Android Resources, Animation and Intents

8/12/2019 Android Resources, Animation and Intents

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Android:

Resources,Animation and

Intents

TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Android: Resources, Animation and Intents

Tommy MacWilliam

Harvard University

February 22, 2011
http://find/http://goback/


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Android:


Intents

TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Announcements

Lecture videos available at:

https://www.cs76.net/Lectures

New section schedule: https://www.cs76.net/Sections section every week here right after lecture office hours weeks projects are due

Tuesday/Wednesday nights walkthroughs on Thursdays after project released

seminars on interesting mobile dev topics onnon-walkthrough weeks

online labs


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Android:


Intents

TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Today

Resources

Styles

Animation

Intent Filters
http://find/


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Android:


Intents

TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Section Feedback

http://tommymacwilliam.com/e76/feedback

let me know how Im doing!

I dont like long surveys either, so give me feedback via

an anonymous (I promise) 140-character tweet!


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Android:


Intents

TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Resources

remember, resources are anything in our project that

isnt code all resources will be placed in a special directory called

res

this directory contains subfolders to organize yourresources by type
http://find/


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Android:


Intents

TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Resources

anim: animations (which well take a look at later)

color: colors used for different states of UI elements

drawable: PNG, JPG, GIF, etc.

layout: layouts for activities (which we saw last week)

menu: app menus (i.e. Options, Context, etc.)

raw: any file needed in its raw for (i.e. plaintext)

xml: configuration XML files
http://find/


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Android:


Intents

TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Accessing Resources

resources can be accessed from XML and Java

XML: @/ Java: R..

: anim, drawable,etc.

: filename (without the extension)
http://find/


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Android:

Resources,Animation andIntents

TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Resources

values: predefined strings, integers, colors, etc.

filenames are arbitrary, can contain arbitrary XMLelements

each element must be a child of from Java: R.. from XML: @/
http://find/


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Android:


TommyMacWilliam

Resources

StylesAnimations

Intent Filters

Alternative Resources

unlike the iPhone, there are many different types of

Android devices

which all have different hardware specs, screen

resolutions, etc.

all of the folders in the resdirectory can be

device-specific

create a new folder called ---... can have any number of qualifiers, which match devices

that match all qualifiers
http://goforward/http://find/


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Android:


TommyMacWilliam

Resources

StylesAnimations

Intent Filters


resource qualifiers

language: en, en-rUS, es, etc. (any valid ISO639-1 code)

http://www.loc.gov/standards/iso639-2/php/code_list.php

screen size: small, normal, large, xlarge screen aspect ratio: long, notlong screen orientation: port, land


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Android:


TommyMacWilliam

Resources

StylesAnimations

Intent Filters

Picking the Best Resource

must be specified in the order they were presented here

4-step process

eliminate any contradictions (device is en, app hasconfig for es)

iterate through qualifiers (all possible qualifiers in thepredefined order)

check if any folder matches the qualifier

if match, eliminate directories that do not include thequalifier (until only one directory is left)


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Android:


TommyMacWilliam

Resources

Styles

Animations

Intent Filters


example time!
http://find/


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Android:


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Styles

define a custom look and feel for UI elements

the Android equivalent of CSS makes View XML much less verbose can apply the same style to multiple Views

stored in XML files located in res/values/
http://find/


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Android:


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Styles

style can inherit from platform styles and themes via

theparentattribute a style can also extend an already defined style

name=MyStyle.Something will automaticallyinherit from the style with name=MyStyle


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Android:


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Styles

example time!
http://find/


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Android:


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Tween Animations

despite its name, unrelated to Justin Bieber

equivalent to CSS3 transitions, can be used to animateany View object

admittedly a bit more verbose than CSS3, though

saved in res/anim

defines properties to be animated concurrently
http://find/


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Android:Resources,

Animation andIntents

TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Tween Animations

transitions

: fade a Views opacity in/out : resize a View

: vertical/horizontal motion : rotate a View

all transitions must be children of a , but a

can contain s
http://find/


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Tween Animations

attributes in the form android:from

and android:to

: fromAlpha, toAlpha : from{X,Y}Scale, to{X,Y}Scale : from{X,Y}, to{X,Y},

from{X,Y}Delta, to{X,Y}Delta : fromDegrees, toDegrees : duration, startOffset
http://goforward/http://find/http://goback/


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Applying Animations

first, we load a newAnimationvia the

AnimationUtils.loadAnimation

recall we can access the animation viaR.anim.

call startAnimationon the View we want to animate

AnimationListenerprovides callbacks to detect

when an animation is complete


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Tween Animations

example time!


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Interpolators

example time!

F A i i


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Frame Animation

used to animate drawableelements

animation consists of multiple s, each a child of

an

eachmust have an android:drawableandandroid:duration

remember, we can access drawableresources via

@drawable/

I t t
http://find/


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Intents

remember, Activities, Broadcast Receivers, and

Services are triggered via Intents

last week:Intent i = new Intent(Context

packageContext, Class cls);

startActivity(i);

Intent objects simply contain a description of what

action is to be performed

has an action, data, and a category

we can use Intents to trigger (private) actions within our

own app and (public) actions within other apps


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I t t


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Intents

contains data for the action (phone number to

call, etc.) formatted as a URI

scheme://host/path/segments getScheme(), getHost(), getPathSegments()

category: additional information about the component

that should respond

CATEGORY_BROWSABLE: component can be invokedby the browser to display content

CATEGORY_LAUNCHER: component can be shown asthe initial activity from the launcher

manage categories with addCategory()and

removeCategory()

Bundles
http://find/


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Bundles

we can pass additional data to Activities with bundles

sending data: intent.putExtra(key,value);

retrieving passed data:

Bundle bundle = getIntent().getExtras();

bundle.getString(key);

Intent Filters


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Intent Filters

we can also allow other apps to open Activities within

our app via Intent Filters

we register these in AndroidManifest.xml

generally not created using Java also where we tell Android what Activities exist in our

app

Intent Filters


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Intent Filters

must be a child of an

and can contain , ,

andelements : action to be performed : format through which data is passed to the

activity

accessed viagetIntent().getData()

: component properties

Intent Filters
http://find/


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Intent Filters

we can also use Intent Filters to open our apps

Activities from within our app the other syntax is kinda ugly

if we give our a unique android:name

attribute, we can just pass that to the Intent constructor

Intent Filters
http://find/


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Android:Resources,


TommyMacWilliam

Resources

Styles

Animations

Intent Filters

Intent Filters

example time!
http://find/

Android Resources, Animation and Intents

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