Use Android R (API 30) getInsets() to compute padding (flutter/engine#18339)

engine/src/flutter/shell/platform/android/embedding_bundle/build.gradle

@@ -37,7 +37,7 @@ configurations {
 }
 
 android {
-  compileSdkVersion 29
+  compileSdkVersion 30
 
   dependencies {
     embedding "androidx.annotation:annotation:1.1.0"

engine/src/flutter/shell/platform/android/io/flutter/embedding/android/FlutterView.java

@@ -461,7 +461,6 @@ public class FlutterView extends FrameLayout implements MouseCursorPlugin.MouseC
     return ZeroSides.NONE;
   }
 
-  // TODO(garyq): Use new Android R getInsets API
   // TODO(garyq): The keyboard detection may interact strangely with
   //   https://github.com/flutter/flutter/issues/22061
 
@@ -469,6 +468,9 @@ public class FlutterView extends FrameLayout implements MouseCursorPlugin.MouseC
   // be padded. When the on-screen keyboard is detected, we want to include the full inset
   // but when the inset is just the hidden nav bar, we want to provide a zero inset so the space
   // can be used.
+  //
+  // This method is replaced by Android API 30 (R/11) getInsets() method which can take the
+  // android.view.WindowInsets.Type.ime() flag to find the keyboard inset.
   @TargetApi(20)
   @RequiresApi(20)
   private int guessBottomKeyboardInset(WindowInsets insets) {
@@ -506,37 +508,61 @@ public class FlutterView extends FrameLayout implements MouseCursorPlugin.MouseC
   public final WindowInsets onApplyWindowInsets(@NonNull WindowInsets insets) {
     WindowInsets newInsets = super.onApplyWindowInsets(insets);
 
-    boolean statusBarHidden = (SYSTEM_UI_FLAG_FULLSCREEN & getWindowSystemUiVisibility()) != 0;
-    boolean navigationBarHidden =
-        (SYSTEM_UI_FLAG_HIDE_NAVIGATION & getWindowSystemUiVisibility()) != 0;
-    // We zero the left and/or right sides to prevent the padding the
-    // navigation bar would have caused.
-    ZeroSides zeroSides = ZeroSides.NONE;
-    if (navigationBarHidden) {
-      zeroSides = calculateShouldZeroSides();
+    boolean statusBarVisible = (SYSTEM_UI_FLAG_FULLSCREEN & getWindowSystemUiVisibility()) == 0;
+    boolean navigationBarVisible =
+        (SYSTEM_UI_FLAG_HIDE_NAVIGATION & getWindowSystemUiVisibility()) == 0;
+
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+      int mask = 0;
+      if (navigationBarVisible) {
+        mask = mask | android.view.WindowInsets.Type.navigationBars();
+      }
+      if (statusBarVisible) {
+        mask = mask | android.view.WindowInsets.Type.statusBars();
+      }
+      mask = mask | android.view.WindowInsets.Type.ime();
+
+      Insets finalInsets = insets.getInsets(mask);
+      viewportMetrics.paddingTop = finalInsets.top;
+      viewportMetrics.paddingRight = finalInsets.right;
+      viewportMetrics.paddingBottom = 0;
+      viewportMetrics.paddingLeft = finalInsets.left;
+
+      viewportMetrics.viewInsetTop = 0;
+      viewportMetrics.viewInsetRight = 0;
+      viewportMetrics.viewInsetBottom = finalInsets.bottom;
+      viewportMetrics.viewInsetLeft = 0;
+    } else {
+      // We zero the left and/or right sides to prevent the padding the
+      // navigation bar would have caused.
+      ZeroSides zeroSides = ZeroSides.NONE;
+      if (!navigationBarVisible) {
+        zeroSides = calculateShouldZeroSides();
+      }
+
+      // Status bar (top) and left/right system insets should partially obscure the content
+      // (padding).
+      viewportMetrics.paddingTop = statusBarVisible ? insets.getSystemWindowInsetTop() : 0;
+      viewportMetrics.paddingRight =
+          zeroSides == ZeroSides.RIGHT || zeroSides == ZeroSides.BOTH
+              ? 0
+              : insets.getSystemWindowInsetRight();
+      viewportMetrics.paddingBottom = 0;
+      viewportMetrics.paddingLeft =
+          zeroSides == ZeroSides.LEFT || zeroSides == ZeroSides.BOTH
+              ? 0
+              : insets.getSystemWindowInsetLeft();
+
+      // Bottom system inset (keyboard) should adjust scrollable bottom edge (inset).
+      viewportMetrics.viewInsetTop = 0;
+      viewportMetrics.viewInsetRight = 0;
+      viewportMetrics.viewInsetBottom =
+          navigationBarVisible
+              ? insets.getSystemWindowInsetBottom()
+              : guessBottomKeyboardInset(insets);
+      viewportMetrics.viewInsetLeft = 0;
     }
 
