Salt package installation/uninstallation even and hooks.

src/doc/doc/about/packages.xml

@@ -209,4 +209,27 @@
   subversion equivalent.
   </p>
 
+  <h2>Installation Hooks</h2>
+
+  <p>
+  Scripts can register an event through <class_doc href="Application#on_salt_changed"/> which 
+  indicates that packages have been installed or uninstalled.
+  </p>
+
+  <p>
+  Packages itself can supply special scripts which are executed after a package was installed
+  or before a package is uninstalled:
+  </p>
+
+  <ul>
+    <li><tt>_install.lym</tt>: if present, this script is executed after the package is installed.</li>
+    <li><tt>_uninstall.lym</tt>: if present, this script is executed before the package is uninstalled.</li>
+  </ul>
+
+  <p>
+  Both scripts need to be stored in the same location as "grain.xml" and have to use 
+  "lym" format. This is the generic XML script format KLayout employs as an interpreter-agnostic
+  script representation.
+  </p>
+
 </doc>

src/lay/lay/gsiDeclLayApplication.cc

@@ -24,6 +24,7 @@
 #include "layMainWindow.h"
 #include "laySignalHandler.h"
 #include "gsiDecl.h"
+#include "gsiSignals.h"
 #include "tlArch.h"
 
 #if defined(HAVE_QTBINDINGS)
@@ -243,6 +244,14 @@ static gsi::Methods application_methods ()
       "\n"
       "There is exactly one instance of the application. This instance can be obtained with this "
       "method."
+    ) +
+    event<C> ("on_salt_changed", &C::salt_changed_event,
+      "@brief This event is triggered when the package status changes.\n"
+      "\n"
+      "Register to this event if you are interested in package changes - i.e. installation or removal of packages or "
+      "package updates.\n"
+      "\n"
+      "This event has been introduced in version 0.28."
     )
   ;
 }

src/lay/lay/layApplication.cc

@@ -672,6 +672,8 @@ ApplicationBase::init_app ()
       }
     }
 
+    sc->salt_changed_event.add (this, &ApplicationBase::salt_changed);
+
   }
 
   if (tc) {
@@ -852,6 +854,14 @@ ApplicationBase::add_macro_category (const std::string &name, const std::string
   }
 }
 
+void
+ApplicationBase::salt_changed ()
+{
+BEGIN_PROTECTED_SILENT
+  salt_changed_event ();
+END_PROTECTED_SILENT
+}
+
 ApplicationBase::~ApplicationBase ()
 {
   tl::set_ui_exception_handlers (0, 0, 0);

src/lay/lay/layApplication.h

@@ -26,6 +26,7 @@
 
 #include "layCommon.h"
 #include "layBusy.h"
+#include "tlEvents.h"
 
 #include <QApplication>
 #include <QEventLoop>
@@ -76,7 +77,7 @@ class LayoutView;
  *  and one for the GUI version (derived from QApplication).
  */
 class LAY_PUBLIC ApplicationBase
-  : public gsi::ObjectBase
+  : public gsi::ObjectBase, public tl::Object
 {
 public:
   /**
@@ -313,6 +314,11 @@ public:
    */
   void init_app ();
 
+  /**
+   *  @brief An event indicating that the package collection has changed
+   */
+  tl::Event salt_changed_event;
+
   /**
    *  @brief Gets the QApplication object
    *  This method will return non-null only if a GUI-enabled application is present.
@@ -376,6 +382,8 @@ private:
   //  in order to maintain a valid MainWindow reference for ruby scripts and Ruby's GC all the time.
   gsi::Interpreter *mp_ruby_interpreter;
   gsi::Interpreter *mp_python_interpreter;
+
+  void salt_changed ();
 };
 
 /**

src/lay/lay/laySalt.cc

@@ -26,6 +26,7 @@
 #include "tlLog.h"
 #include "tlInternational.h"
 #include "tlWebDAV.h"
+#include "lymMacro.h"
 
 #include <QFileInfo>
 #include <QDir>
@@ -281,6 +282,21 @@ Salt::remove_grain (const SaltGrain &grain)
 
