[escher] Add a telemetry API based off ion's

build/config.mak

@@ -8,6 +8,7 @@ EPSILON_VERSION ?= 13.0.0
 EPSILON_APPS ?= calculation graph code statistics probability solver sequence regression settings
 EPSILON_I18N ?= en fr es de pt
 EPSILON_GETOPT ?= 0
+EPSILON_TELEMETRY ?= 0
 ESCHER_LOG_EVENTS_BINARY ?= 0
 
 include build/defaults.mak
@@ -23,4 +24,5 @@ include build/toolchain.$(TOOLCHAIN).mak
 
 SFLAGS += -DDEBUG=$(DEBUG)
 SFLAGS += -DEPSILON_GETOPT=$(EPSILON_GETOPT)
+SFLAGS += -DEPSILON_TELEMETRY=$(EPSILON_TELEMETRY)
 SFLAGS += -DESCHER_LOG_EVENTS_BINARY=$(ESCHER_LOG_EVENTS_BINARY)

build/platform.simulator.android.mak

@@ -1,6 +1,8 @@
 TOOLCHAIN = android
 EXE = so
 
+EPSILON_TELEMETRY ?= 1
+
 ifdef NDK_ABI
 BUILD_DIR := $(BUILD_DIR)/$(NDK_ABI)
 endif

build/platform.simulator.ios.mak

@@ -3,6 +3,7 @@ EXE = bin
 
 APPLE_PLATFORM ?= ios
 APPLE_PLATFORM_MIN_VERSION = 8.0
+EPSILON_TELEMETRY ?= 1
 
 ifeq ($(APPLE_PLATFORM),ios)
 ARCHS ?= arm64 armv7

escher/include/escher/app.h

@@ -10,6 +10,7 @@
 #include <escher/warning_controller.h>
 #include <ion/storage.h>
 #include <poincare/context.h>
+#include <escher/telemetry.h>
 
 /* An app is fed events and outputs drawing calls.
  *
@@ -65,6 +66,9 @@ public:
   virtual int numberOfTimers() { return 0; }
   virtual Timer * timerAtIndex(int i) { assert(false); return nullptr; }
   virtual Poincare::Context * localContext() { return nullptr; }
+#if EPSILON_TELEMETRY
+  virtual const char * telemetryId() const { return nullptr; }
+#endif
 protected:
   App(Snapshot * snapshot, ViewController * rootViewController, I18n::Message warningMessage = (I18n::Message)0) :
     Responder(nullptr),

escher/include/escher/telemetry.h

@@ -0,0 +1,10 @@
+#ifndef ESCHER_TELEMETRY_H
+#define ESCHER_TELEMETRY_H
+
+#if EPSILON_TELEMETRY
+#define TELEMETRY_ID(x) const char * telemetryId() const override { return (x); }
+#else
+#define TELEMETRY_ID(x)
+#endif
+
+#endif

escher/include/escher/view_controller.h

@@ -3,6 +3,7 @@
 
 #include <kandinsky.h>
 #include <escher/i18n.h>
+#include <escher/telemetry.h>
 extern "C" {
 #include <stdint.h>
 }
@@ -51,6 +52,13 @@ public:
   virtual void viewWillAppear();
   virtual void viewDidDisappear() {}
   virtual DisplayParameter displayParameter() { return DisplayParameter::Default; }
+protected:
+#if EPSILON_TELEMETRY
+  virtual const char * telemetryId() const { return nullptr; }
+  void telemetryReportEvent(const char * action, const char * label) const;
+#else
+  void telemetryReportEvent(const char * action, const char * label) const {}
+#endif
 };
 
 #endif

escher/src/view_controller.cpp

@@ -1,4 +1,40 @@
 #include <escher/view_controller.h>
+#include <escher/container.h>
+#include <string.h>
+#include <ion/telemetry.h>
 
 void ViewController::viewWillAppear() {
+#if EPSILON_TELEMETRY
+  const char * screenId = telemetryId();
+  if (screenId == nullptr) {
+    return;
+  }
+
+  const char * appId = Container::activeApp()->telemetryId();
+  if (appId == nullptr) {
+    return;
+  }
+
+  char reportedName[64];
+  assert(strlen(appId) + 1 + strlen(screenId) < sizeof(reportedName));
+
+  reportedName[0] = 0;
+  strlcat(reportedName, appId, sizeof(reportedName));
+  if (strlen(screenId) > 0) {
+    strlcat(reportedName, ".", sizeof(reportedName));
+    strlcat(reportedName, screenId, sizeof(reportedName));
+  }
+
+  Ion::Telemetry::reportScreen(reportedName);
+#endif
 }
+
+#if EPSILON_TELEMETRY
+void ViewController::telemetryReportEvent(const char * action, const char * label) const {
+  const char * category = Container::activeApp()->telemetryId();
+  assert(category != nullptr);
+  assert(action != nullptr);
+  assert(label != nullptr);
+  Ion::Telemetry::reportEvent(category, action, label);
+}
+#endif