-    // Status bar (top) and left/right system insets should partially obscure the content (padding).
-    viewportMetrics.paddingTop = statusBarHidden ? 0 : insets.getSystemWindowInsetTop();
-    viewportMetrics.paddingRight =
-        zeroSides == ZeroSides.RIGHT || zeroSides == ZeroSides.BOTH
-            ? 0
-            : insets.getSystemWindowInsetRight();
-    viewportMetrics.paddingBottom = 0;
-    viewportMetrics.paddingLeft =
-        zeroSides == ZeroSides.LEFT || zeroSides == ZeroSides.BOTH
-            ? 0
-            : insets.getSystemWindowInsetLeft();
-
-    // Bottom system inset (keyboard) should adjust scrollable bottom edge (inset).
-    viewportMetrics.viewInsetTop = 0;
-    viewportMetrics.viewInsetRight = 0;
-    viewportMetrics.viewInsetBottom =
-        navigationBarHidden
-            ? guessBottomKeyboardInset(insets)
-            : insets.getSystemWindowInsetBottom();
-    viewportMetrics.viewInsetLeft = 0;
-
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
       Insets systemGestureInsets = insets.getSystemGestureInsets();
       viewportMetrics.systemGestureInsetTop = systemGestureInsets.top;

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

@@ -4,6 +4,7 @@ import static junit.framework.TestCase.assertEquals;
 import static junit.framework.TestCase.assertFalse;
 import static junit.framework.TestCase.assertTrue;
 import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyInt;
 import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
@@ -15,6 +16,7 @@ import android.annotation.TargetApi;
 import android.content.Context;
 import android.content.res.Configuration;
 import android.content.res.Resources;
+import android.graphics.Insets;
 import android.media.Image;
 import android.media.ImageReader;
 import android.view.View;
@@ -47,7 +49,7 @@ import org.robolectric.shadows.ShadowDisplay;
 
 @Config(manifest = Config.NONE)
 @RunWith(RobolectricTestRunner.class)
-@TargetApi(28)
+@TargetApi(30)
 public class FlutterViewTest {
   @Mock FlutterJNI mockFlutterJni;
   @Mock FlutterLoader mockFlutterLoader;
@@ -375,6 +377,109 @@ public class FlutterViewTest {
     assertEquals(100, viewportMetricsCaptor.getValue().paddingRight);
   }
 
