Lesson 2

Question 1

log messages

Answer 1

messages to communicate information about application

Question 2

log levels;

Answer 2

WTF (rarely/never used), error, warn, info, () debug, verbose “WEW DIV”

Question 3

log syntax

Answer 3

log.x(String TAG, String message); typically use class name as TAG

Question 4

typical ScrollView height, width

Answer 4

android: layout_height = “wrap_content”
android: layout_width=”match_parent”

Question 5

Res folder types

Answer 5

holds resources; Strings, images, layouts.

Layouts: XML layouts
Animator: XML for property animations
Values: XML files that contain simple values, such as strings or integers
Anim: XML for tween animations

MIpmap: drawable launcher icon files
Drawable: visual files

Raw: arbitrary raw files

MEnu: XML for application menus
Xml: arbitrary XML

Color: XML for colors

“LAVA MiD R MeX (of) Color”

Question 6

get layout in res how?

Answer 6

by calling R.layouts.; uses folder res/layouts/ hierarchy

Question 7

get string in res how?

Answer 7

in res/values/strings.xml, call getString

Question 8

set up layouts how/where?

Answer 8

in Android xml

Question 9

xml menu orderInCategory

Answer 9

the order an item appears in a menu

Question 10

action bar

Answer 10

above activity window, contains overflow menu, menu items are actions. can show buttons if room (showAsAction=”ifRoom”)

Question 11

toolbar widget

Answer 11

generalized action bar; animated in and out

Question 12

instantiate menu how?

Answer 12

in Java activity, override onCreateOptionsMenu

Question 13

how to add new resource type

Answer 13

right click “res” folder, add new resource directory, pick appropriate resource type

Question 14

code for inflating menu

Answer 14

@Override
public boolean onCreateOptionsMenu (Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
“OnCOM”

Question 15

Uri.Builder

Answer 15

build uri from base, then parameters (such as search, and sort)

Question 16

url and uri

Answer 16

url is subset of uri

Question 17

Uri.Builder syntax

Answer 17

Uri builtUri = Uri.parse(GITHUB_BASE_URL).buildUpon().appendQueryParameter(PARAM_QUERY, githubSearchQuery).appendQueryParameter(t).build();
        // building blocks of URI building:
        // GITHUB_BASE_URL = http://....
        // PARAM_QUERY = "q"
        // PARAM_SORT = "sort"
        URL url = null;
        try {
            url = new URL(builtUri.toString());
        } catch (MalformedURLException e){
            e.printStackTrace();
        }

Question 18

do things when menu button pressed syntax

Answer 18

In activity,
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int itemThatWasClickedId = item.getItemId();
if (itemThatWasClickedId == R.id.action_search)

Question 19

where to add permissions?

Answer 19

declare permissions in manifest

Question 20

main thread term in android

Answer 20

“Single User Interfacing Thread”

Question 21

network on which thread?

Answer 21

secondary execution thread,

Question 22

AsyncTask runs, publishes to where?

Answer 22

Run task on background thread

Publish results on UI (main) thread

Question 23

UI thread parts

Answer 23

Handler, Message Queue; run and processes messages including from other threads

Question 24

AsyncTask parts, types, generic or not?

Answer 24

generic class (parametrized types in constructor)
"ParProRes"
Params, Progress, Result: type sent to Task, publishing type to update progress, type of result of task completion

Question 25

3 (4) corresponding override-able functions in Async tasks

Answer 25

doInBackground, onProgressUpdate, onPostExecute, (onPreExecute)
call Execute to execute task with parameters
“DOIB OPU OPE OPE)

Question 26

Anko

Answer 26

library for layouts, helpers, coroutines, and SQLite

Question 27

AsyncTask usage, class, doInBackground

Answer 27

create a class that extends async task, override doInBackground

Question 28

URL…urls syntax significance

Answer 28

varag, variable # of args.

Question 29

URL…urls syntax significance

Answer 29

varag, variable # of args.

Question 30

steps to network call

Answer 30

1. create network task;
   a. doInBackground to make network call
   b. onPostExecute to use network results
2. use network task where needed

Question 31

how to look for source of error with logs

Answer 31

“caused by” in logcat

Question 32

member variables naming convention

Answer 32

Non-public, non-static field names start with m; “my” (just to know why the ‘m’<> s; not useful.

