Lab 2 Slides

# CSE 340 Lab 2 (Winter 2020)
## Week 2: Get Help with Doodle

.title-slide-logo[
  ![Android Logo](img/android-logo.png)
]

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# Course Objectives
- Practical applications for learnings in lecture

- Understand design considerations when making mobile apps

- Design and implement basic Android applications

- Debugging in Java and for Android

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# Timeline

- Doodle Due: Thursday, Jan 16 (Today!)

- Lock: Saturday, Jan 18 (If you are using late days)

- Peer Eval: Sunday, January 19 - Tuesday, January 21 @ 1:30pm

- Reflection: Wednesday Jan 22

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# Lab 2 Objectives

- Go through peer evaluation and reflection

- How to debug in Andriod

- Andriod Animation

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# Lab 2 After Implementation

- Peer evaluation - fill the survey that we send out

- The best ones will show off in class

- Part 3: Turn in reflection on Gradescope after peer evaluation

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# Peer Evaluation
- Why?
  - Chance to externalize your work
  - Get user feedback (the user experience is after all the point of HCI :))

- What to expect  
  - Your grade won't be determined by peer evaluating alone
  - You get credit for **doing** the peer evaluation (4 points)
  - Questions about spec requirements -- no room for interpretation
  - Questions that prompt about subjective feedback
    - Provide constructive feedback
  - Anonymous to your peers (but not to the teaching staff)

- Your feedback on the exercise! (be honest)

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# Peer Evaluation Practice

- Download the apk file: https://tinyurl.com/wdgjkcu

- Google form: https://tinyurl.com/raoqnu2

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# Peer Evaluation Instructions

- You will be assigned to peer grade 4 assignments
- If you have an Android phone
  - Click on the download link to install the app on your phone
- If you don't have a phone
  - Download the APK files
  - Open the APK file in Android Studio and run the app in the emulator
- Fill out the google form for each APK file

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# Android Debugging

- Select a device to debug your app on.
- Set breakpoints in your Java, Kotlin, and C/C++ code.
- Examine variables and evaluate expressions at runtime

- How to use Debugger: https://developer.android.com/studio/debug#java
- Helpful tool (Logcat): https://developer.android.com/studio/debug/am-logcat#java

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# Animation on Android

- _Property Animation_ - preferred method; more flexible

- _View Animation_ - simple setup; the old way (but you have to deal with xml...)

- _Drawable Animation_ - load `Drawable` resources and display them one frame after the other (it is like a gif)

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# Property Animation

- Define an animate that changes on object's _property_ (a field in an object) over _a lenght of time_

## `ValueAnimator`

- Keeps track of the animation's timing (how long its been running and current value of property)

```java
ValueAnimator animation = ValueAnimator.ofFloat(0f, 1f);
animation.setDuration(1000);
// Starts the animation
animation.start();
// TODO: need to listen for updates to get the returned value
```

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# `ObjectAnimator` (the one you need in this assignment)

- Rather than listening for a value, we can simply directly animate a property on an object

- **However**: the property that you are animating must have a setter function (in camel case) in the form of set<propertyName>() for this to work (_setDuration()_)

```java
ObjectAnimator anim = ObjectAnimator.ofFloat(foo, "alpha", 0f, 1f);
anim.setDuration(1000);
anim.start();
```

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# Resources

- Vogella Tutorials - http://www.vogella.com/tutorials/AndroidAnimation/article.html

- Android Developer
  - View Animation - https://developer.android.com/guide/topics/graphics/view-animation.html
  - Property Animation - https://developer.android.com/guide/topics/graphics/prop-animation.html

- Relevant supplemental material is provided on the course website
  - Listed in the Doodle assignment
  - Don't stress out :) this isn't required