dash/doc/readme-qt.rst

Litecoin-Qt: Qt4 GUI for Litecoin
===============================

Build instructions
===================

Debian
-------

First, make sure that the required packages for Qt4 development of your
distribution are installed, these are

::

for Debian and Ubuntu  <= 11.10 :

::

    apt-get install qt4-qmake libqt4-dev build-essential libboost-dev libboost-system-dev \
        libboost-filesystem-dev libboost-program-options-dev libboost-thread-dev \
        libssl-dev libdb4.8++-dev

for Ubuntu >= 12.04 (please read the 'Berkely DB version warning' below):

::

    apt-get install qt4-qmake libqt4-dev build-essential libboost-dev libboost-system-dev \
        libboost-filesystem-dev libboost-program-options-dev libboost-thread-dev \
        libssl-dev libdb++-dev libminiupnpc-dev

For Qt 5 you need the following, otherwise you get an error with lrelease when running qmake:

::

    apt-get install qt5-qmake libqt5gui5 libqt5core5 libqt5dbus5 qttools5-dev-tools

then execute the following:

::

    qmake
    make

Alternatively, install `Qt Creator`_ and open the `litecoin-qt.pro` file.

An executable named `litecoin-qt` will be built.

.. _`Qt Creator`: http://qt-project.org/downloads/

Mac OS X
--------

- Download and install the `Qt Mac OS X SDK`_. It is recommended to also install Apple's Xcode with UNIX tools.

- Download and install either `MacPorts`_ or `HomeBrew`_.

- Execute the following commands in a terminal to get the dependencies using MacPorts:

::

	sudo port selfupdate
	sudo port install boost db48 miniupnpc

- Execute the following commands in a terminal to get the dependencies using HomeBrew:

::

	brew update
	brew install boost miniupnpc openssl berkeley-db4

- If using HomeBrew,  edit `litecoin-qt.pro` to account for library location differences. There's a diff in `contrib/homebrew/bitcoin-qt-pro.patch` that shows what you need to change, or you can just patch by doing

        patch -p1 < contrib/homebrew/bitcoin.qt.pro.patch

- Open the litecoin-qt.pro file in Qt Creator and build as normal (cmd-B)

.. _`Qt Mac OS X SDK`: http://qt-project.org/downloads/
.. _`MacPorts`: http://www.macports.org/install.php
.. _`HomeBrew`: http://mxcl.github.io/homebrew/


Build configuration options
============================

UPnP port forwarding
---------------------

To use UPnP for port forwarding behind a NAT router (recommended, as more connections overall allow for a faster and more stable litecoin experience), pass the following argument to qmake:

::

    qmake "USE_UPNP=1"

(in **Qt Creator**, you can find the setting for additional qmake arguments under "Projects" -> "Build Settings" -> "Build Steps", then click "Details" next to **qmake**)

This requires miniupnpc for UPnP port mapping.  It can be downloaded from
http://miniupnp.tuxfamily.org/files/.  UPnP support is not compiled in by default.

Set USE_UPNP to a different value to control this:

+------------+--------------------------------------------------------------------------+
| USE_UPNP=- | no UPnP support, miniupnpc not required;                                 |
+------------+--------------------------------------------------------------------------+
| USE_UPNP=0 | (the default) built with UPnP, support turned off by default at runtime; |
+------------+--------------------------------------------------------------------------+
| USE_UPNP=1 | build with UPnP support turned on by default at runtime.                 |
+------------+--------------------------------------------------------------------------+

Notification support for recent (k)ubuntu versions
---------------------------------------------------

To see desktop notifications on (k)ubuntu versions starting from 10.04, enable usage of the
FreeDesktop notification interface through DBUS using the following qmake option:

::

    qmake "USE_DBUS=1"

Generation of QR codes
-----------------------

libqrencode may be used to generate QRCode images for payment requests.
It can be downloaded from http://fukuchi.org/works/qrencode/index.html.en, or installed via your package manager. Pass the USE_QRCODE
flag to qmake to control this:

+--------------+--------------------------------------------------------------------------+
| USE_QRCODE=0 | (the default) No QRCode support - libarcode not required                 |
+--------------+--------------------------------------------------------------------------+
| USE_QRCODE=1 | QRCode support enabled                                                   |
+--------------+--------------------------------------------------------------------------+


Berkely DB version warning
==========================

A warning for people using the *static binary* version of Litecoin on a Linux/UNIX-ish system (tl;dr: **Berkely DB databases are not forward compatible**).

The static binary version of Litecoin is linked against libdb4.8 (see also `this Debian issue`_).

Now the nasty thing is that databases from 5.X are not compatible with 4.X.

If the globally installed development package of Berkely DB installed on your system is 5.X, any source you
build yourself will be linked against that. The first time you run with a 5.X version the database will be upgraded,
and 4.X cannot open the new format. This means that you cannot go back to the old statically linked version without
significant hassle!

.. _`this Debian issue`: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=621425

Ubuntu 11.10 warning
====================

Ubuntu 11.10 has a package called 'qt-at-spi' installed by default.  At the time of writing, having that package
installed causes litecoin-qt to crash intermittently.  The issue has been reported as `launchpad bug 857790`_, but
isn't yet fixed.

Until the bug is fixed, you can remove the qt-at-spi package to work around the problem, though this will presumably
disable screen reader functionality for Qt apps:

::

    sudo apt-get remove qt-at-spi

.. _`launchpad bug 857790`: https://bugs.launchpad.net/ubuntu/+source/qt-at-spi/+bug/857790