From fac798df934dba45172299d89897a8df8c4e77cb Mon Sep 17 00:00:00 2001
From: brunoherbelin <bruno.herbelin@gmail.com>
Date: Thu, 1 Oct 2020 23:44:14 +0200
Subject: [PATCH] BugFix: prevent from creating twice a source with the same
 device: create a clone of the original device source instead.

---
 DeviceSource.cpp | 42 +++++++++++++++++++++++++++++++++-
 DeviceSource.h   | 59 ++++++++++++++++++++++++++----------------------
 Mixer.cpp        |  3 +--
 3 files changed, 74 insertions(+), 30 deletions(-)

diff --git a/DeviceSource.cpp b/DeviceSource.cpp
index e9fc4fe..2b14f0a 100644
--- a/DeviceSource.cpp
+++ b/DeviceSource.cpp
@@ -251,6 +251,38 @@ bool Device::exists(const std::string &device) const
     return d != src_name_.end();
 }
 
+struct hasDevice: public std::unary_function<DeviceSource*, bool>
+{
+    inline bool operator()(const DeviceSource* elem) const {
+       return (elem && elem->device() == _d);
+    }
+    hasDevice(std::string d) : _d(d) { }
+private:
+    std::string _d;
+};
+
+Source *Device::createSource(const std::string &device) const
+{
+    Source *s = nullptr;
+
+    // find if a DeviceSource with this device is already registered
+    std::list< DeviceSource *>::const_iterator d = std::find_if(device_sources_.begin(), device_sources_.end(), hasDevice(device));
+
+    // if already registered, clone the device source
+    if ( d != device_sources_.end())  {
+        CloneSource *cs = (*d)->clone();
+        s = cs;
+    }
+    // otherwise, we are free to create a new device source
+    else {
+        DeviceSource *ds = new DeviceSource();
+        ds->setDevice(device);
+        s = ds;
+    }
+
+    return s;
+}
+
 bool Device::unplugged(const std::string &device) const
 {
     if (list_uptodate_)
@@ -302,6 +334,12 @@ DeviceSource::DeviceSource() : StreamSource()
     overlays_[View::LAYER]->attach( new Symbol(Symbol::CAMERA, glm::vec3(0.8f, 0.8f, 0.01f)) );
 }
 
+DeviceSource::~DeviceSource()
+{
+    // unregister this device source
+    Device::manager().device_sources_.remove(this);
+}
+
 void DeviceSource::setDevice(const std::string &devicename)
 {   
     device_ = devicename;
@@ -310,6 +348,9 @@ void DeviceSource::setDevice(const std::string &devicename)
     int index = Device::manager().index(device_);
     if (index > -1) {
 
+        // register this device source
+        Device::manager().device_sources_.push_back(this);
+
         // start filling in the gstreamer pipeline
         std::ostringstream pipeline;
         pipeline << Device::manager().description(index);
@@ -360,7 +401,6 @@ bool DeviceSource::failed() const
     return stream_->failed() || Device::manager().unplugged(device_);
 }
 
-
 DeviceConfigSet Device::getDeviceConfigs(const std::string &src_description)
 {
     DeviceConfigSet configs;
diff --git a/DeviceSource.h b/DeviceSource.h
index 7228480..7fc0e78 100644
--- a/DeviceSource.h
+++ b/DeviceSource.h
@@ -7,6 +7,30 @@
 #include "GstToolkit.h"
 #include "StreamSource.h"
 
+class DeviceSource : public StreamSource
+{
+public:
+    DeviceSource();
+    ~DeviceSource();
+
+    // Source interface
+    bool failed() const override;
+    void accept (Visitor& v) override;
+
+    // StreamSource interface
+    Stream *stream() const override { return stream_; }
+
+    // specific interface
+    void setDevice(const std::string &devicename);
+    inline std::string device() const { return device_; }
+
+    glm::ivec2 icon() const override;
+
+private:
+    std::string device_;
+
+};
+
 struct DeviceConfig {
     gint width;
     gint height;
@@ -60,6 +84,8 @@ typedef std::set<DeviceConfig, better_device_comparator> DeviceConfigSet;
 
 class Device
 {
+    friend class DeviceSource;
+
     Device();
     Device(Rendering const& copy);            // Not Implemented
     Device& operator=(Rendering const& copy); // Not Implemented
@@ -78,9 +104,11 @@ public:
     std::string description (int index) const;
     DeviceConfigSet config (int index) const;
 
+    int  index   (const std::string &device) const;
     bool exists (const std::string &device) const;
     bool unplugged (const std::string &device) const;
-    int  index  (const std::string &device) const;
+
+    Source *createSource(const std::string &device) const;
 
     static gboolean callback_device_monitor (GstBus *, GstMessage *, gpointer);
     static DeviceConfigSet getDeviceConfigs(const std::string &src_description);
@@ -88,38 +116,15 @@ public:
 private:
 
     void remove(const char *device);
+
     std::vector< std::string > src_name_;
     std::vector< std::string > src_description_;
-
     std::vector< DeviceConfigSet > src_config_;
-
     bool list_uptodate_;
     GstDeviceMonitor *monitor_;
+
+    std::list< DeviceSource * > device_sources_;
 };
 
 
-class DeviceSource : public StreamSource
-{
-public:
-    DeviceSource();
-
-    // Source interface
-    bool failed() const override;
-    void accept (Visitor& v) override;
-
-    // StreamSource interface
-    Stream *stream() const override { return stream_; }
-
-    // specific interface
-    void setDevice(const std::string &devicename);
-    inline std::string device() const { return device_; }
-
-    glm::ivec2 icon() const override;
-
-private:
-    std::string device_;
-
-
-};
-
 #endif // DEVICESOURCE_H
diff --git a/Mixer.cpp b/Mixer.cpp
index e43aef9..4c2fa0c 100644
--- a/Mixer.cpp
+++ b/Mixer.cpp
@@ -294,8 +294,7 @@ Source * Mixer::createSourcePattern(int pattern, glm::ivec2 res)
 Source * Mixer::createSourceDevice(const std::string &namedevice)
 {
     // ready to create a source
-    DeviceSource *s = new DeviceSource();
-    s->setDevice(namedevice);
+    Source *s = Device::manager().createSource(namedevice);
 
     // propose a new name based on pattern name
     renameSource(s, namedevice);