Android 10+ View.getSystemGestureExclusionRects (#11451)

* SystemGesture.getSystemGestureExclusionRects

* Add getSystemExclusionRects unit tests

shell/platform/android/io/flutter/embedding/engine/systemchannels/PlatformChannel.java

@@ -15,6 +15,7 @@ import org.json.JSONException;
 import org.json.JSONObject;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 
 import io.flutter.Log;
@@ -145,7 +146,7 @@ public class PlatformChannel {
    * @throws JSONException if {@code inputRects} does not contain expected keys and value types.
    */
   @NonNull
-  private ArrayList<Rect> decodeRects(@NonNull JSONArray inputRects) throws JSONException {
+  private ArrayList<Rect> decodeExclusionRects(@NonNull JSONArray inputRects) throws JSONException {
     ArrayList<Rect> exclusionRects = new ArrayList<Rect>();
     for (int i = 0; i < inputRects.length(); i++) {
       JSONObject rect = inputRects.getJSONObject(i);
@@ -173,6 +174,31 @@ public class PlatformChannel {
     return exclusionRects;
   }
 
+  /**
+   * Encodes a List<Rect> provided by the Android host into an
+   * ArrayList<HashMap<String, Integer>>.
+   *
+   * Since View.getSystemGestureExclusionRects returns a list of Rects, these
+   * Rects need to be transformed into UTF-8 encoded JSON messages to be
+   * properly decoded by the Flutter framework.
+   *
+   * This method is used by the SystemGestures.getSystemGestureExclusionRects
+   * platform channel.
+   */
+  private ArrayList<HashMap<String, Integer>> encodeExclusionRects(List<Rect> exclusionRects) {
+    ArrayList<HashMap<String, Integer>> encodedExclusionRects = new ArrayList<HashMap<String, Integer>>();
+    for (Rect rect : exclusionRects) {
+      HashMap<String, Integer> rectMap = new HashMap<String, Integer>();
+      rectMap.put("top", rect.top);
+      rectMap.put("right", rect.right);
+      rectMap.put("bottom", rect.bottom);
+      rectMap.put("left", rect.left);
+      encodedExclusionRects.add(rectMap);
+    }
+
+    return encodedExclusionRects;
+  }
+
   @NonNull
   private AppSwitcherDescription decodeAppSwitcherDescription(@NonNull JSONObject encodedDescription) throws JSONException {
     int color = encodedDescription.getInt("primaryColor");
@@ -337,6 +363,12 @@ public class PlatformChannel {
      */
     void setClipboardData(@NonNull String text);
 
+    /**
+     * The Flutter application would like to get the system gesture exclusion
+     * rects.
+     */
+    List<Rect> getSystemGestureExclusionRects();
+
     /**
      * The Flutter application would like to set the system gesture exclusion
      * rects through the given {@code rects}.
@@ -594,18 +626,6 @@ public class PlatformChannel {
             platformMessageHandler.popSystemNavigator();
             result.success(null);
             break;
-          case "SystemGestures.setSystemGestureExclusionRects":
-            if (!(arguments instanceof JSONArray)) {
-              String inputTypeError = "Input type is incorrect. Ensure that a List<Map<String, int>> is passed as the input for SystemGestureExclusionRects.setSystemGestureExclusionRects.";
-              result.error("inputTypeError", inputTypeError, null);
-              break;
-            }
-
-            JSONArray inputRects = (JSONArray) arguments;
-            ArrayList<Rect> decodedRects = decodeRects(inputRects);
-            platformMessageHandler.setSystemGestureExclusionRects(decodedRects);
-            result.success(null);
-            break;
           case "Clipboard.getData": {
             String contentFormatName = (String) arguments;
             ClipboardContentFormat clipboardFormat = null;
@@ -634,6 +654,30 @@ public class PlatformChannel {
             result.success(null);
             break;
           }
+          case "SystemGestures.setSystemGestureExclusionRects":
+            if (!(arguments instanceof JSONArray)) {
+              String inputTypeError = "Input type is incorrect. Ensure that a List<Map<String, int>> is passed as the input for SystemGestureExclusionRects.setSystemGestureExclusionRects.";
+              result.error("inputTypeError", inputTypeError, null);
+              break;
+            }
+
+            JSONArray inputRects = (JSONArray) arguments;
+            ArrayList<Rect> decodedRects = decodeExclusionRects(inputRects);
+            platformMessageHandler.setSystemGestureExclusionRects(decodedRects);
+            result.success(null);
+            break;
+          case "SystemGestures.getSystemGestureExclusionRects": {
+            List<Rect> exclusionRects = platformMessageHandler.getSystemGestureExclusionRects();
+            if (exclusionRects == null) {
+              String incorrectApiLevel = "Exclusion rects only exist for Android API 29+.";
+              result.error("error", incorrectApiLevel, null);
+              break;
+            }
+
+            ArrayList<HashMap<String, Integer>> encodedExclusionRects = encodeExclusionRects(exclusionRects);
+            result.success(encodedExclusionRects);
+            break;
+          }
           default:
             result.notImplemented();
             break;

