android outlook

ViewPager

• Purpose: To be able to use swipe operations to switch between fragments (or views)

• Why not ListView? ViewPager facilitates paging between fragments integrating the FragmentManager calls.

• Adapter: Use either the FragmentPagerAdapter or FramentStatePagerAdapter to manage fragments. The former detaches instead of removing fragments when done, so they can be relaunched. They are never destroyed, so be careful.

• Support: ViewPager is not standard in recent Android versions, so the support version must be used.

Date and Time Picker

• These widgets are used date and time selections• They have large margins, so it is difficult to

incorporate them in layouts with other widgets– To shrink: android:scaleX, android:scaleY

(scales but doesn’t reduce overall size)

– To reduce margins: android:layout_marginLeft android:layout_marginRight

– Define the format: android:datePickerMode

DialogFragmentImplementation Steps

1.Launch like any fragment, but add call setTargetFragment() in the FragmentManager transaction2.Implement onActivityResult() to receive returned data3.In extension to DialogFragment, override onCreateDialog() to find links to widgets, set listeners, and initialize and show the alert dialog.4.Use getTargetFragmene().setResult() to return data when the ok button is triggered.5.The Back button is equivalent to a cancel operation

User Interface and Handlers

• Can be done in code (like in Swing)– Similar to previous generation UI API's (like Swing, AWT)– Painful with lots of lines of code– Five times more statements than XML version

• Normally done in XML and strongly advised– Progressive enhancement/Model-View (like JavaFX)– Easier to maintain, lots less code and separate from source– Can create specialized views for different environments– Store layout files as text in resource subdirectories

• res/layout: The default version• res/layout-landscape, res/layout-fr-small

Goal: Create an easy to use, intuitive, immersive experience

User Interface Example

• This application contains a series of labels presented vertically.

• There is an outer container and two inner containers• The second inner container contains two lower level

sub-containers

Layout File Structure<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical" android:layout_width="match_parent"android:layout_height="match_parent">



</LinearLayout>

Notes1. Shown is the outer container: like a frame in Java2. Linear layout is similar to BoxLayout in Java 3. match_parent uses all the space provided by the parent container4. Android > 2.2: fill_parent is deprecated; replaced by match_parent5. "http://schemas.android.com/apk/res/android" contains XML android schema6. Layouts and views are nestable, but minimize nesting for maximum performance

Name Container

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="horizontal" android:layout_width="match_parent"android:layout_height="wrap_content"><TextView android:layout_width="wrap_content"

android:layout_height="wrap_content" android:text="Name:" /><TextView android:layout_width="wrap_content"

android:layout_height="wrap_content" android:text="John Doe" />

</LinearLayout>

Notes• Use all available space horizontally and only the space needed vertically• This example uses hard-coded text, which is possible, but not advisable• TextView in this example is similar to Java JLabel components

Shown as a comment in the previous slide

Address Container

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical" android:layout_width="match_parent“ android:layout_height="wrap_content"><TextView android:layout_width="match_parent"

android:layout_height="wrap_content" android:text="Address:" /><TextView android:layout_width="match_parent"

android:layout_height="wrap_content" android:text="911 Hollywood Blvd." />

</LinearLayout>

Notes• Use all available space horizontally and only the space needed vertically• Two sub views (components) containing text strings

Shown as a comment in the previous slide

Using String ids<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="horizontal" android:layout_width="match_parent“ android:layout_height="wrap_content">

<TextView android:id="@+id/nameText" android:text="@string/name_text" android:layout_width="wrap_content“ android:layout_height="wrap_content"/><TextView android:id="@+id/nameValue"

android:layout_width="wrap_content" android:layout_height="wrap_content"/></LinearLayout>

Notes

1. @string/name_text refers to a strings.xml entry in res/values/strings.xml<string name="name_text">Name:</string>

2. The + in @+id/nameValueText adds a code for nameValueText if not defined3. Java Access: TextView name = (TextView)findViewById(R.id.nameValue);

name.setText("John Doe"); or name.setText(R.string.JohnDoe);

Text Views• TextView: Like a smarter Java Jlabel

– Attribute: android:autoLink= "email|web|phone|map"• Creates hyperlink, initiates a phone call, or draws a map• Code: (TextView)findViewById(R.id.tv).setAutoLinkMask(Linkify.ALL);

– Other attributes: android:minLines, android:maxLines, etc.• EditText: Like Java JTextField with additional capabilities

– Autocorrection for captalizing text, etc.– Able to validate syntax for phone numbers, emails, etc.– Display field hints: android:hint="@string/someHint" or setHint()– Additional attributes like android:textMultiLine, etc.

