[Qt] refactor and optimize proxy settings behavior

src/qt/optionsdialog.h

@@ -6,6 +6,7 @@
 #define BITCOIN_QT_OPTIONSDIALOG_H
 
 #include <QDialog>
+#include <QValidator>
 
 class OptionsModel;
 class QValidatedLineEdit;
@@ -18,6 +19,18 @@ namespace Ui {
 class OptionsDialog;
 }
 
+/** Proxy address widget validator, checks for a valid proxy address.
+ */
+class ProxyAddressValidator : public QValidator
+{
+    Q_OBJECT
+
+public:
+    explicit ProxyAddressValidator(QObject *parent);
+
+    State validate(QString &input, int &pos) const;
+};
+
 /** Preferences dialog. */
 class OptionsDialog : public QDialog
 {
@@ -30,14 +43,7 @@ public:
     void setModel(OptionsModel *model);
     void setMapper();
 
-protected:
-    bool eventFilter(QObject *object, QEvent *event);
-
 private Q_SLOTS:
-    /* enable OK button */
-    void enableOkButton();
-    /* disable OK button */
-    void disableOkButton();
     /* set OK button state (enabled / disabled) */
     void setOkButtonState(bool fState);
     void on_resetButton_clicked();
@@ -46,7 +52,7 @@ private Q_SLOTS:
 
     void showRestartWarning(bool fPersistent = false);
     void clearStatusLabel();
-    void doProxyIpChecks(QValidatedLineEdit *pUiProxyIp, int nProxyPort);
+    void updateProxyValidationState(QValidatedLineEdit *pUiProxyIp);
     /* query the networks, for which the default proxy is used */
     void updateDefaultProxyNets();
 
@@ -57,7 +63,6 @@ private:
     Ui::OptionsDialog *ui;
     OptionsModel *model;
     QDataWidgetMapper *mapper;
-    bool fProxyIpsValid;
 };
 
 #endif // BITCOIN_QT_OPTIONSDIALOG_H