Keyboard Animation Fix (flutter#176418)

Fixing Keyboard Animation Issue
Before:


https://github.com/user-attachments/assets/2b863ca1-20e3-47e2-94f1-5cb2083c1e28

After: 


https://github.com/user-attachments/assets/914efc84-13aa-4bde-8c44-d1761f1fe79a

Fixes: flutter#168768

## Pre-launch Checklist

- [X] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [X] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [X] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [X] I signed the [CLA].
- [X] I listed at least one issue that this PR fixes in the description
above.
- [X] I updated/added relevant documentation (doc comments with `///`).
- [X] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [X] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [X] All existing and new tests are passing.

Author: mboetger

engine/src/flutter/shell/platform/android/io/flutter/plugin/editing/ImeSyncDeferringInsetsCallback.java

@@ -8,6 +8,7 @@
 
 import android.annotation.SuppressLint;
 import android.graphics.Insets;
+import android.os.Build;
 import android.view.View;
 import android.view.WindowInsets;
 import android.view.WindowInsetsAnimation;
@@ -146,15 +147,17 @@ public WindowInsets onProgress(
         return insets;
       }
 
-      // The IME insets include the height of the navigation bar. If the app isn't laid out behind
-      // the navigation bar, this causes the IME insets to be too large during the animation.
-      // To fix this, we subtract the navigationBars bottom inset if the system UI flags for laying
-      // out behind the navigation bar aren't present.
+      // Pre 15, the IME insets include the height of the navigation bar. If the app
+      // isn't laid out behind the navigation bar, this causes the IME insets to be too large during
+      // the animation.  To fix this, we subtract the navigationBars bottom inset if the system UI
+      // flags for laying out behind the navigation bar aren't present.
       int excludedInsets = 0;
       int systemUiFlags = view.getWindowSystemUiVisibility();
-      if ((systemUiFlags & View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION) == 0
-          && (systemUiFlags & View.SYSTEM_UI_FLAG_HIDE_NAVIGATION) == 0) {
-        excludedInsets = insets.getInsets(WindowInsets.Type.navigationBars()).bottom;
+      if (Build.VERSION.SDK_INT < API_LEVELS.API_35) {
+        if ((systemUiFlags & View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION) == 0
+            && (systemUiFlags & View.SYSTEM_UI_FLAG_HIDE_NAVIGATION) == 0) {
+          excludedInsets = insets.getInsets(WindowInsets.Type.navigationBars()).bottom;
+        }
       }
 
       WindowInsets.Builder builder = new WindowInsets.Builder(lastWindowInsets);

engine/src/flutter/shell/platform/android/test/io/flutter/plugin/editing/TextInputPluginTest.java

@@ -2707,6 +2707,101 @@ public void ime_windowInsetsSync_notLaidOutBehindNavigation_excludesNavigationBa
     }
   }
 