   QString name = tl::to_qstring (grain.name ());
   tl::info << QObject::tr ("Removing package '%1' ..").arg (name);
+
+  //  Execute "_uninstall.lym" if it exists
+  try {
+    QFile uninstall_lym (QDir (tl::to_qstring (grain.path ())).absoluteFilePath (tl::to_qstring ("_uninstall.lym")));
+    if (uninstall_lym.exists ()) {
+      lym::Macro uninstall;
+      uninstall.load_from (tl::to_string (uninstall_lym.fileName ()));
+      uninstall.set_file_path (tl::to_string (uninstall_lym.fileName ()));
+      uninstall.run ();
+    }
+  } catch (tl::Exception &ex) {
+    //  Errors in the uninstallation script are only logged, but do not prevent uninstallation
+    tl::error << ex.msg ();
+  }
+
   bool res = remove_from_collection (m_root, grain.name ());
   if (res) {
     tl::info << QObject::tr ("Package '%1' removed.").arg (name);
@@ -493,10 +509,25 @@ Salt::create_grain (const SaltGrain &templ, SaltGrain &target, double timeout, t
 
   if (res) {
 
-    tl::info << QObject::tr ("Package '%1' installed").arg (tl::to_qstring (target.name ()));
     target.set_installed_time (QDateTime::currentDateTime ());
     target.save ();
 
+    //  Execute "_install.lym" if it exists
+    try {
+      QFile install_lym (QDir (tl::to_qstring (target.path ())).absoluteFilePath (tl::to_qstring ("_install.lym")));
+      if (install_lym.exists ()) {
+        lym::Macro install;
+        install.load_from (tl::to_string (install_lym.fileName ()));
+        install.set_file_path (tl::to_string (install_lym.fileName ()));
+        install.run ();
+      }
+    } catch (tl::Exception &ex) {
+      //  Errors in the installation script are only logged, but do not prevent installation
+      tl::error << ex.msg ();
+    }
+
+    tl::info << QObject::tr ("Package '%1' installed").arg (tl::to_qstring (target.name ()));
+
     //  NOTE: this is a bit brute force .. we could as well try to insert the new grain into the existing structure
     refresh ();
 

src/lay/lay/laySaltController.cc

@@ -58,13 +58,13 @@ SaltController::initialized (lay::Dispatcher * /*root*/)
     connect (m_file_watcher, SIGNAL (fileRemoved (const QString &)), this, SLOT (file_watcher_triggered ()));
   }
 
-  connect (&m_salt, SIGNAL (collections_changed ()), this, SIGNAL (salt_changed ()));
+  connect (&m_salt, SIGNAL (collections_changed ()), this, SLOT (emit_salt_changed ()));
 }
 
 void
 SaltController::uninitialize (lay::Dispatcher * /*root*/)
 {
-  disconnect (&m_salt, SIGNAL (collections_changed ()), this, SIGNAL (salt_changed ()));
+  disconnect (&m_salt, SIGNAL (collections_changed ()), this, SLOT (emit_salt_changed ()));
 
   if (m_file_watcher) {
     disconnect (m_file_watcher, SIGNAL (fileChanged (const QString &)), this, SLOT (file_watcher_triggered ()));
@@ -168,7 +168,7 @@ void
 SaltController::sync_files ()
 {
   tl::log << tl::to_string (tr ("Detected file system change in packages - updating"));
-  emit salt_changed ();
+  emit_salt_changed ();
 }
 
 bool
@@ -242,6 +242,13 @@ SaltController::file_watcher_triggered ()
   dm_sync_files ();
 }
 
+void
+SaltController::emit_salt_changed ()
+{
+  salt_changed_event ();
+  emit salt_changed ();
+}
+
 void
 SaltController::set_salt_mine_url (const std::string &url)
 {

src/lay/lay/laySaltController.h

@@ -29,6 +29,7 @@
 #include "laySalt.h"
 #include "tlFileSystemWatcher.h"
 #include "tlDeferredExecution.h"
+#include "tlEvents.h"
 
 #include <vector>
 #include <string>
@@ -171,6 +172,11 @@ public:
     return m_salt;
   }
 
+  /**
+   *  @brief Event-style version of "salt_changed"
+   */
+  tl::Event salt_changed_event;
+
   /**
    *  @brief Gets the singleton instance for this object
    */
@@ -182,6 +188,11 @@ private slots:
    */
   void file_watcher_triggered ();
 
+  /**
+   *  @brief Emits a salt_changed event + signal
+   */
+  void emit_salt_changed ();
+
 signals:
   /**
    *  @brief This signal is emitted if the salt changed