Network Settings: Show a warning that proxy settings do not apply to localhost

Only show this if at least one account is detected to have an url that looks
like localhost, because this could otherwise be confusing

Issue #7169

src/gui/networksettings.cpp

@@ -55,6 +55,8 @@ NetworkSettings::NetworkSettings(QWidget *parent)
         _ui->manualSettings, &QWidget::setEnabled);
     connect(_ui->manualProxyRadioButton, &QAbstractButton::toggled,
         _ui->typeComboBox, &QWidget::setEnabled);
+    connect(_ui->manualProxyRadioButton, &QAbstractButton::toggled,
+        this, &NetworkSettings::checkAccountLocalhost);
 
     loadProxySettings();
     loadBWLimitSettings();
@@ -80,6 +82,7 @@ NetworkSettings::NetworkSettings(QWidget *parent)
     // Warn about empty proxy host
     connect(_ui->hostLineEdit, &QLineEdit::textChanged, this, &NetworkSettings::checkEmptyProxyHost);
     checkEmptyProxyHost();
+    checkAccountLocalhost();
 }
 
 NetworkSettings::~NetworkSettings()
@@ -233,8 +236,27 @@ void NetworkSettings::showEvent(QShowEvent *event)
         checkEmptyProxyHost();
         saveProxySettings();
     }
+    checkAccountLocalhost();
 
     QWidget::showEvent(event);
 }
 
+
+void NetworkSettings::checkAccountLocalhost()
+{
+    bool visible = false;
+    if (_ui->manualProxyRadioButton->isChecked()) {
+        // Check if at least one account is using localhost, because Qt proxy settings have no
+        // effect for localhost (#7169)
+        for (const auto &account : AccountManager::instance()->accounts()) {
+            const auto host = account->account()->url().host();
+            // Some typical url for localhost
+            if (host == "localhost" || host.startsWith("127.") || host == "[::1]")
+                visible = true;
+        }
+    }
+    _ui->labelLocalhost->setVisible(visible);
+}
+
+
 } // namespace OCC

src/gui/networksettings.h

@@ -44,6 +44,8 @@ private slots:
     /// Red marking of host field if empty and enabled
     void checkEmptyProxyHost();
 
+    void checkAccountLocalhost();
+
 protected:
     void showEvent(QShowEvent *event) override;
 

src/gui/networksettings.ui

@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>516</width>
-    <height>444</height>
+    <width>623</width>
+    <height>581</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -23,6 +23,13 @@
       <string>Proxy Settings</string>
      </property>
      <layout class="QGridLayout" name="gridLayout">
+      <item row="2" column="1">
+       <widget class="QComboBox" name="typeComboBox">
+        <property name="enabled">
+         <bool>false</bool>
+        </property>
+       </widget>
+      </item>
       <item row="0" column="0">
        <widget class="QRadioButton" name="noProxyRadioButton">
         <property name="text">
@@ -56,13 +63,6 @@
         </attribute>
        </widget>
       </item>
-      <item row="2" column="1">
-       <widget class="QComboBox" name="typeComboBox">
-        <property name="enabled">
-         <bool>false</bool>
-        </property>
-       </widget>
-      </item>
       <item row="3" column="0" colspan="2">
        <widget class="QWidget" name="manualSettings" native="true">
         <property name="enabled">
@@ -170,6 +170,13 @@
            </layout>
           </widget>
          </item>
+         <item>
+          <widget class="QLabel" name="labelLocalhost">
+           <property name="text">
+            <string>Note: proxy settings have no effects for accounts on localhost</string>
+           </property>
+          </widget>
+         </item>
         </layout>
        </widget>
       </item>