Min sdk version raised to 14. Up navigation added for most activities.

app/build.gradle

@@ -6,7 +6,7 @@ android {
 
     defaultConfig {
         applicationId "com.xabber.androiddev"
-        minSdkVersion 7
+        minSdkVersion 14
         targetSdkVersion 21
     }
 

app/src/main/AndroidManifest.xml

@@ -85,19 +85,44 @@
         <activity
             android:label="@string/about_viewer"
             android:name="com.xabber.android.ui.AboutViewer"
-            />
+            android:parentActivityName="com.xabber.android.ui.PreferenceEditor"
+            >
+
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.PreferenceEditor" />
+        </activity>
         <activity
             android:label="@string/preference_accounts"
             android:name="com.xabber.android.ui.AccountList"
-            />
+            android:parentActivityName="com.xabber.android.ui.PreferenceEditor"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.PreferenceEditor" />
+        </activity>
         <activity
             android:label="@string/account_editor"
             android:name="com.xabber.android.ui.AccountEditor"
-            />
+            android:parentActivityName="com.xabber.android.ui.AccountList"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.AccountList" />
+        </activity>
         <activity
             android:label="@string/chat_list"
             android:name="com.xabber.android.ui.ChatList"
-            />
+            android:parentActivityName="com.xabber.android.ui.ContactList"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ContactList" />
+        </activity>
         <activity
             android:label="@string/occupant_list"
             android:name="com.xabber.android.ui.OccupantList"
@@ -107,23 +132,49 @@
             android:name="com.xabber.android.ui.ChatViewer"
             android:windowSoftInputMode="adjustResize"
             android:launchMode="singleTop"
+            android:parentActivityName="com.xabber.android.ui.ContactList"
             >
+
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
             </intent-filter>
+
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ContactList" />
+
         </activity>
         <activity
             android:label="@string/contact_editor"
             android:name="com.xabber.android.ui.ContactEditor"
-            />
+            android:parentActivityName="com.xabber.android.ui.ContactList"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ContactList" />
+        </activity>
         <activity
             android:label="@string/contact_add"
             android:name="com.xabber.android.ui.ContactAdd"
-            />
+            android:parentActivityName="com.xabber.android.ui.AccountList"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.AccountList" />
+        </activity>
         <activity
             android:label="@string/account_add"
             android:name="com.xabber.android.ui.AccountAdd"
-            />
+            android:parentActivityName="com.xabber.android.ui.AccountList"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.AccountList" />
+        </activity>
         <activity
             android:label="@string/account_oauth"
             android:name="com.xabber.android.ui.OAuthActivity"
@@ -131,24 +182,58 @@
         <activity
             android:label="@string/muc_add"
             android:name="com.xabber.android.ui.MUCEditor"
-            />
+            android:parentActivityName="com.xabber.android.ui.ContactList"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ContactList" />
+        </activity>
         <activity
             android:label="@string/status_editor"
             android:name="com.xabber.android.ui.StatusEditor"
-            />
+            android:parentActivityName="com.xabber.android.ui.ContactList"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ContactList" />
+        </activity>
         <activity
             android:label="@string/preference_editor"
             android:name="com.xabber.android.ui.PreferenceEditor"
-            />
+            android:parentActivityName="com.xabber.android.ui.ContactList"
+            >
+
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ContactList" />
+        </activity>
+
         <activity
             android:label="@string/chat_settings"
             android:name="com.xabber.android.ui.ChatEditor"
-            />
+            android:parentActivityName="com.xabber.android.ui.ChatViewer"
+            >
+
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ChatViewer" />
+        </activity>
+
         <activity
             android:label="@string/contact_viewer"
             android:name="com.xabber.android.ui.ContactViewer"
             android:icon="@drawable/ic_information"
+            android:parentActivityName="com.xabber.android.ui.ContactList"
             >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ContactList" />
+
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
@@ -160,11 +245,24 @@
         <activity
             android:name="com.xabber.android.ui.FingerprintViewer"
             android:label="@string/otr_verify_fingerprint"
-            />
+            android:parentActivityName="com.xabber.android.ui.ChatViewer"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ChatViewer" />
+        </activity>
+
         <activity
             android:name="com.xabber.android.ui.QuestionViewer"
             android:label="@string/otr_verify_fingerprint"
-            />
+            android:parentActivityName="com.xabber.android.ui.ChatViewer"
+            >
+            <!-- Parent activity meta-data to support 4.0 and lower -->
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value="com.xabber.android.ui.ChatViewer" />
+        </activity>
 
