Refactor|libshell: Added AbstractLink (based on Link)

An AbstractLink provides the basic mechanism for managing a connection
to a server. Derived classes must implement a protocol for interpreting
incoming messages.

doomsday/libshell/include/de/shell/AbstractLink

@@ -0,0 +1 @@
+#include "abstractlink.h"

doomsday/libshell/include/de/shell/abstractlink.h

@@ -0,0 +1,134 @@
+/** @file abstractlink.h  Network connection to a server.
+ *
+ * @authors Copyright © 2013 Jaakko Keränen <jaakko.keranen@iki.fi>
+ *
+ * @par License
+ * GPL: http://www.gnu.org/licenses/gpl.html
+ *
+ * <small>This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version. This program is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details. You should have received a copy of the GNU
+ * General Public License along with this program; if not, see:
+ * http://www.gnu.org/licenses</small>
+ */
+
+#ifndef LIBSHELL_ABSTRACTLINK_H
+#define LIBSHELL_ABSTRACTLINK_H
+
+#include "libshell.h"
+#include <de/Address>
+#include <de/Socket>
+#include <de/Time>
+#include <de/Transmitter>
+#include <QObject>
+
+namespace de {
+namespace shell {
+
+/**
+ * Abstract network connection to a server.
+ *
+ * Derived implementations must provide a protocol for incoming messages.
+ */
+class LIBSHELL_PUBLIC AbstractLink : public QObject, public Transmitter
+{
+    Q_OBJECT
+
+public:
+    enum Status
+    {
+        Disconnected,
+        Connecting,
+        Connected
+    };
+
+public:
+    AbstractLink();
+
+    virtual ~AbstractLink();
+
+    /**
+     * Opens a connection to a server over the network.
+     *
+     * @param domain   Domain/IP address of the server.
+     * @param timeout  Keep trying until this much time has passed.
+     */
+    void connect(String const &domain, TimeDelta const &timeout = 0);
+
+    /**
+     * Opens a connection to a server over the network.
+     *
+     * @param address  Address of the server.
+     */
+    void connect(Address const &address);
+
+    /**
+     * Takes over an existing socket.
+     *
+     * @param openSocket  Socket. AbstractLink takes ownership.
+     */
+    void takeOver(Socket *openSocket);
+
+    /**
+     * Closes the connection.
+     */
+    void disconnect();
+
+    /**
+     * Peer address of the link. The address may be a null address if the IP
+     * address hasn't been resolved yet.
+     */
+    Address address() const;
+
+    /**
+     * Current status of the connection.
+     */
+    Status status() const;
+
+    /**
+     * Returns the time when the link was successfully connected.
+     */
+    Time connectedAt() const;
+
+    /**
+     * Returns the next received packet. The packet has been interpreted
+     * using the virtual interpret() method.
+     *
+     * @return Received packet. Ownership given to caller. Returns @c NULL if
+     * there are no more packets ready.
+     */
+    Packet *nextPacket();
+
+    // Transmitter.
+    void send(IByteArray const &data);
+
+protected:
+    virtual Packet *interpret(Message const &msg) = 0;
+
+    /**
+     * Called immediately after a connection has been formed.
+     */
+    virtual void initiateCommunications() = 0;
+
+protected slots:
+    void socketConnected();
+    void socketDisconnected();
+
+signals:
+    void addressResolved();
+    void connected();
+    void disconnected();
+    void packetsReady();
+
+private:
+    DENG2_PRIVATE(d)
+};
+
+} // namespace shell
+} // namespace de
+
+#endif // LIBSHELL_ABSTRACTLINK_H

doomsday/libshell/include/de/shell/link.h

@@ -24,6 +24,7 @@
 #include <de/Socket>
 #include <de/Time>
 #include <de/Transmitter>
+#include <de/shell/AbstractLink>
 #include <de/shell/Protocol>
 #include <QObject>
 
@@ -33,18 +34,10 @@ namespace shell {
 /**
  * Network connection to a server using the shell protocol.
  */
-class LIBSHELL_PUBLIC Link : public QObject, public Transmitter
+class LIBSHELL_PUBLIC Link : public AbstractLink
 {
     Q_OBJECT
 
-public:
-    enum Status
-    {
-        Disconnected,
-        Connecting,
-        Connected
-    };
-
 public:
     /**
      * Opens a connection to a server over the network.
@@ -70,47 +63,14 @@ class LIBSHELL_PUBLIC Link : public QObject, public Transmitter
 
     virtual ~Link();
 
-    /**
-     * Peer address of the link. The address may be a null address if the IP
-     * address hasn't been resolved yet.
-     */
-    Address address() const;
-
-    /**
-     * Current status of the connection.
-     */
-    Status status() const;
-
-    /**
-     * Returns the time when the link was successfully connected.
-     */
-    Time connectedAt() const;
-
     /**
      * Shell protocol for constructing and interpreting packets.
      */
     Protocol &protocol();
 
-    /**
-     * Returns the next received packet.
-     *
-     * @return Received packet. Ownership given to caller. Returns @c NULL if
-     * there are no more packets ready.
-     */
-    Packet *nextPacket();
-
-    // Transmitter.
-    void send(IByteArray const &data);
-
-protected slots:
-    void socketConnected();
-    void socketDisconnected();
-
-signals:
-    void addressResolved();
-    void connected();
-    void disconnected();
-    void packetsReady();
+protected:
+    Packet *interpret(Message const &msg);
+    void initiateCommunications();
 
 private:
     DENG2_PRIVATE(d)

doomsday/libshell/libshell.pro

@@ -24,6 +24,7 @@ INCLUDEPATH += include
 
 # Public headers.
 HEADERS += \
+    include/de/shell/AbstractLink \
     include/de/shell/Action \
     include/de/shell/ChoiceWidget \
     include/de/shell/CommandLineWidget \
@@ -44,6 +45,7 @@ HEADERS += \
     include/de/shell/TextRootWidget \
     include/de/shell/TextWidget \
     \
+    include/de/shell/abstractlink.h \
     include/de/shell/action.h \
     include/de/shell/choicewidget.h \
     include/de/shell/commandlinewidget.h \
@@ -67,6 +69,7 @@ HEADERS += \
 
 # Sources and private headers.
 SOURCES += \
+    src/abstractlink.cpp \
     src/action.cpp \
     src/choicewidget.cpp \
     src/commandlinewidget.cpp \