• AutoCompleteTextView: Completion suggestions while user types based on a supplied array of strings (ex: list of states)

• MultiAutoCompleteTextView: Completion Suggestions during partial text entry after token boundaries (like commas, spaces, and periods).

EditText Example

<EditText android:inputType="textMultiLine"  android:lines="8" <!– Desired component height -->

android:minLines="6"  android:gravity="top|left"  android:maxLines="10" 

android:layout_width="match_parent"android:layout_height= "wrap_content " android:scrollbars="vertical" 

android:hint="@string/email_hint" android:inputType="textEmailAddress" />

Button Controls

• Button (Example launches browser) Button btn = (Button)this.findViewById(R.id.btn);btn.setOnClickListener(new OnClickListner()){ Intent intent = new Intent(Intent.ACTION_VIEW, URI.parse("http://www.sou.edu));

startActivity(intent);});

• ImageButton: Clickable image (or icon) in res/drawable directory <ImageButton android:id="@+id/imageBtn" android:src="@drawable/btnImage"

android:layout_width="wrap_content" android:layout_height="wrap_content" />

• ToggleButton: Switch from on to off on each click, bar shows green if on <ToggleButton android:id="@+id/cctglBtn" android:layout_width="wrap_content" android:layout_height="wrap_content"Android:textOn="Stop" Android:textOff="Run" android:text="Toggle Button"/> <-- android:text not used, inherited from TextView -->

Checkbox Buttons<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical" android:layout_width="match_parent

android:layout_height="match_parent“ /><CheckBox android:text="Chicken" android:layout_width="wrap_content"

android:layout_height="wrap_content" android:checked= "true" /><CheckBox android:text="Fish" android:layout_width="wrap_content" android:layout_height="wrap_content" /><CheckBox android:text="Steak" android:layout_width="wrap_content“ android:layout_height="wrap_content"

android:checked="true" /></LinearLayout>

Radio Buttons<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <RadioGroup android:layout_width="wrap_content"

android:layout_height="wrap_content"><RadioButton android:id="@+id/chRBtn" android:text="Chicken" android:layout_width="wrap_content"android:layout_height="wrap_content"/><RadioButton android:id="@+id/fishRBtn" android:text="Fish"android:layout_width="wrap_content"android:layout_height="wrap_content"/>

<RadioButton android:id="@+id/stkRBtn" android:text="Steak"android:layout_width="wrap_content"android:layout_height="wrap_content"/>

</RadioGroup></layout>

Other Android Controls• ImageView: <ImageView android:id="@+id:myImageCode" />

– Display a color: anroid:src="#555555"– Display an image:

android:src="@drawable/manatee" android:scaleType="centerInside"– Specify a picture not in the res/drawable directory

ImageView img = (ImageView)findViewById(R.id.myImageCode);img.setImageUri(Uri.fromFile(new File("/sdcard/cats.jpg")));

• DatePicker, TimePicker: Select a date,time using dropdown menus

• DigitalClock: Display a digital clock updating automatically

• MapView: Display a Google map

• WebView: Display HTML/JavaScript from an Android native application

Layout Managers

• LinearLayout– components arranged horizontally or vertically– Similar to Java BoxLayout

• TableLayout– Specify rows and columns– Similar to laying out HTML tables

• RelativeLayout: positioning relative to other components– layout_centerInParent, alignParentTop, alignParentBottom– layout_above, layout_toRightOf, layout_toLeftOf, layout_below

• FrameLayout– Multiple components in the same space– Similar to Java OverlayLayout and CardLayout

A view that controls how the sub-views are arranged

TableLayoutExample

<TableLayout xmlns:android=http://schemas.android.com/apk/res/androidandroid:layout_width= "match_parent" android:layout_height= "match_parent"android:stretchColumns="0,1,2"> <-- indicate which columns to stretch --><EditText android:text="Full Name:"/><TableRow>

<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Barack"/><TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hussein"/><TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Obama"/>

