[google_maps_flutter] Move iOS inspector to Pigeon (flutter#6937)

Converts the inspector API (only intended for use in integration tests) of the iOS implementation to Pigeon. This is a small, simple API surface to start the migration with, allowing setting up the basic Pigeon plumbing without major changes.

For the cases where the API would always return a hard-coded value due to that query not applying on iOS, that hard-coding has been moved to the Dart side per the general practice of doing logic in Dart rather than native code when convenient.

On the Dart side, this is largely identical to flutter/packages#6958

Part of flutter#117907

Author: stuartmorgan-g

packages/google_maps_flutter/google_maps_flutter_ios/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.8.2
+
+* Converts inspector interface platform calls to Pigeon.
+
 ## 2.8.1
 
 * Improves Objective-C type handling.

packages/google_maps_flutter/google_maps_flutter_ios/ios/Classes/FLTGoogleMapTileOverlayController.h

@@ -8,12 +8,14 @@
 NS_ASSUME_NONNULL_BEGIN
 
 @interface FLTGoogleMapTileOverlayController : NSObject
+/// The layer managed by this controller instance.
+@property(readonly, nonatomic) GMSTileLayer *layer;
+
 - (instancetype)initWithTileLayer:(GMSTileLayer *)tileLayer
                           mapView:(GMSMapView *)mapView
                           options:(NSDictionary *)optionsData;
 - (void)removeTileOverlay;
 - (void)clearTileCache;
-- (NSDictionary *)getTileOverlayInfo;
 @end
 
 @interface FLTTileProviderController : GMSTileLayer
@@ -30,7 +32,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)changeTileOverlays:(NSArray *)tileOverlaysToChange;
 - (void)removeTileOverlayWithIdentifiers:(NSArray *)identifiers;
 - (void)clearTileCacheWithIdentifier:(NSString *)identifier;
-- (nullable NSDictionary *)tileOverlayInfoWithIdentifier:(NSString *)identifier;
+- (nullable FLTGoogleMapTileOverlayController *)tileOverlayWithIdentifier:(NSString *)identifier;
 @end
 
 NS_ASSUME_NONNULL_END

packages/google_maps_flutter/google_maps_flutter_ios/ios/Classes/FLTGoogleMapTileOverlayController.m

@@ -34,17 +34,6 @@ - (void)clearTileCache {
   [self.layer clearTileCache];
 }
 
-- (NSDictionary *)getTileOverlayInfo {
-  NSMutableDictionary *info = [[NSMutableDictionary alloc] init];
-  BOOL visible = self.layer.map != nil;
-  info[@"visible"] = @(visible);
-  info[@"fadeIn"] = @(self.layer.fadeIn);
-  float transparency = 1.0 - self.layer.opacity;
-  info[@"transparency"] = @(transparency);
-  info[@"zIndex"] = @(self.layer.zIndex);
-  return info;
-}
-
 - (void)setFadeIn:(BOOL)fadeIn {
   self.layer.fadeIn = fadeIn;
 }
@@ -182,7 +171,8 @@ - (void)requestTileForX:(NSUInteger)x
 
 @interface FLTTileOverlaysController ()
 
-@property(strong, nonatomic) NSMutableDictionary *tileOverlayIdentifierToController;
+@property(strong, nonatomic) NSMutableDictionary<NSString *, FLTGoogleMapTileOverlayController *>
+    *tileOverlayIdentifierToController;
 @property(strong, nonatomic) FlutterMethodChannel *methodChannel;
 @property(weak, nonatomic) GMSMapView *mapView;
 
@@ -248,11 +238,8 @@ - (void)clearTileCacheWithIdentifier:(NSString *)identifier {
   [controller clearTileCache];
 }
 
-- (nullable NSDictionary *)tileOverlayInfoWithIdentifier:(NSString *)identifier {
-  if (self.tileOverlayIdentifierToController[identifier] == nil) {
-    return nil;
-  }
-  return [self.tileOverlayIdentifierToController[identifier] getTileOverlayInfo];
+- (nullable FLTGoogleMapTileOverlayController *)tileOverlayWithIdentifier:(NSString *)identifier {
+  return self.tileOverlayIdentifierToController[identifier];
 }
 
 + (NSString *)identifierForTileOverlay:(NSDictionary *)tileOverlay {

packages/google_maps_flutter/google_maps_flutter_ios/ios/Classes/GoogleMapController.h

@@ -8,6 +8,7 @@
 #import "GoogleMapMarkerController.h"
 #import "GoogleMapPolygonController.h"
 #import "GoogleMapPolylineController.h"
+#import "messages.g.h"
 
 NS_ASSUME_NONNULL_BEGIN
 

packages/google_maps_flutter/google_maps_flutter_ios/ios/Classes/GoogleMapController.m

@@ -5,6 +5,7 @@
 #import "GoogleMapController.h"
 #import "FLTGoogleMapJSONConversions.h"
 #import "FLTGoogleMapTileOverlayController.h"
+#import "messages.g.h"
 
 #pragma mark - Conversion of JSON-like values sent via platform channels. Forward declarations.
 
