JUCE/extras/NetworkGraphicsDemo/Source/SlaveComponent.h

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

   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.

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


/**
    This component runs in a slave process, draws the part of the canvas that this
    particular client covers, and updates itself when messages arrive from the master
    containing new canvas states.
*/
class SlaveCanvasComponent  : public Component,
                              private OSCSender,
                              private OSCReceiver,
                              private OSCReceiver::Listener<OSCReceiver::RealtimeCallback>,
                              private AsyncUpdater,
                              private Timer
{
public:
    SlaveCanvasComponent (PropertiesFile& p, int windowIndex)  : properties (p)
    {
        {
            String uuidPropName ("UUID" + String (windowIndex));
            clientName = properties.getValue (uuidPropName);

            if (clientName.isEmpty())
            {
                clientName = "CLIENT_" + String (Random().nextInt (10000)).toUpperCase();
                properties.setValue (uuidPropName, clientName);
            }
        }

        setOpaque (true);
        setSize (1500, 900);

        if (! OSCSender::connect (getBroadcastIPAddress(), clientPortNumber))
            error = "Client app OSC sender: network connection error.";

        if (! OSCReceiver::connect (masterPortNumber))
            error = "Client app OSC receiver: network connection error.";

        OSCReceiver::addListener (this);

        timerCallback();
        startTimer (2000);
    }

    ~SlaveCanvasComponent() override
    {
        OSCReceiver::removeListener (this);
    }

private:
    void mouseDrag (const MouseEvent& e) override
    {
        auto clientArea = getAreaInGlobalSpace();

        if (! clientArea.isEmpty())
        {
            OSCMessage message (userInputOSCAddress);

            message.addString (clientName);
            message.addFloat32 (e.position.x * clientArea.getWidth()  / getWidth()  + clientArea.getX());
            message.addFloat32 (e.position.y * clientArea.getHeight() / getHeight() + clientArea.getY());

            send (message);
        }
    }

    //==============================================================================
    void oscMessageReceived (const OSCMessage& message) override
    {
        auto address = message.getAddressPattern();

        if (address.matches (canvasStateOSCAddress))
            canvasStateOSCMessageReceived (message);
    }

    struct NewStateMessage  : public Message
    {
        NewStateMessage (const MemoryBlock& d) : data (d) {}
        MemoryBlock data;
    };

    void canvasStateOSCMessageReceived (const OSCMessage& message)
    {
        if (message.isEmpty() || ! message[0].isBlob())
            return;

        if (packetiser.appendIncomingBlock (message[0].getBlob()))
        {
            const ScopedLock sl (canvasLock);

            MemoryBlock newCanvasData;

            if (packetiser.reassemble (newCanvasData))
            {
                MemoryInputStream i (newCanvasData.getData(), newCanvasData.getSize(), false);
                canvas2.load (i);
                triggerAsyncUpdate();
            }
        }
    }

    //==============================================================================
    String getMachineInfoToDisplay() const
    {
        auto display = Desktop::getInstance().getDisplays().findDisplayForPoint (getScreenBounds().getCentre());
        return getOSName() + "   " + String (display.dpi) + "   "  + String (display.scale);
    }

    static String getOSName()
    {
       #if JUCE_MAC
        return "Mac OSX";
       #elif JUCE_ANDROID
        return "Android";
       #elif JUCE_IOS
        return "iOS";
       #elif JUCE_WINDOWS
        return "Windows";
       #elif JUCE_LINUX
        return "Linux";
       #endif
    }

    void paint (Graphics& g) override
    {
        g.fillAll (canvas.backgroundColour);

        auto clientArea = getAreaInGlobalSpace();

        if (clientArea.isEmpty())
        {
            g.setColour (Colours::red.withAlpha (0.5f));
            g.setFont (20.0f);
            g.drawText ("Not Connected", getLocalBounds(), Justification::centred, false);
            return;
        }

        canvas.draw (g, getLocalBounds().toFloat(), clientArea);

        g.setFont (Font (34.0f));
        g.setColour (Colours::white.withAlpha (0.6f));

        g.drawText (getMachineInfoToDisplay(),
                    getLocalBounds().reduced (10).removeFromBottom (20),
                    Justification::centredRight, true);

        if (error.isNotEmpty())
        {
            g.setColour (Colours::red);
            g.drawText (error, getLocalBounds().reduced (10).removeFromBottom (80),
                        Justification::centredRight, true);
        }
    }

    Rectangle<float> getAreaInGlobalSpace() const
    {
        if (auto client = canvas.findClient (clientName))
        {
            auto screenBounds = getScreenBounds();
            auto display = Desktop::getInstance().getDisplays().findDisplayForPoint (screenBounds.getCentre());
            return ((screenBounds - display.userArea.getCentre()).toFloat() / (client->scaleFactor * display.dpi / display.scale)) + client->centre;
        }

        return {};
    }

    Rectangle<float> getScreenAreaInGlobalSpace() const
    {
        if (auto client = canvas.findClient (clientName))
        {
            auto display = Desktop::getInstance().getDisplays().findDisplayForPoint (getScreenBounds().getCentre());
            return (display.userArea.toFloat() / (client->scaleFactor * display.dpi / display.scale)).withCentre (client->centre);
        }

        return {};
    }

    void timerCallback() override
    {
        send (newClientOSCAddress, clientName + ":" + IPAddress::getLocalAddress().toString()
                                              + ":" + getScreenAreaInGlobalSpace().toString());
    }

    void handleAsyncUpdate() override
    {
        const ScopedLock sl (canvasLock);
        canvas.swapWith (canvas2);
        repaint();
    }

    SharedCanvasDescription canvas, canvas2;
    PropertiesFile& properties;
    String clientName, error;

    CriticalSection canvasLock;
    BlockPacketiser packetiser;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SlaveCanvasComponent)
};