</TableRow></TableLayout>

One row/ three columnsStretch to fill entire width

android:layout_span="2" to span two view columns

http://schemas.android.com/apk/res/android

Example: FrameLayout

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:id="@+id/frmLayout" android:layout_width="match_parent"android:layout_height="match_parent"><ImageView android:id="@+id/one" android:src="@drawable/one" android:layout_width="match_parent" android:layout_height="match_parent" android:scaleType="fitCenter" /><ImageView android:id="@+id/two" android:src="@drawable/two" android:layout_width="match_parent" android:layout_height="match_parent" android:scaleType="fitCenter" android:visibility="gone" />

</FrameLayout>

Only the first picture is visible

Similar to Java OverlayLayout

Android Code for Frame Layout@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);

setContentView(R.layout.frame);ImageView one = (ImageView)this.findViewById(R.id.one);ImageView two = (ImageView)this.findViewById(R.id.two);

one.setOnClickListener(new OnClickListener(){ @Override public void onClick(View view)

{ ImageView two=(ImageView) FramelayoutActivity.this.findViewById(R.id.two);

two.setVisibility(View.VISIBLE); view.setVisibility(View.GONE); }});

two.setOnClickListener(new OnClickListener(){ @Override public void onClick(View view) { ImageView

one=(ImageView)FramelayoutActivity.this.findViewById(R.id.one);one.setVisibility(View.VISIBLE); view.setVisibility(View.GONE);

}}); }

Reusable layoutsInserting one layout into another

<?xml version="1.0" encoding="utf-8"?><LinearLayout

xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"

android:layout_height="match_parent" android:orientation="vertical">

<include android:id="@+id/my_actionbar" layout= "android:layout/actionbar" /> <include android:id= "@+id/my_image_text_layout"

layout = "@layout/image_text_layout" />

</LinearLayout>

Frame Layout Example<FrameLayout xmlns:android

= http://schemas.android.com/apk/res/android android:layout_width=“match_parent" android:layout_height=“match_parent">

<ImageView android:layout_width=“match_parent" android:layout_height=“match_parent"

android:scaleType="center"android:src="@drawable/golden_gate" />

<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="20dp" android:layout_gravity="center_horizontal|bottom" android:padding="12dp“ android:background="#AA000000" android:textColor="#ffffffff" android:text="Golden Gate" /></FrameLayout>


Frame Inefficiency<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent"> <ImageView android:layout_width="fill_parent" android:layout_height="fill_parent" android:scaleType="center" android:src="@drawable/golden_gate" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="20dip" android:layout_gravity="center_horizontal|bottom" android:padding="12dip" android:background="#AA000000" android:textColor="#ffffffff" android:text="Golden Gate" /></FrameLayout>

Merging Directly into Parent View

?xml version="1.0" encoding="utf-8"?><merge xmlns:android="http://schemas.android.com/apk/res/android"

<ImageView android:id="@+id/one" android:src="@drawable/one" android:layout_width=“match_parent"

android:layout_height=“match_parent" android:scaleType="fitCenter" /><ImageView android:id="@+id/two" android:src="@drawable/two" android:layout_width=“match_parent" android:layout_height=“match_parent" android:scaleType="fitCenter" android:visibility="gone" />

</merge>

Note: no fill specifications

Lazy View (Inflate only when needed)<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent" android:layout_height="match_parent"><ListView android:id="@+id/myListView" android:src="@drawable/one" android:layout_width="match_parent" android:layout_height="match_parent“ />

<ViewStub android:id="@+id/progress" android:inflateId="@+id/progress_inflate" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_gravity= "bottom" android:layout= "@layout/progress_panel" />

</FrameLayout>

Java CodeView stub = findViewById(R.id.progress_inflate);Stub.setVisibility(true); Later: Stub.setVisibility(false);

Weight and Gravity

• Weight: Sizing a component in a view– Controls size relative to other components– Android:layout_weight– Components with large weights expand more

• Gravity: Component alignment– android:gravity: applies to the text within a view– android:layout_gravity: applies to the view alignment– Possible values: "right", "left", "center", "top", "bottom",

"center_vertical", "clip_horizontal"

Padding<LinearLayout xmlns:android=http://schemas.android.com/apk/res/android

android:orientation="vertical" android:layout_width="match_parent“ android:layout_height="match_parent"><EditText android:layout_width="wrap_content" android:text="one"

android:layout_height="wrap_content" android:padding="40dp" />

</LinearLayout>

Measurements• Well known measurements:

Pixels: px, Inches: in, Millimeters: mm, Points: pt (1/72 of an inch)

