Fix crash when calling sendToView while the Presenter attaches the view

thirtyinch/src/main/java/net/grandcentrix/thirtyinch/TiPresenter.java

@@ -89,6 +89,15 @@ public enum State {
 
     private LinkedBlockingQueue<ViewAction<V>> mPostponedViewActions = new LinkedBlockingQueue<>();
 
+    /**
+     * view is attached and all {@link #mLifecycleObservers} have been notified about the attache
+     * event. The view is now in a "running" state
+     *
+     * This is a temporary field without public getter until the presenter state and notifications
+     * get completely refactored
+     */
+    private volatile boolean mRunning = false;
+
     private State mState = State.INITIALIZED;
 
     /**
@@ -198,6 +207,10 @@ public void attachView(@NonNull final V view) {
         }
         moveToState(State.VIEW_ATTACHED, true);
 
+        // TODO refactor events and add a new state HERE when the view is attached and prepared by all observers.
+        // Calling this a "running" state for now, prevents executing postponed actions before this point
+        mRunning = true;
+
         sendPostponedActionsToView(view);
     }
 
@@ -269,6 +282,7 @@ public final void detachView() {
             TiLog.v(TAG, "not calling onDetachView(), not woken up");
             return;
         }
+        mRunning = false;
         moveToState(State.VIEW_DETACHED, false);
         mCalled = false;
         TiLog.v(TAG, "deprecated onSleep()");
@@ -515,7 +529,7 @@ protected void onWakeUp() {
      */
     protected void sendToView(final ViewAction<V> action) {
         final V view = getView();
-        if (view != null) {
+        if (mRunning) {
             runOnUiThread(new Runnable() {
                 @Override
                 public void run() {

thirtyinch/src/test/java/net/grandcentrix/thirtyinch/SendToViewTest.java

@@ -31,8 +31,10 @@
 import static junit.framework.Assert.assertNotSame;
 import static junit.framework.Assert.assertTrue;
 import static org.assertj.core.api.Java6Assertions.assertThat;
+import static org.assertj.core.api.Java6Assertions.failBecauseExceptionWasNotThrown;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.verifyZeroInteractions;
@@ -97,6 +99,68 @@ public void call(final TestView view) {
         inOrder.verify(view).doSomething2();
     }
 
+    @Test
+    public void sendToView_fires_after_view_and_executor_are_ready() throws Exception {
+
+        // Given a presenter without attached view
+        final TestPresenter presenter = new TestPresenter();
+        presenter.create();
+        final TestView view = mock(TestView.class);
+
+        // When calling sendToView
+        presenter.sendToView(new ViewAction<TestView>() {
+            @Override
+            public void call(final TestView testView) {
+                testView.doSomething1();
+            }
+        });
+        // Then the action will be postponed and not executed
+        verify(view, never()).doSomething1();
+
+        // When setting an executor
+        presenter.setUiThreadExecutor(new Executor() {
+            @Override
+            public void execute(@NonNull final Runnable command) {
+                command.run();
+            }
+        });
+        // The postponed actions will not be executed immediately, no view is attached
+        verify(view, never()).doSomething1();
+
+        // When view and executor are both attached
+        presenter.attachView(view);
+        // The postponed actions will be executed
+        verify(view).doSomething1();
+    }
+
+    @Test
+    public void sendToView_withRunningView_crashes_without_uiThreadExecutor() throws Exception {
+
+        // Given a presenter with a attached view (running state)
+        // No uiThreadExecutor is attached
+        final TestPresenter presenter = new TestPresenter();
+        presenter.create();
+        final TestView view = mock(TestView.class);
+        presenter.attachView(view);
+
+        // When calling sendToView without attaching a uiThreadExecutor
+        try {
+            presenter.sendToView(new ViewAction<TestView>() {
+                @Override
+                public void call(final TestView testView) {
+                    testView.doSomething1();
+                }
+            });
+            failBecauseExceptionWasNotThrown(IllegalStateException.class);
+        } catch (IllegalStateException e) {
+            // Then an Exception is thrown
+            // Whoever creates and manages the TiPresenter has to provide an executor
+            assertThat(e).hasMessageContaining("no ui thread executor");
+        }
+
+        verify(view, never()).doSomething1();
+    }
+
     @Test
     public void testSendToViewRunsOnTheMainThread() throws Exception {