shell/platform/android/io/flutter/plugin/platform/PlatformPlugin.java

@@ -88,6 +88,11 @@ public class PlatformPlugin {
             PlatformPlugin.this.setClipboardData(text);
         }
 
+        @Override
+        public List<Rect> getSystemGestureExclusionRects() {
+            return PlatformPlugin.this.getSystemGestureExclusionRects();
+        }
+
         @Override
         public void setSystemGestureExclusionRects(@NonNull ArrayList rects) {
             PlatformPlugin.this.setSystemGestureExclusionRects(rects);
@@ -281,6 +286,16 @@ public class PlatformPlugin {
         clipboard.setPrimaryClip(clip);
     }
 
+    private List<Rect> getSystemGestureExclusionRects() {
+        if (Build.VERSION.SDK_INT >= 29) {
+            Window window = activity.getWindow();
+            View view = window.getDecorView();
+            return view.getSystemGestureExclusionRects();
+        }
+
+        return null;
+    }
+
     private void setSystemGestureExclusionRects(ArrayList<Rect> rects) {
         if (Build.VERSION.SDK_INT < 29) {
             return;

shell/platform/android/test/io/flutter/embedding/engine/systemchannels/PlatformChannelTest.java

@@ -3,6 +3,7 @@ package io.flutter.embedding.engine.systemchannels;
 import android.graphics.Rect;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 
 import io.flutter.embedding.engine.dart.DartExecutor;
 import io.flutter.embedding.engine.systemchannels.PlatformChannel;
@@ -21,6 +22,7 @@ import org.robolectric.annotation.Config;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 @Config(manifest=Config.NONE)
 @RunWith(RobolectricTestRunner.class)
@@ -50,12 +52,12 @@ public class PlatformChannelTest {
         Rect gestureRect = new Rect(left, top, right, bottom);
         expectedDecodedRects.add(gestureRect);
 
-        MethodCall callSystemGestureExclusionRects = new MethodCall(
+        MethodCall callSetSystemGestureExclusionRects = new MethodCall(
             "SystemGestures.setSystemGestureExclusionRects",
             inputRects
         );
 
-        platformChannel.parsingMethodCallHandler.onMethodCall(callSystemGestureExclusionRects, resultsMock);
+        platformChannel.parsingMethodCallHandler.onMethodCall(callSetSystemGestureExclusionRects, resultsMock);
         verify(platformMessageHandler, times(1)).setSystemGestureExclusionRects(expectedDecodedRects);
         verify(resultsMock, times(1)).success(null);
     }
@@ -69,11 +71,11 @@ public class PlatformChannelTest {
 
         ResultsMock resultsMock = mock(ResultsMock.class);
         String nonJsonInput = "Non-JSON";
-        MethodCall callSystemGestureExclusionRects = new MethodCall(
+        MethodCall callSetSystemGestureExclusionRects = new MethodCall(
             "SystemGestures.setSystemGestureExclusionRects",
             nonJsonInput
         );
-        platformChannel.parsingMethodCallHandler.onMethodCall(callSystemGestureExclusionRects, resultsMock);
+        platformChannel.parsingMethodCallHandler.onMethodCall(callSetSystemGestureExclusionRects, resultsMock);
 