• Density-independent pixels: See next slide

• Scale-independent pixels: sp scales dp to font sizes

if Font size is normal normal, sp=dp; if font size is large, sp>dp

Definition: Space around the text


Density Independent pixels• Physical screen width 1.5 inches• Lower resolution screen

– Dots Per Inch (dpi) 160– Actual pixels 240 (width * dpi) – Density 1.0 (dpi/160)– Density Independent pixels 160 or (160 * density)

• Higher resolution– Dots Per Inch (dpi) 240– Actual pixels 360 (width * dpi)– Density 1.5 (dpi/160)– Density Independent pixels 240 or (160 * density)

• Notes: – Most devices now define a pt as 1/72 of an inch– Android devices define dp as 1/160 of an inch

dp and sp measurements

• dp: density independent pixels (margins, padding)• sp: Scale independent pixels (font sizes)• pt, mm, in: text doesn’t recommend. However, I’ve found

that modern device pt sizes are accurate (1/72 of an inch)

Complex Views

• ListView: A scrollable list displayed vertically

• GridView: A scrollable list of items displayed with a fixed number of columns

• SpinnerView: (Like a Java combo box)A scrollable drop down menu of choices

• GalleryView: (now deprecated, use ViewPager)Horizontally scrollable list focusing on the center of the list

Displays a set of data using a single view

Note: Analogous to Swing JTree, JList, JTable components

AdapterViews

• Purposes– Connect a complex view to the data– Define the display format of a particular cell, which can contain a

variety of sub views– Reuse the cell layout component for memory, performance efficiency

• Adapters Required Because: It is unworkable to display a large lists with thousands of components, each requiring megabytes of memory.

• Built in Android adapter classes– ArrayAdapter: Data items stored in an array– SimpleCursorAdapter: Data are rows of an SQL table

• Custom Adapter: Class that overrides various adapter methods

Adapter: object that formats the display of a single cell of a complex view

Activity using ArrayAdapterpublic class MyActivity extends Activity { private ArrayAdapter<String> instance;

@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);

setContentView(R.layout.main); // main.xml in res/layout ListView view = (ListView)findViewById(R.id.my_list_view); // scrollable list ArrayList<String> words = new ArrayList<String> // create some data (Arrays.asList("the", "quick", "green", "Android", "jumped“); int layoutID = android.R.layout.simple_list_item_1; // format of list itemsadapter = new ArrayAdapter<String>(this, layoutID, words); view.setAdapter(adapter); // Attach array adapter to the listadapter.notifyDataSetChanged(); // force redisplay of items

}}

Item class for a To Do list Applicationpublic class ToDoItem { String task; Date created; SimpleDataFormat sdf;

public ToDoItem(String task, Date created) { sdf = new SimpleDateFormat("dd/mm/yy");

task = this.task; created = this.created; } public ToDoItem(String task) { this(task, new Date(java.lang.System.currentTimeMillis())); }

public String getTask() { return task; } public Date getCreated() { return created; }

@Override public String toString() { return "("+sdf.format(created)+") "+task; }}

Goal: display a list of these To Do items

public class ToDoItemAdapter extends ArrayAdapter<ToDoItem>{ private int resource; private items = List<ToDoItem> items; private SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");

public ToDoItemAdapter(Context context, int resource, List<ToDoItem> items) { super(context, layout, items); this.resource = resource; this.items = item; } @Override public View getView(int position, View view, ViewGroup parent) { if (view == null)

{ LayoutInflater inflater = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

view = inflater.inflate(resource, null); // null = use existing context }

ToDoItem item = getItem(position); view.findViewById(R.id.rowDate).setText(sdf.format(item.getCreated())); view.findViewById(R.id.row).setText(item.getTask()); return view;

} }

Custom Adapter Code

Menu Categories• Regular option menus: Activity associated (onCreateOptionsMenu())

• Secondary menus: Rarely used menu items created separately from the parent menu appearing after regular menu items

• Submenus: A menu within a menu that appears in a floating window; options appear when the user selects a parent item

• Context menus: triggered by a long press on a view

• Popup menus: An alternate way to attach menus to a view

• Icon menus: List of icons displayed along the screen bottom

• Alternative menus: Link to applications that can handle and manipulate data from a content provider

