[ui] Add toggle for unblinding password fields

src/qt/askpassphrasedialog.cpp

@@ -70,6 +70,7 @@ AskPassphraseDialog::AskPassphraseDialog(Mode _mode, QWidget *parent) :
             break;
     }
     textChanged();
+    connect(ui->toggleShowPasswordButton, SIGNAL(toggled(bool)), this, SLOT(toggleShowPassword(bool)));
     connect(ui->passEdit1, SIGNAL(textChanged(QString)), this, SLOT(textChanged()));
     connect(ui->passEdit2, SIGNAL(textChanged(QString)), this, SLOT(textChanged()));
     connect(ui->passEdit3, SIGNAL(textChanged(QString)), this, SLOT(textChanged()));
@@ -234,6 +235,15 @@ bool AskPassphraseDialog::event(QEvent *event)
     return QWidget::event(event);
 }
 
+void AskPassphraseDialog::toggleShowPassword(bool show)
+{
+    ui->toggleShowPasswordButton->setDown(show);
+    const auto mode = show ? QLineEdit::Normal : QLineEdit::Password;
+    ui->passEdit1->setEchoMode(mode);
+    ui->passEdit2->setEchoMode(mode);
+    ui->passEdit3->setEchoMode(mode);
+}
+
 bool AskPassphraseDialog::eventFilter(QObject *object, QEvent *event)
 {
     /* Detect Caps Lock.

src/qt/askpassphrasedialog.h

@@ -43,6 +43,7 @@ private:
 private Q_SLOTS:
     void textChanged();
     void secureClearPassFields();
+    void toggleShowPassword(bool);
 
 protected:
     bool event(QEvent *event);

src/qt/forms/askpassphrasedialog.ui

@@ -93,6 +93,13 @@
       </widget>
      </item>
      <item row="3" column="1">
+      <widget class="QCheckBox" name="toggleShowPasswordButton">
+       <property name="text">
+        <string>Show password</string>
+       </property>
+      </widget>
+     </item>
+     <item row="4" column="1">
       <widget class="QLabel" name="capsLabel">
        <property name="font">
         <font>