Feature: Preference

app/build.gradle

@@ -41,4 +41,5 @@ dependencies {
     testCompile 'junit:junit:4.12'
     compile 'com.android.support.constraint:constraint-layout:1.0.2'
     compile project(':chrome-tabs')
+    implementation 'com.android.support:design:25.3.1'
 }

app/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="io.neoterm">
 
+    <uses-permission android:name="android.permission.VIBRATE" />
+
     <application
         android:allowBackup="true"
         android:extractNativeLibs="true"
@@ -22,19 +24,15 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
-
         <activity
             android:name=".ui.settings.SettingActivity"
             android:theme="@style/Theme.AppCompat" />
-
         <activity
             android:name=".ui.settings.GeneralSettingsActivity"
             android:theme="@style/Theme.AppCompat" />
-
         <activity
             android:name=".ui.settings.UISettingsActivity"
             android:theme="@style/Theme.AppCompat" />
-
         <activity
             android:name=".ui.settings.PackageSettingsActivity"
             android:theme="@style/Theme.AppCompat" />
@@ -42,6 +40,11 @@
         <service
             android:name=".services.NeoTermService"
             android:enabled="true" />
+
+        <activity
+            android:name=".ui.AboutActivity"
+            android:label="@string/about"
+            android:theme="@style/AppTheme.NoActionBar" />
     </application>
 
 </manifest>

app/src/main/java/io/neoterm/preference/NeoTermPreference.kt

@@ -1,6 +1,7 @@
 package io.neoterm.preference
 
 import android.content.Context
+import android.content.SharedPreferences
 import android.preference.PreferenceManager
 import io.neoterm.backend.TerminalSession
 import io.neoterm.services.NeoTermService
@@ -10,17 +11,66 @@ import io.neoterm.services.NeoTermService
  */
 
 object NeoTermPreference {
-    var CURRENT_SESSION_KEY = "neoterm_current_session"
+    const val KEY_FONT_SIZE = "neoterm_general_font_size"
+    const val KEY_CURRENT_SESSION = "neoterm_service_current_session"
 
-    fun storeCurrentSession(context: Context, session: TerminalSession) {
+    var preference: SharedPreferences? = null
-        PreferenceManager.getDefaultSharedPreferences(context)
+    var context: Context? = null
-                .edit()
+
-                .putString(NeoTermPreference.CURRENT_SESSION_KEY, session.mHandle)
+    fun init(context: Context) {
+        this.context = context
+        preference = PreferenceManager.getDefaultSharedPreferences(context)
+    }
+
+    fun cleanup() {
+        preference = null
+        context = null
+    }
+
+    fun store(key: Int, value: Any) {
+        store(context!!.getString(key), value)
+    }
+
+    fun store(key: String, value: Any) {
+        when (value) {
+            is Int -> preference!!.edit().putInt(key, value).apply()
+            is String -> preference!!.edit().putString(key, value).apply()
+            is Boolean -> preference!!.edit().putBoolean(key, value).apply()
+        }
+    }
+
+    fun loadInt(key: Int, defaultValue: Int): Int {
+        return loadInt(context!!.getString(key), defaultValue)
+    }
+
+    fun loadString(key: Int, defaultValue: String?): String {
+        return loadString(context!!.getString(key), defaultValue)
+    }
+
+    fun loadBoolean(key: Int, defaultValue: Boolean): Boolean {
+        return loadBoolean(context!!.getString(key), defaultValue)
+    }
+
+    fun loadInt(key: String, defaultValue: Int): Int {
+        return preference!!.getInt(key, defaultValue)
+    }
+
+    fun loadString(key: String, defaultValue: String?): String {
+        return preference!!.getString(key, defaultValue)
+    }
+
+    fun loadBoolean(key: String, defaultValue: Boolean): Boolean {
+        return preference!!.getBoolean(key, defaultValue)
+    }
+
+    fun storeCurrentSession(session: TerminalSession) {
+        preference!!.edit()
+                .putString(NeoTermPreference.KEY_CURRENT_SESSION, session.mHandle)
                 .apply()
     }
 
     fun getCurrentSession(termService: NeoTermService?): TerminalSession? {
-        val sessionHandle = PreferenceManager.getDefaultSharedPreferences(termService!!).getString(CURRENT_SESSION_KEY, "")
+        val sessionHandle = PreferenceManager.getDefaultSharedPreferences(termService!!).getString(KEY_CURRENT_SESSION, "")
         var i = 0
         val len = termService.sessions.size
         while (i < len) {

