JUCE/modules/juce_audio_utils/native/juce_android_BluetoothMidiDevicePairingDialogue.cpp

/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD, CALLBACK) \
 STATICMETHOD (getAndroidBluetoothManager, "getAndroidBluetoothManager", "(Landroid/content/Context;)Lcom/rmsl/juce/JuceMidiSupport$BluetoothManager;")

DECLARE_JNI_CLASS_WITH_MIN_SDK (AndroidJuceMidiSupport, "com/rmsl/juce/JuceMidiSupport", 23)
#undef JNI_CLASS_MEMBERS

#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD, CALLBACK) \
 METHOD (getMidiBluetoothAddresses, "getMidiBluetoothAddresses", "()[Ljava/lang/String;") \
 METHOD (pairBluetoothMidiDevice, "pairBluetoothMidiDevice", "(Ljava/lang/String;)Z") \
 METHOD (unpairBluetoothMidiDevice, "unpairBluetoothMidiDevice", "(Ljava/lang/String;)V") \
 METHOD (getHumanReadableStringForBluetoothAddress, "getHumanReadableStringForBluetoothAddress", "(Ljava/lang/String;)Ljava/lang/String;") \
 METHOD (getBluetoothDeviceStatus, "getBluetoothDeviceStatus", "(Ljava/lang/String;)I") \
 METHOD (startStopScan, "startStopScan", "(Z)V")

DECLARE_JNI_CLASS_WITH_MIN_SDK (AndroidBluetoothManager, "com/rmsl/juce/JuceMidiSupport$BluetoothManager", 23)
#undef JNI_CLASS_MEMBERS

//==============================================================================
struct AndroidBluetoothMidiInterface
{
    static void startStopScan (bool startScanning)
    {
        JNIEnv* env = getEnv();
        LocalRef<jobject> btManager (env->CallStaticObjectMethod (AndroidJuceMidiSupport, AndroidJuceMidiSupport.getAndroidBluetoothManager, getAppContext().get()));

        if (btManager.get() != nullptr)
            env->CallVoidMethod (btManager.get(), AndroidBluetoothManager.startStopScan, (jboolean) (startScanning ? 1 : 0));
    }

    static StringArray getBluetoothMidiDevicesNearby()
    {
        StringArray retval;

        JNIEnv* env = getEnv();

        LocalRef<jobject> btManager (env->CallStaticObjectMethod (AndroidJuceMidiSupport, AndroidJuceMidiSupport.getAndroidBluetoothManager, getAppContext().get()));

        // if this is null then bluetooth is not enabled
        if (btManager.get() == nullptr)
            return {};

        jobjectArray jDevices = (jobjectArray) env->CallObjectMethod (btManager.get(),
                                                                      AndroidBluetoothManager.getMidiBluetoothAddresses);
        LocalRef<jobjectArray> devices (jDevices);

        const int count = env->GetArrayLength (devices.get());

        for (int i = 0; i < count; ++i)
        {
            LocalRef<jstring> string ((jstring)  env->GetObjectArrayElement (devices.get(), i));
            retval.add (juceString (string));
        }

        return retval;
    }

    //==============================================================================
    static bool pairBluetoothMidiDevice (const String& bluetoothAddress)
    {
        JNIEnv* env = getEnv();

        LocalRef<jobject> btManager (env->CallStaticObjectMethod (AndroidJuceMidiSupport, AndroidJuceMidiSupport.getAndroidBluetoothManager, getAppContext().get()));
        if (btManager.get() == nullptr)
            return false;

        jboolean result = env->CallBooleanMethod (btManager.get(), AndroidBluetoothManager.pairBluetoothMidiDevice,
                                                  javaString (bluetoothAddress).get());

        return result;
    }

    static void unpairBluetoothMidiDevice (const String& bluetoothAddress)
    {
        JNIEnv* env = getEnv();

        LocalRef<jobject> btManager (env->CallStaticObjectMethod (AndroidJuceMidiSupport, AndroidJuceMidiSupport.getAndroidBluetoothManager, getAppContext().get()));

        if (btManager.get() != nullptr)
            env->CallVoidMethod (btManager.get(), AndroidBluetoothManager.unpairBluetoothMidiDevice,
                                 javaString (bluetoothAddress).get());
    }

    //==============================================================================
    static String getHumanReadableStringForBluetoothAddress (const String& address)
    {
        JNIEnv* env = getEnv();

