flutter view add test 2 (flutter#55188)

- **add test back with no other changes**
- **Add legacy test and setup shadow**
2 and 3 of 5 flutter/flutter/issues/154746

Improved legacy testing by validating a fullscreen and non fullscreen codepaths. 

Added `.git-blame-ignore-revs` because git was failing to give blame values with that file missing. I dont think I added a global config anywhere but adding an empty file should not cause a problem.

shell/platform/android/test/README.md

@@ -39,3 +39,8 @@ See [Updating Embedding Dependencies](/tools/cipd/android_embedding_bundle).
 ### My new test won't compile. It can't find one of my imports.
 
 See [Updating Embedding Dependencies](/tools/cipd/android_embedding_bundle).
+
+### My test does not show log output in the console
+
+Import `org.robolectric.shadows.ShadowLog;` then
+Use `ShadowLog.stream = System.out;` in your test or setup method.

shell/platform/android/test/io/flutter/embedding/android/FlutterViewTest.java

@@ -9,6 +9,7 @@
 import static junit.framework.TestCase.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.clearInvocations;
 import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
@@ -36,7 +37,6 @@
 import android.view.DisplayCutout;
 import android.view.Surface;
 import android.view.View;
-import android.view.ViewGroup;
 import android.view.WindowInsets;
 import android.view.WindowManager;
 import android.widget.FrameLayout;
@@ -69,6 +69,7 @@
 import org.robolectric.annotation.Implementation;
 import org.robolectric.annotation.Implements;
 import org.robolectric.shadows.ShadowDisplay;
+import org.robolectric.shadows.ShadowViewGroup;
 
 @Config(manifest = Config.NONE)
 @RunWith(AndroidJUnit4.class)
@@ -83,6 +84,8 @@ public class FlutterViewTest {
   public void setUp() {
     MockitoAnnotations.openMocks(this);
     when(mockFlutterJni.isAttached()).thenReturn(true);
+    // Uncomment the following line to enable logging output in test.
+    // ShadowLog.stream = System.out;
   }
 
   @SuppressWarnings("deprecation")
@@ -937,6 +940,92 @@ public void ViewportMetrics_initializedPhysicalTouchSlop() {
     assertFalse(-1 == viewportMetricsCaptor.getValue().physicalTouchSlop);
   }
 