app/src/main/java/io/neoterm/ui/AboutActivity.kt

@@ -0,0 +1,25 @@
+package io.neoterm.ui
+
+import android.os.Bundle
+import android.support.design.widget.FloatingActionButton
+import android.support.design.widget.Snackbar
+import android.support.v7.app.AppCompatActivity
+import android.support.v7.widget.Toolbar
+
+import io.neoterm.R
+
+class AboutActivity : AppCompatActivity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_about)
+        val toolbar = findViewById(R.id.about_toolbar) as Toolbar
+        setSupportActionBar(toolbar)
+
+        val fab = findViewById(R.id.about_fab) as FloatingActionButton
+        fab.setOnClickListener({ view ->
+            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
+                    .setAction("Action", null).show()
+        })
+    }
+}

app/src/main/java/io/neoterm/ui/NeoTermActivity.kt

@@ -12,6 +12,7 @@ import android.support.v7.app.AppCompatActivity
 import android.support.v7.widget.Toolbar
 import android.view.KeyEvent
 import android.view.View
+import android.view.WindowManager
 import android.widget.ImageButton
 import de.mrapp.android.tabswitcher.*
 import de.mrapp.android.tabswitcher.view.TabSwitcherButton
@@ -45,11 +46,20 @@ class NeoTermActivity : AppCompatActivity(), ServiceConnection {
                 addNewSession(session)
             }
             switchToSession(getStoredCurrentSessionOrLast())
+        } else {
+            tabSwitcher.showSwitcher()
+            addNewSession("NeoTerm #0", createRevealAnimation())
         }
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        NeoTermPreference.init(this)
+        if (NeoTermPreference.loadBoolean(R.string.key_ui_fullscreen, false)) {
+            window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
+                    WindowManager.LayoutParams.FLAG_FULLSCREEN)
+        }
+
         setContentView(R.layout.tab_main)
 
         tabSwitcher = findViewById(R.id.tab_switcher) as TabSwitcher
@@ -68,16 +78,16 @@ class NeoTermActivity : AppCompatActivity(), ServiceConnection {
     override fun onResume() {
         super.onResume()
         tabSwitcher.addListener(object : TabSwitcherListener {
-            private var tabSwitcherButtonInited = false
+            private var tabSwitcherButtonInit = false
 
             override fun onSwitcherShown(tabSwitcher: TabSwitcher) {
-                if (tabSwitcherButtonInited) {
+                if (tabSwitcherButtonInit) {
                     return
                 }
 
                 val menu = tabSwitcher.toolbarMenu
                 if (menu != null) {
-                    tabSwitcherButtonInited = true
+                    tabSwitcherButtonInit = true
                     val tabSwitcherButton = menu.findItem(R.id.toggle_tab_switcher_menu_item).actionView as TabSwitcherButton
                     tabSwitcherButton.setOnClickListener {
                         if (tabSwitcher.isSwitcherShown) {
@@ -94,7 +104,7 @@ class NeoTermActivity : AppCompatActivity(), ServiceConnection {
 
             override fun onSelectionChanged(tabSwitcher: TabSwitcher, selectedTabIndex: Int, selectedTab: Tab?) {
                 if (selectedTab is TermTab && selectedTab.termSession != null) {
-                    NeoTermPreference.storeCurrentSession(this@NeoTermActivity, selectedTab.termSession!!)
+                    NeoTermPreference.storeCurrentSession(selectedTab.termSession!!)
                 }
             }
 
@@ -125,6 +135,7 @@ class NeoTermActivity : AppCompatActivity(), ServiceConnection {
             termService = null
         }
         unbindService(this)
+        NeoTermPreference.cleanup()
     }
 
     override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {

app/src/main/java/io/neoterm/view/tab/TermSessionChangedCallback.kt

@@ -3,7 +3,11 @@ package io.neoterm.view.tab
 import android.content.ClipData
 import android.content.ClipboardManager
 import android.content.Context
+import android.media.SoundPool
+import android.os.Vibrator
+import io.neoterm.R
 import io.neoterm.backend.TerminalSession
+import io.neoterm.preference.NeoTermPreference
 import io.neoterm.view.TerminalView
 
 /**
@@ -13,6 +17,9 @@ class TermSessionChangedCallback : TerminalSession.SessionChangedCallback {
     var termView: TerminalView? = null
     var termTab: TermTab? = null
 