Question 33

member variables naming convention

Answer 33

m<>

Question 34

member variable

Answer 34

In object-oriented programming, a member variable (sometimes called a member field) is a variable that is associated with a specific object, and accessible for all its methods (member functions).

Question 35

layout_gravity = “center” does what?

Answer 35

android:layout_gravity sets the gravity of the View or Layout relative to its parent; Gravity specifies how a component should be placed in its group of cells.

Question 36

JSON stands for

Answer 36

Java Script Object Notation

Question 37

why JSON used for web?

Answer 37

Its format is syntactically identical to the code for creating JavaScript objects. JS programs can use standard functions to read JSON data.

Question 38

Object:
name
first = John
last = Chuter

Answer 38

{“name”:
{“first”:”John”,
“last”:”Chuter”}
}

Question 39

JSON key idea1

Answer 39

key value pairs

Question 40

JSON key idea2

Answer 40

objects inside {}, values can be objects

Question 41

JSON key idea3

Answer 41

key is string; “”, value can be object, string, or raw number

Question 42

JSON key idea4

Answer 42

objects inside {}, contain list of key-value pairs separated by commas
{ 
    "k1":v1,
    "k2":v2
}

Question 43

where permissions

Answer 43

in manifest

Question 44

permissions tag, where

Answer 44

manifest parent

Question 45

AsyncTask doInBackground usage

Answer 45

override in class extending AsyncTask (to perform task in background; return of task is what is passed into onPostExecute

Question 46

4 steps of AsyncTask, detail

Answer 46

The 4 steps
When an asynchronous task is executed, the task goes through 4 steps:

1. onPreExecute(), invoked on the UI thread before the task is executed. This step is normally used to setup the task, for instance by showing a progress bar in the user interface.
2. doInBackground(Params…), invoked on the background thread immediately after onPreExecute() finishes executing. This step is used to perform background computation that can take a long time. The parameters of the asynchronous task are passed to this step. The result of the computation must be returned by this step and will be passed back to the last step. This step can also use publishProgress(Progress…) to publish one or more units of progress. These values are published on the UI thread, in the onProgressUpdate(Progress…) step.
3. onProgressUpdate(Progress…), invoked on the UI thread after a call to publishProgress(Progress…). The timing of the execution is undefined. This method is used to display any form of progress in the user interface while the background computation is still executing. For instance, it can be used to animate a progress bar or show logs in a text field.
4. onPostExecute(Result), invoked on the UI thread after the background computation finishes. The result of the background computation is passed to this step as a parameter.

Question 47

Java Class Constructors Syntax

Answer 47

Class ClassName {
    ClassName(type param1, type param2){
        // init code
    }
}

Question 48

Java access control

Answer 48

Public | Y | Y | Y | Y
Protected| Y | Y | Y | N
(no mod) | Y | Y | N | N
Private | Y | N | N | N

Question 49

get context from activity, when in activity

Answer 49

this (this@Activity)

Question 50

get context from activity, when outside activity

Answer 50

MainActivity.this

Question 51

add to a textView without replacing text

Answer 51

mTextView.append(text)

Question 52

Override onCreateOptionsMenu to inflate the menu for this Activity

Answer 52

@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater menuInflater = getMenuInflater();
menuInflater.inflate(R.menu.forecast, menu);
return true;
}

Question 53

internal, external

Answer 53

internal, external to the app. Primary + secondary external; secondary often SD card.

Question 54

layout_gravity

Answer 54

android:layout_gravity Gravity specifies how a component should be placed in its group of cells.
; of
public static class LinearLayout.LayoutParams

android: gravity sets the gravity of the contents (i.e. it’s subviews) of the View it’s used on.
android: layout_gravity sets the gravity of the View or Layout relative to its parent.
https: //stackoverflow.com/questions/3482742/difference-between-gravity-and-layout-gravity-on-android

Question 55

“A good app should be like a good…”

Answer 55

“butler, giving what you want before you must ask for it”

applies to save, refresh.

Question 56

“coupling a background operation with a foreground component, the activity.” is bad or good

Answer 56

BAD