UIPinchGestureRecognizerとUIPanGestureRecognizerを組み合わせた単一の組み合わせジェスチャレコグナイザーを作成できるかどうかを理解しようと少し苦労しています。
ビューの変換にはパンを使用し、ビューのスケーリングにはピンチを使用しています。ビューに適用される結果の最終変換行列を導出するために、増分行列連結を実行しています。このマトリックスには、スケールと変換の両方があります。個別のジェスチャレコグナイザーを使用すると、動きやスケーリングが不安定になります。私が欲しいものではありません。したがって、1つのジェスチャ内でスケールと変換の連結を1回処理したいと思います。誰かがこれを行う方法に光を当てることができますか？
2014 年 6 月 14 日: ARC を使用する iOS 7 以降のサンプル コードを更新しました。
UIGestureRecognizers は連携して動作し、現在のビューの変換マトリックスを破棄しないようにする必要があります。変換を最初から作成するのではなく、変換を入力として受け取る CGAffineTransformScale メソッドおよび関連メソッドを使用します (現在の回転、スケール、または移動を自分で維持する場合を除く)。
注: iOS 7 は、パン/ピンチ/回転ジェスチャが適用された IB の UIView で奇妙な動作をします。iOS 8 では修正されていますが、私の回避策は、このコード例のようにすべてのビューをコードに追加することです。
それらをビューに追加し、UIGestureRecognizerDelegate プロトコルに準拠します
@interface ViewController () <UIGestureRecognizerDelegate>
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
UIView *blueView = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 150, 150)];
blueView.backgroundColor = [UIColor blueColor];
[self.view addSubview:blueView];
[self addMovementGesturesToView:blueView];
// UIImageView's and UILabel's don't have userInteractionEnabled by default!
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"BombDodge.png"]]; // Any image in Xcode project
imageView.center = CGPointMake(100, 250);
[imageView sizeToFit];
[self.view addSubview:imageView];
[self addMovementGesturesToView:imageView];
// Note: Changing the font size would be crisper than zooming a font!
UILabel *label = [[UILabel alloc] init];
label.text = @"Hello Gestures!";
label.font = [UIFont systemFontOfSize:30];
label.textColor = [UIColor blackColor];
[label sizeToFit];
label.center = CGPointMake(100, 400);
[self.view addSubview:label];
[self addMovementGesturesToView:label];
}
- (void)addMovementGesturesToView:(UIView *)view {
view.userInteractionEnabled = YES; // Enable user interaction
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanGesture:)];
panGesture.delegate = self;
[view addGestureRecognizer:panGesture];
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinchGesture:)];
pinchGesture.delegate = self;
[view addGestureRecognizer:pinchGesture];
}
ジェスチャーメソッドを実装する
- (void)handlePanGesture:(UIPanGestureRecognizer *)panGesture {
CGPoint translation = [panGesture translationInView:panGesture.view.superview];
if (UIGestureRecognizerStateBegan == panGesture.state ||UIGestureRecognizerStateChanged == panGesture.state) {
panGesture.view.center = CGPointMake(panGesture.view.center.x + translation.x,
panGesture.view.center.y + translation.y);
// Reset translation, so we can get translation delta's (i.e. change in translation)
[panGesture setTranslation:CGPointZero inView:self.view];
}
// Don't need any logic for ended/failed/canceled states
}
- (void)handlePinchGesture:(UIPinchGestureRecognizer *)pinchGesture {
if (UIGestureRecognizerStateBegan == pinchGesture.state ||
UIGestureRecognizerStateChanged == pinchGesture.state) {
// Use the x or y scale, they should be the same for typical zooming (non-skewing)
float currentScale = [[pinchGesture.view.layer valueForKeyPath:@"transform.scale.x"] floatValue];
// Variables to adjust the max/min values of zoom
float minScale = 1.0;
float maxScale = 2.0;
float zoomSpeed = .5;
float deltaScale = pinchGesture.scale;
// You need to translate the zoom to 0 (origin) so that you
// can multiply a speed factor and then translate back to "zoomSpace" around 1
deltaScale = ((deltaScale - 1) * zoomSpeed) + 1;
