Refactor BeforeInstallPromptEvent to use ScriptPromiseProperty

Source/modules/app_banner/BeforeInstallPromptEvent.cpp

Index: Source/modules/app_banner/BeforeInstallPromptEvent.cpp
diff --git a/Source/modules/app_banner/BeforeInstallPromptEvent.cpp b/Source/modules/app_banner/BeforeInstallPromptEvent.cpp
index c4d117dd853329d8168d27b16327fbb5f745a663..391f514ad1ad1cdb6b3445bda99372399496709c 100644
--- a/Source/modules/app_banner/BeforeInstallPromptEvent.cpp
+++ b/Source/modules/app_banner/BeforeInstallPromptEvent.cpp
@@ -5,12 +5,9 @@
 #include "config.h"
 #include "modules/app_banner/BeforeInstallPromptEvent.h"
 
-#include "bindings/core/v8/CallbackPromiseAdapter.h"
 #include "bindings/core/v8/ScriptPromise.h"
-#include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/ExceptionCode.h"
-#include "modules/app_banner/AppBannerPromptResult.h"
 #include "modules/app_banner/BeforeInstallPromptEventInit.h"
 #include "public/platform/modules/app_banner/WebAppBannerClient.h"
 
@@ -20,12 +17,14 @@ BeforeInstallPromptEvent::BeforeInstallPromptEvent()
 {
 }
 
-BeforeInstallPromptEvent::BeforeInstallPromptEvent(const AtomicString& name, const Vector<String>& platforms, int requestId, WebAppBannerClient* client)
+BeforeInstallPromptEvent::BeforeInstallPromptEvent(const AtomicString& name, ExecutionContext* executionContext, const Vector<String>& platforms, int requestId, WebAppBannerClient* client)
     : Event(name, false, true)
     , m_platforms(platforms)
     , m_requestId(requestId)
     , m_client(client)
     , m_redispatched(false)
+    , m_userChoice(new UserChoiceProperty(executionContext, this, UserChoiceProperty::UserChoice))
+    , m_prompt(new PromptProperty(executionContext, this, PromptProperty::Prompt))
 {
 }
 
@@ -50,14 +49,9 @@ Vector<String> BeforeInstallPromptEvent::platforms() const
 
 ScriptPromise BeforeInstallPromptEvent::userChoice(ScriptState* scriptState)
 {
-    if (m_userChoice.isEmpty() && m_client) {
-        ASSERT(m_requestId != -1);
-        RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
-        m_userChoice = resolver->promise();
-        m_client->registerBannerCallbacks(m_requestId, new CallbackPromiseAdapter<AppBannerPromptResult, void>(resolver));
-    }
-
-    return m_userChoice;
+    if (m_userChoice)
+        return m_userChoice->promise(scriptState->world());
+    return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(InvalidStateError, "The prompt() method cannot be called on this event."));
 }
 
 const AtomicString& BeforeInstallPromptEvent::interfaceName() const
@@ -67,14 +61,27 @@ const AtomicString& BeforeInstallPromptEvent::interfaceName() const
 
 ScriptPromise BeforeInstallPromptEvent::prompt(ScriptState* scriptState)
 {
-    if (m_client && defaultPrevented() && !m_redispatched) {
-        ASSERT(m_requestId != -1);
-        m_redispatched = true;
-        m_client->showAppBanner(m_requestId);
-        return ScriptPromise::cast(scriptState, v8::Undefined(scriptState->isolate()));
+    if (m_prompt) {
+        if (m_prompt->state() == PromptProperty::Pending) {
+            if (m_client && defaultPrevented() && !m_redispatched) {
+                ASSERT(m_requestId != -1);
+                m_redispatched = true;
+                m_prompt->resolve(ToV8UndefinedGenerator());
+                m_client->showAppBanner(m_requestId);
+            } else {
+                m_prompt->reject(DOMException::create(InvalidStateError, "The prompt() method may only be called once, following preventDefault()."));
+            }
+        }
+        return m_prompt->promise(scriptState->world());
     }
+    return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(InvalidStateError, "The prompt() method cannot be called on this event."));

[mlamouri (slow - plz ping), 2015/07/24 15:08:25]

Linus Torvalds once said "If you need more than 3 levels of indentation, you're
screwed". You have 4 ;)

Maybe you can do:
if (!m_prompt)
    return ScriptPromise::reject....

if (m_prompt->state() != PromptPropertyPending)
    return m_prompt->promise(scriptState->world();

if (!m_client || !defaultPrevented() || m_redispatched) {
    m_prompt->reject(DOMException::create(InvalidStateError, ...
    return m_prompt->promise(scriptState->world();
}

// the rest of the code.

[dominickn, 2015/07/24 23:53:36]

Done, and I even removed m_redispatched because the promise check should be all
that's required here.

+}
 
-    return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(InvalidStateError, "The prompt() method may only be called once, following preventDefault()."));
+DEFINE_TRACE(BeforeInstallPromptEvent)
+{
+    visitor->trace(m_userChoice);
+    visitor->trace(m_prompt);
+    Event::trace(visitor);
 }
 
 } // namespace blink