@@ -56,6 +57,33 @@ - (instancetype)initWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar
 
 @end
 
+#pragma mark -
+
+/// Implementation of the Pigeon maps inspector API.
+///
+/// This is a separate object from the maps controller because the Pigeon API registration keeps a
+/// strong reference to the implementor, but as the FlutterPlatformView, the lifetime of the
+/// FLTGoogleMapController instance is what needs to trigger Pigeon unregistration, so can't be
+/// the target of the registration.
+@interface FGMMapInspector : NSObject <FGMMapsInspectorApi>
+- (instancetype)initWithMapController:(nonnull FLTGoogleMapController *)controller
+                            messenger:(NSObject<FlutterBinaryMessenger> *)messenger
+                         pigeonSuffix:(NSString *)suffix;
+@end
+
+/// Private declarations.
+// This is separate in case the above is made public in the future (e.g., for unit testing).
+@interface FGMMapInspector ()
+/// The map controller this inspector corresponds to.
+@property(nonatomic, weak) FLTGoogleMapController *controller;
+/// The messenger this instance was registered with by Pigeon.
+@property(nonatomic, copy) NSObject<FlutterBinaryMessenger> *messenger;
+/// The suffix this instance was registered under with Pigeon.
+@property(nonatomic, copy) NSString *pigeonSuffix;
+@end
+
+#pragma mark -
+
 @interface FLTGoogleMapController ()
 
 @property(nonatomic, strong) GMSMapView *mapView;
@@ -72,6 +100,8 @@ @interface FLTGoogleMapController ()
 // creation time and there's no mechanism to return non-fatal error details during platform view
 // initialization.
 @property(nonatomic, copy) NSString *styleError;
+// The inspector API implementation, separate to avoid lifetime extension.
+@property(nonatomic, strong) FGMMapInspector *inspector;
 
 @end
 
@@ -114,9 +144,7 @@ - (instancetype)initWithMapView:(GMSMapView *_Nonnull)mapView
                                            binaryMessenger:registrar.messenger];
     __weak __typeof__(self) weakSelf = self;
     [_channel setMethodCallHandler:^(FlutterMethodCall *call, FlutterResult result) {
-      if (weakSelf) {
-        [weakSelf onMethodCall:call result:result];
-      }
+      [weakSelf onMethodCall:call result:result];
     }];
     _mapView.delegate = weakSelf;
     _mapView.paddingAdjustmentBehavior = kGMSMapViewPaddingAdjustmentBehaviorNever;
@@ -158,10 +186,22 @@ - (instancetype)initWithMapView:(GMSMapView *_Nonnull)mapView
     }
 
     [_mapView addObserver:self forKeyPath:@"frame" options:0 context:nil];
+
+    NSString *suffix = [NSString stringWithFormat:@"%lld", viewId];
+    _inspector = [[FGMMapInspector alloc] initWithMapController:self
+                                                      messenger:registrar.messenger
+                                                   pigeonSuffix:suffix];
+    SetUpFGMMapsInspectorApiWithSuffix(registrar.messenger, _inspector, suffix);
   }
   return self;
 }
 