         String inputTypeError = "Input type is incorrect. Ensure that a List<Map<String, int>> is passed as the input for SystemGestureExclusionRects.setSystemGestureExclusionRects.";
         verify(resultsMock, times(1)).error(
@@ -100,11 +102,11 @@ public class PlatformChannelTest {
         JSONArray inputArray = new JSONArray();
         inputArray.put(jsonObject);
 
-        MethodCall callSystemGestureExclusionRects = new MethodCall(
+        MethodCall callSetSystemGestureExclusionRects = new MethodCall(
             "SystemGestures.setSystemGestureExclusionRects",
             inputArray
         );
-        platformChannel.parsingMethodCallHandler.onMethodCall(callSystemGestureExclusionRects, resultsMock);
+        platformChannel.parsingMethodCallHandler.onMethodCall(callSetSystemGestureExclusionRects, resultsMock);
         verify(resultsMock, times(1)).error(
             "error",
             "JSON error: Incorrect JSON data shape. To set system gesture exclusion rects, \n" +
@@ -113,6 +115,67 @@ public class PlatformChannelTest {
         );
     }
 
+    @Test
+    public void itSendsSuccessMessageToFrameworkWhenGettingSystemGestureExclusionRects() throws JSONException {
+        // --- Test Setup ---
+        DartExecutor dartExecutor = mock(DartExecutor.class);
+        PlatformChannel platformChannel = new PlatformChannel(dartExecutor);
+        PlatformMessageHandler platformMessageHandler = mock(PlatformMessageHandler.class);
+        platformChannel.setPlatformMessageHandler(platformMessageHandler);
+        Result result = mock(Result.class);
+
+        // Fake API output setup
+        ArrayList<Rect> fakeExclusionRects = new ArrayList<Rect>();
+        Rect gestureRect = new Rect(0, 0, 500, 250);
+        fakeExclusionRects.add(gestureRect);
+        when(platformMessageHandler.getSystemGestureExclusionRects()).thenReturn(fakeExclusionRects);
+
+        // Parsed API output that should be passed to result.success()
+        ArrayList<HashMap<String, Integer>> expectedEncodedOutputRects = new ArrayList<HashMap<String, Integer>>();
+        HashMap<String, Integer> rectMap = new HashMap<String, Integer>();
+        rectMap.put("top", 0);
+        rectMap.put("right", 500);
+        rectMap.put("bottom", 250);
+        rectMap.put("left", 0);
+        expectedEncodedOutputRects.add(rectMap);
+        MethodCall callGetSystemGestureExclusionRects = new MethodCall(
+            "SystemGestures.getSystemGestureExclusionRects",
+            null
+        );
+
+        // --- Execute Test ---
+        platformChannel.parsingMethodCallHandler.onMethodCall(callGetSystemGestureExclusionRects, result);
+
+        // --- Verify Results ---
+        verify(result, times(1)).success(expectedEncodedOutputRects);
+    }
+
+    @Test
+    public void itSendsAPILevelErrorWhenAndroidVersionIsTooLowWhenGettingSystemGestureExclusionRects() {
+        // --- Test Setup ---
+        DartExecutor dartExecutor = mock(DartExecutor.class);
+        PlatformChannel platformChannel = new PlatformChannel(dartExecutor);
+        PlatformMessageHandler platformMessageHandler = mock(PlatformMessageHandler.class);
+        platformChannel.setPlatformMessageHandler(platformMessageHandler);
+        when(platformMessageHandler.getSystemGestureExclusionRects()).thenReturn(null);
+        Result result = mock(Result.class);
+
+        MethodCall callGetSystemGestureExclusionRects = new MethodCall(
+            "SystemGestures.getSystemGestureExclusionRects",
+            null
+        );
+
+        // --- Execute Test ---
+        platformChannel.parsingMethodCallHandler.onMethodCall(callGetSystemGestureExclusionRects, result);
+
+        // --- Verify Results ---
+        verify(result, times(1)).error(
+            "error",
+            "Exclusion rects only exist for Android API 29+.",
+            null
+        );
+    }
+
     private class ResultsMock implements Result {
         @Override
         public void success(Object result) {}