Prevent overlap of views

Question

I have an array of subviews of my container view, added programmatically setting the frame manually.
When the user select a filter I would like to zoom the selected views (matching the filter) increasing their size by 1.1 and maintaining the center but preventing the overlap.
Here's my code so far:

- (void) positionSubviewsWithoutOverlapping: (NSArray *) views {
    for (UIView *v in views){
        CGPoint center = v.center;
        v.frame = CGRectMake(v.frame.origin.x, v.frame.origin.y, v.frame.size.width*1.1, v.frame.size.height*1.1);
        v.center = center;
    }
    while ([self repositionSubviews:views]) {
    }
}

- (BOOL) repositionSubviews: (NSArray *) views{
    BOOL somethingChanged = FALSE;
    for (UIView *v1 in views){
        for (UIView *v2 in views){
            if (v1 != v2){
                if (CGRectIntersectsRect(v1.frame, v2.frame)){
                    somethingChanged = TRUE;
                    [self preventOverlapOfView1:v1 View2:v2];
                }
            }
        }
    }
    return somethingChanged;
}

- (void) preventOverlapOfView1: (UIView *) v1 View2: (UIView *) v2  {
    if (CGRectGetMaxX(v1.frame) > CGRectGetMinX(v2.frame)){
        CGFloat diff = CGRectGetMaxX(v1.frame)-CGRectGetMinX(v2.frame);
        v1.frame = CGRectMake(v1.frame.origin.x-diff, v1.frame.origin.y, v1.frame.size.width, v1.frame.size.height);
    }
    else if (CGRectGetMinX(v1.frame) < CGRectGetMaxX(v2.frame)){
        CGFloat diff = CGRectGetMaxX(v2.frame)-CGRectGetMinX(v1.frame);
        v2.frame = CGRectMake(v2.frame.origin.x-diff, v2.frame.origin.y, v2.frame.size.width, v2.frame.size.height);
    }
    if (CGRectGetMaxY(v1.frame) > CGRectGetMinY(v2.frame)){
        CGFloat diff = CGRectGetMaxY(v1.frame)-CGRectGetMinY(v2.frame);
        v2.frame = CGRectMake(v2.frame.origin.x, v2.frame.origin.y-diff, v2.frame.size.width, v2.frame.size.height);
    }
    else if (CGRectGetMinY(v1.frame) < CGRectGetMaxY(v2.frame)){
        CGFloat diff = CGRectGetMaxY(v2.frame)-CGRectGetMinY(v1.frame);
        v1.frame = CGRectMake(v1.frame.origin.x, v1.frame.origin.y-diff, v1.frame.size.width, v1.frame.size.height);
    }
}

The problem is in - (void) preventOverlapOfView1: (UIView *) v1 View2: (UIView *) v2, I should use CGRectIntersection but I can't figure out how to use it. Does anyone have a suggestion?

score 0 · Answer 1 · answered May 23 '16 at 10:14

0

As a slightly leftfield suggestion, why dont you just use a UICollectionView? Its designed precisely for the type of application you are suggesting. You can zoom in a certain cell and it will automatically move the other cells around to accomodate the change in size.

If not, then I would suggest you use autolayout for this. That again will better help other views not to overlap. But the collection view would be the best option.

answered May 23 '16 at 10:14

Luke Smith

1,218
12
17

Thanks for the answer! Unfortunately I cannot use UICollectionView, the views are loaded using the SVGKit library from a map of a floor that is basically an svg file. I have to zoom the rooms of the map selected from the filter. – LorenzOliveto May 23 '16 at 10:19
Your use of CGRectIntersectsRect looks ok to me. Am afraid Im not sure what the issue is, good luck :( – Luke Smith May 23 '16 at 10:33

Prevent overlap of views

1 Answers1