+- (void)dealloc {
+  // Unregister the API implementations so that they can be released; the registration created an
+  // owning reference.
+  SetUpFGMMapsInspectorApiWithSuffix(_inspector.messenger, nil, _inspector.pigeonSuffix);
+}
+
 - (UIView *)view {
   return self.mapView;
 }
@@ -356,41 +396,8 @@ - (void)onMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result {
     id rawTileOverlayId = call.arguments[@"tileOverlayId"];
     [self.tileOverlaysController clearTileCacheWithIdentifier:rawTileOverlayId];
     result(nil);
-  } else if ([call.method isEqualToString:@"map#isCompassEnabled"]) {
-    NSNumber *isCompassEnabled = @(self.mapView.settings.compassButton);
-    result(isCompassEnabled);
-  } else if ([call.method isEqualToString:@"map#isMapToolbarEnabled"]) {
-    NSNumber *isMapToolbarEnabled = @NO;
-    result(isMapToolbarEnabled);
-  } else if ([call.method isEqualToString:@"map#getMinMaxZoomLevels"]) {
-    NSArray *zoomLevels = @[ @(self.mapView.minZoom), @(self.mapView.maxZoom) ];
-    result(zoomLevels);
   } else if ([call.method isEqualToString:@"map#getZoomLevel"]) {
     result(@(self.mapView.camera.zoom));
-  } else if ([call.method isEqualToString:@"map#isZoomGesturesEnabled"]) {
-    NSNumber *isZoomGesturesEnabled = @(self.mapView.settings.zoomGestures);
-    result(isZoomGesturesEnabled);
-  } else if ([call.method isEqualToString:@"map#isZoomControlsEnabled"]) {
-    NSNumber *isZoomControlsEnabled = @NO;
-    result(isZoomControlsEnabled);
-  } else if ([call.method isEqualToString:@"map#isTiltGesturesEnabled"]) {
-    NSNumber *isTiltGesturesEnabled = @(self.mapView.settings.tiltGestures);
-    result(isTiltGesturesEnabled);
-  } else if ([call.method isEqualToString:@"map#isRotateGesturesEnabled"]) {
-    NSNumber *isRotateGesturesEnabled = @(self.mapView.settings.rotateGestures);
-    result(isRotateGesturesEnabled);
-  } else if ([call.method isEqualToString:@"map#isScrollGesturesEnabled"]) {
-    NSNumber *isScrollGesturesEnabled = @(self.mapView.settings.scrollGestures);
-    result(isScrollGesturesEnabled);
-  } else if ([call.method isEqualToString:@"map#isMyLocationButtonEnabled"]) {
-    NSNumber *isMyLocationButtonEnabled = @(self.mapView.settings.myLocationButton);
-    result(isMyLocationButtonEnabled);
-  } else if ([call.method isEqualToString:@"map#isTrafficEnabled"]) {
-    NSNumber *isTrafficEnabled = @(self.mapView.trafficEnabled);
-    result(isTrafficEnabled);
-  } else if ([call.method isEqualToString:@"map#isBuildingsEnabled"]) {
-    NSNumber *isBuildingsEnabled = @(self.mapView.buildingsEnabled);
-    result(isBuildingsEnabled);
   } else if ([call.method isEqualToString:@"map#setStyle"]) {
     id mapStyle = [call arguments];
     self.styleError = [self setMapStyle:(mapStyle == [NSNull null] ? nil : mapStyle)];
@@ -401,9 +408,6 @@ - (void)onMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result {
     }
   } else if ([call.method isEqualToString:@"map#getStyleError"]) {
     result(self.styleError);
-  } else if ([call.method isEqualToString:@"map#getTileOverlayInfo"]) {
-    NSString *rawTileOverlayId = call.arguments[@"tileOverlayId"];
-    result([self.tileOverlaysController tileOverlayInfoWithIdentifier:rawTileOverlayId]);
   } else {
     result(FlutterMethodNotImplemented);
   }
@@ -659,3 +663,81 @@ - (void)interpretMapOptions:(NSDictionary *)data {
 }
 
 @end
+
+#pragma mark -
+
+@implementation FGMMapInspector
+
+- (instancetype)initWithMapController:(nonnull FLTGoogleMapController *)controller
+                            messenger:(NSObject<FlutterBinaryMessenger> *)messenger
+                         pigeonSuffix:(NSString *)suffix {
+  self = [super init];
+  if (self) {
+    _controller = controller;
+    _messenger = messenger;
+    _pigeonSuffix = suffix;
+  }
+  return self;
+}
+
+- (nullable NSNumber *)areBuildingsEnabledWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  return @(self.controller.mapView.buildingsEnabled);
+}
+
+- (nullable NSNumber *)areRotateGesturesEnabledWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  return @(self.controller.mapView.settings.rotateGestures);
+}
+
+- (nullable NSNumber *)areScrollGesturesEnabledWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  return @(self.controller.mapView.settings.scrollGestures);
+}
+
+- (nullable NSNumber *)areTiltGesturesEnabledWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  return @(self.controller.mapView.settings.tiltGestures);
+}
+
+- (nullable NSNumber *)areZoomGesturesEnabledWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  return @(self.controller.mapView.settings.zoomGestures);
+}
+
+- (nullable FGMPlatformTileLayer *)
+    getInfoForTileOverlayWithIdentifier:(nonnull NSString *)tileOverlayId
+                                  error:(FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  GMSTileLayer *layer =
+      [self.controller.tileOverlaysController tileOverlayWithIdentifier:tileOverlayId].layer;
+  if (!layer) {
+    return nil;
+  }
+  return [FGMPlatformTileLayer makeWithVisible:(layer.map != nil)
+                                        fadeIn:layer.fadeIn
+                                       opacity:layer.opacity
+                                        zIndex:layer.zIndex];
+}
+
+- (nullable NSNumber *)isCompassEnabledWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  return @(self.controller.mapView.settings.compassButton);
+}
+
+- (nullable NSNumber *)isMyLocationButtonEnabledWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  return @(self.controller.mapView.settings.myLocationButton);
+}
+
+- (nullable NSNumber *)isTrafficEnabledWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  return @(self.controller.mapView.trafficEnabled);
+}
+
+- (nullable FGMPlatformZoomRange *)zoomRange:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  return [FGMPlatformZoomRange makeWithMin:self.controller.mapView.minZoom
+                                       max:self.controller.mapView.maxZoom];
+}
+
+@end

