Added empty screen when no search results.

.idea/assetWizardSettings.xml

@@ -147,7 +147,7 @@
                                 <PersistentState>
                                   <option name="values">
                                     <map>
-                                      <entry key="url" value="jar:file:/home/chronosx/%D0%94%D0%BE%D0%BA%D1%83%D0%BC%D0%B5%D0%BD%D1%82%D1%8B/bin/Android%20Studio/plugins/android/lib/android.jar!/images/material_design_icons/action/ic_favorite_black_24dp.xml" />
+                                      <entry key="url" value="jar:file:/home/chronosx/%D0%94%D0%BE%D0%BA%D1%83%D0%BC%D0%B5%D0%BD%D1%82%D1%8B/bin/Android%20Studio/plugins/android/lib/android.jar!/images/material_design_icons/content/ic_clear_black_24dp.xml" />
                                     </map>
                                   </option>
                                 </PersistentState>
@@ -157,7 +157,8 @@
                         </option>
                         <option name="values">
                           <map>
-                            <entry key="outputName" value="ic_favorite_black_24dp" />
+                            <entry key="color" value="d3d3d3" />
+                            <entry key="outputName" value="ic_clear_gray_24dp" />
                             <entry key="sourceFile" value="$USER_HOME$" />
                           </map>
                         </option>

app/src/main/java/ru/volgorobot/vrcatalog/view/SearchableActivity.java

@@ -35,6 +35,9 @@ public class SearchableActivity extends AppCompatActivity implements MainContrac
     private ImageView mConnectionErrorImageView;
     private NestedScrollView mTreeViewContainer;
     private TextView mErrorTextView;
+    private ImageView mEmptySearchImageView;
+    private TextView mEmptySearchTextView;
+    private boolean isInErrorState = false;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -53,9 +56,12 @@ public class SearchableActivity extends AppCompatActivity implements MainContrac
         mTreeViewContainer = findViewById(R.id.searchableTreeViewContainer);
         mErrorTextView = findViewById(R.id.searchableErrorTextView);
 
+        mEmptySearchImageView = findViewById(R.id.emptySearchImage);
+        mEmptySearchTextView = findViewById(R.id.emptySearchText);
+
         treeView = new TreeView(rootNode, SearchableActivity.this, new SearchableNodeViewFactory(SearchableActivity.this, this));
         treeView.setItemAnimator(new DefaultItemAnimator());
-        ((ViewGroup) findViewById(R.id.searchableTreeViewContainer)).addView(treeView.getView());
+        mTreeViewContainer.addView(treeView.getView());
         Intent intent = getIntent();
         if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
             detailName = intent.getStringExtra(SearchManager.QUERY);
@@ -72,6 +78,15 @@ public class SearchableActivity extends AppCompatActivity implements MainContrac
         rootNode.setChildren(children);
         treeView.expandAll();
         treeView.refreshTreeView();
+        if(children.size() == 0 && !isInErrorState) {
+            mEmptySearchImageView.setVisibility(View.VISIBLE);
+            mEmptySearchTextView.setVisibility(View.VISIBLE);
+            mTreeViewContainer.setVisibility(View.GONE);
+        } else {
+            mEmptySearchImageView.setVisibility(View.INVISIBLE);
+            mEmptySearchTextView.setVisibility(View.INVISIBLE);
+            mTreeViewContainer.setVisibility(View.VISIBLE);
+        }
     }
 
     public void onFailureAnswer(int errorCode) {
@@ -84,6 +99,7 @@ public class SearchableActivity extends AppCompatActivity implements MainContrac
                 mTreeViewContainer.setVisibility(View.GONE);
                 mConnectionErrorImageView.setVisibility(View.VISIBLE);
                 mErrorTextView.setVisibility(View.VISIBLE);
+                isInErrorState = true;
                 break;
             }
             case 2: {
@@ -94,6 +110,7 @@ public class SearchableActivity extends AppCompatActivity implements MainContrac
                 mTreeViewContainer.setVisibility(View.GONE);
                 mConnectionErrorImageView.setVisibility(View.VISIBLE);
                 mErrorTextView.setVisibility(View.VISIBLE);
+                isInErrorState = true;
                 break;
             }
             case 3: {
@@ -103,6 +120,7 @@ public class SearchableActivity extends AppCompatActivity implements MainContrac
                 mTreeViewContainer.setVisibility(View.GONE);
                 mConnectionErrorImageView.setVisibility(View.VISIBLE);
                 mErrorTextView.setVisibility(View.VISIBLE);
+                isInErrorState = true;
                 break;
             }
         }
@@ -116,6 +134,7 @@ public class SearchableActivity extends AppCompatActivity implements MainContrac
         rootNode.setChildren(new ArrayList<TreeNode>());
         treeView.refreshTreeView();
         searchablePresenter.fetchDetailsTreeByName(detailName);
+        isInErrorState = false;
     }
 
     @Override

app/src/main/res/drawable/ic_clear_gray_24dp.xml

@@ -0,0 +1,5 @@
+<vector android:height="24dp" android:tint="#D3D3D3"
+    android:viewportHeight="24.0" android:viewportWidth="24.0"
+    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="#FF000000" android:pathData="M19,6.41L17.59,5 12,10.59 6.41,5 5,6.41 10.59,12 5,17.59 6.41,19 12,13.41 17.59,19 19,17.59 13.41,12z"/>
+</vector>

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

@@ -49,6 +49,36 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@+id/searchableConnectionErrorImageView" />
 
+        <ImageView
+            android:id="@+id/emptySearchImage"
+            android:layout_width="0dp"
+            android:layout_height="0dp"
+            android:layout_marginTop="70dp"
+            android:layout_marginBottom="52dp"
+            android:src="@drawable/ic_clear_gray_24dp"
+            android:visibility="invisible"
+            app:layout_constraintBottom_toTopOf="@+id/emptySearchText"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="parent" />
+
+        <TextView
+            android:id="@+id/emptySearchText"
+            android:layout_width="0dp"
+            android:layout_height="77dp"
+            android:layout_marginStart="9dp"
+            android:layout_marginEnd="9dp"
+            android:layout_marginBottom="68dp"
+            android:text="@string/empty_search"
+            android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+            android:visibility="invisible"
+            android:textSize="18sp"
+            android:gravity="center"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@+id/emptySearchImage" />
+
     </android.support.constraint.ConstraintLayout>
 
 </android.support.v4.widget.SwipeRefreshLayout>

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

@@ -3,4 +3,5 @@
     <string name="navigation_drawer_open">Open navigation drawer</string>
     <string name="navigation_drawer_close">Close navigation drawer</string>
     <string name="favorites_empty">Ваш список избранного пуст</string>
+    <string name="empty_search">По вашему запросу ничего не найдено.</string>
 </resources>