Note: When more menu items exist than can show, a more button appears

Steps to create menus1. Choose icons to be used

• Create your own in the required sizes• Use the image asset wizard to choose one that is

standard

2. Define the menu items in XML3. Call setHasOptionsMenu(true); in onCreate() or

onCreateView()4. Code onCreateOptionsMenu() to inflate the menu5. Code the onOptionsItemSelected() menu to listen

for and handle selections

Option Menu FrameworkClasses: android.view.Menu, android.view.SubMenu, android.view.MenuItem

Regular Menu From XMLXML in file game_menu.xml<?xml version="1.0" encoding="utf-8"?>

<menu xmlns:android="http://schemas.android.com/apk/res/android"> <group android:id="@+id/menuGroup"> // Group of items tied together <item android:id="@+id/new_game" android:title="@string/new" /> <item android:id="@+id/help" android:title="@string/help" /> <group></menu>

Java Code to include the menu@Override public boolean onCreateOptionsMenu(Menu menu) { super.onCreateOptionsMenu(menu); // Allow for system menu items

MenuInflater inflater = getMenuInflater();inflater.inflate(R.menu.game_menu, menu);return true; // Force menu to be visible

} Note: Android calls onPrepareMenuOption every time a menu is invoked. Overriding this method enables dynamically changing menu items.

Menu Groups

• Definition: A sequence of items from a menu

• Purpose: Control all grouped items at once

• Examples:– menu.setGroupCheckable(id, checkable, exclusive): Check

selected items; if exclusive, only one group item can be checked

– menu.setGroupEnabled(id, enabled): Control ghosted items

– menu.setGroupVisible(id, visible): Show or hide the group items

– menu.removeGroup(id): Remove all items from the group

Creating a Menu in Code• Regular menu items

int group = Menu.CATEGORY_NONE, order=Menu.FIRST, menuID = 99;menu.add(group, menuID++, order++, "append");menu.add(group, menuID++, order++, "clear");

• Secondary menu itemsint group = Menu.CATEGORY_SECONDARYint order=Menu.FIRST, menuID = Menu.FIRST;menu.add(group, menuID++, order++, "secondary item #1");menu.add(group, menuID++, order++, R.string.secItem2);

• Java Setup code@Override public boolean onCreateOptionsMenu(Menu menu){ super.onCreateOptionsMenu(menu); // Allow for system menu items

addRegularMenuItems(menu); addSecondaryMenuItems(menu);return true; // Force menu to show

}

Respond to Menu Item Selections

@Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId())

{ case R.id.new_game: newGame(); return true; // consume this selection here

case R.id.help:showHelp(); return true; // consume this selection here

case R.id.secondary: this.myMenu.setGroupVisible(Menu.CATEGORY_SECONDARY,

true);return true; // consume this selection here

default: return super.onOptionsItemSelected(item);

} }

Android calls onOptionItemSelected method when an item is selected

Icon Menus

• In XML: android:icon="@drawable/ballons"

• In Code: item.setIcon(R.drawable.balloons);

• Restrictions – Will not appear on expanded menu options (those which

show only when the more item is selected)– Check marks are not supported

Submenus• In XML: <item android:title="Outer Menu Item>

<menu><item> . . .</item></menu>

• In Code:int base = Menu.FIRST;

∙ ∙ ∙SubMenu sub = menu.addSubMenu(base, item++ ,Menu.NONE, "submenu");sub.add(base, order++, menuID++, "sub item # 1");sub.add(base,order++, menuID++, R.string.subItem2 );

• Restrictions– Icons work with submenus, but not with individual submenu items– You cannot nest a submenu to a submenu

• Advantage: Android automatically controls the visibility

• Note: The order argument is optional; Menu.NONE indicates a default order.

Context Menus

View

onContextItemSelected()

Context Menu Creation• Ownership: view

• Creation: Activity– Register in the activities onCreate method

@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);

setContentView(R.layout.main);TextView tv = (TextView)this.findViewById(R.id.textViewId);registerForContextMenu(tv); // Indicate that view has context menu

}

– Populate: (note: info can get position for complex views)onCreateContextMenu(ContextMenu m, View v, ContextMenuInfo info)

– Listener: onContextItemSelected(MenuItem item)

Popup Menu

• Specify in an XML view declaration<ImageButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_overflow_holo_dark" android:contentDescription="@string/descr_overflow_button" android:onClick= "showPopup" />

• Activity code to display the popup public void showPopup(View v) { PopupMenu popup = new PopupMenu(this, v); MenuInflater inflater = popup.getMenuInflater(); inflater.inflate(R.menu.actions, popup.getMenu()); popup.show();} // Note: R.menu.actions refers to the XML menu declaration

