BNMA w/ Flutter, by Udacity

Question 1

child property

Answer 1

exists only in objects that expect one child; e.g. container

Question 2

children prop

Answer 2

exists in objects that expect multiple children

Question 3

runApp()

Answer 3

function to run app

Question 4

main()

Answer 4

in main.dart, entry point into app

Question 5

MaterialApp

Answer 5

basic widget for app which comes with title, home, theme, text directionality, back-button press handling, …

Question 6

scaffold

Answer 6

drawers, app bars, bottom navigation, tabs, and floating action buttons

Question 7

AppBar

Answer 7

bar at top of app

Question 8

Text

Answer 8

text widget

Question 9

Dart top level functions means

Answer 9

functions can exist outside classes

Question 10

ColorSwatch

Answer 10

a color that has a swatch of related colors

Question 11

IconData

Answer 11

a description of an icon fulfilled by a font glyph

Question 12

crossAxisAlignment

Answer 12

How the children should be placed along the cross axis.

Question 13

edgeInsets

Answer 13

An immutable set of offsets in each of the four cardinal directions.
Used by: Padding, a widget that accepts EdgeInsets to describe its margins.

Question 14

Icon

Answer 14

A graphical icon widget drawn with a glyph from a font described in an IconData such as material’s predefined IconDatas in Icons.

Icons are not interactive. For an interactive icon, consider material’s IconButton.

There must be an ambient Directionality widget when using Icon. Typically this is introduced automatically by the WidgetsApp or MaterialApp.

This widget assumes that the rendered icon is squared. Non-squared icons may render incorrectly.

Question 15

_var

Answer 15

A leading underscore character ( _ ) indicates that a member is private to its library. This is not mere convention, but is built into the language itself.

Question 16

InkWell

Answer 16

A rectangular area of a Material that responds to touch; like touchable opacity

Question 17

all layout is done with …

Answer 17

widgets

Question 18

Route is…

Answer 18

a widget which takes you to a page or screen

Question 19

use route where?

Answer 19

e.g.
MaterialApp(
    home: CategoryRoute
\_\_\_
CategoryRoute(
    Scaffold

Question 20

ListView, GridView

Answer 20

efficiently show a grid/list of items

Question 21

navigator widget

Answer 21

manages routes; push and pop routes to move from screen to screen

Question 22

Navigator, detail

Answer 22

A widget that manages a set of child widgets with a stack discipline.

Many apps have a navigator near the top of their widget hierarchy in order to display their logical history using an Overlay with the most recently visited pages visually on top of the older pages. Using this pattern lets the navigator visually transition from one page to another by moving the widgets around in the overlay. Similarly, the navigator can be used to show a dialog by positioning the dialog widget above the current page

Question 23

Navigator.of(context)

Answer 23

it’s most common to use the navigator created by a WidgetsApp or a MaterialApp widget. You can refer to that navigator with Navigator.of

Question 24

MaterialPageRoute

Answer 24

A modal route that replaces the entire screen with a platform-adaptive transition.

Question 25

parts of widgets:

StatelessWidget & StatefulWidget, constructor & ?

Answer 25

stateless: constructor -> build (loop)
stateful: constructor -> createState (loop)

Question 26

when variables inside the state are modified, widget does or does not automatically re-render?

Answer 26

does not

Question 27

how to get re-render with state change?

Answer 27

call setState from widget implementor, changing the state object associated with StatefulWidget

Question 28

State<>

Answer 28

State<> is a widget class extended to create state objects for a StatefulWidget. 
_StatefulWidgetClassState extends State

Question 29

widgets extending State inherit overrides for:

Answer 29

<ul>
<li>build, which describes the part of the user interface represented by this widget</li>
<li>setState, to notify the framework that the internal state of this object has changed</li>
<li>
</ul>
</li></ul>

Question 30

widgets extending StatefulWidget inherit overrides for:

Answer 30

<ul>
<li>createElement</li>
<li>createState</li>
</ul>

Question 31

State class property .widget; accessed inside extended State class via widget, is what?

Answer 31

A State object’s configuration is the corresponding StatefulWidget instance

Question 32

stateless -> stateful, what happens to build()?

Answer 32

moves from stateless class to state class

Question 33

Theme used for?

Answer 33

Applies a theme to descendant widgets.

A theme describes the colors and typographic choices of an application.
e.g.
determine platform, and render widgets appropriately