+    var bellId: Int = 0
+    var soundPool: SoundPool? = null
+
     override fun onTextChanged(changedSession: TerminalSession?) {
         termView?.onScreenUpdated()
     }
@@ -35,6 +42,22 @@ class TermSessionChangedCallback : TerminalSession.SessionChangedCallback {
     }
 
     override fun onBell(session: TerminalSession?) {
+        if (termView == null) {
+            return
+        }
+
+        if (NeoTermPreference.loadBoolean(R.string.key_general_bell, false)) {
+            if (soundPool == null) {
+                soundPool = SoundPool.Builder().setMaxStreams(1).build()
+                bellId = soundPool!!.load(termView!!.context, R.raw.bell, 1)
+            }
+            soundPool?.play(bellId, 1f, 1f, 0, 0, 1f)
+        }
+
+        if (NeoTermPreference.loadBoolean(R.string.key_general_vibrate, false)) {
+            val vibrator = termView!!.context.getSystemService(Context.VIBRATOR_SERVICE) as Vibrator
+            vibrator.vibrate(100)
+        }
     }
 
     override fun onColorsChanged(session: TerminalSession?) {

app/src/main/java/io/neoterm/view/tab/TermTabDecorator.kt

@@ -10,9 +10,9 @@ import android.view.ViewGroup
 import de.mrapp.android.tabswitcher.Tab
 import de.mrapp.android.tabswitcher.TabSwitcher
 import de.mrapp.android.tabswitcher.TabSwitcherDecorator
-import io.neoterm.ui.NeoTermActivity
 import io.neoterm.R
-import io.neoterm.customize.color.builtin.MaterialColorScheme
+import io.neoterm.preference.NeoTermPreference
+import io.neoterm.ui.NeoTermActivity
 import io.neoterm.view.ExtraKeysView
 import io.neoterm.view.TerminalView
 
@@ -59,7 +59,7 @@ class TermTabDecorator(val context: NeoTermActivity) : TabSwitcherDecorator() {
         if (view == null) {
             return
         }
-        view.textSize = 30
+        view.textSize = NeoTermPreference.loadInt(NeoTermPreference.KEY_FONT_SIZE, 30)
         view.setTypeface(Typeface.MONOSPACE)
 
         if (tab is TermTab) {

app/src/main/java/io/neoterm/view/tab/TermViewClient.kt

@@ -5,7 +5,9 @@ import android.view.InputDevice
 import android.view.KeyEvent
 import android.view.MotionEvent
 import android.view.inputmethod.InputMethodManager
+import io.neoterm.R
 import io.neoterm.backend.TerminalSession
+import io.neoterm.preference.NeoTermPreference
 import io.neoterm.view.ExtraKeysView
 import io.neoterm.view.TerminalView
 import io.neoterm.view.TerminalViewClient
@@ -27,7 +29,9 @@ class TermViewClient(val context: Context) : TerminalViewClient {
         if (scale < 0.9f || scale > 1.1f) {
             val increase = scale > 1f
             val changedSize = (if (increase) 1 else -1) * 2
-            termView!!.textSize = termView!!.textSize + changedSize
+            val fontSize = termView!!.textSize + changedSize
+            termView!!.textSize = fontSize
+            NeoTermPreference.store(NeoTermPreference.KEY_FONT_SIZE, fontSize)
             return 1.0f
         }
         return scale
@@ -39,7 +43,7 @@ class TermViewClient(val context: Context) : TerminalViewClient {
     }
 
     override fun shouldBackButtonBeMappedToEscape(): Boolean {
-        return false
+        return NeoTermPreference.loadBoolean(R.string.key_generaL_backspace_map_to_esc, false)
     }
 
     override fun copyModeChanged(copyMode: Boolean) {

app/src/main/res/drawable/ic_terminal_running_white.xml

@@ -0,0 +1,33 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:height="48dp"
+    android:width="48dp"
+    android:viewportWidth="48"
+    android:viewportHeight="48">
+    <!--
+        https://material.google.com/style/icons.html
+    -->
+
+    <!-- Screen border. -->
+    <path android:fillColor="#fafafa"
+          android:strokeColor="#212121"
+          android:strokeWidth="3"
+          android:pathData="M7,4
+                            l34,0
+                            q3 0,3 3
+                            l0,34
+                            q0 3, -3 3
+                            l-34,0
+                            q-3 0, -3-3
+                            l0 -34
+                            q0 -3, 3 -3"
+          />
+
+    <!-- Block cursor. -->
+    <path android:fillColor="#000"
+          android:pathData="M14,14
+                            l5,0
+                            l0,10
+                            l-5,0"
+        />
+
+</vector>

