[ios platform view] fix overlay zPosition (#29930)

flutter · Dec 8, 2021 · 6981c04 · 6981c04
1 parent e32d04a
commit 6981c04
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Showing 5 changed files with 234 additions and 75 deletions.
diff --git a/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm b/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm
@@ -575,15 +575,19 @@
 
     if (platform_view_root.superview != flutter_view) {
       [flutter_view addSubview:platform_view_root];
-    } else {
-      platform_view_root.layer.zPosition = zIndex++;
     }
+    // Make sure the platform_view_root is higher than the last platform_view_root in
+    // composition_order_.
+    platform_view_root.layer.zPosition = zIndex++;
+
     for (const std::shared_ptr<FlutterPlatformViewLayer>& layer : layers) {
-      if ([layer->overlay_view_wrapper superview] != flutter_view) {
+      if ([layer->overlay_view_wrapper.get() superview] != flutter_view) {
         [flutter_view addSubview:layer->overlay_view_wrapper];
-      } else {
-        layer->overlay_view_wrapper.get().layer.zPosition = zIndex++;
       }
+      // Make sure all the overlays are higher than the platform view.
+      layer->overlay_view_wrapper.get().layer.zPosition = zIndex++;
+      FML_DCHECK(layer->overlay_view_wrapper.get().layer.zPosition >
+                 platform_view_root.layer.zPosition);
     }
     active_composition_order_.push_back(platform_view_id);
   }

diff --git a/testing/scenario_app/ios/Scenarios/Scenarios/AppDelegate.m b/testing/scenario_app/ios/Scenarios/Scenarios/AppDelegate.m
@@ -61,6 +61,7 @@ - (BOOL)application:(UIApplication*)application
     @"--bogus-font-text" : @"bogus_font_text",
     @"--spawn-engine-works" : @"spawn_engine_works",
     @"--pointer-events" : @"pointer_events",
+    @"--platform-view-scrolling-under-widget" : @"platform_view_scrolling_under_widget"
   };
   __block NSString* flutterViewControllerTestName = nil;
   [launchArgsMap

diff --git a/testing/scenario_app/ios/Scenarios/ScenariosUITests/PlatformViewUITests.m b/testing/scenario_app/ios/Scenarios/ScenariosUITests/PlatformViewUITests.m
@@ -257,3 +257,40 @@ - (void)testPlatformViewWithContinuousTexture {
 }
 
 @end
+
+@interface PlatformViewScrollingUnderWidget : XCTestCase
+
+@end
+
+@implementation PlatformViewScrollingUnderWidget
+
+- (void)setUp {
+  [super setUp];
+  self.continueAfterFailure = NO;
+}
+
+- (void)testPlatformViewScrollingUnderWidget {
+  XCUIApplication* app = [[XCUIApplication alloc] init];
+  app.launchArguments =
+      @[ @"--platform-view-scrolling-under-widget", @"--with-continuous-texture" ];
+  [app launch];
+
+  XCUIElement* platformView = app.textViews.firstMatch;
+  BOOL exists = [platformView waitForExistenceWithTimeout:kSecondsToWaitForPlatformView];
+  if (!exists) {
+    XCTFail(@"It took longer than %@ second to find the platform view."
+            @"There might be issues with the platform view's construction,"
+            @"or with how the scenario is built.",
+            @(kSecondsToWaitForPlatformView));
+  }
+
+  // Wait and let the scenario app scroll a bit.
+  XCTWaiterResult waitResult = [XCTWaiter
+      waitForExpectations:@[ [[XCTestExpectation alloc] initWithDescription:@"Wait for 5 seconds"] ]
+                  timeout:5];
+  // If the waiter is not interrupted, we know the app is in a valid state after timeout, thus the
+  // test passes.
+  XCTAssert(waitResult != XCTWaiterResultInterrupted);
+}
+
+@end