[auth] Added updateNetworkProxy method to auth manager

This allows to apply stored proxy auth settings to the
proxy configuration.

python/core/auth/qgsauthmanager.sip

@@ -359,6 +359,17 @@ Get list of authentication ids from database
  :rtype: bool
 %End
 
+    bool updateNetworkProxy( QNetworkProxy &proxy /In,Out/, const QString &authcfg,
+                             const QString &dataprovider = QString() );
+%Docstring
+ Provider call to update a QNetworkProxy with an authentication config
+ \param proxy the QNetworkProxy
+ \param authcfg Associated authentication config id
+ \param dataprovider Provider key filter, offering logic branching in authentication method
+ :return: Whether operation succeeded
+ :rtype: bool
+%End
+
 
     bool storeAuthSetting( const QString &key, const QVariant &value, bool encrypt = false );
 %Docstring

python/core/auth/qgsauthmethod.sip

@@ -28,6 +28,7 @@ class QgsAuthMethod : QObject
       NetworkReply,
       DataSourceUri,
       GenericDataSourceUri,
+      NetworkProxy,
       All
     };
     typedef QFlags<QgsAuthMethod::Expansion> Expansions;
@@ -110,6 +111,18 @@ Increment this if method is significantly updated, allow updater code to be writ
  :rtype: bool
 %End
 
+    virtual bool updateNetworkProxy( QNetworkProxy &proxy, const QString &authcfg,
+                                     const QString &dataprovider = QString() );
+%Docstring
+ Update proxy settings with authentication components
+ \param proxy
+ \param authcfg Authentication configuration ID
+ \param dataprovider Textual key for a data provider, e.g. 'proxy', that allows
+ for custom updater code specific to the provider
+ :return: Whether the update succeeded
+ :rtype: bool
+%End
+
     virtual void clearCachedConfig( const QString &authcfg ) = 0;
 %Docstring
  Clear any cached configuration. Called when the QgsAuthManager deletes an authentication configuration (authcfg).

src/auth/basic/qgsauthbasicmethod.cpp

@@ -20,6 +20,8 @@
 #include "qgsauthmanager.h"
 #include "qgslogger.h"
 
+#include <QNetworkProxy>
+
 static const QString AUTH_METHOD_KEY = QStringLiteral( "Basic" );
 static const QString AUTH_METHOD_DESCRIPTION = QStringLiteral( "Basic authentication" );
 
@@ -127,6 +129,28 @@ bool QgsAuthBasicMethod::updateDataSourceUriItems( QStringList &connectionItems,
   return true;
 }
 
+bool QgsAuthBasicMethod::updateNetworkProxy( QNetworkProxy &proxy, const QString &authcfg, const QString &dataprovider )
+{
+  Q_UNUSED( dataprovider )
+
+  QgsAuthMethodConfig mconfig = getMethodConfig( authcfg );
+  if ( !mconfig.isValid() )
+  {
+    QgsDebugMsg( QString( "Update proxy config FAILED for authcfg: %1: config invalid" ).arg( authcfg ) );
+    return false;
+  }
+
+  QString username = mconfig.config( QStringLiteral( "username" ) );
+  QString password = mconfig.config( QStringLiteral( "password" ) );
+
+  if ( !username.isEmpty() )
+  {
+    proxy.setUser( username );
+    proxy.setPassword( password );
+  }
+  return true;
+}
+
 void QgsAuthBasicMethod::updateMethodConfig( QgsAuthMethodConfig &mconfig )
 {
   if ( mconfig.hasConfig( QStringLiteral( "oldconfigstyle" ) ) )

src/auth/basic/qgsauthbasicmethod.h

@@ -44,6 +44,10 @@ class QgsAuthBasicMethod : public QgsAuthMethod
     bool updateDataSourceUriItems( QStringList &connectionItems, const QString &authcfg,
                                    const QString &dataprovider = QString() ) override;
 
