Platform game fall to ground function

I have gotten to a point with my platform game where I am completely stuck. I have the player movement working fine but the only thing is, it doesn’t fall off the blocks.

I have a Floor class which references the Character class and tells it to stop jumping when it is on a block. I have tried to research how other games have added functions but can’t seem to find one which will work in mine.

Would anybody have any ideas how I could add this function? I have included my game files below if anyone would be kind enough to look at them.