iOS CGRect is inside another CGRect

Question

Anyone has a good solution for the following task?

I need to check if a CGRect is inside another CGRect and return a CGPoint, that gives the offset if the rect window is outside in any dimension from the containing.

thanks in advance

Therrien

have you tried to write such function for your own, maybe? – Brad

what offset do you refer to? the overlap? in x? in y? in both? – Ob

Nope @holex, because I was expecting that this is a community where people make others jobs easier. I'll write the solution and post it for other intrests. Have a nice day :) – Therrien

Answer 1

Swift 4.1

// Returns how much is the rect outside of the view, 0 if inside
func isRectVisibleInView(rect: CGRect, inRect: CGRect) -> CGPoint {
    var offset = CGPoint()

    if inRect.contains(rect) {
        return CGPoint(x: 0, y: 0)
    }

    if rect.origin.x < inRect.origin.x {
        // It's out to the left
        offset.x = inRect.origin.x - rect.origin.x
    } else if (rect.origin.x + rect.width) > (inRect.origin.x + inRect.width) {
        // It's out to the right
        offset.x = (rect.origin.x + rect.width) - (inRect.origin.x + inRect.width)
    }

    if rect.origin.y < inRect.origin.y {
        // It's out to the top
        offset.y = inRect.origin.y - rect.origin.y
    } else if rect.origin.y + rect.height > inRect.origin.y + inRect.height {
        // It's out to the bottom
        offset.y = (rect.origin.y + rect.height) - inRect.origin.y + inRect.height
    }


    return offset
}

Swift 3 update

// Returns how much is the rect outside of the view, 0 if inside
func isRectVisibleInView(rect: CGRect, inRect: CGRect) -> CGPoint {
    var offset = CGPoint()

    if CGRectContainsRect(inRect, rect) {
        return CGPointMake(0, 0)
    }

    if rect.origin.x < inRect.origin.x {
        // It's out to the left
        offset.x = inRect.origin.x - rect.origin.x
    } else if (rect.origin.x + rect.width) > (inRect.origin.x + inRect.width) {
        // It's out to the right
        offset.x = (rect.origin.x + rect.width) - (inRect.origin.x + inRect.width)
    }

    if rect.origin.y < inRect.origin.y {
        // It's out to the top
        offset.y = inRect.origin.y - rect.origin.y
    } else if rect.origin.y + rect.height > inRect.origin.y + inRect.height {
        // It's out to the bottom
        offset.y = (rect.origin.y + rect.height) - inRect.origin.y + inRect.height
    }


    return offset
}

Therrien

I meant this function – Therrien

Thanks for the answer, however it seems have bug at the line next to comment *// It's out to the bottom . Needs to be offset.y = (self.origin.y + self.height) - (inRect.origin.y + inRect.height) – Tempt

Answer 2

Maybe

CGRectContainsRect(CGRect rect1, CGRect rect2)

to check if cgrect is inside another, this method return a bool.

Ricebird

This only answers half of the question. – Urana

+1 for people like me who needed to know that this method exists :). I need the bool, not the point so thanx. – Caruncle

Answer 3

Swift 4

Simple use let boolValue = tableView.bounds.contains(cellRect)

//CoreGraphics Module-

@available(iOS 2.0, *)
public func contains(_ point: CGPoint) -> Bool


@available(iOS 2.0, *)
public func contains(_ rect2: CGRect) -> Bool

Orris

Answer 4

Here's a C# translation of the accepted answer for the Xamarin folk:

    CGPoint isRectVisibleInView(CGRect rect, CGRect inRect) {
        var offset = new CGPoint ();

        if (inRect.Contains(rect)) {
            return new CGPoint (0, 0);
        }

        if (rect.X < inRect.X) {
            // It's out to the left
            offset.X = inRect.X - rect.X;
        } else if (rect.GetMaxX () > inRect.GetMaxX ()) {
            // It's out to the right
            offset.X = rect.GetMaxX () - inRect.GetMaxX ();
        }

        if (rect.Y < inRect.Y) {
            // It's out to the top
            offset.Y = inRect.Y - rect.Y;
        } else if (rect.GetMaxY () > inRect.GetMaxY ()) {
            // It's out to the bottom
            offset.Y = rect.GetMaxY () - inRect.GetMaxY ();
        }


        return offset;
    }

Noman

Answer 5

Really? OK... here it is:

+ (CGPoint) isRect:(CGRect)inRect1 inRect:(CGRect)inRect2
{
    CGPoint offsetPoint = {0, 0};
    if (!CGRectContainsRect(inRect1, inRect2)) {
        offsetPoint.x = inRect1.origin.x - inRect2.origin.x;
        offsetPoint.y = inRect1.origin.y - inRect2.origin.y;
    }

    return offsetPoint;
}

Karmen

This is only checking the origin point, doesn't calculate with the height, width. I'll post my solution soon. – Therrien

He didn't ask for that: "return a CGPoint, that gives the offset if it's not inside the container rect or 0,0 if it's inside". – Karmen