Custom PSTableCell for displaying numerical values in a formatted manor, also implements a custom ToolBar for the inputAccessoryView

CSPValueCell.h

/**
 * @Author: Dana Buehre <creaturesurvive>
 * @Date:   11-09-2017 1:22:14
 * @Email:  [email protected]
 * @Filename: CSPValueCell.h
 * @Last modified by:   creaturesurvive
 * @Last modified time: 16-09-2017 10:45:22
 * @Copyright: Copyright © 2014-2017 CreatureSurvive
 */

#import <Preferences/PSEditableTableCell.h>
#import <Preferences/PSSpecifier.h>

@interface CSPValueCell : PSEditableTableCell
- (NSString *)formattedValueForValue:(id)value;
@end

CSPValueCell.m

/**
 * @Author: Dana Buehre <creaturesurvive>
 * @Date:   10-09-2017 9:08:26
 * @Email:  [email protected]
 * @Filename: CSPValueCell.m
 * @Last modified by:   creaturesurvive
 * @Last modified time: 16-09-2017 10:57:34
 * @Copyright: Copyright © 2014-2017 CreatureSurvive
 */

#include "CSPValueCell.h"

@implementation CSPValueCell {
    NSNumberFormatter *_numberFormatter;
    NSMutableDictionary *_accessoryTitlesAndKeys;
    UIScrollView *_scrollView;
    UIToolbar *_toolbar;
    BOOL _formatsDecimals;
    BOOL _localeDecimalInvalid;
}

#pragma mark - PSTableCell

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)identifier specifier:(PSSpecifier *)specifier {
    if ((self = [super initWithStyle:style reuseIdentifier:identifier specifier:specifier])) {
        _numberFormatter = [NSNumberFormatter new];
        [_numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
        [_numberFormatter setMaximumFractionDigits:4];
        [_numberFormatter setDecimalSeparator:@"."];

        _scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, self.bounds.size.width, 40)];
        _scrollView.backgroundColor = [UIColor colorWithRed:209.f/255.f green:213.f/255.f blue:219.f/255.f alpha:1.0];
        _scrollView.showsVerticalScrollIndicator = NO;
        _scrollView.showsHorizontalScrollIndicator = NO;
        _scrollView.hidden = YES;

        _toolbar = [[UIToolbar alloc] initWithFrame:_scrollView.bounds];
        [[(UIView *) _toolbar valueForKey:@"_backgroundView"] setHidden:YES];
        _toolbar.tintColor = self.textLabel.textColor;
        _toolbar.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
        _toolbar.hidden = YES;

        [_scrollView addSubview:_toolbar];
        [self textField].inputAccessoryView = _scrollView;
        _localeDecimalInvalid = ![[[NSLocale currentLocale] objectForKey:NSLocaleDecimalSeparator] isEqualToString:@"."];

        [self refreshCellWithContentsOfSpecifier:specifier];
    }
    return self;
}

- (void)refreshCellWithContentsOfSpecifier:(PSSpecifier *)specifier {

    _accessoryTitlesAndKeys = [NSMutableDictionary new];
    NSMutableArray *accessoryButtons = [NSMutableArray new];

    // check for accessoryButtons in the specifier
    NSArray *specifierButtons = [NSArray new];
    if ((specifierButtons = [specifier propertyForKey:@"accessoryButtons"])) {
        for (NSDictionary *item in specifierButtons) {
            if ([item[@"separator"] boolValue]) {
                [accessoryButtons insertObject:[self accessoryButtonSpace] atIndex:[item[@"index"] integerValue]];
            } else {
                [accessoryButtons insertObject:[self accessoryButtonWithTitle:item[@"title"] action:@selector(replaceOrInsertText:)] atIndex:[item[@"index"] integerValue]];
                [_accessoryTitlesAndKeys setObject:item[@"value"] forKey:item[@"title"]];
            }
        }
    }

    // check the keyboard type
    _formatsDecimals = [[specifier propertyForKey:@"formatsDecimals"] boolValue];
    if ([[specifier propertyForKey:@"isDecimalWithNegative"] boolValue]) {
        [self.textField setKeyboardType:UIKeyboardTypeDecimalPad];
        [accessoryButtons addObject:[self accessoryButtonWithTitle:@"+/-" action:@selector(toggleNegetiveValue)]];
    }

    if (_localeDecimalInvalid) {
        [_accessoryTitlesAndKeys setObject:@"." forKey:@"."];
        [accessoryButtons addObject:[self accessoryButtonWithTitle:@"." action:@selector(replaceOrInsertText:)]];
    }

    // setup toolbar if necessary
    if ((accessoryButtons.count)) {
        _scrollView.hidden = _toolbar.hidden = NO;
        _toolbar.items = [accessoryButtons copy];

        CGRect lastButtonRect = _toolbar.subviews.lastObject.frame;
        CGFloat width = lastButtonRect.origin.x + lastButtonRect.size.width + 40;

        _toolbar.frame = CGRectMake(0, 0, width, 40);
        _scrollView.contentSize = _toolbar.frame.size;
    }
}

- (void)setValue:(id)value {
    value = _formatsDecimals ? [self formattedValueForValue:value] : value;
    [super setValue:value];
}

#pragma mark - Buttons

- (UIBarButtonItem *)accessoryButtonWithTitle:(NSString *)title action:(SEL)action {
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.contentEdgeInsets = UIEdgeInsetsMake(5.0f, 10.0f, 5.0f, 10.0f);
    button.showsTouchWhenHighlighted = YES;
    button.layer.backgroundColor = [UIColor whiteColor].CGColor;
    button.layer.cornerRadius = 5.0;

    [button setTitle:title forState:UIControlStateNormal];
    [button setTitleColor:[UIColor darkTextColor] forState:UIControlStateNormal];
    [button setTitleColor:[[UIColor darkTextColor] colorWithAlphaComponent:0.5] forState:UIControlStateHighlighted];

    [button addTarget:self action:action forControlEvents:UIControlEventTouchUpInside];

    [button sizeToFit];
    return [[UIBarButtonItem alloc] initWithCustomView:button];
}

- (UIBarButtonItem *)accessoryButtonSpace {
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.contentEdgeInsets = UIEdgeInsetsMake(-3.0f, 2.0f, -3.0f, 2.0f);

    [button setTitle:@"︱" forState:UIControlStateNormal];
    [button setTitleColor:[[UIColor darkTextColor] colorWithAlphaComponent:0.2] forState:UIControlStateNormal];

    [button sizeToFit];
    return [[UIBarButtonItem alloc] initWithCustomView:button];
}

#pragma mark - Text Manipulation

- (NSString *)formattedValueForValue:(id)value {
    NSNumber *numberValue = [NSNumber numberWithFloat:[value floatValue]];
    return [_numberFormatter stringFromNumber:numberValue];
}

- (void)toggleNegetiveValue {
    NSString *value = [self textField].text;
    if (value.length > 0) {
        NSString *firstCharacter = [value substringToIndex:1];
        self.textField.text = ([firstCharacter isEqualToString:@"-"]) ? [value substringFromIndex:1] : [NSString stringWithFormat:@"-%@", value];
    }
}

- (void)replaceOrInsertText:(UIButton *)item {
    NSString *newText = _accessoryTitlesAndKeys[[item currentTitle]];
    [self.textField replaceRange:self.textField.selectedTextRange withText:newText];
}

@end