replace some ugly code in addressbookpage.cpp

- add signals signMessage() and verifyMessage() in addressbookpage.cpp
- connect to them in bitcoingui.cpp to switch to the corresponding tab in the Sign/Verify Message dialog
- make gotoSignMessageTab() and gotoVerifyMessageTab() private slots

src/qt/addressbookpage.cpp

@@ -190,10 +190,7 @@ void AddressBookPage::on_signMessage_clicked()
         addr = address.toString();
     }
 
-    QObject *qoGUI = parent()->parent();
-    BitcoinGUI *gui = qobject_cast<BitcoinGUI *>(qoGUI);
-    if (gui)
-        gui->gotoSignMessageTab(addr);
+    emit signMessage(addr);
 }
 
 void AddressBookPage::on_verifyMessage_clicked()
@@ -208,10 +205,7 @@ void AddressBookPage::on_verifyMessage_clicked()
         addr = address.toString();
     }
 
-    QObject *qoGUI = parent()->parent();
-    BitcoinGUI *gui = qobject_cast<BitcoinGUI *>(qoGUI);
-    if (gui)
-        gui->gotoVerifyMessageTab(addr);
+    emit verifyMessage(addr);
 }
 
 void AddressBookPage::on_newAddressButton_clicked()

src/qt/addressbookpage.h

@@ -76,6 +76,10 @@ private slots:
 
     /** New entry/entries were added to address table */
     void selectNewAddress(const QModelIndex &parent, int begin, int end);
+
+signals:
+    void signMessage(QString addr);
+    void verifyMessage(QString addr);
 };
 
 #endif // ADDRESSBOOKDIALOG_H

src/qt/bitcoingui.cpp

@@ -165,6 +165,11 @@ BitcoinGUI::BitcoinGUI(QWidget *parent):
     rpcConsole = new RPCConsole(this);
     connect(openRPCConsoleAction, SIGNAL(triggered()), rpcConsole, SLOT(show()));
 
+    // Clicking on "Verify Message" in the address book sends you to the verify message tab
+    connect(addressBookPage, SIGNAL(verifyMessage(QString)), this, SLOT(gotoVerifyMessageTab(QString)));
+    // Clicking on "Sign Message" in the receive coins page sends you to the sign message tab
+    connect(receiveCoinsPage, SIGNAL(signMessage(QString)), this, SLOT(gotoSignMessageTab(QString)));
+
     gotoOverviewPage();
 }
 

src/qt/bitcoingui.h

@@ -132,9 +132,6 @@ public slots:
     void askFee(qint64 nFeeRequired, bool *payFee);
     void handleURI(QString strURI);
 
-    void gotoSignMessageTab(QString addr = "");
-    void gotoVerifyMessageTab(QString addr = "");
-
 private slots:
     /** Switch to overview (home) page */
     void gotoOverviewPage();
@@ -147,6 +144,11 @@ private slots:
     /** Switch to send coins page */
     void gotoSendCoinsPage();
 
+    /** Show Sign/Verify Message dialog and switch to sign message tab */
+    void gotoSignMessageTab(QString addr = "");
+    /** Show Sign/Verify Message dialog and switch to verify message tab */
+    void gotoVerifyMessageTab(QString addr = "");
+
     /** Show configuration dialog */
     void optionsClicked();
     /** Show about dialog */