fix bug for zoom position

loopeer · Sep 15, 2017 · cc47d34 · cc47d34
1 parent 245e4f6
commit cc47d34
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Showing 2 changed files with 38 additions and 9 deletions.
diff --git a/LPAlbum/Others/AlbumManager.swift b/LPAlbum/Others/AlbumManager.swift
@@ -25,6 +25,7 @@ public class AlbumManager {
     }
 
     // 根据Asset获取photo
+    @discardableResult
     public class func getPhoto(asset: PHAsset, targetSize: CGSize, option: PHImageRequestOptions? = nil, resultHandler: @escaping ((UIImage?, [AnyHashable: Any]?) -> Void)) -> PHImageRequestID {
 
         let defalutOption = PHImageRequestOptions()

diff --git a/LPAlbum/Views/PhotoPreviewCell.swift b/LPAlbum/Views/PhotoPreviewCell.swift
@@ -12,9 +12,11 @@ class PhotoPreviewCell: UICollectionViewCell {
 
     var assetModel: AssetModel! {
         didSet{
-
             AlbumManager.getPhoto(asset: assetModel.asset, targetSize: bounds.size) { (image, _) in
                 self.photoView.image = image
+                let size = self.scrollView.frame.size
+                let newSize = (image?.size ?? size).constrainedSize(toSize: size)
+                self.photoView.bounds = CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height)
             }
         }
     }
@@ -33,14 +35,40 @@ class PhotoPreviewCell: UICollectionViewCell {
         scrollView.delaysContentTouches = true
         scrollView.canCancelContentTouches = true
         scrollView.delegate = self
+        scrollView.showsVerticalScrollIndicator = false
+        scrollView.showsHorizontalScrollIndicator = false
 
         photoView.contentMode = .scaleAspectFit
         photoView.frame = scrollView.bounds
         scrollView.addSubview(photoView)
         contentView.addSubview(scrollView)
 
+        let singleTap = UITapGestureRecognizer(target: self, action: #selector(singleTapAction))
+        let doubleTap = UITapGestureRecognizer(target: self, action: #selector(doubleTapAction))
+        doubleTap.numberOfTapsRequired = 2
+        singleTap.require(toFail: doubleTap)
+        contentView.addGestureRecognizer(singleTap)
+        contentView.addGestureRecognizer(doubleTap)
+
     }
 
+    func singleTapAction() {
+
+    }
+
+    func doubleTapAction(ges: UITapGestureRecognizer) {
+        if scrollView.zoomScale > 1.0 {
+            scrollView.contentInset = .zero
+            scrollView.setZoomScale(1.0, animated: true)
+        }else{
+            let point = ges.location(in: photoView)
+            let zoonScale = scrollView.maximumZoomScale
+            let xSize = bounds.size.width / zoonScale
+            let ySize = bounds.size.height / zoonScale
+            scrollView.zoom(to: CGRect(x: point.x - xSize/2, y: point.y - ySize/2, width: xSize, height: ySize), animated: true)
+        }
+    }
+
     required init?(coder aDecoder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
@@ -56,14 +84,14 @@ extension PhotoPreviewCell: UIScrollViewDelegate {
     }
 
     func scrollViewDidZoom(_ scrollView: UIScrollView) {
-//        let scrollViewW = scrollView.frame.width
-//        let scrollViewH = scrollView.frame.height
-//        let contentSizeW = scrollView.contentSize.width
-//        let contentSizeH = scrollView.contentSize.height
-//        
-//        let offsetX = scrollViewW > contentSizeW ? scrollViewW - contentSizeW * 0.5 : 0
-//        let offsetY = scrollViewH > contentSizeH ? scrollViewH - contentSizeH * 0.5 : 0
-//        photoView.center = CGPoint(x: contentSizeW * 0.5 + offsetX, y: contentSizeH * 0.5 + offsetY)
+        let scrollViewW = scrollView.frame.width
+        let scrollViewH = scrollView.frame.height
+        let contentSizeW = scrollView.contentSize.width
+        let contentSizeH = scrollView.contentSize.height
+        // 缩小
+        let offsetX = scrollViewW > contentSizeW ? (scrollViewW - contentSizeW) * 0.5 : 0
+        let offsetY = scrollViewH > contentSizeH ? (scrollViewH - contentSizeH) * 0.5 : 0
+        photoView.center = CGPoint(x: contentSizeW * 0.5 + offsetX, y: contentSizeH * 0.5 + offsetY)
     }
 
 }