Feature Missing: iOS app is missing “Scroll Bar” to scroll through ol…

…der ‘Photos’ #519

Libraries external/TOScrollBar/TOScrollBar.h

@@ -0,0 +1,123 @@
+//
+//  TOScrollBar.h
+//
+//  Copyright 2016-2017 Timothy Oliver. All rights reserved.
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to
+//  deal in the Software without restriction, including without limitation the
+//  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+//  sell copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+//  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+//  IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#import <UIKit/UIKit.h>
+#import "UIScrollView+TOScrollBar.h"
+
+typedef NS_ENUM(NSInteger, TOScrollBarStyle) {
+    TOScrollBarStyleDefault,
+    TOScrollBarStyleDark
+};
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface TOScrollBar : UIView
+
+/* The visual style of the scroll bar, either light or dark */
+@property (nonatomic, assign) TOScrollBarStyle style;
+
+/** Aligns the scroll bar to the top of the scroll view content offset.
+     Set this to `YES` when using this in a view controller with iOS 11 large titles. */
+@property (nonatomic, assign) BOOL insetForLargeTitles;
+
+/** The amount of padding above and below the scroll bar (Only top and bottom values are counted. Default is {20,20} ) */
+@property (nonatomic, assign) UIEdgeInsets verticalInset;
+
+/** The inset, in points of the middle of track from the edge of the scroll view */
+@property (nonatomic, assign) CGFloat edgeInset;
+
+/** The tint color of the track */
+@property (nonatomic, strong) UIColor *trackTintColor;
+
+/** The width in points, of the track (Default value is 2.0) */
+@property (nonatomic, assign) CGFloat trackWidth;
+
+/** The tint color of the handle (Defaults to the system tint color) */
+@property (nonatomic, strong, nullable) UIColor *handleTintColor;
+
+/** The width in points, of the handle. (Default value is 4.0) */
+@property (nonatomic, assign) CGFloat handleWidth;
+
+/** The minimum height in points the handle may be in relation to the content height. (Default value is 64.0) */
+@property (nonatomic, assign) CGFloat handleMinimiumHeight;
+
+/** The user is currently dragging the handle */
+@property (nonatomic, assign, readonly) BOOL dragging;
+
+/** The minimum required scale of the scroll view's content height before the scroll bar is shown (Default is 5.0) */
+@property (nonatomic, assign) CGFloat minimumContentHeightScale;
+
+/** The scroll view in which this scroll bar has been added. */
+@property (nonatomic, weak, readonly) UIScrollView *scrollView;
+
+/** When enabled, the scroll bar will only respond to direct touches to the handle control.
+ Touches to the track will be passed to the UI controls beneath it.
+ Default is NO. */
+@property (nonatomic, assign) BOOL handleExclusiveInteractionEnabled;
+
+/** 
+ Creates a new instance of the scroll bar view 
+ 
+ @param style The initial style of the scroll bar upon creation
+ */
+- (instancetype)initWithStyle:(TOScrollBarStyle)style;
+
+/**
+ Adds the scroll bar to a scroll view
+ 
+ @param scrollView The scroll view that will receive this scroll bar
+ */
+- (void)addToScrollView:(UIScrollView *)scrollView;
+
+/**
+ Removes the scroll bar from the scroll view and resets the scroll view's state
+ */
+- (void)removeFromScrollView;
+
+/**
+ If added to a table view, this convienience method will compute the appropriate
+ inset values for the table separator so they don't underlap the scroll bar
+ 
+ @param inset The original separator inset value of the table view
+ */
+- (UIEdgeInsets)adjustedTableViewSeparatorInsetForInset:(UIEdgeInsets)inset;
+
+/**
+ If added to a table view, this convienience method will compute the appropriate
+ insets values for each cell's layout margins in order to appropriately push the cell's
+ content inwards
+ 
+ @param layoutMargins The current `layoutMargins` value of the `UITableViewCell` instance.
+ @param offset If desired, any additional horizontal offset for this specific use case
+ 
+ */
+- (UIEdgeInsets)adjustedTableViewCellLayoutMarginsForMargins:(UIEdgeInsets)layoutMargins manualOffset:(CGFloat)offset;
+
+/**
+ Shows or hides the scroll bar from the scroll view with an optional animation
+ */
+- (void)setHidden:(BOOL)hidden animated:(BOOL)animated;
+
+@end
+
+NS_ASSUME_NONNULL_END
+