Fix parent for new graph window, fix empty graphs are impossible to

selectively remove or edit, add associated signal to graphs so they
bring up the proper signal in the list on the right in the editing
window.

re/newgraphdialog.cpp

@@ -32,6 +32,7 @@ NewGraphDialog::NewGraphDialog(DBCHandler *handler, QWidget *parent) :
 
     startBit = 0;
     dataLen = 1;
+    assocSignal = nullptr;
 
     loadMessages();
 
@@ -104,6 +105,9 @@ void NewGraphDialog::setParams(GraphParams &params)
     ui->cbSigned->setChecked(params.isSigned);
     ui->cbIntel->setChecked(params.intelFormat);
 
+    assocSignal = params.associatedSignal;
+    qDebug() << "Signal addr: " << params.associatedSignal;
+
     startBit = params.startBit;
     dataLen = params.numBits;
     ui->txtDataLen->setText(QString::number(dataLen));
@@ -113,6 +117,7 @@ void NewGraphDialog::setParams(GraphParams &params)
     p.setColor(QPalette::Button, params.color);
     ui->colorSwatch->setPalette(p);
     loadMessages();
+    loadSignals(0);
     drawBitfield();
 }
 
@@ -132,6 +137,8 @@ void NewGraphDialog::getParams(GraphParams &params)
     params.startBit = startBit;
     params.numBits = dataLen;
 
+    params.associatedSignal = assocSignal;
+
     //now catch stupidity and bring it to defaults
     if (params.mask == 0) params.mask = 0xFFFFFFFF;
     if (fabs(params.scale) < 0.00000001) params.scale = 1.0f;
@@ -140,6 +147,7 @@ void NewGraphDialog::getParams(GraphParams &params)
 
 void NewGraphDialog::loadMessages()
 {
+    DBC_MESSAGE *msg;
     ui->cbMessages->clear();
     if (dbcHandler == NULL) return;
     if (dbcHandler->getFileCount() == 0) return;
@@ -147,7 +155,16 @@ void NewGraphDialog::loadMessages()
     {
         for (int x = 0; x < dbcHandler->getFileByIdx(y)->messageHandler->getCount(); x++)
         {
-            ui->cbMessages->addItem(dbcHandler->getFileByIdx(y)->messageHandler->findMsgByIdx(x)->name);
+            msg = dbcHandler->getFileByIdx(y)->messageHandler->findMsgByIdx(x);
+            if (msg)
+            {
+                ui->cbMessages->addItem(msg->name);
+                if (assocSignal && msg->name == assocSignal->parentMessage->name)
+                {
+                    ui->cbMessages->setCurrentIndex(ui->cbMessages->count() -1);
+                    qDebug() << "Found my parent";
+                }
+            }
         }
     }
 }
@@ -160,12 +177,23 @@ void NewGraphDialog::loadSignals(int idx)
     //look it up based on index but by name is probably safer and this operation
     //is not time critical at all.
     DBC_MESSAGE *msg = dbcHandler->getFileByIdx(0)->messageHandler->findMsgByName(ui->cbMessages->currentText());
+    DBC_SIGNAL *sig;
 
     if (msg == NULL) return;
+
     ui->cbSignals->clear();
     for (int x = 0; x < msg->sigHandler->getCount(); x++)
     {
-        ui->cbSignals->addItem(msg->sigHandler->findSignalByIdx(x)->name);
+        sig = msg->sigHandler->findSignalByIdx(x);
+        if (sig)
+        {
+            ui->cbSignals->addItem(sig->name);
+            if (assocSignal && sig->name == assocSignal->name)
+            {
+                ui->cbSignals->setCurrentIndex(ui->cbSignals->count() - 1);
+                qDebug() << "Found me";
+            }
+        }
     }
 }
 
@@ -242,4 +270,5 @@ void NewGraphDialog::copySignalToParamsUI()
     if (sig->valType == SIGNED_INT) ui->cbSigned->setChecked(true);
         else ui->cbSigned->setChecked(false);
     drawBitfield();
+    assocSignal = sig;
 }