Fix for issues Qucs#550 and Qucs#553

It was found that QucsLib tool didn't update neither the default
symbol nor the name/library of the selected component.

LoadDefaultSymbol() was removed and its code was placed where the
function was called.

The code for reloading the default symbol was moved to SymbolWidget
class.

qucs-core/src/logging.c

@@ -26,7 +26,7 @@
 # include <config.h>
 #endif
 
-#include <stdio.h>
+
 #include <stdlib.h>
 #include <stdarg.h>
 

qucs-core/src/logging.h

@@ -27,7 +27,7 @@
 
 #define LOG_ERROR  0
 #define LOG_STATUS 1
-
+#include <stdio.h>
 __BEGIN_DECLS
 
 void logprint (int, const char *, ...);

qucs/qucs-lib/qucslib.cpp

@@ -48,7 +48,6 @@
 #include "displaydialog.h"
 #include "symbolwidget.h"
 
-
 /* Constructor setups the GUI. */
 QucsLib::QucsLib()
 {
@@ -112,6 +111,7 @@ QucsLib::QucsLib()
     CompList = new QListWidget();
     connect(CompList, SIGNAL(itemActivated(QListWidgetItem*)), SLOT(slotShowComponent(QListWidgetItem*)));
     connect(CompList,SIGNAL(currentItemChanged(QListWidgetItem*,QListWidgetItem*)),SLOT(slotShowComponent(QListWidgetItem*)));
+    connect(CompList, SIGNAL(itemClicked(QListWidgetItem*)), SLOT(slotShowComponent(QListWidgetItem*)));
 
     CompSearch = new QLineEdit(this);
     CompSearch->setPlaceholderText(tr("Search Lib Components"));
@@ -458,7 +458,6 @@ void QucsLib::slotSearchClear()
 // ----------------------------------------------------
 void QucsLib::slotShowComponent(QListWidgetItem *Item)
 {
-
     if(!Item) return;
 
     //QString CompString = LibraryComps.at(CompList->index(Item));
@@ -468,6 +467,7 @@ void QucsLib::slotShowComponent(QListWidgetItem *Item)
     CompDescr->append("Library: " + LibName);
     CompDescr->append("----------------------------");
 
+
     // FIXME: here we assume that LibName is the same as the actual filename...
     int i = Library->findText(LibName);
 
@@ -510,11 +510,11 @@ void QucsLib::slotShowComponent(QListWidgetItem *Item)
         QMessageBox::critical(this, tr("Error"), tr("Library is corrupt."));
         return;
     }
-    if(!content.isEmpty())
-        Symbol->setSymbol(content, LibName, Item->text());
-    else if(!DefaultSymbol.isEmpty())   // has library a default symbol ?
-        Symbol->setSymbol(DefaultSymbol, LibName, Item->text());
 
+
+    Symbol->setSymbol(content, LibName, Item->text());
+
+
     // change currently selected category, so the user will 
     //   learn where the component comes from
     Library->setCurrentIndex(i);

qucs/qucs-lib/symbolwidget.cpp

@@ -360,6 +360,29 @@ int SymbolWidget::createSymbol(const QString& Lib_, const QString& Comp_)
 int SymbolWidget::setSymbol( QString& SymbolString,
                             const QString& Lib_, const QString& Comp_)
 {
+  if (SymbolString.isEmpty())//Whenever SymbolString is empty, it tries to load the default symbol
+  {
+      //Load the default symbol for the current Qucs library
+      ComponentLibrary parsedlib;
+      QString libpath = QucsSettings.LibDir + Lib_ + ".lib";
+      int result = parseComponentLibrary (libpath, parsedlib);
+
+      switch (result)//Check if the library was properly loaded
+      {
+        case QUCS_COMP_LIB_IO_ERROR:
+            QMessageBox::critical(0, tr ("Error"), tr("Cannot open \"%1\".").arg (libpath));
+            return -1;
+        case QUCS_COMP_LIB_CORRUPT:
+            QMessageBox::critical(0, tr("Error"), tr("Library is corrupt."));
+            return -1;
+        default:
+            break;
+      }
+
+    // copy the contents of default symbol section to a string
+    SymbolString = parsedlib.defaultSymbol;
+  }
+
   Arcs.clear();
   Lines.clear();
   Rects.clear();

qucs/qucs-lib/symbolwidget.h

@@ -27,6 +27,7 @@
 #include <QList>
 #include <QMouseEvent>
 #include <QPaintEvent>
+#include <QMessageBox>
 
 #include "element.h"