+
+    bool updateNetworkProxy( QNetworkProxy &proxy, const QString &authcfg,
+                             const QString &dataprovider = QString() ) override;
+
     void clearCachedConfig( const QString &authcfg ) override;
 
     void updateMethodConfig( QgsAuthMethodConfig &mconfig ) override;

src/core/auth/qgsauthmanager.cpp

@@ -1457,6 +1457,31 @@ bool QgsAuthManager::updateDataSourceUriItems( QStringList &connectionItems, con
   return false;
 }
 
+bool QgsAuthManager::updateNetworkProxy( QNetworkProxy &proxy, const QString &authcfg, const QString &dataprovider )
+{
+  if ( isDisabled() )
+    return false;
+
+  QgsAuthMethod *authmethod = configAuthMethod( authcfg );
+  if ( authmethod )
+  {
+    if ( !( authmethod->supportedExpansions() & QgsAuthMethod::NetworkProxy ) )
+    {
+      QgsDebugMsg( QString( "Network request updating not supported by authcfg: %1" ).arg( authcfg ) );
+      return true;
+    }
+
+    if ( !authmethod->updateNetworkProxy( proxy, authcfg, dataprovider.toLower() ) )
+    {
+      authmethod->clearCachedConfig( authcfg );
+      return false;
+    }
+    return true;
+  }
+
+  return false;
+}
+
 bool QgsAuthManager::storeAuthSetting( const QString &key, const QVariant &value, bool encrypt )
 {
   if ( key.isEmpty() )

src/core/auth/qgsauthmanager.h

@@ -332,6 +332,16 @@ class CORE_EXPORT QgsAuthManager : public QObject
     bool updateDataSourceUriItems( QStringList &connectionItems SIP_INOUT, const QString &authcfg,
                                    const QString &dataprovider = QString() );
 
+    /**
+     * Provider call to update a QNetworkProxy with an authentication config
+     * \param proxy the QNetworkProxy
+     * \param authcfg Associated authentication config id
+     * \param dataprovider Provider key filter, offering logic branching in authentication method
+     * \returns Whether operation succeeded
+     */
+    bool updateNetworkProxy( QNetworkProxy &proxy SIP_INOUT, const QString &authcfg,
+                             const QString &dataprovider = QString() );
+
     ////////////////// Generic settings ///////////////////////
 
     //! Store an authentication setting (stored as string via QVariant( value ).toString() )

src/core/auth/qgsauthmethod.h

@@ -51,7 +51,8 @@ class CORE_EXPORT QgsAuthMethod : public QObject
       NetworkReply         = 0x2,
       DataSourceUri        = 0x4,
       GenericDataSourceUri = 0x8,
-      All = NetworkRequest | NetworkReply | DataSourceUri | GenericDataSourceUri
+      NetworkProxy                = 0x16,
+      All = NetworkRequest | NetworkReply | DataSourceUri | GenericDataSourceUri | NetworkProxy
     };
     Q_DECLARE_FLAGS( Expansions, Expansion )
 
@@ -126,6 +127,22 @@ class CORE_EXPORT QgsAuthMethod : public QObject
       return true; // noop
     }
 
+    /** Update proxy settings with authentication components
+     * \param proxy
+     * \param authcfg Authentication configuration ID
+     * \param dataprovider Textual key for a data provider, e.g. 'proxy', that allows
+     * for custom updater code specific to the provider
+     * \returns Whether the update succeeded
+     */
+    virtual bool updateNetworkProxy( QNetworkProxy &proxy, const QString &authcfg,
+                                     const QString &dataprovider = QString() )
+    {
+      Q_UNUSED( proxy )
+      Q_UNUSED( authcfg )
+      Q_UNUSED( dataprovider )
+      return true; // noop
+    }
+
     /** Clear any cached configuration. Called when the QgsAuthManager deletes an authentication configuration (authcfg).
      * \note It is highly recommended that a cache of authentication components (per requested authcfg)
      * be implemented, to avoid excessive queries on the auth database. Such a cache could be as