}
@end