+  // 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 systemInsetGetInsetsFullscreen() {
+    RuntimeEnvironment.setQualifiers("+land");
+    FlutterView flutterView = spy(new FlutterView(RuntimeEnvironment.systemContext));
+    ShadowDisplay display =
+        Shadows.shadowOf(
+            ((WindowManager)
+                    RuntimeEnvironment.systemContext.getSystemService(Context.WINDOW_SERVICE))
+                .getDefaultDisplay());
+    display.setRotation(3);
+    assertEquals(0, flutterView.getSystemUiVisibility());
+    when(flutterView.getWindowSystemUiVisibility())
+        .thenReturn(View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
+    when(flutterView.getContext()).thenReturn(RuntimeEnvironment.systemContext);
+
+    FlutterEngine flutterEngine =
+        spy(new FlutterEngine(RuntimeEnvironment.application, 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().paddingTop);
+
+    Insets insets = Insets.of(100, 100, 100, 100);
+    // Then we simulate the system applying a window inset.
+    WindowInsets windowInsets = mock(WindowInsets.class);
+    when(windowInsets.getSystemWindowInsetTop()).thenReturn(-1);
+    when(windowInsets.getSystemWindowInsetBottom()).thenReturn(-1);
+    when(windowInsets.getSystemWindowInsetLeft()).thenReturn(-1);
+    when(windowInsets.getSystemWindowInsetRight()).thenReturn(-1);
+    when(windowInsets.getInsets(anyInt())).thenReturn(insets);
+
+    flutterView.onApplyWindowInsets(windowInsets);
+
+    verify(flutterRenderer, times(2)).setViewportMetrics(viewportMetricsCaptor.capture());
+    // Top padding is removed due to full screen.
+    assertEquals(0, viewportMetricsCaptor.getValue().paddingTop);
+    // Padding bottom is always 0.
+    assertEquals(0, viewportMetricsCaptor.getValue().paddingBottom);
+    // Left padding is zero because the rotation is 270deg
+    assertEquals(0, viewportMetricsCaptor.getValue().paddingLeft);
+    assertEquals(100, viewportMetricsCaptor.getValue().paddingRight);
+  }
+
+  // This test uses the pre-API 30 Algorithm for window insets.
+  @Test
+  @TargetApi(29)
+  @Config(sdk = 29)
+  public void systemInsetGetInsetsFullscreenLegacy() {
+    RuntimeEnvironment.setQualifiers("+land");
+    FlutterView flutterView = spy(new FlutterView(RuntimeEnvironment.systemContext));
+    ShadowDisplay display =
+        Shadows.shadowOf(
+            ((WindowManager)
+                    RuntimeEnvironment.systemContext.getSystemService(Context.WINDOW_SERVICE))
+                .getDefaultDisplay());
+    display.setRotation(3);
+    assertEquals(0, flutterView.getSystemUiVisibility());
+    when(flutterView.getWindowSystemUiVisibility())
+        .thenReturn(View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
+    when(flutterView.getContext()).thenReturn(RuntimeEnvironment.systemContext);
+
+    FlutterEngine flutterEngine =
+        spy(new FlutterEngine(RuntimeEnvironment.application, 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().paddingTop);
+
+    // Then we simulate the system applying a window inset.
+    WindowInsets windowInsets = mock(WindowInsets.class);
+    when(windowInsets.getSystemWindowInsetTop()).thenReturn(100);
+    when(windowInsets.getSystemWindowInsetBottom()).thenReturn(101);
+    when(windowInsets.getSystemWindowInsetLeft()).thenReturn(102);
+    when(windowInsets.getSystemWindowInsetRight()).thenReturn(103);
+
+    flutterView.onApplyWindowInsets(windowInsets);
+
+    verify(flutterRenderer, times(2)).setViewportMetrics(viewportMetricsCaptor.capture());
+    // Top padding is removed due to full screen.
+    assertEquals(0, viewportMetricsCaptor.getValue().paddingTop);
+    // Padding bottom is always 0.
+    assertEquals(0, viewportMetricsCaptor.getValue().paddingBottom);
+    // Left padding is zero because the rotation is 270deg
+    assertEquals(0, viewportMetricsCaptor.getValue().paddingLeft);
+    assertEquals(103, viewportMetricsCaptor.getValue().paddingRight);
+  }
+
   @Test
   public void flutterImageView_acquiresImageAndInvalidates() {
     final ImageReader mockReader = mock(ImageReader.class);

engine/src/flutter/testing/scenario_app/android/app/build.gradle

@@ -15,7 +15,7 @@ android {
     defaultConfig {
         applicationId "dev.flutter.scenarios"
         minSdkVersion 18
-        targetSdkVersion 28
+        targetSdkVersion 30
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "dev.flutter.TestRunner"