Merge #13043: [qt] OptionsDialog: add prune setting

cbede7dbfde83d53ef38d257e9940af5f163b03c [qt] OptionsDialog: add prune setting (Sjors Provoost)

Pull request description:

  The default suggested value is 2 GB. Minimum is 1 GB (550 MB rounded up).

  When the user toggles this setting, a strong warning appears that undoing requires re-downloading the chain:

  <img width="478" alt="schermafbeelding 2018-05-15 om 12 35 24" src="https://user-images.githubusercontent.com/10217/40051858-7939cc20-583c-11e8-9120-327a75376732.png">

  Tooltip points out that actual disk usage can be higher. It's a bit vague on the "advanced features", because I'm assuming anyone who needs to use `-rescan` and `-txindex` will read the documentation, and a more detailed text would needlessly confuse everyone else.

  <img width="450" alt="schermafbeelding 2018-05-15 om 12 33 51" src="https://user-images.githubusercontent.com/10217/40051791-49d6156a-583c-11e8-97b9-7de6dfd8c481.png">

  The UI uses gigabytes for readability and easy of use. There is also no manual pruning UI (`prune=1`). The user will have to use `bitcoin.conf` for those things.

  Fixes #6461. When combined with #13029 the user, after pruning their node, can safely reset settings and/or use bitcoind without having to edit `bitcoin.conf`. However I don't think that's an essential prerequisite.

Tree-SHA512: e17aff276d7235fbd40796adb6431d430620788a753ee13bc064abd35d2edc4280a3d3cddc18e42b4e00edff13ed18fd4f2a966c6f0b43b689afd13673e0c4bf

1 files changed, 65 insertions, 2 deletions

diff --git a/src/qt/forms/optionsdialog.ui b/src/qt/forms/optionsdialog.ui
index a3721991ee..8f34e6bc82 100644
--- a/src/qt/forms/optionsdialog.ui
+++ b/src/qt/forms/optionsdialog.ui
@@ -38,6 +38,69 @@
         </widget>
        </item>
        <item>
+        <spacer name="horizontalSpacer_0_Main">
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>40</width>
+           <height>5</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+       <layout class="QHBoxLayout" name="horizontalLayout_Main_Prune">
+        <item>
+         <widget class="QCheckBox" name="prune">
+          <property name="toolTip">
+           <string>Disables some advanced features but all blocks will still be fully validated. Reverting this setting requires re-downloading the entire blockchain. Actual disk usage may be somewhat higher.</string>
+          </property>
+          <property name="text">
+           <string>Prune &amp;block storage to</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="pruneSize"/>
+        </item>
+         <item>
+          <widget class="QLabel" name="pruneSizeUnitLabel">
+           <property name="text">
+            <string>GB</string>
+           </property>
+           <property name="textFormat">
+            <enum>Qt::PlainText</enum>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <spacer name="horizontalSpacer_Main_Prune">
+           <property name="orientation">
+            <enum>Qt::Horizontal</enum>
+           </property>
+           <property name="sizeHint" stdset="0">
+            <size>
+             <width>40</width>
+             <height>20</height>
+            </size>
+           </property>
+          </spacer>
+         </item>
+        </layout>
+       </item>
+       <item>
+        <widget class="QLabel" name="pruneWarning">
+         <property name="text">
+          <string>Reverting this setting requires re-downloading the entire blockchain.</string>
+         </property>
+         <property name="textFormat">
+          <enum>Qt::PlainText</enum>
+         </property>
+        </widget>
+       </item>
+       <item>
         <layout class="QHBoxLayout" name="horizontalLayout_2_Main">
          <item>
           <widget class="QLabel" name="databaseCacheLabel">
@@ -81,7 +144,7 @@
         </layout>
        </item>
        <item>
-        <layout class="QHBoxLayout" name="horizontalLayout_3_Main">
+        <layout class="QHBoxLayout" name="horizontalLayout_Main_VerifyLabel">
          <item>
           <widget class="QLabel" name="threadsScriptVerifLabel">
            <property name="text">
@@ -103,7 +166,7 @@
           </widget>
          </item>
          <item>
-          <spacer name="horizontalSpacer_3_Main">
+          <spacer name="horizontalSpacer_Main_Threads">
            <property name="orientation">
             <enum>Qt::Horizontal</enum>
            </property>