LDDrawingView

Purpose

On iOS, if you want to do any amount of custom drawing in a UIView you'll have to subclass it and override methods like drawRect: or layoutSubviews:. This isn't much of a problem if you are doing significant drawing. However, for simpler cases, this becomes somewhat cumbersome. LDDrawingView overcomes this by using two blocks settable from outside of the object: drawRectBlock and layoutBlock. In the example, I've provided an more complicated example with AutoLayout and such, but this isn't necessarily the optimum use. I would suggest that this class is used when you have a simple logo or drawing you need to have, but you don't want to subclass UIView.

If you want to simply write this code, take a look at LDDrawingView.m. It's not very complicated, but is a nice addition to UIView.

Install

Manually

Download the zip of the project and put the class LDDrawingView in your project. Then simply import "LDDrawingView.h" in the file(s) you would like to use it in.

CocoaPods

Add this to your Podfile: pod 'LDDrawingView', '>= 0.1'

To learn more about CocoaPods, please visit their website.

How To Use

drawRect

Simply set the block and it will be called inside of drawRect: when drawing is necessary:

[drawingView setDrawRectBlock:^(CGContextRef context, CGRect rect){
	// Drawing code goes here
}];

layoutSubviews

Simply set the layoutBlock and it will be called inside of layoutSubviews when drawing is necessary:

[drawingView setLayoutBlock:^(LDDrawingView *view){
	// Layout code goes here
}];

## Sample

Here's the code from the sample inside of a view controller:

- (void)loadView {
    [super loadView];
    LDDrawingView *drawingView = [[LDDrawingView alloc] init];
    drawingView.translatesAutoresizingMaskIntoConstraints = NO;
    drawingView.backgroundColor = [UIColor clearColor];
    
    [drawingView setDrawRectBlock:^(CGContextRef context, CGRect rect){
        CGContextSetFillColorWithColor(context, [UIColor darkGrayColor].CGColor);
        CGContextAddEllipseInRect(context, rect);
        CGContextFillPath(context);
    }];
    
    [drawingView setLayoutBlock:^(LDDrawingView *view){
        LDDrawingView *subview = [[LDDrawingView alloc] init];
        subview.backgroundColor = [UIColor clearColor];
        subview.translatesAutoresizingMaskIntoConstraints = NO;
        
        [subview setDrawRectBlock:^(CGContextRef context, CGRect rect){
            CGContextSetFillColorWithColor(context, [UIColor lightGrayColor].CGColor);
            UIRectFill(rect);
        }];
        
        [view addSubview:subview];
        [view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-(100)-[subview]-(100)-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(subview)]];
        [view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-(100)-[subview]-(100)-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(subview)]];
    }];
    
    [self.view addSubview:drawingView];
    
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-[drawingView]-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(drawingView)]];
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[drawingView]-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(drawingView)]];
}

MIT License

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.

lightdesign/LDDrawingView