        LocalRef<jobject> btManager (env->CallStaticObjectMethod (AndroidJuceMidiSupport, AndroidJuceMidiSupport.getAndroidBluetoothManager, getAppContext().get()));

        if (btManager.get() == nullptr)
            return address;

        LocalRef<jstring> string ((jstring) env->CallObjectMethod (btManager.get(),
                                                                   AndroidBluetoothManager.getHumanReadableStringForBluetoothAddress,
                                                                   javaString (address).get()));


        if (string.get() == nullptr)
            return address;

        return juceString (string);
    }

    //==============================================================================
    enum PairStatus
    {
        unpaired = 0,
        paired = 1,
        pairing = 2
    };

    static PairStatus isBluetoothDevicePaired (const String& address)
    {
        JNIEnv* env = getEnv();

        LocalRef<jobject> btManager (env->CallStaticObjectMethod (AndroidJuceMidiSupport, AndroidJuceMidiSupport.getAndroidBluetoothManager, getAppContext().get()));

        if (btManager.get() == nullptr)
            return unpaired;

        return static_cast<PairStatus> (env->CallIntMethod (btManager.get(), AndroidBluetoothManager.getBluetoothDeviceStatus,
                                                            javaString (address).get()));
    }
};

//==============================================================================
struct AndroidBluetoothMidiDevice
{
    enum ConnectionStatus
    {
        offline,
        connected,
        disconnected,
        connecting,
        disconnecting
    };

    AndroidBluetoothMidiDevice (String deviceName, String address, ConnectionStatus status)
        : name (deviceName), bluetoothAddress (address), connectionStatus (status)
    {
        // can't create a device without a valid name and bluetooth address!
        jassert (! name.isEmpty());
        jassert (! bluetoothAddress.isEmpty());
    }

    bool operator== (const AndroidBluetoothMidiDevice& other) const noexcept
    {
        return bluetoothAddress == other.bluetoothAddress;
    }

    bool operator!= (const AndroidBluetoothMidiDevice& other) const noexcept
    {
        return ! operator== (other);
    }

    const String name, bluetoothAddress;
    ConnectionStatus connectionStatus;
};

//==============================================================================
class AndroidBluetoothMidiDevicesListBox   : public ListBox,
                                             private ListBoxModel,
                                             private Timer
{
public:
    //==============================================================================
    AndroidBluetoothMidiDevicesListBox()
        : timerPeriodInMs (1000)
    {
        setRowHeight (40);
        setModel (this);
        setOutlineThickness (1);
        startTimer (timerPeriodInMs);
    }

    void pairDeviceThreadFinished() // callback from PairDeviceThread
    {
        updateDeviceList();
        startTimer (timerPeriodInMs);
    }

private:
    //==============================================================================
    typedef AndroidBluetoothMidiDevice::ConnectionStatus DeviceStatus;

    int getNumRows() override
    {
        return devices.size();
    }

    void paintListBoxItem (int rowNumber, Graphics& g,
                           int width, int height, bool) override
    {
        if (isPositiveAndBelow (rowNumber, devices.size()))
        {
            const AndroidBluetoothMidiDevice& device = devices.getReference (rowNumber);
            const String statusString (getDeviceStatusString (device.connectionStatus));

            g.fillAll (Colours::white);

            const float xmargin = 3.0f;
            const float ymargin = 3.0f;
            const float fontHeight = 0.4f * height;
            const float deviceNameWidth = 0.6f * width;

            g.setFont (fontHeight);

            g.setColour (getDeviceNameFontColour (device.connectionStatus));
            g.drawText (device.name,
                        Rectangle<float> (xmargin, ymargin, deviceNameWidth - (2.0f * xmargin), height - (2.0f * ymargin)),
                        Justification::topLeft, true);

            g.setColour (getDeviceStatusFontColour (device.connectionStatus));
            g.drawText (statusString,
                        Rectangle<float> (deviceNameWidth + xmargin, ymargin,
                                          width - deviceNameWidth - (2.0f * xmargin), height - (2.0f * ymargin)),
                        Justification::topRight, true);

            g.setColour (Colours::grey);
            g.drawHorizontalLine (height - 1, xmargin, width);
        }
    }