         <activity
             android:name="com.xabber.android.ui.ContactSubscription"
@@ -200,6 +298,8 @@
             android:stateNotNeeded="true"
             android:excludeFromRecents="true"
             />
+
+
         <service android:name="com.xabber.android.service.XabberService" />
         <service
             android:name="com.xabber.android.service.SyncAdapterService"

app/src/main/java/com/xabber/android/ui/AboutViewer.java

@@ -17,7 +17,9 @@ package com.xabber.android.ui;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
+import android.support.v4.app.NavUtils;
 import android.text.method.LinkMovementMethod;
+import android.view.MenuItem;
 import android.widget.TextView;
 
 import com.xabber.android.ui.helper.ManagedActivity;
@@ -34,10 +36,23 @@ public class AboutViewer extends ManagedActivity {
 						getString(R.string.application_version)));
 		((TextView) findViewById(R.id.about_license))
 				.setMovementMethod(LinkMovementMethod.getInstance());
+
+        getActionBar().setDisplayHomeAsUpEnabled(true);
 	}
 
 	public static Intent createIntent(Context context) {
 		return new Intent(context, AboutViewer.class);
 	}
 
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            // Respond to the action bar's Up/Home button
+            case android.R.id.home:
+                NavUtils.navigateUpFromSameTask(this);
+                return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
 }

app/src/main/java/com/xabber/android/ui/AccountAdd.java

@@ -83,6 +83,8 @@ public class AccountAdd extends ManagedActivity implements
 		InputMethodManager inputManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
 		inputManager.hideSoftInputFromWindow(findViewById(R.id.ok)
 				.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
+
+        getActionBar().setDisplayHomeAsUpEnabled(true);
 	}
 
 	@Override

app/src/main/java/com/xabber/android/ui/AccountEditor.java

@@ -50,6 +50,12 @@ public class AccountEditor extends BaseSettingsActivity implements
 
 	private Preference oauthPreference;
 
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        getActionBar().setDisplayHomeAsUpEnabled(true);
+    }
+
     @Override
 	protected void onInflate(Bundle savedInstanceState) {
 		account = AccountEditor.getAccount(getIntent());

app/src/main/java/com/xabber/android/ui/AccountList.java

@@ -37,6 +37,12 @@ public class AccountList extends BaseListEditor<String> implements
 	private static final int CONTEXT_MENU_VIEW_ACCOUNT_ID = 0x20;
 	private static final int CONTEXT_MENU_STATUS_EDITOR_ID = 0x30;
 
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        getActionBar().setDisplayHomeAsUpEnabled(true);
+    }
+
     @Override
 	protected int getAddTextResourceId() {
 		return R.string.account_add;

app/src/main/java/com/xabber/android/ui/ChatEditor.java

@@ -35,6 +35,13 @@ public class ChatEditor extends BaseSettingsActivity {
 	private String account;
 	private String user;
 
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        getActionBar().setDisplayHomeAsUpEnabled(true);
+    }
+
     @Override
 	protected void onInflate(Bundle savedInstanceState) {
 		account = getAccount(getIntent());

app/src/main/java/com/xabber/android/ui/ChatList.java

@@ -49,6 +49,8 @@ public class ChatList extends ManagedListActivity implements
 		listAdapter = new ChatListAdapter(this);
 		setListAdapter(listAdapter);
 		getListView().setOnItemClickListener(this);
+
+        getActionBar().setDisplayHomeAsUpEnabled(true);
 	}
 
 	@Override

app/src/main/java/com/xabber/android/ui/ChatViewer.java

@@ -19,8 +19,10 @@ import java.util.Collection;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
+import android.support.v4.app.NavUtils;
 import android.view.KeyEvent;
 import android.view.Menu;
+import android.view.MenuItem;
 import android.view.View;
 
 import com.xabber.android.data.ActivityManager;
@@ -113,6 +115,8 @@ public class ChatViewer extends ManagedActivity implements OnSelectListener,
 		if (actionWithUser == null)
 			actionWithUser = user;
 