+  @Test
+  @TargetApi(API_LEVELS.API_35)
+  @Config(minSdk = API_LEVELS.API_35)
+  @SuppressWarnings("deprecation")
+  // getWindowSystemUiVisibility, SYSTEM_UI_FLAG_LAYOUT_STABLE.
+  // flutter#133074 tracks migration work.
+  public void ime_windowInsetsSync_notLaidOutBehindNavigation_post15_includesNavigationBars() {
+    try (ActivityScenario<Activity> scenario = ActivityScenario.launch(Activity.class)) {
+      scenario.onActivity(
+          activity -> {
+            FlutterView testView = spy(new FlutterView(activity));
+            when(testView.getWindowSystemUiVisibility())
+                .thenReturn(View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
+
+            TextInputChannel textInputChannel = new TextInputChannel(mock(DartExecutor.class));
+            ScribeChannel scribeChannel = new ScribeChannel(mock(DartExecutor.class));
+            TextInputPlugin textInputPlugin =
+                new TextInputPlugin(
+                    testView,
+                    textInputChannel,
+                    scribeChannel,
+                    mock(PlatformViewsController.class),
+                    mock(PlatformViewsController2.class));
+            ImeSyncDeferringInsetsCallback imeSyncCallback = textInputPlugin.getImeSyncCallback();
+            FlutterEngine flutterEngine =
+                spy(new FlutterEngine(ctx, mockFlutterLoader, mockFlutterJni));
+            FlutterRenderer flutterRenderer = spy(new FlutterRenderer(mockFlutterJni));
+            when(flutterEngine.getRenderer()).thenReturn(flutterRenderer);
+            testView.attachToFlutterEngine(flutterEngine);
+
+            WindowInsetsAnimation animation = mock(WindowInsetsAnimation.class);
+            when(animation.getTypeMask()).thenReturn(WindowInsets.Type.ime());
+
+            List<WindowInsetsAnimation> animationList = new ArrayList();
+            animationList.add(animation);
+
+            ArgumentCaptor<FlutterRenderer.ViewportMetrics> viewportMetricsCaptor =
+                ArgumentCaptor.forClass(FlutterRenderer.ViewportMetrics.class);
+
+            WindowInsets.Builder builder = new WindowInsets.Builder();
+
+            // Set the initial insets and verify that they were set and the bottom view inset is
+            // correct
+            imeSyncCallback.getInsetsListener().onApplyWindowInsets(testView, builder.build());
+
+            verify(flutterRenderer, atLeast(1)).setViewportMetrics(viewportMetricsCaptor.capture());
+            assertEquals(0, viewportMetricsCaptor.getValue().viewInsetBottom);
+
+            // Call onPrepare and set the lastWindowInsets - these should be stored for the end of
+            // the
+            // animation instead of being applied immediately
+            imeSyncCallback.getAnimationCallback().onPrepare(animation);
+            builder.setInsets(WindowInsets.Type.ime(), Insets.of(0, 0, 0, 100));
+            builder.setInsets(WindowInsets.Type.navigationBars(), Insets.of(0, 0, 0, 0));
+            imeSyncCallback.getInsetsListener().onApplyWindowInsets(testView, builder.build());
+
+            verify(flutterRenderer, atLeast(1)).setViewportMetrics(viewportMetricsCaptor.capture());
+            assertEquals(0, viewportMetricsCaptor.getValue().viewInsetBottom);
+
+            // Call onStart and apply new insets - these should be ignored completely
+            imeSyncCallback.getAnimationCallback().onStart(animation, null);
+            builder.setInsets(WindowInsets.Type.ime(), Insets.of(0, 0, 0, 50));
+            builder.setInsets(WindowInsets.Type.navigationBars(), Insets.of(0, 0, 0, 40));
+            imeSyncCallback.getInsetsListener().onApplyWindowInsets(testView, builder.build());
+
+            verify(flutterRenderer, atLeast(1)).setViewportMetrics(viewportMetricsCaptor.capture());
+            assertEquals(0, viewportMetricsCaptor.getValue().viewInsetBottom);
+
+            // Progress the animation and ensure that the navigation bar insets have not been
+            // subtracted from the IME insets
+            builder.setInsets(WindowInsets.Type.ime(), Insets.of(0, 0, 0, 25));
+            builder.setInsets(WindowInsets.Type.navigationBars(), Insets.of(0, 0, 0, 40));
+            imeSyncCallback.getAnimationCallback().onProgress(builder.build(), animationList);
+
+            verify(flutterRenderer, atLeast(1)).setViewportMetrics(viewportMetricsCaptor.capture());
+            assertEquals(25, viewportMetricsCaptor.getValue().viewInsetBottom);
+
+            builder.setInsets(WindowInsets.Type.ime(), Insets.of(0, 0, 0, 50));
+            builder.setInsets(WindowInsets.Type.navigationBars(), Insets.of(0, 0, 0, 40));
+            imeSyncCallback.getAnimationCallback().onProgress(builder.build(), animationList);
+
+            verify(flutterRenderer, atLeast(1)).setViewportMetrics(viewportMetricsCaptor.capture());
+            assertEquals(50, viewportMetricsCaptor.getValue().viewInsetBottom);
+
+            // End the animation and ensure that the bottom insets match the lastWindowInsets that
+            // we set
+            // during onPrepare
+            imeSyncCallback.getAnimationCallback().onEnd(animation);
+
+            verify(flutterRenderer, atLeast(1)).setViewportMetrics(viewportMetricsCaptor.capture());
+            assertEquals(100, viewportMetricsCaptor.getValue().viewInsetBottom);
+          });
+    }
+  }
+
   @Test
   @TargetApi(API_LEVELS.API_30)
   @Config(sdk = API_LEVELS.API_30)