From 631dbafa6a98ab0bfec3ccceddf16852259bfc98 Mon Sep 17 00:00:00 2001
From: questbeat <questbeat@gmail.com>
Date: Mon, 6 Apr 2015 17:05:45 +0900
Subject: [PATCH] Add auto-deselect

---
 QBImagePicker/Info.plist               |  2 +-
 QBImagePicker/QBAssetsViewController.m | 60 ++++++++++++++++++++++----
 QBImagePickerController.podspec        |  2 +-
 README.md                              |  4 +-
 4 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/QBImagePicker/Info.plist b/QBImagePicker/Info.plist
index fcc63473..3d73e614 100644
--- a/QBImagePicker/Info.plist
+++ b/QBImagePicker/Info.plist
@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>3.0.2</string>
+	<string>3.1.0</string>
 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>
diff --git a/QBImagePicker/QBAssetsViewController.m b/QBImagePicker/QBAssetsViewController.m
index b26ecf75..6923071b 100644
--- a/QBImagePicker/QBAssetsViewController.m
+++ b/QBImagePicker/QBAssetsViewController.m
@@ -59,11 +59,13 @@ @interface QBAssetsViewController () <PHPhotoLibraryChangeObserver, UICollection
 
 @property (nonatomic, strong) IBOutlet UIBarButtonItem *doneButton;
 
+@property (nonatomic, strong) PHFetchResult *fetchResult;
+
 @property (nonatomic, strong) PHCachingImageManager *imageManager;
 @property (nonatomic, assign) CGRect previousPreheatRect;
 
-@property (nonatomic, strong) PHFetchResult *fetchResult;
 @property (nonatomic, assign) BOOL disableScrollToBottom;
+@property (nonatomic, strong) NSIndexPath *lastSelectedItemIndexPath;
 
 @end
 
@@ -73,8 +75,6 @@ - (void)viewDidLoad
 {
     [super viewDidLoad];
     
-    self.imageManager = [PHCachingImageManager new];
-    
     [self setUpToolbarItems];
     [self resetCachedAssets];
     
@@ -100,7 +100,7 @@ - (void)viewWillAppear:(BOOL)animated
         [self.navigationItem setRightBarButtonItem:nil animated:NO];
     }
     
-    [self updateControlState];
+    [self updateDoneButtonState];
     [self updateSelectionInfo];
     
     // Scroll to bottom
@@ -157,6 +157,21 @@ - (void)setAssetCollection:(PHAssetCollection *)assetCollection
     [self.collectionView reloadData];
 }
 
+- (PHCachingImageManager *)imageManager
+{
+    if (_imageManager == nil) {
+        _imageManager = [PHCachingImageManager new];
+    }
+    
+    return _imageManager;
+}
+
+- (BOOL)isAutoDeselectEnabled
+{
+    return (self.imagePickerController.maximumNumberOfSelection == 1
+            && self.imagePickerController.maximumNumberOfSelection >= self.imagePickerController.minimumNumberOfSelection);
+}
+
 
 #pragma mark - Actions
 
@@ -230,6 +245,13 @@ - (void)updateFetchRequest
         }
         
         self.fetchResult = [PHAsset fetchAssetsInAssetCollection:self.assetCollection options:options];
+        
+        if ([self isAutoDeselectEnabled] && self.imagePickerController.selectedAssets.count > 0) {
+            // Get index of previous selected asset
+            PHAsset *asset = [self.imagePickerController.selectedAssets firstObject];
+            NSInteger assetIndex = [self.fetchResult indexOfObject:asset];
+            self.lastSelectedItemIndexPath = [NSIndexPath indexPathForItem:assetIndex inSection:0];
+        }
     } else {
         self.fetchResult = nil;
     }
@@ -254,7 +276,7 @@ - (BOOL)isMaximumSelectionLimitReached
     return NO;
 }
 
-- (void)updateControlState
+- (void)updateDoneButtonState
 {
     self.doneButton.enabled = [self isMinimumSelectionLimitFulfilled];
 }
@@ -525,20 +547,37 @@ - (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtInde
         return [self.imagePickerController.delegate qb_imagePickerController:self.imagePickerController shouldSelectAsset:asset];
     }
     
+    if ([self isAutoDeselectEnabled]) {
+        return YES;
+    }
+    
     return ![self isMaximumSelectionLimitReached];
 }
 
 - (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
 {
     QBImagePickerController *imagePickerController = self.imagePickerController;
+    NSMutableOrderedSet *selectedAssets = imagePickerController.selectedAssets;
+    
     PHAsset *asset = self.fetchResult[indexPath.item];
     
     if (imagePickerController.allowsMultipleSelection) {
+        if ([self isAutoDeselectEnabled] && selectedAssets.count > 0) {
+            // Remove previous selected asset from set
+            [selectedAssets removeObjectAtIndex:0];
+            
+            // Deselect previous selected asset
+            if (self.lastSelectedItemIndexPath) {
+                [collectionView deselectItemAtIndexPath:self.lastSelectedItemIndexPath animated:NO];
+            }
+        }
+        
         // Add asset to set
-        NSMutableOrderedSet *selectedAssets = imagePickerController.selectedAssets;
         [selectedAssets addObject:asset];
         
-        [self updateControlState];
+        self.lastSelectedItemIndexPath = indexPath;
+        
+        [self updateDoneButtonState];
         
         if (imagePickerController.showsNumberOfSelectedAssets) {
             [self updateSelectionInfo];
@@ -568,11 +607,14 @@ - (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndex
     QBImagePickerController *imagePickerController = self.imagePickerController;
     NSMutableOrderedSet *selectedAssets = imagePickerController.selectedAssets;
     
-    // Remove asset from set
     PHAsset *asset = self.fetchResult[indexPath.item];
+    
+    // Remove asset from set
     [selectedAssets removeObject:asset];
     
-    [self updateControlState];
+    self.lastSelectedItemIndexPath = nil;
+    
+    [self updateDoneButtonState];
     
     if (imagePickerController.showsNumberOfSelectedAssets) {
         [self updateSelectionInfo];
diff --git a/QBImagePickerController.podspec b/QBImagePickerController.podspec
index c7444c4e..c2012504 100644
--- a/QBImagePickerController.podspec
+++ b/QBImagePickerController.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = "QBImagePickerController"
-  s.version          = "3.0.2"
+  s.version          = "3.1.0"
   s.summary          = "A clone of UIImagePickerController with multiple selection support."
   s.homepage         = "https://github.com/questbeat/QBImagePicker"
   s.license          = "MIT"
diff --git a/README.md b/README.md
index ff653f0c..d433de57 100755
--- a/README.md
+++ b/README.md
@@ -34,7 +34,9 @@ A clone of UIImagePickerController with multiple selection support.
 
 ## Requirements
 
-- iOS 8.0 or later
+- Version `>= 3.0.0` : iOS 8 or later (Using PhotoKit)
+- Version `< 3.0.0` : iOS 6 or later (Using AssetsLibrary)
+