qt: allow user to choose data directory

This adds an introduction screen that is shown when the client is first
started in which the user can choose a data directory.

It is also possible to force the intro screen to appear using command
line argument `-choosedatadir`.

The user is warned that the client will download and store 10Gb of data.
The intro screen shows how much space is available on the device that
contains the chosen directory and warns if this is less than the 10Gb.

To make it possible to translate the introduction dialog, the initialization
sequence is changed so that translations are
loaded before the data directory. This has the by-effect that it is
no longer possible to specify a language in bitcoin.conf inside the data
directory.

1 files changed, 266 insertions, 0 deletions

diff --git a/src/qt/forms/intro.ui b/src/qt/forms/intro.ui
new file mode 100644
index 0000000000..0f6ae5a7d0
--- /dev/null
+++ b/src/qt/forms/intro.ui
@@ -0,0 +1,266 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>Intro</class>
+ <widget class="QDialog" name="Intro">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>674</width>
+    <height>363</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Welcome</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QLabel" name="label_2">
+     <property name="styleSheet">
+      <string notr="true">QLabel { font-style:italic; }</string>
+     </property>
+     <property name="text">
+      <string>Welcome to Bitcoin-Qt.</string>
+     </property>
+     <property name="wordWrap">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <spacer name="verticalSpacer_4">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+     <property name="sizeType">
+      <enum>QSizePolicy::Minimum</enum>
+     </property>
+     <property name="sizeHint" stdset="0">
+      <size>
+       <width>20</width>
+       <height>15</height>
+      </size>
+     </property>
+    </spacer>
+   </item>
+   <item>
+    <widget class="QLabel" name="label_4">
+     <property name="text">
+      <string>As this is the first time the program is launched, you can choose where Bitcoin-Qt will store its data.</string>
+     </property>
+     <property name="wordWrap">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QLabel" name="sizeWarningLabel">
+     <property name="text">
+      <string>Bitcoin-Qt will download and store a copy of the Bitcoin block chain. At least %1GB of data will be stored in this directory, and it will grow over time. The wallet will also be stored in this directory.</string>
+     </property>
+     <property name="wordWrap">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QRadioButton" name="dataDirDefault">
+     <property name="text">
+      <string>Use the default data directory</string>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QRadioButton" name="dataDirCustom">
+     <property name="text">
+      <string>Use a custom data directory:</string>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <layout class="QHBoxLayout" name="horizontalLayout">
+     <property name="spacing">
+      <number>0</number>
+     </property>
+     <property name="sizeConstraint">
+      <enum>QLayout::SetDefaultConstraint</enum>
+     </property>
+     <item>
+      <spacer name="horizontalSpacer">
+       <property name="orientation">
+        <enum>Qt::Horizontal</enum>
+       </property>
+       <property name="sizeType">
+        <enum>QSizePolicy::Fixed</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>60</width>
+         <height>20</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+     <item>
+      <layout class="QVBoxLayout" name="verticalLayout_2">
+       <property name="sizeConstraint">
+        <enum>QLayout::SetDefaultConstraint</enum>
+       </property>
+       <item>
+        <layout class="QHBoxLayout" name="horizontalLayout_2">
+         <item>
+          <widget class="QLineEdit" name="dataDirectory"/>
+         </item>
+         <item>
+          <widget class="QPushButton" name="ellipsisButton">
+           <property name="sizePolicy">
+            <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
+             <horstretch>0</horstretch>
+             <verstretch>0</verstretch>
+            </sizepolicy>
+           </property>
+           <property name="maximumSize">
+            <size>
+             <width>30</width>
+             <height>16777215</height>
+            </size>
+           </property>
+           <property name="text">
+            <string notr="true">…</string>
+           </property>
+           <property name="autoDefault">
+            <bool>false</bool>
+           </property>
+          </widget>
+         </item>
+        </layout>
+       </item>
+       <item>
+        <spacer name="verticalSpacer_3">
+         <property name="orientation">
+          <enum>Qt::Vertical</enum>
+         </property>
+         <property name="sizeType">
+          <enum>QSizePolicy::Fixed</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>20</width>
+           <height>5</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+        <widget class="QLabel" name="freeSpace">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Preferred" vsizetype="Expanding">
+           <horstretch>1</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="text">
+          <string/>
+         </property>
+         <property name="wordWrap">
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <spacer name="verticalSpacer_2">
+         <property name="orientation">
+          <enum>Qt::Vertical</enum>
+         </property>
+         <property name="sizeType">
+          <enum>QSizePolicy::Fixed</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>20</width>
+           <height>5</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+        <widget class="QLabel" name="errorMessage">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Preferred" vsizetype="Expanding">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="textFormat">
+          <enum>Qt::RichText</enum>
+         </property>
+         <property name="wordWrap">
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </item>
+    </layout>
+   </item>
+   <item>
+    <spacer name="verticalSpacer">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+     <property name="sizeHint" stdset="0">
+      <size>
+       <width>20</width>
+       <height>40</height>
+      </size>
+     </property>
+    </spacer>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>Intro</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>248</x>
+     <y>254</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>Intro</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>316</x>
+     <y>260</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>