It displays when touching the image, It disappears when selecting if selected or touching outside its bounds

Note: Listener attached with onMenuItemClick() method

Alternative Menus

• Application menus items can launch content providers that provide an intent filter in their manifest

• Content Providers expose data by defining a MIME type and a content URI access point for other applications

• Example: (The application Employees maintains employee data)1. MIME type: vnd.android.cursor.item/mina.android.Emps 2. Other application can access the data by calling the Uri

content://mina.android.Emps/All access all employees or the Uri content://mina.android.Emps/1 access a single employee instance

• An alternative menu item in an Application, when clicked, launches the content provider using the Uri in an intent

The Employee Content Provider• The content provider manifest defines an activity with the xml file

can handle external employee requests

<activity android:name=".Demo" android:label="@string/app_name"> <intent-filter android:label="Access Employees">

<action android:name="android.intent.action.VIEW" /> <category android:name="android.intent.category.DEFAULT" /> <category android:name="android.intent.category.ALTERNATIVE" /> <data android:mimeType="vnd.android.cursor.item/employees" />

</intent-filter> </activity>

• This activity responds to implicit launch intents with Action: Intent.ACTION_VIEW. Category: android.intent.category.ALTERNATIVE.MIME type: vnd.android.cursor.item/employees

Alternative Menu Launchpublic boolean onCreateOptionsMenu(Menu menu) { menu.add("Regular item"); //adds a regular menu item

//create intent with the employee content provider Uri Intent alternativeIntent =

new Intent(Intent.ACTION_VIEW, Uri.parse("content://employees/All")); alternativeIntent.addCategory(Intent.CATEGORY_ALTERNATIVE); menu.addIntentOptions(Menu.CATEGORY_ALTERNATIVE, // applicable group id

Menu.CATEGORY_ALTERNATIVE, //item id Menu.CATEGORY_ALTERNATIVE, //item order this.getComponentName(), //our activity class name null, //Specific menu items to place first alternativeIntent, // the intent corresponding to this selection 0, //no special flags to control menu itemsnull); // Place menu into optional array generated from specific menu items

return true; }

Add menu item to launch employee application to do alternative actions other than View, Pick, or Edit

Dialogs

• Functionality: Popup windows for user interaction

– Asynchronous: Returns immediately from the dialog call

– Modal: The dialog gets focus while the dialog popup shows– Call Back Listeners: Required to receive user inputs– Layout: Dialogs can have a layout with subcomponents

• Examples– Alerts: Simple output messages– Prompts: Accept user input– Toast: Alerts that disappear after a designated time period

Analogous to Java's JOptionPane

Alertsif (validate(field1) == false) { showAlert("Very Bad"); }

public static void showAlert(String message, Context ctx){ AlertDialog.Builder builder = new AlertDialog.Builder(ctx); //Create a builder

builder.setTitle("Alert Window");// Configure the anonymous listenerbuilder.setPositiveButton("OK", new OnClickListener(){ public void onClick(DialogInterface v, int buttonId) { /* auto dismiss */ }} ); AlertDialog alert = builder.create(); // Create the dialogalert.show(); // Make it visible

}

Prompts• Create a layout for a prompt dialog: using xml in res/layout

• Create a builder objectAlertDialog.Builder builder = new AlertDialog.Builder(context);Builder.setTitle("Why this?");

• Set the layout as the builder viewLayoutInflater promptLayout = LayoutInflater.from(activity);View view = promptLayout.inflate(R.layout.prompt, null);builder.setView(view);

• Add buttons and callbacksPromptListener listener = new PromptListener(view); // User-defined classBuilder.setPositiveButton("OK", listener); Builder.setNegativeButton("Cancel", listener);

• Create and show the dialog: AlertDialog ad = builder.create(); ad.show();

Note: For applications with many dialogs, Android provides a Managed-Dialog factory scheme for reusing previously created dialog objects

Toast

• Toast display (could be a useful debug tool)public void toastDisplay(String message){

String data = "MY_CLASS" + ":" + message;Toast toast = Toast.makeText

(activity, data, Toast.LENGTH_SHORT); // user definableToast.show();

}• Exercise the toast display function

toastDisplay("hello");toastDisplay(resources.getString(R.string.toast_msg);

An alert that displays for a period of time, and then disappears

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