UIView+PYJExtension

UIView+PYJExtension.h:

//
//  UIView+PYJExtension.h
//  扩展
//
//  Created by 彭运京 on 16/6/21.
//  Copyright © 2016年 PYJ. All rights reserved.
//

#import <UIKit/UIKit.h>

CGPoint CGRectGetCenter(CGRect rect);
CGRect  CGRectMoveToCenter(CGRect rect, CGPoint center);

@interface UIView (PYJExtension)

@property CGPoint origin;
@property CGSize size;

@property (readonly) CGPoint bottomLeft;
@property (readonly) CGPoint bottomRight;
@property (readonly) CGPoint topRight;

/// 高
@property CGFloat height;
/// 宽
@property CGFloat width;
/// Y坐标
@property CGFloat top;
/// X坐标
@property CGFloat left;
/// 底部 Y坐标+高度
@property CGFloat bottom;
/// 右侧 X坐标+宽度
@property CGFloat right;

- (void) moveBy: (CGPoint) delta;
- (void) scaleBy: (CGFloat) scaleFactor;
- (void) fitInSize: (CGSize) aSize;

/**
 * 判断一个控件是否真正显示在主窗口
 */
- (BOOL)isShowingOnKeyWindow;

//- (CGFloat)x;
//- (void)setX:(CGFloat)x;
/** 在分类中声明@property, 只会生成方法的声明, 不会生成方法的实现和带有_下划线的成员变量*/

+ (instancetype)viewFromXib;

@end

UIView+PYJExtension.m:

//
//  UIView+PYJExtension.m
//  扩展
//
//  Created by 彭运京 on 16/6/21.
//  Copyright © 2016年 PYJ. All rights reserved.
//

#import "UIView+PYJExtension.h"

CGPoint CGRectGetCenter(CGRect rect)
{
    CGPoint pt;
    pt.x = CGRectGetMidX(rect);
    pt.y = CGRectGetMidY(rect);
    return pt;
}

CGRect CGRectMoveToCenter(CGRect rect, CGPoint center)
{
    CGRect newrect = CGRectZero;
    newrect.origin.x = center.x-CGRectGetMidX(rect);
    newrect.origin.y = center.y-CGRectGetMidY(rect);
    newrect.size = rect.size;
    return newrect;
}

@implementation UIView (PYJExtension)

// Retrieve and set the origin
- (CGPoint) origin
{
    return self.frame.origin;
}

- (void) setOrigin: (CGPoint) aPoint
{
    CGRect newframe = self.frame;
    newframe.origin = aPoint;
    self.frame = newframe;
}

// Retrieve and set the size
- (CGSize) size
{
    return self.frame.size;
}

- (void) setSize: (CGSize) aSize
{
    CGRect newframe = self.frame;
    newframe.size = aSize;
    self.frame = newframe;
}

// Query other frame locations
- (CGPoint) bottomRight
{
    CGFloat x = self.frame.origin.x + self.frame.size.width;
    CGFloat y = self.frame.origin.y + self.frame.size.height;
    return CGPointMake(x, y);
}

- (CGPoint) bottomLeft
{
    CGFloat x = self.frame.origin.x;
    CGFloat y = self.frame.origin.y + self.frame.size.height;
    return CGPointMake(x, y);
}

- (CGPoint) topRight
{
    CGFloat x = self.frame.origin.x + self.frame.size.width;
    CGFloat y = self.frame.origin.y;
    return CGPointMake(x, y);
}

// Retrieve and set height, width, top, bottom, left, right
- (CGFloat) height
{
    return self.frame.size.height;
}

- (void) setHeight: (CGFloat) newheight
{
    CGRect newframe = self.frame;
    newframe.size.height = newheight;
    self.frame = newframe;
}

- (CGFloat) width
{
    return self.frame.size.width;
}

- (void) setWidth: (CGFloat) newwidth
{
    CGRect newframe = self.frame;
    newframe.size.width = newwidth;
    self.frame = newframe;
}

- (CGFloat) top
{
    return self.frame.origin.y;
}

- (void) setTop: (CGFloat) newtop
{
    CGRect newframe = self.frame;
    newframe.origin.y = newtop;
    self.frame = newframe;
}

- (CGFloat) left
{
    return self.frame.origin.x;
}

- (void) setLeft: (CGFloat) newleft
{
    CGRect newframe = self.frame;
    newframe.origin.x = newleft;
    self.frame = newframe;
}

- (CGFloat) bottom
{
    return self.frame.origin.y + self.frame.size.height;
}

- (void) setBottom: (CGFloat) newbottom
{
    CGRect newframe = self.frame;
    newframe.origin.y = newbottom - self.frame.size.height;
    self.frame = newframe;
}

- (CGFloat) right
{
    return self.frame.origin.x + self.frame.size.width;
}

- (void) setRight: (CGFloat) newright
{
    CGFloat delta = newright - (self.frame.origin.x + self.frame.size.width);
    CGRect newframe = self.frame;
    newframe.origin.x += delta ;
    self.frame = newframe;
}

// Move via offset
- (void) moveBy: (CGPoint) delta
{
    CGPoint newcenter = self.center;
    newcenter.x += delta.x;
    newcenter.y += delta.y;
    self.center = newcenter;
}

// Scaling
- (void) scaleBy: (CGFloat) scaleFactor
{
    CGRect newframe = self.frame;
    newframe.size.width *= scaleFactor;
    newframe.size.height *= scaleFactor;
    self.frame = newframe;
}

// Ensure that both dimensions fit within the given size by scaling down
- (void) fitInSize: (CGSize) aSize
{
    CGFloat scale;
    CGRect newframe = self.frame;

    if (newframe.size.height && (newframe.size.height > aSize.height))
    {
        scale = aSize.height / newframe.size.height;
        newframe.size.width *= scale;
        newframe.size.height *= scale;
    }

    if (newframe.size.width && (newframe.size.width >= aSize.width))
    {
        scale = aSize.width / newframe.size.width;
        newframe.size.width *= scale;
        newframe.size.height *= scale;
    }

    self.frame = newframe;
}

- (BOOL)isShowingOnKeyWindow
{
    // 主窗口
    UIWindow *keyWindow = [UIApplication sharedApplication].keyWindow;

    // 以主窗口左上角为坐标原点, 计算self的矩形框
    CGRect newFrame = [keyWindow convertRect:self.frame fromView:self.superview];
    CGRect winBounds = keyWindow.bounds;

    // 主窗口的bounds 和 self的矩形框 是否有重叠
    BOOL intersects = CGRectIntersectsRect(newFrame, winBounds);

    return !self.isHidden && self.alpha > 0.01 && self.window == keyWindow && intersects;
}

+ (instancetype)viewFromXib
{
    return [[[NSBundle mainBundle] loadNibNamed:NSStringFromClass(self) owner:nil options:nil] lastObject];

}

@end