Question

I am drawing reactangles in a loop based on the parameters that I get from the looping variable event as below :

CGRectMake(cellWidth * event.xOffset,(cellHeight / MINUTES_IN_TWO_HOURS * [event minutesSinceEvent]), cellWidth,cellHeight / MINUTES_IN_TWO_HOURS * [event durationInMinutes]);

in every loop the minutesSinceEvent and durationInMinutes changes, so a different reactangle gets drawn every time.

I want to get the lowest y value in the loop and the greatest height in the loop. Simply saying, I want to have the y value of the rectangle which is above all. And the height of the rectangle which extends below all.

Please let me know, if any other information is needed?

Answer 1

A very simple way would be to accumulate all rectangles in a union rectangle:

CGRect unionRect = CGRectNull;
for (...) {
    CGRect currentRect = ...;
    unionRect = CGRectUnion(unionRect, currentRect);
}
NSLog(@"min Y : %f", CGRectGetMinY(unionRect));
NSLog(@"height: %f", CGRectGetHeight(unionRect));

What this does is basically to calculate a rectangle that is large enough to contain all rectangles that were created in the loop (but no larger).