    //==============================================================================
    static Colour getDeviceNameFontColour (DeviceStatus deviceStatus) noexcept
    {
        if (deviceStatus == AndroidBluetoothMidiDevice::offline)
            return Colours::grey;

        return Colours::black;
    }

    static Colour getDeviceStatusFontColour (DeviceStatus deviceStatus) noexcept
    {
        if (deviceStatus == AndroidBluetoothMidiDevice::offline
            || deviceStatus == AndroidBluetoothMidiDevice::connecting
            || deviceStatus == AndroidBluetoothMidiDevice::disconnecting)
            return Colours::grey;

        if (deviceStatus == AndroidBluetoothMidiDevice::connected)
            return Colours::green;

        return Colours::black;
    }

    static String getDeviceStatusString (DeviceStatus deviceStatus) noexcept
    {
        if (deviceStatus == AndroidBluetoothMidiDevice::offline)        return "Offline";
        if (deviceStatus == AndroidBluetoothMidiDevice::connected)      return "Connected";
        if (deviceStatus == AndroidBluetoothMidiDevice::disconnected)   return "Not connected";
        if (deviceStatus == AndroidBluetoothMidiDevice::connecting)     return "Connecting...";
        if (deviceStatus == AndroidBluetoothMidiDevice::disconnecting)  return "Disconnecting...";

        // unknown device state!
        jassertfalse;
        return "Status unknown";
    }

    //==============================================================================
    void listBoxItemClicked (int row, const MouseEvent&) override
    {
        const AndroidBluetoothMidiDevice& device = devices.getReference (row);

        if (device.connectionStatus == AndroidBluetoothMidiDevice::disconnected)
            disconnectedDeviceClicked (row);

        else if (device.connectionStatus == AndroidBluetoothMidiDevice::connected)
            connectedDeviceClicked (row);
    }

    void timerCallback() override
    {
        updateDeviceList();
    }

    //==============================================================================
    struct PairDeviceThread  : public Thread,
                               private AsyncUpdater
    {
        PairDeviceThread (const String& bluetoothAddressOfDeviceToPair,
                          AndroidBluetoothMidiDevicesListBox& ownerListBox)
            : Thread ("JUCE Bluetooth MIDI Device Pairing Thread"),
              bluetoothAddress (bluetoothAddressOfDeviceToPair),
              owner (&ownerListBox)
        {
            startThread();
        }

        void run() override
        {
            AndroidBluetoothMidiInterface::pairBluetoothMidiDevice (bluetoothAddress);
            triggerAsyncUpdate();
        }

        void handleAsyncUpdate() override
        {
            if (owner != nullptr)
                owner->pairDeviceThreadFinished();

            delete this;
        }

    private:
        String bluetoothAddress;
        Component::SafePointer<AndroidBluetoothMidiDevicesListBox> owner;
    };

    //==============================================================================
    void disconnectedDeviceClicked (int row)
    {
        stopTimer();

        AndroidBluetoothMidiDevice& device = devices.getReference (row);
        device.connectionStatus = AndroidBluetoothMidiDevice::connecting;
        updateContent();
        repaint();

        new PairDeviceThread (device.bluetoothAddress, *this);
    }

    void connectedDeviceClicked (int row)
    {
        AndroidBluetoothMidiDevice& device = devices.getReference (row);
        device.connectionStatus = AndroidBluetoothMidiDevice::disconnecting;
        updateContent();
        repaint();
        AndroidBluetoothMidiInterface::unpairBluetoothMidiDevice (device.bluetoothAddress);
    }

    //==============================================================================
    void updateDeviceList()
    {
        StringArray bluetoothAddresses = AndroidBluetoothMidiInterface::getBluetoothMidiDevicesNearby();

        Array<AndroidBluetoothMidiDevice> newDevices;

        for (String* address = bluetoothAddresses.begin();
             address != bluetoothAddresses.end(); ++address)
        {
            String name = AndroidBluetoothMidiInterface::getHumanReadableStringForBluetoothAddress (*address);

            DeviceStatus status;
            switch (AndroidBluetoothMidiInterface::isBluetoothDevicePaired (*address))
            {
                case AndroidBluetoothMidiInterface::pairing:
                    status = AndroidBluetoothMidiDevice::connecting;
                    break;
                case AndroidBluetoothMidiInterface::paired:
                    status = AndroidBluetoothMidiDevice::connected;
                    break;
                case AndroidBluetoothMidiInterface::unpaired:
                default:
                    status = AndroidBluetoothMidiDevice::disconnected;
            }

            newDevices.add (AndroidBluetoothMidiDevice (name, *address, status));
        }

        devices.swapWith (newDevices);
        updateContent();
        repaint();
    }

    Array<AndroidBluetoothMidiDevice> devices;
    const int timerPeriodInMs;
};

