Mobile App Dev 2022W: Tutorial 4 - Revision history

Soma: /* Questions */

2022-02-02T18:20:22Z

Questions

← Older revision		Revision as of 18:20, 2 February 2022
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	# Select different images from the menu. Try different interactions with the image. What can you do? What actions are recognized? (Note that you can do pinch to zoomoperations in the simulator by holding down the option key and dragging the circles that appear.)		# Select different images from the menu. Try different interactions with the image. What can you do? What actions are recognized? (Note that you can do pinch to zoomoperations in the simulator by holding down the option key and dragging the circles that appear.)
	# If you remove the VStack on line 28, does that change the program's behavior? Why or why not?		# If you remove the VStack on line 29, does that change the program's behavior? Why or why not?
	# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.		# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.
	# Why is the declaration on line 44 needed? What does this tell you about the development of SwiftUI?		# Why is the declaration on line 45 needed? What does this tell you about the development of SwiftUI?
	# Why is the moved variable needed? Why not always just set the position to the position variable?		# Why is the moved variable needed? Why not always just set the position to the position variable?
	# What's the purpose of resetState()?		# What's the purpose of resetState()?

Soma: /* Code: remotePicViewer ContentView.swift */

2022-02-02T18:20:08Z

Code: remotePicViewer ContentView.swift

← Older revision		Revision as of 18:20, 2 February 2022
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	import SwiftUI		import SwiftUI

			@available(macOS 12.0, *)
	struct ContentView: View {		struct ContentView: View {
	@State private var theImage = "kittens"		@State private var theImage = "kittens"

Soma at 15:47, 2 February 2022

2022-02-02T15:47:16Z

← Older revision		Revision as of 15:47, 2 February 2022
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	~~'''This tutorial is still being developed.'''~~

	In this tutorial you will be playing with [https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift remotePicViewer], a simple image viewer in Swift that downloads images from a server.		In this tutorial you will be playing with [https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift remotePicViewer], a simple image viewer in Swift that downloads images from a server.

Soma: /* Questions */

2022-02-02T15:47:05Z

Questions

← Older revision		Revision as of 15:47, 2 February 2022
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	# If you remove the VStack on line 28, does that change the program's behavior? Why or why not?		# If you remove the VStack on line 28, does that change the program's behavior? Why or why not?
	# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.		# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.
	# Why is the declaration on line 50 needed? What does this tell you about the development of SwiftUI?		# Why is the declaration on line 44 needed? What does this tell you about the development of SwiftUI?
	# Why is the moved variable needed? Why not always just set the position to the position variable?		# Why is the moved variable needed? Why not always just set the position to the position variable?
	# What's the purpose of resetState()?		# What's the purpose of resetState()?

Soma: /* Questions */

2022-02-02T15:46:50Z

Questions

← Older revision		Revision as of 15:46, 2 February 2022
Line 23:		Line 23:
	# If you remove the VStack on line 28, does that change the program's behavior? Why or why not?		# If you remove the VStack on line 28, does that change the program's behavior? Why or why not?
	# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.		# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.
			# Why is the declaration on line 50 needed? What does this tell you about the development of SwiftUI?
	# Why is the moved variable needed? Why not always just set the position to the position variable?		# Why is the moved variable needed? Why not always just set the position to the position variable?
	# What's the purpose of resetState()?		# What's the purpose of resetState()?

Soma: /* Tasks */

2022-02-02T15:45:55Z

Tasks

← Older revision		Revision as of 15:45, 2 February 2022
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	# Change the rotation on each click to be 90 degrees.		# Change the rotation on each click to be 90 degrees.
			# Change the program so that when you double tap it doubles the magnification of the image.
	# Add an image to the menu. Either do this by adding images from a new URL or by adding images to the app's assets and instead using Image (rather than AsyncImage). Be sure to add that image to the menu so it can be selected like the others. What did you have to do?		# Add an image to the menu. Either do this by adding images from a new URL or by adding images to the app's assets and instead using Image (rather than AsyncImage). Be sure to add that image to the menu so it can be selected like the others. What did you have to do?
	~~# Change the program so that when you double tap it doubles the magnification of the image.~~

