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So in the last lesson, we've incorporated a progress bar into our design and we've figured out how we
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can change the amount of progress that shows by updating a number that, essentially, it represents a percentage
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from zero to 100. And that number has a data type of a Float,
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so it's a floating point. And one 1.0 is completion,
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so 100 percent. 0.0 is the starting point,
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so it's zero percent.
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Now, we know that we've managed to get the seconds remaining variable to reduce itself by 1 every time.
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But we're still a little bit far from what we want which is for the progressBar to show the amount
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of time that's left. So in order to solve this we have to think about it logically
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and so here's what we know so far.
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We're going to need a percentage that's expressed as a floating point or decimal number.
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So, for example, 56 percent would be naught .56,
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And we need that percentage to increase from 0.0 to 1.0 representing how far
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along our egg is,
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so from just put into the pan all the way to finished boiling, at least for the chosen hardness.
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Now, the next thing we know is that we have a different amount of time to count down depending on which
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egg hardness was selected.
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So soft eggs require a total of 300 seconds, hard eggs require 720.
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Now, we also have a function called updateTime that can do something every second because it gets called
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by our timer which ticks every second and triggers update time.
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So at the moment, we've got this variable code Seconds Remaining which basically shrinks by one every
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second and we're printing it out, but we can't really use it directly in our progress bar.
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So what if we thought about it the other way?
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What if instead of having a second remaining, we had something called Seconds Passed, and we look at how
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Seconds Passed varies compared to the total amount of time that the particular egg hardness requires.
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So then we can track our progress from zero to 90 depending on how many Seconds Passed out of the Total
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Time.
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So effectively, we can express this as an equation.
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We could say that the percentageProgress is equal to the seconds that have passed, divided by the total
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amount of time that the egg requires. Applying that logic to our code then involves a couple of things.
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Firstly, I'm going to delete this line of code because we don't need it.
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We're not updating the progressBar in the IBAction.
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And the second thing is that notice I've still got these quick and easy-to-test seconds 3, 4, and
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7, and I'm not going to change this until the very end when we are actually ready to wait 5 minutes
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for our egg to be done.
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So at the moment, we have all secondsRemaining
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and I'm actually going to delete this variable and replace it with two others.
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One is totalTime, which I'll set to zero, and another is the secondsPassed.
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So this secondsPassed, unlike secondsRemaining, is actually going to go up. So it's gonna go from zero
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to 1 to 2, whereas secondsRemaining counted down from the total amount of time.
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So the place where we need to set the total amount of time for our egg is, of course, here.
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So instead of setting secondsRemaining, the total amount of time is going to be based on the hardness
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that's selected,
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so it's either going to be 3, 4, or 7. And then we need to have this secondsPassed variable increase
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by 1 every single second.
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So instead of minus equals, we changed that to plus equals.
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So now secondsPassed is gonna go from zero to 1 to 
2 every time
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updateTimer is called which is every 1 second.
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So now I'm going to delete this print statement which uses that old secondsRemaining, and instead of
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checking for whether secondsRemaining is greater than zero,
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I'm going to check to see if the secondsPassed is less than the total amount of time.
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So let's say that we selected the Soft egg in our button selection.
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So the total amount of time gets set to 3 and the first time updateTimer gets called, secondPassed
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is zero,
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totalTime is 3..
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So zero is less than 3 and, therefore, secondsPassed gets increased by 1, and then the next time, and
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then the next time, until secondsPassed is equal to 3. At which point, it's no longer less than totalTime,
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At which point, our egg is done.
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So this "if" statement is the place where we're going to update our percentage progress.
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So just before we increase it, we're going to create a new constant code percentageProgress and we're
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going to set it equal to the secondsPassed divided by the total amount of time. And so now we have this
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thing called percentageProgress and we're going to set that as the progressBar's progress property.
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So we'll set that equal to percentageProgress.
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Now, we're going to have an error there because it says that the percentage progress has a data type
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of a whole number,
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but the progressBar.progress needs a floating point number.
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And we can verify this by, again, holding down option and clicking on that percentageProgress is, in fact,
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an integer.
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So how can we convert an integer into a float?
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Well, Xcode seems to know. It says, "Well, why don't you wrap your percentageProgress inside a float?"
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So let's try it and you'll see that Xcode doesn't always know what it's doing.
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So if we click fix and we try to run our code and we press on a button, you can see that it goes straight
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down to zero.
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In fact, our progressBar doesn't do anything other than just make the progress go down to zero.
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So what's going on here?
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Well, this is a bug in our code. And like the olden days where the computers would get a moth stuck in
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it and some bit of circuit won't work, in modern days, we don't have to worry about moths so much, but
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we do have to worry about ourselves.
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We are our own greatest enemies and are fallacies and logic leads to our code-breaking and not working.
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In the next lesson,
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we've got a five-step process.
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Again, five steps.
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I really like the number five.
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And it's a five-step process for you to figure out how to debug any problem you come across.
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So join me on the next lesson where we're going to fix this.