//==============================================================================
class BluetoothMidiSelectorOverlay  : public Component
{
public:
    BluetoothMidiSelectorOverlay (ModalComponentManager::Callback* exitCallbackToUse,
                                  const Rectangle<int>& boundsToUse)
        : bounds (boundsToUse)
    {
        std::unique_ptr<ModalComponentManager::Callback> exitCallback (exitCallbackToUse);

        AndroidBluetoothMidiInterface::startStopScan (true);

        setAlwaysOnTop (true);
        setVisible (true);
        addToDesktop (ComponentPeer::windowHasDropShadow);

        if (bounds.isEmpty())
            setBounds (0, 0, getParentWidth(), getParentHeight());
        else
            setBounds (bounds);

        toFront (true);
        setOpaque (! bounds.isEmpty());

        addAndMakeVisible (bluetoothDevicesList);
        enterModalState (true, exitCallback.release(), true);
    }

    ~BluetoothMidiSelectorOverlay() override
    {
        AndroidBluetoothMidiInterface::startStopScan (false);
    }

    void paint (Graphics& g) override
    {
        g.fillAll (bounds.isEmpty() ? Colours::black.withAlpha (0.6f) : Colours::black);

        g.setColour (Colour (0xffdfdfdf));
        Rectangle<int> overlayBounds = getOverlayBounds();
        g.fillRect (overlayBounds);

        g.setColour (Colours::black);
        g.setFont (16);
        g.drawText ("Bluetooth MIDI Devices",
                    overlayBounds.removeFromTop (20).reduced (3, 3),
                    Justification::topLeft, true);

        overlayBounds.removeFromTop (2);

        g.setFont (12);
        g.drawText ("tap to connect/disconnect",
                    overlayBounds.removeFromTop (18).reduced (3, 3),
                    Justification::topLeft, true);
    }

    void inputAttemptWhenModal() override           { exitModalState (0); }
    void mouseDrag (const MouseEvent&) override     {}
    void mouseDown (const MouseEvent&) override     { exitModalState (0); }
    void resized() override                         { update(); }
    void parentSizeChanged() override               { update(); }

private:
    Rectangle<int> bounds;

    void update()
    {
        if (bounds.isEmpty())
            setBounds (0, 0, getParentWidth(), getParentHeight());
        else
            setBounds (bounds);

        bluetoothDevicesList.setBounds (getOverlayBounds().withTrimmedTop (40));
    }

    Rectangle<int> getOverlayBounds() const noexcept
    {
        if (bounds.isEmpty())
        {
            const int pw = getParentWidth();
            const int ph = getParentHeight();

            return Rectangle<int> (pw, ph).withSizeKeepingCentre (jmin (400, pw - 14),
                                                                  jmin (300, ph - 40));
        }

        return bounds.withZeroOrigin();
    }

    AndroidBluetoothMidiDevicesListBox bluetoothDevicesList;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (BluetoothMidiSelectorOverlay)
};

//==============================================================================
bool BluetoothMidiDevicePairingDialogue::open (ModalComponentManager::Callback* exitCallbackPtr,
                                               Rectangle<int>* btBounds)
{
    std::unique_ptr<ModalComponentManager::Callback> exitCallback (exitCallbackPtr);

    if (getAndroidSDKVersion() < 23)
        return false;

    auto boundsToUse = (btBounds != nullptr ? *btBounds : Rectangle<int> {});

    if (! RuntimePermissions::isGranted (RuntimePermissions::bluetoothMidi))
    {
        // If you hit this assert, you probably forgot to get RuntimePermissions::bluetoothMidi.
        // This is not going to work, boo! The pairing dialogue won't be able to scan for or
        // find any devices, it will just display an empty list, so don't bother opening it.
        jassertfalse;
        return false;
    }

    new BluetoothMidiSelectorOverlay (exitCallback.release(), boundsToUse);
    return true;
}

bool BluetoothMidiDevicePairingDialogue::isAvailable()
{
    if (getAndroidSDKVersion() < 23)
        return false;

    auto* env = getEnv();

    LocalRef<jobject> btManager (env->CallStaticObjectMethod (AndroidJuceMidiSupport, AndroidJuceMidiSupport.getAndroidBluetoothManager, getAppContext().get()));
    return btManager != nullptr;
}

} // namespace juce