画板画图

    //
    //  DrawboardView.m
    //  画板画图
    //
    //  Created by 品德信息 on 2017/4/17.
    //  Copyright © 2017年 品德信息. All rights reserved.
    //

#import "DrawboardView.h"

@interface DrawboardView ()
//is use eraser 使用橡皮擦
@property (nonatomic, assign) BOOL isEraserEnabled;

//pan color set
@property (nonatomic, strong) UIColor *panColor;
//pan line width

@property (nonatomic, assign) CGFloat panLineWidth;

@property (nonatomic, assign) CGFloat eraserLineWidth;
@property (nonatomic, strong) CAShapeLayer *currentDrawLayer;
@property (nonatomic, strong) UIBezierPath *currentDrawPath;
@property (nonatomic, strong) NSMutableArray *drawLayerArray;

@end

@implementation DrawboardView

//FIXME: MARK --lief cycle ---

- (instancetype)init {
if (self = [super init]) {
    self.backgroundColor = [UIColor whiteColor];
    self.isEraserEnabled = false;
    self.panColor = [UIColor blackColor];
    self.panLineWidth = 2.f;
    self.eraserLineWidth = 10.f;
}
return self;
}

-(instancetype)initWithFrame:(CGRect)frame{
if (self = [super initWithFrame:frame]) {
    self.backgroundColor = [UIColor whiteColor];
    self.isEraserEnabled = false;
    self.panColor = [UIColor blackColor];
    self.panLineWidth = 2.f;
    self.eraserLineWidth = 10.f;
}
return  self;
}

- (void)dealloc{
[self releaseAllLayers];
}

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {

UITouch *touch = touches.anyObject;
CGPoint startPoint = [touch locationInView: self];

self.currentDrawLayer = [self makeDrawLayer:self.isEraserEnabled];
self.currentDrawPath = [self makeDrawPath];

[self.currentDrawPath moveToPoint:startPoint];
}

-(void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

UITouch *touch = touches.anyObject;
CGPoint currentPoint = [touch locationInView:self];

[self.currentDrawPath addLineToPoint:currentPoint];
self.currentDrawLayer.path  = self.currentDrawPath.CGPath;
}
-(NSMutableArray *)drawLayerArray {

if (!_drawLayerArray) {
    _drawLayerArray = [NSMutableArray arrayWithCapacity:10];
}
return _drawLayerArray;
}

#pragma mark -- Custom Methods -- 
-(CAShapeLayer *)makeDrawLayer:(BOOL)isEraserEnable {

CAShapeLayer *drawLayer = [CAShapeLayer layer];
drawLayer.frame = self.bounds;
drawLayer.fillColor = [UIColor clearColor].CGColor;
//擦除
if (!isEraserEnable) {
    drawLayer.lineWidth = self.panLineWidth;
    drawLayer.strokeColor = self.panColor.CGColor;
    
}else{
    drawLayer.lineWidth = self.eraserLineWidth;
    drawLayer.strokeColor = self.backgroundColor.CGColor;
}

[self.layer insertSublayer:drawLayer atIndex:(unsigned)self.drawLayerArray.count];
[self.drawLayerArray addObject:drawLayer];

return drawLayer;
}
-(UIBezierPath *)makeDrawPath{

UIBezierPath *drawPath = [UIBezierPath bezierPath];
drawPath.lineCapStyle = kCGLineCapRound;
drawPath.lineJoinStyle = kCGLineJoinRound;

return drawPath;
}

- (void)releaseAllLayers {

[self.drawLayerArray makeObjectsPerformSelector:@selector(removeFromSuperlayer)];
[self.drawLayerArray removeAllObjects];
}
@end