Merge pull request #601 from czan/welcome-section-rotation

Fix first run wizard crashes on screen rotation - fixes #596

Author: codinguser

app/src/main/java/org/gnucash/android/ui/wizard/FirstRunWizardActivity.java

@@ -83,19 +83,17 @@ public class FirstRunWizardActivity extends AppCompatActivity implements
 
 
     public void onCreate(Bundle savedInstanceState) {
+        // we need to construct the wizard model before we call super.onCreate, because it's used in
+        // onGetPage (which is indirectly called through super.onCreate if savedInstanceState is not
+        // null)
+        mWizardModel = createWizardModel(savedInstanceState);
+
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_first_run_wizard);
         ButterKnife.bind(this);
 
         setTitle(getString(R.string.title_setup_gnucash));
 
-        mWizardModel = new FirstRunWizardModel(this);
-        if (savedInstanceState != null) {
-            mWizardModel.load(savedInstanceState.getBundle("model"));
-        }
-
-        mWizardModel.registerListener(this);
-
         mPagerAdapter = new MyPagerAdapter(getSupportFragmentManager());
         mPager.setAdapter(mPagerAdapter);
         mStepPagerStrip
@@ -197,6 +195,24 @@ public void onClick(View view) {
         updateBottomBar();
     }
 
+    /**
+     * Create the wizard model for the activity, taking into accoun the savedInstanceState if it
+     * exists (and if it contains a "model" key that we can use).
+     * @param savedInstanceState    the instance state available in {{@link #onCreate(Bundle)}}
+     * @return  an appropriate wizard model for this activity
+     */
+    private AbstractWizardModel createWizardModel(Bundle savedInstanceState) {
+        AbstractWizardModel model = new FirstRunWizardModel(this);
+        if (savedInstanceState != null) {
+            Bundle wizardModel = savedInstanceState.getBundle("model");
+            if (wizardModel != null) {
+                model.load(wizardModel);
+            }
+        }
+        model.registerListener(this);
+        return model;
+    }
+
     /**
      * Create accounts depending on the user preference (import or default set) and finish this activity
      * <p>This method also removes the first run flag from the application</p>