PyQt4: полоса прокрутки не отображается в области прокрутки при изменении размера док-виджета

Я изменил InfoPanel.ui (чтобы заменить фрейм на gridLayout в виджете scrollArea).

InfoPanel.ui:

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow_InfoPanel</class>
 <widget class="QMainWindow" name="MainWindow_InfoPanel">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>602</width>
    <height>263</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow Info Panel</string>
  </property>
  <property name="documentMode">
   <bool>false</bool>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QFrame" name="frame_Info_Panel">
    <property name="geometry">
     <rect>
      <x>20</x>
      <y>50</y>
      <width>261</width>
      <height>161</height>
     </rect>
    </property>
   </widget>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
  <widget class="QDockWidget" name="dockWidget_Info_Panel">
   <property name="minimumSize">
    <size>
     <width>300</width>
     <height>140</height>
    </size>
   </property>
   <property name="font">
    <font>
     <weight>75</weight>
     <italic>true</italic>
     <bold>true</bold>
    </font>
   </property>
   <property name="layoutDirection">
    <enum>Qt::LeftToRight</enum>
   </property>
   <property name="allowedAreas">
    <set>Qt::LeftDockWidgetArea|Qt::RightDockWidgetArea</set>
   </property>
   <property name="windowTitle">
    <string>Info Panel</string>
   </property>
   <attribute name="dockWidgetArea">
    <number>2</number>
   </attribute>
   <widget class="QWidget" name="dockWidgetContents_Info_Panel">
    <widget class="QTabWidget" name="tabWidget_Info_Panel">
     <property name="geometry">
      <rect>
       <x>0</x>
       <y>0</y>
       <width>300</width>
       <height>215</height>
      </rect>
     </property>
     <property name="font">
      <font>
       <weight>50</weight>
       <italic>false</italic>
       <bold>false</bold>
      </font>
     </property>
     <property name="currentIndex">
      <number>0</number>
     </property>
     <widget class="QWidget" name="tab_1">
      <attribute name="title">
       <string>Info_Pg 1</string>
      </attribute>
      <widget class="QScrollArea" name="scrollArea_Info_Panel">
       <property name="geometry">
        <rect>
         <x>9</x>
         <y>9</y>
         <width>271</width>
         <height>171</height>
        </rect>
       </property>
       <property name="verticalScrollBarPolicy">
        <enum>Qt::ScrollBarAsNeeded</enum>
       </property>
       <property name="widgetResizable">
        <bool>true</bool>
       </property>
       <widget class="QWidget" name="scrollAreaWidgetContents">
        <property name="geometry">
         <rect>
          <x>0</x>
          <y>0</y>
          <width>269</width>
          <height>169</height>
         </rect>
        </property>
        <widget class="QWidget" name="gridLayoutWidget">
         <property name="geometry">
          <rect>
           <x>0</x>
           <y>0</y>
           <width>261</width>
           <height>161</height>
          </rect>
         </property>
         <layout class="QGridLayout" name="gridLayout_Info_Panel">
          <item row="0" column="0">
           <widget class="QLabel" name="label_Eqpt_Model">
            <property name="text">
             <string>Eqpt Model:</string>
            </property>
           </widget>
          </item>
          <item row="1" column="1">
           <widget class="QLineEdit" name="lineEdit_State">
            <property name="enabled">
             <bool>false</bool>
            </property>
            <property name="palette">
             <palette>
              <active>
               <colorrole role="Text">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>60</red>
                  <green>60</green>
                  <blue>60</blue>
                 </color>
                </brush>
               </colorrole>
              </active>
              <inactive>
               <colorrole role="Text">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>60</red>
                  <green>60</green>
                  <blue>60</blue>
                 </color>
                </brush>
               </colorrole>
              </inactive>
              <disabled>
               <colorrole role="Text">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>127</blue>
                 </color>
                </brush>
               </colorrole>
              </disabled>
             </palette>
            </property>
            <property name="text">
             <string>Working</string>
            </property>
           </widget>
          </item>
          <item row="1" column="0">
           <widget class="QLabel" name="label_State">
            <property name="text">
             <string>State:</string>
            </property>
           </widget>
          </item>
          <item row="0" column="1">
           <widget class="QLineEdit" name="lineEdit_Eqpt_Model">
            <property name="enabled">
             <bool>false</bool>
            </property>
            <property name="palette">
             <palette>
              <active>
               <colorrole role="Text">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>60</red>
                  <green>60</green>
                  <blue>60</blue>
                 </color>
                </brush>
               </colorrole>
              </active>
              <inactive>
               <colorrole role="Text">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>60</red>
                  <green>60</green>
                  <blue>60</blue>
                 </color>
                </brush>
               </colorrole>
              </inactive>
              <disabled>
               <colorrole role="Text">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>127</blue>
                 </color>
                </brush>
               </colorrole>
              </disabled>
             </palette>
            </property>
            <property name="text">
             <string>ABC</string>
            </property>
           </widget>
          </item>
          <item row="2" column="0" colspan="2">
           <widget class="QGroupBox" name="groupBox_Current_Position">
            <property name="palette">
             <palette>
              <active>
               <colorrole role="WindowText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Button">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>85</red>
                  <green>255</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Light">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>170</red>
                  <green>255</green>
                  <blue>127</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Midlight">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>127</red>
                  <green>255</green>
                  <blue>63</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Dark">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>42</red>
                  <green>127</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Mid">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>56</red>
                  <green>170</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Text">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="BrightText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>255</red>
                  <green>255</green>
                  <blue>255</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="ButtonText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Base">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>255</red>
                  <green>255</green>
                  <blue>255</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Window">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>85</red>
                  <green>255</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Shadow">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="AlternateBase">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>170</red>
                  <green>255</green>
                  <blue>127</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="ToolTipBase">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>255</red>
                  <green>255</green>
                  <blue>220</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="ToolTipText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
              </active>
              <inactive>
               <colorrole role="WindowText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Button">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>85</red>
                  <green>255</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Light">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>170</red>
                  <green>255</green>
                  <blue>127</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Midlight">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>127</red>
