Made vocabularyAdapter nullable

.idea/misc.xml

@@ -35,7 +35,7 @@
       </value>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">

app/src/main/java/com/paktalin/vocabularynotebook/ui/activities/MainActivity.kt

@@ -27,7 +27,7 @@ import kotlinx.android.synthetic.main.word_item.*
 class MainActivity : AppCompatActivity() {
 
     var searchView: SearchView? = null
-    lateinit var vocabularyAdapter: VocabularyAdapter
+    var vocabularyAdapter: VocabularyAdapter? = null
     private var tagFragment = TagFragment()
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -52,7 +52,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     override fun onOptionsItemSelected(item: MenuItem?): Boolean {
-        vocabularyAdapter.sort = when (item!!.itemId) {
+        vocabularyAdapter?.sort = when (item!!.itemId) {
             R.id.sortByWord -> Sort.BY_WORD
             R.id.sortByTranslation -> Sort.BY_TRANSLATION
             else -> Sort.BY_TIME
@@ -66,7 +66,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun refreshVocabulary() {
-        vocabularyAdapter.refresh()
+        vocabularyAdapter?.refresh()
         swipeRefresh.isRefreshing = false
     }
 
@@ -128,20 +128,22 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun setUpSelectionTracker() {
-        vocabularyAdapter.selectionTracker = MySelectionTracker().apply {
+        vocabularyAdapter?.selectionTracker = MySelectionTracker().apply {
             init(recyclerView)
             addObserver { selection -> whenSelectionChanges(selection) }
         }
     }
 
     private fun whenSelectionChanges(selection: Selection<Long>) {
-        if (!selection.isEmpty && vocabularyAdapter.state.notAddOrEdit()) {
-            vocabularyAdapter.state = State.TAG
-            tagFragment.setSelection(selection.toList())
-            addFragment(supportFragmentManager, tagFragment, R.id.main_activity_container)
-        } else {
-            vocabularyAdapter.state = State.NONE
-            removeFragment(supportFragmentManager, tagFragment)
+        vocabularyAdapter?.let {
+            if (!selection.isEmpty && it.state.notAddOrEdit()) {
+                vocabularyAdapter?.state = State.TAG
+                tagFragment.setSelection(selection.toList())
+                addFragment(supportFragmentManager, tagFragment, R.id.main_activity_container)
+            } else {
+                vocabularyAdapter?.state = State.NONE
+                removeFragment(supportFragmentManager, tagFragment)
+            }
         }
     }
 
@@ -149,7 +151,7 @@ class MainActivity : AppCompatActivity() {
         super.onPause()
         hideKeyboard()
         try {
-            FirestoreManager().saveWords(vocabularyAdapter.getModifiedWords())
+            vocabularyAdapter?.getModifiedWords()?.let { FirestoreManager().saveWords(it) }
         } catch (ignored: Exception) {
         }
     }

app/src/main/java/com/paktalin/vocabularynotebook/ui/fragments/SubmitAddedFragment.kt

@@ -8,13 +8,13 @@ import kotlinx.android.synthetic.main.word_item.*
 class SubmitAddedFragment : SubmitFragment() {
 
     override fun init() {
-        mainActivity.vocabularyAdapter.state = State.ADD
+        mainActivity.vocabularyAdapter?.state = State.ADD
         wordEt = mainActivity.word
         translationEt = mainActivity.translation
     }
 
     override fun submit() {
-        mainActivity.vocabularyAdapter.addWord(WordPojo(wordEt.text.toString(), translationEt.text.toString()))
+        mainActivity.vocabularyAdapter?.addWord(WordPojo(wordEt.text.toString(), translationEt.text.toString()))
         wordEt.requestFocus()
         finish()
         return
@@ -28,7 +28,7 @@ class SubmitAddedFragment : SubmitFragment() {
     override fun finish() {
         wordEt.text.clear()
         translationEt.text.clear()
-        mainActivity.vocabularyAdapter.state = State.NONE
+        mainActivity.vocabularyAdapter?.state = State.NONE
         removeFragment(mainActivity.supportFragmentManager, this)
         return
     }

app/src/main/java/com/paktalin/vocabularynotebook/ui/fragments/SubmitEditedFragment.kt

@@ -22,7 +22,7 @@ class SubmitEditedFragment : SubmitFragment() {
             scrollToPositionWithOffset(recyclerViewPosition, 2)
             isScrollEnabled = false
         }
-        mainActivity.vocabularyAdapter.state = State.EDIT
+        mainActivity.vocabularyAdapter?.state = State.EDIT
         gone(clickableView)
         wordEt.requestFocus()
         wordEt.setSelection(wordEt.text.length)
@@ -32,7 +32,7 @@ class SubmitEditedFragment : SubmitFragment() {
     override fun submit() {
         wordPojo.word = wordEt.text.toString()
         wordPojo.translation = translationEt.text.toString()
-        mainActivity.vocabularyAdapter.updateWord(wordPojo)
+        mainActivity.vocabularyAdapter?.updateWord(wordPojo)
         finish()
     }
 
@@ -47,7 +47,7 @@ class SubmitEditedFragment : SubmitFragment() {
         translationEt.clearFocus()
         visible(clickableView)
         mainActivity.hideKeyboardNotFromActivity(mainActivity)
-        mainActivity.vocabularyAdapter.state = State.NONE
+        mainActivity.vocabularyAdapter?.state = State.NONE
         (mainActivity.recyclerView.layoutManager as LockableLayoutManager).isScrollEnabled = true
         removeFragment(mainActivity.supportFragmentManager, this)
         return

app/src/main/java/com/paktalin/vocabularynotebook/ui/fragments/TagFragment.kt

@@ -36,12 +36,12 @@ class TagFragment : Fragment() {
             if (it.isBlank())
                 shortToast(mainActivity, mainActivity.getString(R.string.toast_tag_cannot_be_empty))
             else
-                mainActivity.vocabularyAdapter.addTagToSelected(it)
+                mainActivity.vocabularyAdapter?.addTagToSelected(it)
         }
     }
 
     private fun cancel() {
-        mainActivity.vocabularyAdapter.selectionTracker.clearSelection()
+        mainActivity.vocabularyAdapter?.selectionTracker?.clearSelection()
         removeFragment(mainActivity.supportFragmentManager, this)
     }