+        getActionBar().setDisplayHomeAsUpEnabled(true);
+
 		selectChat(actionWithAccount, actionWithUser);
 	}
 
@@ -392,4 +396,15 @@ public class ChatViewer extends ManagedActivity implements OnSelectListener,
 		return ACTION_ATTENTION.equals(intent.getAction());
 	}
 
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            // Respond to the action bar's Up/Home button
+            case android.R.id.home:
+                NavUtils.navigateUpFromSameTask(this);
+                return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
 }

app/src/main/java/com/xabber/android/ui/ContactAdd.java

@@ -58,6 +58,13 @@ public class ContactAdd extends GroupListActivity implements
 	private EditText userView;
 	private EditText nameView;
 
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        getActionBar().setDisplayHomeAsUpEnabled(true);
+    }
+
     @Override
 	protected void onInflate(Bundle savedInstanceState) {
 		setContentView(R.layout.contact_add);

app/src/main/java/com/xabber/android/ui/ContactEditor.java

@@ -43,6 +43,13 @@ public class ContactEditor extends GroupListActivity implements
 	private String account;
 	private String user;
 
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        getActionBar().setDisplayHomeAsUpEnabled(true);
+    }
+
     @Override
 	protected void onInflate(Bundle savedInstanceState) {
 		setContentView(R.layout.contact_editor);

app/src/main/java/com/xabber/android/ui/ContactViewer.java

@@ -203,6 +203,8 @@ public class ContactViewer extends ManagedPreferenceActivity implements
 				}
 		}
 		setTitle(getString(R.string.contact_viewer_for, bareAddress));
+
+        getActionBar().setDisplayHomeAsUpEnabled(true);
 	}
 
 	@Override

app/src/main/java/com/xabber/android/ui/FingerprintViewer.java

@@ -119,6 +119,8 @@ public class FingerprintViewer extends ManagedActivity implements
 		copyView = findViewById(R.id.copy);
 		copyView.setOnClickListener(this);
 		isUpdating = false;
+
+        getActionBar().setDisplayHomeAsUpEnabled(true);
 	}
 
 	@Override

app/src/main/java/com/xabber/android/ui/MUCEditor.java

@@ -72,6 +72,8 @@ public class MUCEditor extends ManagedActivity implements View.OnClickListener,
 
 		setContentView(R.layout.muc_editor);
 
+        getActionBar().setDisplayHomeAsUpEnabled(true);
+
 		accountView = (Spinner) findViewById(R.id.contact_account);
 		serverView = (EditText) findViewById(R.id.muc_server);
 		roomView = (EditText) findViewById(R.id.muc_room);

app/src/main/java/com/xabber/android/ui/PreferenceEditor.java

@@ -53,6 +53,8 @@ public class PreferenceEditor extends ManagedPreferenceActivity implements
 		if (isFinishing())
 			return;
 
+        getActionBar().setDisplayHomeAsUpEnabled(true);
+
 		addPreferencesFromResource(R.xml.preference_editor);
 
 		getPreferenceScreen().findPreference(

app/src/main/java/com/xabber/android/ui/QuestionViewer.java

@@ -98,6 +98,8 @@ public class QuestionViewer extends ManagedActivity implements
 			setContentView(R.layout.secret_viewer);
 		findViewById(R.id.cancel).setOnClickListener(this);
 		findViewById(R.id.send).setOnClickListener(this);
+
+        getActionBar().setDisplayHomeAsUpEnabled(true);
 	}
 
 	@Override

app/src/main/java/com/xabber/android/ui/StatusEditor.java

@@ -72,6 +72,8 @@ public class StatusEditor extends ManagedListActivity implements
 
 		setContentView(R.layout.status_editor);
 
+        getActionBar().setDisplayHomeAsUpEnabled(true);
+
 		Intent intent = getIntent();
 		account = StatusEditor.getAccount(intent);
 		if (account == null)