Implemented cDeviceHook

6 files changed, 89 insertions, 5 deletions

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 16889e05..58045fc9 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -1246,6 +1246,7 @@ Reinhard Nissl <rnissl@gmx.de>
  for increasing the value of MAXFRAMESIZE to better suit HD recordings
  for improving handling frames at the beginning and end of a recording in cDvbPlayer
  for devices with large buffers
+ for implementing cDeviceHook
 
 Richard Robson <richard_robson@beeb.net>
  for reporting freezing replay if a timer starts while in Transfer Mode from the
diff --git a/HISTORY b/HISTORY
index cfd60e71..12b411f3 100644
--- a/HISTORY
+++ b/HISTORY
@@ -6319,3 +6319,5 @@ Video Disk Recorder Revision History
   "EPG scan" is active (suggested by Halim Sahim).
 - Improved handling frames at the beginning and end of a recording in cDvbPlayer for
   devices with large buffers (thanks to Reinhard Nissl).
+- Implemented cDeviceHook to allow plugins more control over which device can
+  provide which transponder (thanks to Reinhard Nissl).
diff --git a/PLUGINS.html b/PLUGINS.html
index 9167a4b9..05fb7ed0 100644
--- a/PLUGINS.html
+++ b/PLUGINS.html
@@ -1970,6 +1970,46 @@ shut down (delete) all devices when the program terminates. It is therefore
 important that the devices are created on the heap, using the <tt>new</tt>
 operator!
 
+<div class="modified">
+<p>
+<b>Device hooks</b>
+<p>
+VDR has builtin facilities that select which device is able to provide a given
+transponder. However, there may be situations where the setup is so special
+that it requires considerations that exceed the scope of the core VDR code.
+This is where <i>device hooks</i> can be used. 
+
+<p><table><tr><td class="code"><pre>
+class cMyDeviceHook : public cDeviceHook {
+public:
+  cMyDeviceHook(void);
+  virtual bool DeviceProvidesTransponder(const cDevice *Device, const cChannel *Channel) const;
+  };
+</pre></td></tr></table><p>
+
+In its <tt>DeviceProvidesTransponder()</tt> function the device hook can take
+whatever actions are necessary to determine whether the given Device can
+provide the given Channel's transponder, as in
+
+<p><table><tr><td class="code"><pre>
+void cMyDeviceHook::DeviceProvidesTransponder(const cDevice *Device, const cChannel *Channel) const
+{
+  if (<i>condition where Device can't provide Channel</i>)
+     return false;
+  return true;
+}
+</pre></td></tr></table><p>
+
+A plugin that creates a derived cDeviceHook shall do so in its <tt>Initialize()</tt>
+function, as in
+
+<p><table><tr><td class="code"><pre>
+new cMyDeviceHook;
+</pre></td></tr></table><p>
+
+and shall not delete this object. It will be automatically deleted when the program ends.
+</div modified>
+
 <hr><h2><a name="Audio">Audio</a></h2>
 
 <div class="blurb">"The stereo effect may only be experienced if stereo equipment is used!"</div><p>
diff --git a/device.c b/device.c
index cb31b834..88c46736 100644
--- a/device.c
+++ b/device.c
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: device.c 2.32 2010/01/30 11:06:51 kls Exp $
+ * $Id: device.c 2.33 2010/02/06 13:55:50 kls Exp $
  */
 
 #include "device.h"
@@ -44,6 +44,18 @@ void cLiveSubtitle::Receive(uchar *Data, int Length)
   cDevice::PrimaryDevice()->PlayTs(Data, Length);
 }
 
+// --- cDeviceHook -----------------------------------------------------------
+
+cDeviceHook::cDeviceHook(void)
+{
+  cDevice::deviceHooks.Add(this);
+}
+
+bool cDeviceHook::DeviceProvidesTransponder(const cDevice *Device, const cChannel *Channel) const
+{
+  return true;
+}
+
 // --- cDevice ---------------------------------------------------------------
 