app/src/main/res/layout/activity_about.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:fitsSystemWindows="true"
+    tools:context="io.neoterm.ui.AboutActivity">
+
+    <android.support.design.widget.AppBarLayout
+        android:id="@+id/app_bar"
+        android:layout_width="match_parent"
+        android:layout_height="@dimen/app_bar_height"
+        android:fitsSystemWindows="true"
+        android:theme="@style/AppTheme.AppBarOverlay">
+
+        <android.support.design.widget.CollapsingToolbarLayout
+            android:id="@+id/toolbar_layout"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:fitsSystemWindows="true"
+            app:contentScrim="?attr/colorPrimary"
+            app:layout_scrollFlags="scroll|exitUntilCollapsed"
+            app:toolbarId="@+id/about_toolbar">
+
+            <android.support.v7.widget.Toolbar
+                android:id="@+id/about_toolbar"
+                android:layout_width="match_parent"
+                android:layout_height="?attr/actionBarSize"
+                app:layout_collapseMode="pin"
+                app:popupTheme="@style/AppTheme.PopupOverlay" />
+
+        </android.support.design.widget.CollapsingToolbarLayout>
+    </android.support.design.widget.AppBarLayout>
+
+    <include layout="@layout/content_about" />
+
+    <android.support.design.widget.FloatingActionButton
+        android:id="@+id/about_fab"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_margin="@dimen/fab_margin"
+        app:layout_anchor="@id/app_bar"
+        app:layout_anchorGravity="bottom|end"
+        app:srcCompat="@drawable/ic_terminal_running_white" />
+
+</android.support.design.widget.CoordinatorLayout>

app/src/main/res/layout/content_about.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    app:layout_behavior="@string/appbar_scrolling_view_behavior"
+    tools:context="io.neoterm.ui.AboutActivity"
+    tools:showIn="@layout/activity_about">
+
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_margin="@dimen/text_margin"
+        android:text="@string/large_text" />
+
+</android.support.v4.widget.NestedScrollView>

app/src/main/res/layout/tab_main.xml

@@ -5,7 +5,7 @@
     xmlns:custom="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:background="#ff14181c"
+    android:background="@color/terminal_background"
     custom:layoutPolicy="auto"
     custom:tabBackgroundColor="@color/tab_background_color"
     custom:tabIcon="@drawable/ic_tab_icon"

app/src/main/res/values/colors.xml

@@ -2,6 +2,6 @@
 <resources>
     <color name="colorPrimary">#607D8B</color>
     <color name="colorPrimaryDark">#455A64</color>
-    <color name="colorAccent">#03A9F4</color>
+    <color name="colorAccent">#FF5252</color>
-    <color name="terminal_background">#13181a</color>
+    <color name="terminal_background">#ff14181c</color>
 </resources>

app/src/main/res/values/dimens.xml

@@ -0,0 +1,5 @@
+<resources>
+    <dimen name="app_bar_height">180dp</dimen>
+    <dimen name="fab_margin">16dp</dimen>
+    <dimen name="text_margin">16dp</dimen>
+</resources>

app/src/main/res/values/preference_keys.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="key_general_bell" translatable="false">neoterm_general_bell</string>
+    <string name="key_general_vibrate" translatable="false">neoterm_general_vibrate</string>
+    <string name="key_generaL_backspace_map_to_esc">neoterm_general_backspace_map_to_esc</string>
+
+    <string name="key_ui_fullscreen" translatable="false">neoterm_ui_fullscreen</string>
+    <string name="key_ui_font" translatable="false">neoterm_ui_font</string>
+    <string name="key_ui_color_scheme" translatable="false">neoterm_ui_color_scheme</string>
+
+    <string name="key_package_source" translatable="false">neoterm_package_source</string>
+</resources>

app/src/main/res/values/strings.xml

@@ -12,4 +12,17 @@
     <string name="general_settings">General Settings</string>
     <string name="ui_settings">UI Settings</string>
     <string name="package_settings">Package Settings</string>
+
+    <string name="large_text">Hello NeoTerm.</string>
+
+    <string name="pref_general_bell">Bell</string>
+    <string name="pref_general_bell_desc">Bell when receiving \'\\a\'</string>
+    <string name="pref_general_vibrate">Vibrate</string>
+    <string name="pref_general_vibrate_desc">Vibrate when receiving \'\\a\'</string>
+    <string name="pref_general_backspace_map_to_esc">BackSpace Mapped to Esc</string>
+    <string name="pref_general_backspace_map_to_esc_desc">Send esc when backspace is pressed</string>
+    <string name="pref_ui_fullscreen">Full Screen</string>
+    <string name="pref_ui_font">Font</string>
+    <string name="pref_ui_color_scheme">Color Scheme</string>
+    <string name="pref_package_source">Source</string>
 </resources>

app/src/main/res/values/styles.xml

@@ -1,7 +1,7 @@
 <resources>
 
     <!-- Base application theme. -->
-    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar" >
+    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
         <item name="colorAccent">@color/colorAccent</item>
         <item name="colorPrimary">@color/colorPrimary</item>
         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
@@ -12,4 +12,8 @@
         <item name="windowNoTitle">true</item>
     </style>
 