                  <green>255</green>
                  <blue>63</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Dark">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>42</red>
                  <green>127</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Mid">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>56</red>
                  <green>170</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Text">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="BrightText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>255</red>
                  <green>255</green>
                  <blue>255</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="ButtonText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Base">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>255</red>
                  <green>255</green>
                  <blue>255</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Window">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>85</red>
                  <green>255</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Shadow">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="AlternateBase">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>170</red>
                  <green>255</green>
                  <blue>127</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="ToolTipBase">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>255</red>
                  <green>255</green>
                  <blue>220</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="ToolTipText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
              </inactive>
              <disabled>
               <colorrole role="WindowText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>42</red>
                  <green>127</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Button">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>85</red>
                  <green>255</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Light">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>170</red>
                  <green>255</green>
                  <blue>127</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Midlight">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>127</red>
                  <green>255</green>
                  <blue>63</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Dark">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>42</red>
                  <green>127</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Mid">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>56</red>
                  <green>170</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Text">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>42</red>
                  <green>127</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="BrightText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>255</red>
                  <green>255</green>
                  <blue>255</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="ButtonText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>42</red>
                  <green>127</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Base">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>85</red>
                  <green>255</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Window">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>85</red>
                  <green>255</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="Shadow">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="AlternateBase">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>85</red>
                  <green>255</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="ToolTipBase">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>255</red>
                  <green>255</green>
                  <blue>220</blue>
                 </color>
                </brush>
               </colorrole>
               <colorrole role="ToolTipText">
                <brush brushstyle="SolidPattern">
                 <color alpha="255">
                  <red>0</red>
                  <green>0</green>
                  <blue>0</blue>
                 </color>
                </brush>
               </colorrole>
              </disabled>
             </palette>
            </property>
            <property name="title">
             <string>Current Position:</string>
            </property>
            <widget class="QLabel" name="label_Current_Position_X">
             <property name="geometry">
              <rect>
               <x>20</x>
               <y>20</y>
               <width>41</width>
               <height>27</height>
              </rect>
             </property>
             <property name="text">
              <string>X =</string>
             </property>
            </widget>
            <widget class="QLineEdit" name="lineEdit_Current_Position_X">
             <property name="enabled">
              <bool>false</bool>
             </property>
             <property name="geometry">
              <rect>
               <x>60</x>
               <y>20</y>
               <width>161</width>
               <height>27</height>
              </rect>
             </property>
             <property name="palette">
              <palette>
               <active>
                <colorrole role="Text">
                 <brush brushstyle="SolidPattern">
                  <color alpha="255">
                   <red>60</red>
                   <green>60</green>
                   <blue>60</blue>
                  </color>
                 </brush>
                </colorrole>
               </active>
               <inactive>
                <colorrole role="Text">
                 <brush brushstyle="SolidPattern">
                  <color alpha="255">
                   <red>60</red>
                   <green>60</green>
                   <blue>60</blue>
                  </color>
                 </brush>
                </colorrole>
               </inactive>
               <disabled>
                <colorrole role="Text">
                 <brush brushstyle="SolidPattern">
                  <color alpha="255">
                   <red>0</red>
                   <green>0</green>
                   <blue>127</blue>
                  </color>
                 </brush>
                </colorrole>
               </disabled>
              </palette>
             </property>
             <property name="text">
              <string>1000.00 m</string>
             </property>
            </widget>
            <widget class="QLabel" name="label_Current_Position_Y">
             <property name="geometry">
              <rect>
               <x>20</x>
               <y>50</y>
               <width>41</width>
               <height>27</height>
              </rect>
             </property>
             <property name="text">
              <string>Y =</string>
             </property>
            </widget>
            <widget class="QLineEdit" name="lineEdit_Current_Position_Y">
             <property name="enabled">
              <bool>false</bool>
             </property>
             <property name="geometry">
              <rect>
               <x>60</x>
               <y>50</y>
               <width>161</width>
               <height>27</height>
              </rect>
             </property>
             <property name="palette">
              <palette>
               <active>
                <colorrole role="Text">
                 <brush brushstyle="SolidPattern">
                  <color alpha="255">
                   <red>60</red>
                   <green>60</green>
                   <blue>60</blue>
                  </color>
                 </brush>
                </colorrole>
               </active>
               <inactive>
                <colorrole role="Text">
                 <brush brushstyle="SolidPattern">
                  <color alpha="255">
                   <red>60</red>
                   <green>60</green>
                   <blue>60</blue>
                  </color>
                 </brush>
                </colorrole>
               </inactive>
               <disabled>
                <colorrole role="Text">
                 <brush brushstyle="SolidPattern">
                  <color alpha="255">
                   <red>0</red>
                   <green>0</green>
                   <blue>127</blue>
                  </color>
                 </brush>
                </colorrole>
               </disabled>
              </palette>
             </property>
             <property name="text">
              <string>1000.00 m</string>
             </property>
            </widget>
           </widget>
          </item>
         </layout>
        </widget>
       </widget>
      </widget>
     </widget>
     <widget class="QWidget" name="tab_2">
      <attribute name="title">
       <string>Info_Pg 2</string>
      </attribute>
     </widget>
    </widget>
   </widget>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>