 // The default priority for non-primary devices:
@@ -59,6 +71,7 @@ int cDevice::currentChannel = 1;
 cDevice *cDevice::device[MAXDEVICES] = { NULL };
 cDevice *cDevice::primaryDevice = NULL;
 cDevice *cDevice::avoidDevice = NULL;
+cList<cDeviceHook> cDevice::deviceHooks;
 
 cDevice::cDevice(void)
 :patPmtParser(true)
@@ -570,6 +583,17 @@ bool cDevice::ProvidesSource(int Source) const
   return false;
 }
 
+bool cDevice::DeviceHooksProvidesTransponder(const cChannel *Channel) const
+{
+  cDeviceHook *Hook = deviceHooks.First();
+  while (Hook) {
+        if (!Hook->DeviceProvidesTransponder(this, Channel))
+           return false;
+        Hook = deviceHooks.Next(Hook);
+        }
+  return true;
+}
+
 bool cDevice::ProvidesTransponder(const cChannel *Channel) const
 {
   return false;
diff --git a/device.h b/device.h
index 897de2af..9318bb1b 100644
--- a/device.h
+++ b/device.h
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: device.h 2.19 2010/01/01 15:04:27 kls Exp $
+ * $Id: device.h 2.20 2010/02/06 13:55:41 kls Exp $
  */
 
 #ifndef __DEVICE_H
@@ -88,10 +88,18 @@ class cPlayer;
 class cReceiver;
 class cLiveSubtitle;
 
+class cDeviceHook : public cListObject {
+public:
+  cDeviceHook(void);
+  virtual bool DeviceProvidesTransponder(const cDevice *Device, const cChannel *Channel) const;
+          ///< Returns true if the given Device can provide the given Channel's transponder.
+  };
+
 /// The cDevice class is the base from which actual devices can be derived.
 
 class cDevice : public cThread {
   friend class cLiveSubtitle;
+  friend class cDeviceHook;
 private:
   static int numDevices;
   static int useDevice;
@@ -187,6 +195,13 @@ public:
   virtual bool HasDecoder(void) const;
          ///< Tells whether this device has an MPEG decoder.
 
+// Device hooks
+
+private:
+  static cList<cDeviceHook> deviceHooks;
+protected:
+  bool DeviceHooksProvidesTransponder(const cChannel *Channel) const;
+
 // SPU facilities
 
 private:
diff --git a/dvbdevice.c b/dvbdevice.c
index 07e2dbb1..05b89fc1 100644
--- a/dvbdevice.c
+++ b/dvbdevice.c
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: dvbdevice.c 2.24 2010/01/04 14:06:24 kls Exp $
+ * $Id: dvbdevice.c 2.25 2010/02/06 13:44:08 kls Exp $
  */
 
 #include "dvbdevice.h"
@@ -608,10 +608,12 @@ bool cDvbDevice::ProvidesTransponder(const cChannel *Channel) const
   if (!ProvidesSource(Channel->Source()))
      return false; // doesn't provide source
   if (!cSource::IsSat(Channel->Source()))
-     return true; // source is sufficient for non sat
+     return DeviceHooksProvidesTransponder(Channel); // source is sufficient for non sat
   if (frontendType == SYS_DVBS && Channel->System() == SYS_DVBS2)
      return false; // requires modulation system which frontend doesn't provide
-  return !Setup.DiSEqC || Diseqcs.Get(Channel->Source(), Channel->Frequency(), Channel->Polarization());
+  if (!Setup.DiSEqC || Diseqcs.Get(Channel->Source(), Channel->Frequency(), Channel->Polarization()))
+     return DeviceHooksProvidesTransponder(Channel);
+  return false;
 }
 
 bool cDvbDevice::ProvidesChannel(const cChannel *Channel, int Priority, bool *NeedsDetachReceivers) const