	==[https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift Code: remotePicViewer ContentView.swift]==		==[https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift Code: remotePicViewer ContentView.swift]==

Soma: /* Tasks */

2022-02-02T15:45:22Z

Tasks

← Older revision		Revision as of 15:45, 2 February 2022
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	==Tasks==		==Tasks==

			# Change the rotation on each click to be 90 degrees.
	# Add an image to the menu. Either do this by adding images from a new URL or by adding images to the app's assets and instead using Image (rather than AsyncImage). Be sure to add that image to the menu so it can be selected like the others. What did you have to do?		# Add an image to the menu. Either do this by adding images from a new URL or by adding images to the app's assets and instead using Image (rather than AsyncImage). Be sure to add that image to the menu so it can be selected like the others. What did you have to do?
	# Change the program so that when you ~~single~~ tap it ~~switches between rotating or magnifying modes (rather than doing both at once). Make double tap reset~~ the image~~. '''Hint:''' Don't try to add and remove handlers when switching between modes, that won't work. Instead, change how the magnifying and rotating handlers work~~.		# Change the program so that when you double tap it doubles the magnification of the image.

	==[https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift Code: remotePicViewer ContentView.swift]==		==[https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift Code: remotePicViewer ContentView.swift]==

Soma: /* Questions */

2022-02-02T15:43:37Z

Questions

← Older revision		Revision as of 15:43, 2 February 2022
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	==Questions==		==Questions==

	# Select different images from the menu. Try different interactions with the image. What can you do? (Note that you can do pinch to zoomoperations in the simulator by holding down the option key and dragging the circles that appear.)		# Select different images from the menu. Try different interactions with the image. What can you do? What actions are recognized? (Note that you can do pinch to zoomoperations in the simulator by holding down the option key and dragging the circles that appear.)
	# If you remove the VStack on line 28, does that change the program's behavior? Why or why not?		# If you remove the VStack on line 28, does that change the program's behavior? Why or why not?
	# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.		# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.

Soma: /* Questions */

2022-02-02T15:43:09Z

Questions

← Older revision		Revision as of 15:43, 2 February 2022
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	# Select different images from the menu. Try different interactions with the image. What can you do? (Note that you can do pinch to zoomoperations in the simulator by holding down the option key and dragging the circles that appear.)		# Select different images from the menu. Try different interactions with the image. What can you do? (Note that you can do pinch to zoomoperations in the simulator by holding down the option key and dragging the circles that appear.)
	# If you remove the VStack on line 16, does that change the program's behavior? Why or why not?		# If you remove the VStack on line 28, does that change the program's behavior? Why or why not?
	# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.		# Why are so many state variables declared in ContentView but used in ActiveImage? Why not keep them local to ActiveImage? Explain for each parameter.
	# Why is the moved variable needed? Why not always just set the position to the position variable?		# Why is the moved variable needed? Why not always just set the position to the position variable?

Soma at 15:42, 2 February 2022

2022-02-02T15:42:17Z

← Older revision		Revision as of 15:42, 2 February 2022
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	In this tutorial you will be playing with [https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift remotePicViewer], a simple image viewer in Swift that downloads images from a server.		In this tutorial you will be playing with [https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift remotePicViewer], a simple image viewer in Swift that downloads images from a server.

			As before, create a new project and replace ContentView.swift with the one for [https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift remotePicViewer]. Build and run the program, then move on to the questions as tasks below.

	==Key Concepts & APIs==		==Key Concepts & APIs==
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	* [https://developer.apple.com/documentation/swiftui/magnificationgesture MagnificationGesture]		* [https://developer.apple.com/documentation/swiftui/magnificationgesture MagnificationGesture]
	* [https://www.hackingwithswift.com/books/ios-swiftui/how-to-use-gestures-in-swiftui How to use Gestures in SwiftUI] (Hacking with Swift)		* [https://www.hackingwithswift.com/books/ios-swiftui/how-to-use-gestures-in-swiftui How to use Gestures in SwiftUI] (Hacking with Swift)

	As before, create a new project and replace ContentView.swift with the one for [https://homeostasis.scs.carleton.ca/~soma/mad-2022w/code/remotePicViewer/ContentView.swift remotePicViewer]. Build and run the program.

	==Questions==		==Questions==