Workshop on Android Programming

Why Android?

Distribution - Chart

API Level

Android Architecture

Android Components

• ActivityUI component typically corresponds to one screen

• Intent ReceiverReceives events from phone

• ServiceFaceless task that runs in the background

• Content ProviderStores data and makes it available to other applications

Activity Life Cycle

Back Stack

App Resources

Same Resource

App Resources

Multiple Resource

App Resources

Providing Resources

App Resources

Accessing Resources

App Resources

Localization• res/values/strings.xml

Contains English text for all the strings that the application uses, including text for a string named title.

• res/values-fr/strings.xmlContain French text for all the strings, including title.

• res/values-ja/strings.xmlContain Japanese text for all the strings except title.

App Resources

Resources Types• Animation Resources

Define pre-determined animations.Tween animations are saved in res/anim/ and accessed from the R.anim class.Frame animations are saved in res/drawable/ and accessed from the R.drawable class.

• Color State List ResourceDefine a color resources that changes based on the View state.Saved in res/color/ and accessed from the R.color class.

App Resources

Resources Types• Drawable Resources

Define various graphics with bitmaps or XML.Saved in res/drawable/ and accessed from the R.drawable class.

• Layout ResourceDefine the layout for your application UI.Saved in res/layout/ and accessed from the R.layout class.

• Menu ResourceDefine the contents of your application menus.Saved in res/menu/ and accessed from the R.menu class.

App Resources

Resource Types• String Resources

Define strings, string arrays, and plurals (and include string formatting and styling).Saved in res/values/ and accessed from the R.string, R.array, and R.plurals classes.

• Style ResourceDefine the look and format for UI elements.Saved in res/values/ and accessed from the R.style class.

User Interface

Layouts – Linear Layout

VerticalHorizontal

User Interface

Layouts – Relative Layout

User Interface

Layouts – List View/ Grid View

Displays a scrolling single column list.

Displays a scrolling grid of columns and rows

User Interface

Input Controls

User Interface

Input Controls – Spinner

User Interface

Input Controls – Picker

Supporting Multiple Screens

Screen sizeScreen densityOrientationResolutionDevice Independent Pixel

px = dp * (dpi / 160)

Supporting Multiple Screen

◦ ldpi (low) ~120dpi◦ mdpi (medium) ~160dpi◦ hdpi (high) ~240dpi◦ xhdpi (extra-high) ~320dpi◦ xxhdpi (extra-extra-high) ~480dpi◦ xxxhdpi (extra-extra-extra-high) ~640dpi

Supporting Multiple Screen

Supporting Multiple Screen

Supporting Multiple Screen

• 36x36 (0.75x) for low-density• 48x48 (1.0x baseline) for medium-density• 72x72 (1.5x) for high-density• 96x96 (2.0x) for extra-high-density• 144x144 (3.0x) for extra-extra-high-density• 192x192 (4.0x) for extra-extra-extra-high-density

Code Snippets

Views

• TextView• Button• ToggleButton• CheckBox• RadioButton• Spinner• SeekBar• Switch

Views

• TextFields• Layouts• Containers• Images• AppCompat

Events• onClick()• onLongClick()• onFocusChange()• onKey()• onTouch()• onCreateContextMenu()

Utilities to Know

Call to PhoneIntent callIntent = new Intent(Intent.ACTION_CALL); callIntent.setData(Uri.parse("tel:"+number)); startActivity(callIntent); <uses-permission android:name="android.permission.CALL_PHONE" />

Utilities to Know

Open URL in browser

Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.google.com"));startActivity(browserIntent);

Utilities to Know

Open E-mail App

Intent i = new Intent(Intent.ACTION_SEND);i.putExtra(android.content.Intent.EXTRA_EMAIL, new String[]{ emailAddress });i.putExtra(android.content.Intent.EXTRA_SUBJECT, subject);i.putExtra(android.content.Intent.EXTRA_TEXT, text);startActivity(Intent.createChooser(i, "Send email"));

Data Storage

Shared PreferencesStore private primitive data in key-value

pairs.Internal Storage

Store private data on the device memory.External Storage

Store public data on the shared external storage.SQLite Databases

Store structured data in a private database.Network Connection

Store data on the web with your own network server.

Data Storage

Shared Preferences

// Restore preferencesSharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);boolean silent = settings.getBoolean("silentMode", false);

SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);SharedPreferences.Editor editor = settings.edit();editor.putBoolean("silentMode", mSilentMode);// Commit the edits!editor.commit();

Fragments• A fragment has its own layout and its own behavior with its

own life cycle callbacks.• You can add or remove fragments in an activity while the

activity is running.• You can combine multiple fragments in a single activity to

build a multi-plane UI.• A fragment can be used in multiple activities.

Android Challanges

• Software Fragmentation• Hardware Fragmentation• No Software/Hardware Standardization• Several Carriers• Security

References• https://developer.android.com• http://stackoverflow.com/questions/tagged/android• https://developer.android.com/design/index.html• https://material.google.com

Questions?

THANK YOU!