iOS: Update diagnostic screen on state update

Summary: Update the diagnostic screen whenever the sonar state changes.

Reviewed By: priteshrnandgaonkar

Differential Revision: D9218765

fbshipit-source-id: 654a35e309cb43df18bc8c8a645d469eddc1031d

iOS/SonarKit/FlipperDiagnosticsViewController.h

@@ -7,11 +7,13 @@
  */
 #ifdef FB_SONARKIT_ENABLED
 
+#include "FlipperStateUpdateListener.h"
 #import <UIKit/UIKit.h>
 
-@interface FlipperDiagnosticsViewController : UIViewController
+@interface FlipperDiagnosticsViewController : UIViewController <FlipperStateUpdateListener>
 @property(strong, nonatomic) UIScrollView *scrollView;
 @property(strong, nonatomic) UILabel *stateLabel;
+- (void)onUpdate;
 @end
 
 #endif

iOS/SonarKit/FlipperDiagnosticsViewController.m

@@ -12,8 +12,9 @@
   text.text = @"Flipper Diagnostics";
   [self.view addSubview:text];
 
-  self.scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 50, self.view.frame.size.width, self.view.frame.size.height - 50)];
+  self.scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 50, self.view.frame.size.width, self.view.frame.size.height - 100)];
   self.stateLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 1000)];
+
   self.stateLabel.numberOfLines = 0;
   self.stateLabel.text = [[SonarClient sharedClient] getState];
   [self.scrollView addSubview:self.stateLabel];
@@ -22,8 +23,23 @@
 }
 
 - (void)onUpdate {
-  self.stateLabel.text = [[SonarClient sharedClient] getState];
-  self.scrollView.contentSize = self.stateLabel.frame.size;
+  FlipperDiagnosticsViewController __weak *weakSelf = self;
+  dispatch_async(dispatch_get_main_queue(), ^{
+    FlipperDiagnosticsViewController *strongSelf = weakSelf;
+    if (!strongSelf) {
+      return;
+    }
+    NSString *state = [[SonarClient sharedClient] getState];
+    strongSelf.stateLabel.text = state;
+    [strongSelf.stateLabel sizeToFit];
+    strongSelf.scrollView.contentSize = strongSelf.stateLabel.frame.size;
+  });
+}
+
+- (void)viewWillAppear:(BOOL)animated {
+  [super viewWillAppear:animated];
+  id<FlipperStateUpdateListener> weakSelf = self;
+  [[SonarClient sharedClient] subscribeForUpdates:weakSelf];
 }
 
 - (UIInterfaceOrientationMask)supportedInterfaceOrientations {

iOS/SonarKit/FlipperStateUpdateListener.h

@@ -0,0 +1,14 @@
+/*
+ *  Copyright (c) 2018-present, Facebook, Inc.
+ *
+ *  This source code is licensed under the MIT license found in the LICENSE
+ *  file in the root directory of this source tree.
+ *
+ */
+#ifdef FB_SONARKIT_ENABLED
+
+@protocol FlipperStateUpdateListener
+- (void)onUpdate;
+@end
+
+#endif

iOS/SonarKit/SKStateUpdateCPPWrapper.h

@@ -0,0 +1,19 @@
+#ifdef FB_SONARKIT_ENABLED
+
+#include <Sonar/SonarStateUpdateListener.h>
+#import "FlipperStateUpdateListener.h"
+
+/*
+ * This class exists to bridge the gap between Objective C and C++.
+ * A SKStateUpdateCPPWrapper instance allows for wrapping an Objective-C object
+ * and passing it to the pure C++ SonarClient, so it can be triggered when updates occur.
+ */
+class SKStateUpdateCPPWrapper : public SonarStateUpdateListener {
+public:
+  SKStateUpdateCPPWrapper(id<FlipperStateUpdateListener> delegate_);
+  void onUpdate();
+private:
+  __weak id<FlipperStateUpdateListener> delegate_;
+};
+
+#endif

iOS/SonarKit/SKStateUpdateCPPWrapper.mm

@@ -0,0 +1,16 @@
+#ifdef FB_SONARKIT_ENABLED
+
+#include "SKStateUpdateCPPWrapper.h"
+
+SKStateUpdateCPPWrapper::SKStateUpdateCPPWrapper(id<FlipperStateUpdateListener> controller) {
+  delegate_ = controller;
+}
+
+void SKStateUpdateCPPWrapper::onUpdate() {
+  if (!delegate_) {
+    return;
+  }
+  [delegate_ onUpdate];
+}
+
+#endif

iOS/SonarKit/SonarClient.h

@@ -8,6 +8,7 @@
 #import <Foundation/Foundation.h>
 
 #import "SonarPlugin.h"
+#import "FlipperStateUpdateListener.h"
 
 /**
 Represents a connection between the Sonar desktop och client side. Manages the lifecycle of attached
@@ -50,6 +51,11 @@ Get the current state of the sonar client
 */
 - (NSString *)getState;
 
+/**
+Subscribe a ViewController to state update change notifications
+*/
+- (void)subscribeForUpdates:(id<FlipperStateUpdateListener>)controller;
+
 // initializers are disabled. You must use `+[SonarClient sharedClient]` instance.
 - (instancetype)init NS_UNAVAILABLE;
 + (instancetype)new NS_UNAVAILABLE;

iOS/SonarKit/SonarClient.mm

@@ -13,6 +13,8 @@
 #include <folly/io/async/EventBase.h>
 #include <folly/io/async/ScopedEventBaseThread.h>
 #import <UIKit/UIKit.h>
+#include "SKStateUpdateCPPWrapper.h"
+#import "FlipperDiagnosticsViewController.h"
 
 #if !TARGET_OS_SIMULATOR
 //#import "SKPortForwardingServer.h"
@@ -125,6 +127,11 @@ using WrapperPlugin = facebook::sonar::SonarCppWrapperPlugin;
   return @(_cppClient->getState().c_str());
 }
 
+- (void)subscribeForUpdates:(id<FlipperStateUpdateListener>)controller {
+  auto stateListener = std::make_shared<SKStateUpdateCPPWrapper>(controller);
+  _cppClient->setStateListener(stateListener);
+}
+
 @end
 
 #endif