// Limit to min/max size (i.e maxScale = 2, current scale = 2, 2/2 = 1.0)
// A deltaScale is ~0.99 for decreasing or ~1.01 for increasing
// A deltaScale of 1.0 will maintain the zoom size
deltaScale = MIN(deltaScale, maxScale / currentScale);
deltaScale = MAX(deltaScale, minScale / currentScale);
CGAffineTransform zoomTransform = CGAffineTransformScale(pinchGesture.view.transform, deltaScale, deltaScale);
pinchGesture.view.transform = zoomTransform;
// Reset to 1 for scale delta's
// Note: not 0, or we won't see a size: 0 * width = 0
pinchGesture.scale = 1;
}
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
return YES; // Works for most use cases of pinch + zoom + pan
}
Metal を使用してレンダリングを行う Swift 実装に興味がある人は、ここでプロジェクトを利用できます。
ポールに感謝します!!! これが彼の Swift バージョンです。
import UIKit
class ViewController: UIViewController, UIGestureRecognizerDelegate {
var editorView: EditorView!
override func viewDidLoad() {
super.viewDidLoad()
let blueView = UIView(frame: .init(x: 100, y: 100, width: 300, height: 300))
view.addSubview(blueView)
blueView.backgroundColor = .blue
addMovementGesturesToView(blueView)
}
func addMovementGesturesToView(_ view: UIView) {
view.isUserInteractionEnabled = true
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(handlePanGesture(_:)))
panGesture.delegate = self
view.addGestureRecognizer(panGesture)
let pinchGesture = UIPinchGestureRecognizer(target: self, action: #selector(handlePinchGesture(_:)))
pinchGesture.delegate = self
view.addGestureRecognizer(pinchGesture)
}
@objc private func handlePanGesture(_ panGesture: UIPanGestureRecognizer) {
guard let panView = panGesture.view else { return }
let translation = panGesture.translation(in: panView.superview)
if panGesture.state == .began || panGesture.state == .changed {
panGesture.view?.center = CGPoint(x: panView.center.x + translation.x, y: panView.center.y + translation.y)
// Reset translation, so we can get translation delta's (i.e. change in translation)
panGesture.setTranslation(.zero, in: self.view)
}
// Don't need any logic for ended/failed/canceled states
}
@objc private func handlePinchGesture(_ pinchGesture: UIPinchGestureRecognizer) {
guard let pinchView = pinchGesture.view else { return }
if pinchGesture.state == .began || pinchGesture.state == .changed {
let currentScale = scale(for: pinchView.transform)
// Variables to adjust the max/min values of zoom
let minScale: CGFloat = 0.2
let maxScale: CGFloat = 3
let zoomSpeed: CGFloat = 0.8
var deltaScale = pinchGesture.scale
// You need to translate the zoom to 0 (origin) so that you
// can multiply a speed factor and then translate back to "zoomSpace" around 1
deltaScale = ((deltaScale - 1) * zoomSpeed) + 1
// Limit to min/max size (i.e maxScale = 2, current scale = 2, 2/2 = 1.0)
// A deltaScale is ~0.99 for decreasing or ~1.01 for increasing
// A deltaScale of 1.0 will maintain the zoom size
deltaScale = min(deltaScale, maxScale / currentScale)
deltaScale = max(deltaScale, minScale / currentScale)
let zoomTransform = pinchView.transform.scaledBy(x: deltaScale, y: deltaScale)
pinchView.transform = zoomTransform
// Reset to 1 for scale delta's
// Note: not 0, or we won't see a size: 0 * width = 0
pinchGesture.scale = 1
}
}
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}
private func scale(for transform: CGAffineTransform) -> CGFloat {
return sqrt(CGFloat(transform.a * transform.a + transform.c * transform.c))
}
}