+  @SuppressWarnings("deprecation")
+  // Robolectric.setupActivity
+  // TODO(reidbaker): https://github.com/flutter/flutter/issues/133151
+  // This test uses the API 30+ Algorithm for window insets. The legacy algorithm is
+  // set to -1 values, so it is clear if the wrong algorithm is used.
+  @Test
+  @TargetApi(30)
+  @Config(sdk = 30)
+  public void setPaddingTopToZeroForFullscreenMode() {
+    FlutterView flutterView = new FlutterView(Robolectric.setupActivity(Activity.class));
+    FlutterEngine flutterEngine = spy(new FlutterEngine(ctx, mockFlutterLoader, mockFlutterJni));
+    FlutterRenderer flutterRenderer = spy(new FlutterRenderer(mockFlutterJni));
+    when(flutterEngine.getRenderer()).thenReturn(flutterRenderer);
+
+    // When we attach a new FlutterView to the engine without any system insets, the viewport
+    // metrics
+    // default to 0.
+    flutterView.attachToFlutterEngine(flutterEngine);
+    ArgumentCaptor<FlutterRenderer.ViewportMetrics> viewportMetricsCaptor =
+        ArgumentCaptor.forClass(FlutterRenderer.ViewportMetrics.class);
+    verify(flutterRenderer).setViewportMetrics(viewportMetricsCaptor.capture());
+    assertEquals(0, viewportMetricsCaptor.getValue().viewPaddingTop);
+
+    // Then we simulate the system applying a window inset.
+    WindowInsets windowInsets =
+        new WindowInsets.Builder()
+            .setInsets(
+                android.view.WindowInsets.Type.navigationBars()
+                    | android.view.WindowInsets.Type.statusBars(),
+                Insets.of(100, 100, 100, 100))
+            .build();
+    flutterView.onApplyWindowInsets(windowInsets);
+
+    // Verify.
+    verify(flutterRenderer, times(3)).setViewportMetrics(viewportMetricsCaptor.capture());
+    validateViewportMetricPadding(viewportMetricsCaptor, 100, 100, 100, 100);
+  }
+
+  @SuppressWarnings("deprecation")
+  // Robolectric.setupActivity
+  // TODO(reidbaker): https://github.com/flutter/flutter/issues/133151
+  // This test uses the pre-API 30 Algorithm for window insets.
+  @Test
+  @TargetApi(28)
+  @Config(
+      sdk = 28,
+      shadows = {
+        FlutterViewTest.ShadowFullscreenView.class,
+      })
+  public void setPaddingTopToZeroForFullscreenModeLegacy() {
+    FlutterView flutterView = spy(new FlutterView(ctx));
+    FlutterEngine flutterEngine = spy(new FlutterEngine(ctx, mockFlutterLoader, mockFlutterJni));
+    FlutterRenderer flutterRenderer = spy(new FlutterRenderer(mockFlutterJni));
+    when(flutterEngine.getRenderer()).thenReturn(flutterRenderer);
+
+    // When we attach a new FlutterView to the engine without any system insets, the viewport
+    // metrics
+    // default to 0.
+    flutterView.attachToFlutterEngine(flutterEngine);
+    ArgumentCaptor<FlutterRenderer.ViewportMetrics> viewportMetricsCaptor =
+        ArgumentCaptor.forClass(FlutterRenderer.ViewportMetrics.class);
+    verify(flutterRenderer).setViewportMetrics(viewportMetricsCaptor.capture());
+    assertEquals(0, viewportMetricsCaptor.getValue().viewPaddingTop);
+    clearInvocations(flutterRenderer);
+    // Then we simulate the system applying a window inset.
+    WindowInsets windowInsets = mock(WindowInsets.class);
+    mockSystemWindowInsets(windowInsets, 100, 100, 100, 100);
+    flutterView.onApplyWindowInsets(windowInsets);
+
+    // Verify.
+    verify(flutterRenderer, times(1)).setViewportMetrics(viewportMetricsCaptor.capture());
+    validateViewportMetricPadding(viewportMetricsCaptor, 100, 100, 100, 0);
+    clearInvocations(flutterRenderer);
+
+    // Validation when fullscreen
+    when(flutterView.getWindowSystemUiVisibility()).thenReturn(View.SYSTEM_UI_FLAG_FULLSCREEN);
+
+    // Then we simulate the system applying a window inset.
+    mockSystemWindowInsets(windowInsets, 100, 100, 100, 100);
+    flutterView.onApplyWindowInsets(windowInsets);
+
+    // Verify.
+    verify(flutterRenderer, times(1)).setViewportMetrics(viewportMetricsCaptor.capture());
+    validateViewportMetricPadding(viewportMetricsCaptor, 100, 0, 100, 0);
+  }
+
   @SuppressWarnings("deprecation")
   private void setExpectedDisplayRotation(int rotation) {
     ShadowDisplay display =
@@ -976,17 +1065,12 @@ private void mockSystemGestureInsetsIfNeed(WindowInsets windowInsets) {
   /*
    * A custom shadow that reports fullscreen flag for system UI visibility
    */
-  @Implements(View.class)
+  @Implements(FrameLayout.class)
   @SuppressWarnings("deprecation")
-  public static class ShadowFullscreenView {
+  public static class ShadowFullscreenView extends ShadowViewGroup {
     @Implementation
     public int getWindowSystemUiVisibility() {
       return View.SYSTEM_UI_FLAG_FULLSCREEN;
     }
   }
-
-  // ViewGroup is the first shadow in the type hierarchy for FlutterView. Shadows need to mimic
-  // production classes' view hierarchy.
-  @Implements(ViewGroup.class)
-  public static class ShadowFullscreenViewGroup extends ShadowFullscreenView {}
 }