Web MIDI: introduce WebMIDIClient API to request a permission

Source/modules/webmidi/MIDIAccess.cpp

Index: Source/modules/webmidi/MIDIAccess.cpp
diff --git a/Source/modules/webmidi/MIDIAccess.cpp b/Source/modules/webmidi/MIDIAccess.cpp
index 2e616069eee0111cc5c8435cc6c65dde87d30dcc..ff8d34bdd21582cb6195dad56fecf186437f41cf 100644
--- a/Source/modules/webmidi/MIDIAccess.cpp
+++ b/Source/modules/webmidi/MIDIAccess.cpp
@@ -38,6 +38,7 @@
 #include "core/loader/DocumentLoader.h"
 #include "modules/webmidi/MIDIAccessPromise.h"
 #include "modules/webmidi/MIDIConnectionEvent.h"
+#include "modules/webmidi/MIDIController.h"
 #include "modules/webmidi/MIDIInput.h"
 #include "modules/webmidi/MIDIOutput.h"
 #include "modules/webmidi/MIDIPort.h"
@@ -48,6 +49,7 @@ PassRefPtr<MIDIAccess> MIDIAccess::create(ScriptExecutionContext* context, MIDIA
 {
     RefPtr<MIDIAccess> midiAccess(adoptRef(new MIDIAccess(context, promise)));
     midiAccess->suspendIfNeeded();
+    midiAccess->startRequest();
     return midiAccess.release();
 }
 
@@ -60,16 +62,28 @@ MIDIAccess::MIDIAccess(ScriptExecutionContext* context, MIDIAccessPromise* promi
     : ActiveDOMObject(context)
     , m_promise(promise)
     , m_hasAccess(false)
+    , m_enableSysEx(false)
+    , m_requesting(false)
 {
     ScriptWrappable::init(this);
     m_accessor = MIDIAccessor::create(this);
-    m_accessor->requestAccess(promise->options()->sysex);
+}
+
+void MIDIAccess::enableSysEx(bool enable)
+{
+    m_requesting = false;
+    m_enableSysEx = enable;
+    if (enable)
+        m_accessor->requestAccess();
+    else
+        didBlockAccess();
 }
 
 void MIDIAccess::didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version)
 {
     ASSERT(isMainThread());
 
+    // FIXME: Pass m_enableSysEx flag to filter system exclusive messages correctly.
     m_inputs.append(MIDIInput::create(scriptExecutionContext(), id, manufacturer, name, version));
 }
 
@@ -77,6 +91,7 @@ void MIDIAccess::didAddOutputPort(const String& id, const String& manufacturer,
 {
     ASSERT(isMainThread());
 
+    // FIXME: Pass m_enableSysEx flag to filter system exclusive messages correctly.
     m_outputs.append(MIDIOutput::create(scriptExecutionContext(), id, manufacturer, name, version));
 }
 
@@ -117,6 +132,31 @@ void MIDIAccess::didReceiveMIDIData(unsigned portIndex, const unsigned char* dat
 void MIDIAccess::stop()
 {
     m_hasAccess = false;
+    if (!m_requesting)
+        return;
+    m_requesting = false;
+    Document* document = toDocument(scriptExecutionContext());
+    ASSERT(document);
+    MIDIController* controller = MIDIController::from(document->page());
+    ASSERT(controller);
+    controller->cancelSysExPermissionRequest(this);
+}
+
+void MIDIAccess::startRequest()
+{
+    if (!m_promise->options()->sysex) {
+        m_accessor->requestAccess();
+        return;
+    }
+    Document* document = toDocument(scriptExecutionContext());
+    ASSERT(document);
+    MIDIController* controller = MIDIController::from(document->page());
+    if (controller) {
+        m_requesting = true;
+        controller->requestSysExPermission(this);
+    } else {
+        didBlockAccess();
+    }
 }
 
 } // namespace WebCore