@2011 mihail l. sichitiu1 android introduction gui menu many thanks to jun bum lim for his help with...
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@2011 Mihail L. Sichitiu 1
Android Introduction
GUI Menu
Many thanks to Jun Bum Lim for his help with this tutorial.
@2011 Mihail L. Sichitiu 2
Goal Create an application that supports
options/sub/context menus
<option menu> <sub-menu> <context menu>
Automatically fill “Hi!” in the EditText
Plus menu willalso open a sub-menu
Display messages whena menu clicked
@2011 Mihail L. Sichitiu 3
Menu Composition
Plus
Home
Pre
Next
<option menu>
Sub1
Sub2
Hi
Hola
Hello<sub-menu>
<context menu from EditText>
Long press in EditText
@2011 Mihail L. Sichitiu 4
Create HelloMenu Project Create the two TextViews
and an EditText Create “menu” folder in
res/ Create menu.xml in
res/menu/ (New > Other > Android XML File)
Create context_menu.xml in res/menu/
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res/menu/menu.xml
<?xml version="1.0" encoding="utf-8"?><menu xmlns:android="http://schemas.android.com/apk/res/android"> <item android:id="@+id/menuItemPlus" android:title="@string/plus" android:icon="@drawable/plus" > <menu> <item android:id="@+id/menuItemSub1" android:title="@string/sub1"></item> <item android:id="@+id/menuItemSub2" android:title="@string/sub2"></item> </menu> </item> <item android:icon="@drawable/home" android:id="@+id/menuItemHome" android:title="@string/home"></item> <item android:icon="@drawable/pre" android:id="@+id/menuItemPre" android:title="@string/pre"></item> <item android:icon="@drawable/next" android:id="@+id/menuItemNext" android:title="@string/next"></item></menu>
Sub-menu items
Option menu items
Define Option menu and sub-menu
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res/menu/context.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"> <item android:id="@+id/menuItemHi" android:title="@string/hi_msg"></item> <item android:id="@+id/menuItemHola" android:title="@string/hola_msg"></item> <item android:id="@+id/menuItemHello" android:title="@string/hello_msg"></item></menu>
Define context menu for EditText
@2011 Mihail L. Sichitiu 7
res/values/strings.xml
<?xml version="1.0" encoding="utf-8"?><resources> <string name="hello">Click Menu Button ! </string> <string name="app_name">Android Menu Example</string> <string name="plus">Plus</string> <string name="pre">Pre</string> <string name="next">Next</string> <string name="home">Home</string> <string name="sub1">Sub1</string> <string name="sub2">Sub2</string> <string name="hi_msg">Hi !</string> <string name="hola_msg">Hola !</string> <string name="hello_msg">Hello !</string></resources>
Define constant strings used in the application
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icons Place icons used in menu.xml in res/drawable/
icons
Download icons at:http://www4.ncsu.edu/~mlsichit/UCAB/resources.html
@2011 Mihail L. Sichitiu 9
Inflating a option menu resource Inflating a menu resource (menu.xml) by adding onCreateOptionsMenu(Menu menu) in the main Activity.
Menu items in menu.xml will appear when the user touches the MENU button
public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.menu, menu); return true;}
public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.menu, menu); return true;}
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Response to user action Response to menu click events by overriding onOptionsItemSelected(Menu menu) in the main Activity.
@Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.menuItemPlus: Toast.makeText(this, "Plus Button Clicked !", Toast.LENGTH_SHORT).show(); Log.i(TAG,"menuItemPlus"); return true; : : case R.id.menuItemNext: Toast.makeText(this, "Next Button Clicked !", Toast.LENGTH_SHORT).show(); Log.i(TAG,"menuItemNext"); return true; } return false; }
@Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.menuItemPlus: Toast.makeText(this, "Plus Button Clicked !", Toast.LENGTH_SHORT).show(); Log.i(TAG,"menuItemPlus"); return true; : : case R.id.menuItemNext: Toast.makeText(this, "Next Button Clicked !", Toast.LENGTH_SHORT).show(); Log.i(TAG,"menuItemNext"); return true; } return false; }
@2011 Mihail L. Sichitiu 11
Register View for a context menu By calling registerForContextMenu() and
passing it a View (an EditText in this example) you assign it a context menu.
When this View (EditText) receives a long-press, it displays a context menu.
public class AndroidMenuExampleActivity extends Activity {
private EditText mOutEditText; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mOutEditText = (EditText) findViewById(R.id.editText); registerForContextMenu(mOutEditText); } : :
public class AndroidMenuExampleActivity extends Activity {
private EditText mOutEditText; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mOutEditText = (EditText) findViewById(R.id.editText); registerForContextMenu(mOutEditText); } : :
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Define context menu’s appearanceBy overriding the activity's context menu create callback method, onCreateContextMenu().
@Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.context_menu, menu); }
@Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.context_menu, menu); }
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Define context menu’s behavior
By overriding your activity's menu selection callback method for context menu , onContextItemSelected().
@Override public boolean onContextItemSelected(MenuItem item) { Log.i(TAG,"ContextItem selected"); AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo(); switch (item.getItemId()) { case R.id.menuItemHi: mOutEditText.setText( this.getResources().getText( R.string.hi_msg) ); return true; case R.id.menuItemHola: : : default: return super.onContextItemSelected(item); } }
@Override public boolean onContextItemSelected(MenuItem item) { Log.i(TAG,"ContextItem selected"); AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo(); switch (item.getItemId()) { case R.id.menuItemHi: mOutEditText.setText( this.getResources().getText( R.string.hi_msg) ); return true; case R.id.menuItemHola: : : default: return super.onContextItemSelected(item); } }