packages/google_maps_flutter/google_maps_flutter_ios/ios/Classes/messages.g.h

@@ -0,0 +1,77 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+// Autogenerated from Pigeon (v20.0.1), do not edit directly.
+// See also: https://pub.dev/packages/pigeon
+
+#import <Foundation/Foundation.h>
+
+@protocol FlutterBinaryMessenger;
+@protocol FlutterMessageCodec;
+@class FlutterError;
+@class FlutterStandardTypedData;
+
+NS_ASSUME_NONNULL_BEGIN
+
+@class FGMPlatformTileLayer;
+@class FGMPlatformZoomRange;
+
+/// Pigeon equivalent of GMSTileLayer properties.
+@interface FGMPlatformTileLayer : NSObject
+/// `init` unavailable to enforce nonnull fields, see the `make` class method.
+- (instancetype)init NS_UNAVAILABLE;
++ (instancetype)makeWithVisible:(BOOL)visible
+                         fadeIn:(BOOL)fadeIn
+                        opacity:(double)opacity
+                         zIndex:(NSInteger)zIndex;
+@property(nonatomic, assign) BOOL visible;
+@property(nonatomic, assign) BOOL fadeIn;
+@property(nonatomic, assign) double opacity;
+@property(nonatomic, assign) NSInteger zIndex;
+@end
+
+/// Possible outcomes of launching a URL.
+@interface FGMPlatformZoomRange : NSObject
+/// `init` unavailable to enforce nonnull fields, see the `make` class method.
+- (instancetype)init NS_UNAVAILABLE;
++ (instancetype)makeWithMin:(double)min max:(double)max;
+@property(nonatomic, assign) double min;
+@property(nonatomic, assign) double max;
+@end
+
+/// The codec used by all APIs.
+NSObject<FlutterMessageCodec> *FGMGetMessagesCodec(void);
+
+/// Inspector API only intended for use in integration tests.
+@protocol FGMMapsInspectorApi
+/// @return `nil` only when `error != nil`.
+- (nullable NSNumber *)areBuildingsEnabledWithError:(FlutterError *_Nullable *_Nonnull)error;
+/// @return `nil` only when `error != nil`.
+- (nullable NSNumber *)areRotateGesturesEnabledWithError:(FlutterError *_Nullable *_Nonnull)error;
+/// @return `nil` only when `error != nil`.
+- (nullable NSNumber *)areScrollGesturesEnabledWithError:(FlutterError *_Nullable *_Nonnull)error;
+/// @return `nil` only when `error != nil`.
+- (nullable NSNumber *)areTiltGesturesEnabledWithError:(FlutterError *_Nullable *_Nonnull)error;
+/// @return `nil` only when `error != nil`.
+- (nullable NSNumber *)areZoomGesturesEnabledWithError:(FlutterError *_Nullable *_Nonnull)error;
+/// @return `nil` only when `error != nil`.
+- (nullable NSNumber *)isCompassEnabledWithError:(FlutterError *_Nullable *_Nonnull)error;
+/// @return `nil` only when `error != nil`.
+- (nullable NSNumber *)isMyLocationButtonEnabledWithError:(FlutterError *_Nullable *_Nonnull)error;
+/// @return `nil` only when `error != nil`.
+- (nullable NSNumber *)isTrafficEnabledWithError:(FlutterError *_Nullable *_Nonnull)error;
+- (nullable FGMPlatformTileLayer *)
+    getInfoForTileOverlayWithIdentifier:(NSString *)tileOverlayId
+                                  error:(FlutterError *_Nullable *_Nonnull)error;
+/// @return `nil` only when `error != nil`.
+- (nullable FGMPlatformZoomRange *)zoomRange:(FlutterError *_Nullable *_Nonnull)error;
+@end
+
+extern void SetUpFGMMapsInspectorApi(id<FlutterBinaryMessenger> binaryMessenger,
+                                     NSObject<FGMMapsInspectorApi> *_Nullable api);
+
+extern void SetUpFGMMapsInspectorApiWithSuffix(id<FlutterBinaryMessenger> binaryMessenger,
+                                               NSObject<FGMMapsInspectorApi> *_Nullable api,
+                                               NSString *messageChannelSuffix);
+
+NS_ASSUME_NONNULL_END