Tag: 2015

Please note, this blog entry is from a previous course. You might want to check out the current one.

All of the changes to the Calculator made in lecture must be applied to your Assignment 1. Get this fully functioning before proceeding to the rest of the Required Tasks. And, as last week, type the changes in, do not copy/paste from anywhere.

… done …

Please note, this blog entry is from a previous course. You might want to check out the current one.

When running on a real device, which region is set to something having not a “.” as comma symbol, the app crashes. Strangely it does not crash on the simulator.

One way to cope with this behavior is to force the number formatter to use the US locale all the time:

           if let displayText = display.text {
                let numberFormatter = NSNumberFormatter()
                numberFormatter.locale = NSLocale(localeIdentifier: "en_US")
                if let displayNumber = numberFormatter.numberFromString(displayText) {
                    return displayNumber.doubleValue
                }
            }

Continue reading “cs193p – Project #1 Assignment #1 Internationalization”

Please note, this blog entry is from a previous course. You might want to check out the current one.

Use Autolayout to make your calculator look good on all different kinds of iPhones in both Portrait and Landscape orientations (don’t worry about iPads for now). Just like we used ctrl-drag to the edges of our scene to position display, you can you ctrl-drag between your UILabels (and/or your C button) to fix their vertical/horizontal spacing relative to each other. Use the blue gridlines! It’s probably a good idea to reset all of your autolayout (via the button in lower right corner), then use ctrl-drag to add constraints to things that are not part of the grid of keypad and operation buttons, then use the buttons in the lower right to lay out those (after you’ve moved them in to place relative to your UILabel(s), etc., using dashed blue lines, of course!).

… which we did already for the previous task …

Please note, this blog entry is from a previous course. You might want to check out the current one.

Change the computed instance variable displayValue to be an Optional Double rather than a Double. Its value should be nil if the contents of display.text cannot be interpreted as a Double (you’ll need to use the documentation to understand the NSNumberFormatter code). Setting its value to nil should clear the display out.

Make the display value an optional. When getting the display value, check first if there is a text, then if the text is a number and return the double value. Otherwise return nil. When setting the display value, check if it is nil. If not set the text label to the value otherwise to zero.
Continue reading “cs193p – Project #1 Assignment #1 Extra Task #4”