Fix viewInset.bottom and viewPadding.bottom… (#21730)

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

@@ -580,14 +580,17 @@ public class FlutterView extends FrameLayout implements MouseCursorPlugin.MouseC
         zeroSides = calculateShouldZeroSides();
       }
 
-      // Status bar (top) and left/right system insets should partially obscure the content
-      // (padding).
+      // Status bar (top), navigation bar (bottom) 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.paddingBottom =
+          navigationBarVisible && guessBottomKeyboardInset(insets) == 0
+              ? insets.getSystemWindowInsetBottom()
+              : 0;
       viewportMetrics.paddingLeft =
           zeroSides == ZeroSides.LEFT || zeroSides == ZeroSides.BOTH
               ? 0
@@ -596,10 +599,7 @@ public class FlutterView extends FrameLayout implements MouseCursorPlugin.MouseC
       // Bottom system inset (keyboard) should adjust scrollable bottom edge (inset).
       viewportMetrics.viewInsetTop = 0;
       viewportMetrics.viewInsetRight = 0;
-      viewportMetrics.viewInsetBottom =
-          navigationBarVisible
-              ? insets.getSystemWindowInsetBottom()
-              : guessBottomKeyboardInset(insets);
+      viewportMetrics.viewInsetBottom = guessBottomKeyboardInset(insets);
       viewportMetrics.viewInsetLeft = 0;
     }
 

shell/platform/android/io/flutter/view/FlutterView.java

@@ -662,14 +662,17 @@ public class FlutterView extends SurfaceView
         zeroSides = calculateShouldZeroSides();
       }
 
-      // Status bar (top) and left/right system insets should partially obscure the content
-      // (padding).
+      // Status bar (top), navigation bar (bottom) and left/right system insets should
+      // partially obscure the content (padding).
       mMetrics.physicalPaddingTop = statusBarVisible ? insets.getSystemWindowInsetTop() : 0;
       mMetrics.physicalPaddingRight =
           zeroSides == ZeroSides.RIGHT || zeroSides == ZeroSides.BOTH
               ? 0
               : insets.getSystemWindowInsetRight();
-      mMetrics.physicalPaddingBottom = 0;
+      mMetrics.physicalPaddingBottom =
+          navigationBarVisible && guessBottomKeyboardInset(insets) == 0
+              ? insets.getSystemWindowInsetBottom()
+              : 0;
       mMetrics.physicalPaddingLeft =
           zeroSides == ZeroSides.LEFT || zeroSides == ZeroSides.BOTH
               ? 0
@@ -678,10 +681,7 @@ public class FlutterView extends SurfaceView
       // Bottom system inset (keyboard) should adjust scrollable bottom edge (inset).
       mMetrics.physicalViewInsetTop = 0;
       mMetrics.physicalViewInsetRight = 0;
-      mMetrics.physicalViewInsetBottom =
-          navigationBarVisible
-              ? insets.getSystemWindowInsetBottom()
-              : guessBottomKeyboardInset(insets);
+      mMetrics.physicalViewInsetBottom = guessBottomKeyboardInset(insets);
       mMetrics.physicalViewInsetLeft = 0;
     }
 

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

@@ -210,8 +210,12 @@ public class FlutterViewTest {
     assertEquals(SettingsChannel.PlatformBrightness.dark, reportedBrightness.get());
   }
 
+  // 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,
       shadows = {
         FlutterViewTest.ShadowFullscreenView.class,
         FlutterViewTest.ShadowFullscreenViewGroup.class
@@ -249,7 +253,52 @@ public class FlutterViewTest {
     assertEquals(100, viewportMetricsCaptor.getValue().paddingRight);
   }
 
+  // This test uses the pre-API 30 Algorithm for window insets.
+  @Test
+  @TargetApi(29)
+  @Config(
+      sdk = 29,
+      shadows = {
+        FlutterViewTest.ShadowFullscreenView.class,
+        FlutterViewTest.ShadowFullscreenViewGroup.class
+      })
+  public void setPaddingTopToZeroForFullscreenModeLegacy() {
+    FlutterView flutterView = new FlutterView(RuntimeEnvironment.application);
+    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(100);
+    when(windowInsets.getSystemWindowInsetLeft()).thenReturn(100);
+    when(windowInsets.getSystemWindowInsetRight()).thenReturn(100);
+    flutterView.onApplyWindowInsets(windowInsets);
+
+    // Verify.
+    verify(flutterRenderer, times(2)).setViewportMetrics(viewportMetricsCaptor.capture());
+    assertEquals(0, viewportMetricsCaptor.getValue().paddingTop);
+    assertEquals(100, viewportMetricsCaptor.getValue().paddingBottom);
+    assertEquals(100, viewportMetricsCaptor.getValue().paddingLeft);
+    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 reportSystemInsetWhenNotFullscreen() {
     // Without custom shadows, the default system ui visibility flags is 0.
     FlutterView flutterView = new FlutterView(RuntimeEnvironment.application);
@@ -287,6 +336,46 @@ public class FlutterViewTest {
     assertEquals(100, viewportMetricsCaptor.getValue().paddingRight);
   }
 
+  // This test uses the pre-API 30 Algorithm for window insets.
+  @Test
+  @TargetApi(29)
+  @Config(sdk = 29)
+  public void reportSystemInsetWhenNotFullscreenLegacy() {
+    // Without custom shadows, the default system ui visibility flags is 0.
+    FlutterView flutterView = new FlutterView(RuntimeEnvironment.application);
+    assertEquals(0, flutterView.getSystemUiVisibility());
+
+    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(100);
+    when(windowInsets.getSystemWindowInsetLeft()).thenReturn(100);
+    when(windowInsets.getSystemWindowInsetRight()).thenReturn(100);
+    flutterView.onApplyWindowInsets(windowInsets);
+
+    // Verify.
+    verify(flutterRenderer, times(2)).setViewportMetrics(viewportMetricsCaptor.capture());
+    // Top padding is reported as-is.
+    assertEquals(100, viewportMetricsCaptor.getValue().paddingTop);
+    assertEquals(0, viewportMetricsCaptor.getValue().paddingBottom);
+    assertEquals(100, viewportMetricsCaptor.getValue().paddingLeft);
+    assertEquals(100, viewportMetricsCaptor.getValue().paddingRight);
+  }
+
   @Test
   public void systemInsetHandlesFullscreenNavbarRight() {
     RuntimeEnvironment.setQualifiers("+land");
@@ -327,10 +416,10 @@ public class FlutterViewTest {
     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.
+    // Bottom padding is removed due to hide navigation.
     assertEquals(0, viewportMetricsCaptor.getValue().paddingBottom);
     assertEquals(100, viewportMetricsCaptor.getValue().paddingLeft);
-    // Right padding is zero because the rotation is 270deg
+    // Right padding is zero because the rotation is 90deg
     assertEquals(0, viewportMetricsCaptor.getValue().paddingRight);
   }
 
@@ -374,7 +463,7 @@ public class FlutterViewTest {
     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.
+    // Bottom padding is removed due to hide navigation.
     assertEquals(0, viewportMetricsCaptor.getValue().paddingBottom);
     // Left padding is zero because the rotation is 270deg
     assertEquals(0, viewportMetricsCaptor.getValue().paddingLeft);
@@ -477,7 +566,7 @@ public class FlutterViewTest {
     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.
+    // Bottom padding is removed due to hide navigation.
     assertEquals(0, viewportMetricsCaptor.getValue().paddingBottom);
     // Left padding is zero because the rotation is 270deg
     assertEquals(0, viewportMetricsCaptor.getValue().paddingLeft);