iOS Programming: The Big Nerd Ranch Guide

Drawing with BNRDrawView

BNRDrawView will keep track of all of the lines that have been drawn and the line that is currently being drawn. In BNRDrawView.m, create two instance variables in the class extension that will hold the lines in their two states. Make sure to import BNRLine.h and implement initWithFrame:.

#import "BNRDrawView.h"
#import "BNRLine.h"

@interface BNRDrawView ()

@property (nonatomic, strong) BNRLine *currentLine;
@property (nonatomic, strong) NSMutableArray *finishedLines;

@end

@implementation BNRDrawView

- (instancetype)initWithFrame:(CGRect)r
{
    self = [super initWithFrame:r];

    if (self) {
        self.finishedLines = [[NSMutableArray alloc] init];
        self.backgroundColor = [UIColor grayColor];
    }

    return self;
}

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