+    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
+
+    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
+
 </resources>

app/src/main/res/xml/setting_general.xml

@@ -1,4 +1,21 @@
 <?xml version="1.0" encoding="utf-8"?>
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
+    <CheckBoxPreference
+        android:defaultValue="false"
+        android:key="@string/key_general_bell"
+        android:summary="@string/pref_general_bell_desc"
+        android:title="@string/pref_general_bell" />
+
+    <CheckBoxPreference
+        android:defaultValue="false"
+        android:key="@string/key_general_vibrate"
+        android:summary="@string/pref_general_vibrate_desc"
+        android:title="@string/pref_general_vibrate" />
+
+    <CheckBoxPreference
+        android:defaultValue="false"
+        android:key="@string/key_generaL_backspace_map_to_esc"
+        android:summary="@string/pref_general_backspace_map_to_esc_desc"
+        android:title="@string/pref_general_backspace_map_to_esc" />
 
 </PreferenceScreen>

app/src/main/res/xml/settings_main.xml

@@ -1,25 +1,33 @@
 <?xml version="1.0" encoding="utf-8"?>
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
 
-    <Preference android:title="@string/general_settings">
+    <Preference
+        android:icon="@drawable/ic_general_white_36dp"
+        android:title="@string/general_settings">
         <intent
             android:targetClass="io.neoterm.ui.settings.GeneralSettingsActivity"
             android:targetPackage="io.neoterm" />
     </Preference>
 
-    <Preference android:title="@string/ui_settings" >
+    <Preference
+        android:icon="@drawable/ic_ui_white_36dp"
+        android:title="@string/ui_settings">
         <intent
             android:targetClass="io.neoterm.ui.settings.UISettingsActivity"
             android:targetPackage="io.neoterm" />
     </Preference>
 
-    <Preference android:title="@string/package_settings" >
+    <Preference
+        android:icon="@drawable/ic_apps_white_36dp"
+        android:title="@string/package_settings">
         <intent
             android:targetClass="io.neoterm.ui.settings.PackageSettingsActivity"
             android:targetPackage="io.neoterm" />
     </Preference>
 
-    <Preference android:title="@string/about" >
+    <Preference
+        android:icon="@drawable/ic_info_white_36dp"
+        android:title="@string/about">
         <intent
             android:targetClass="io.neoterm.ui.AboutActivity"
             android:targetPackage="io.neoterm" />

app/src/main/res/xml/settings_package.xml

@@ -1,4 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
 
+    <EditTextPreference
+        android:key="@string/key_package_source"
+        android:title="@string/pref_package_source" />
 </PreferenceScreen>

app/src/main/res/xml/settings_ui.xml

@@ -1,4 +1,18 @@
 <?xml version="1.0" encoding="utf-8"?>
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
 
+    <CheckBoxPreference
+        android:defaultValue="false"
+        android:key="@string/key_ui_fullscreen"
+        android:title="@string/pref_ui_fullscreen" />
+
+    <EditTextPreference
+        android:key="@string/key_ui_font"
+        android:title="@string/pref_ui_font" />
+
+    <ListPreference
+        android:entries="@null"
+        android:entryValues="@null"
+        android:key="@string/key_ui_color_scheme"
+        android:title="@string/pref_ui_color_scheme" />
 </PreferenceScreen>

chrome-tabs/src/main/java/de/mrapp/android/tabswitcher/TabSwitcher.java

@@ -1418,7 +1418,7 @@ public class TabSwitcher extends FrameLayout implements TabSwitcherLayout, Model
         savedState.modelState = new Bundle();
 
         Pair<Integer, Float> pair = null;
-        if (getCount() > 0) {
+        if (getCount() > 0 && layout != null) {
             pair = layout.detachLayout(true);
         }
 
@@ -1434,8 +1434,10 @@ public class TabSwitcher extends FrameLayout implements TabSwitcherLayout, Model
             model.setFirstVisibleTabIndex(-1);
         }
 
-        model.removeListener(layout);
+        if (layout != null) {
-        layout = null;
+            model.removeListener(layout);
+            layout = null;
+        }
         executePendingAction();
         getViewTreeObserver().addOnGlobalLayoutListener(
                 new LayoutListenerWrapper(this, createGlobalLayoutListener(true)));