Создал *_UI.pt с pyuic4 -o InfoPanel_UI.py InfoPanel.ui в командной строке.

Запуск с Test_InfoPanel.py по-прежнему показывает тот же результат, когда полоса прокрутки не отображается при изменении размера по вертикали. :(

У вас нет макетов в файле ui. Не ставьте виджеты только на определенные позиции. Используйте соответствующие макеты для размещения ваших виджетов. Макеты гарантируют, что виджеты будут правильно увеличиваться/уменьшаться при изменении размера.

В официальной документации есть раздел для использования макетов в Qt Designer.

Изменить

Пример файла ui, демонстрирующий правильное использование макетов:

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>539</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <layout class="QGridLayout" name="gridLayout">
    <item row="0" column="0">
     <widget class="QFrame" name="frame">
      <property name="frameShape">
       <enum>QFrame::StyledPanel</enum>
      </property>
      <property name="frameShadow">
       <enum>QFrame::Raised</enum>
      </property>
     </widget>
    </item>
   </layout>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>539</width>
     <height>21</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
  <widget class="QDockWidget" name="dockWidget_2">
   <attribute name="dockWidgetArea">
    <number>2</number>
   </attribute>
   <widget class="QWidget" name="dockWidgetContents_2">
    <layout class="QVBoxLayout" name="verticalLayout_2">
     <item>
      <widget class="QTabWidget" name="tabWidget">
       <widget class="QWidget" name="tab">
        <attribute name="title">
         <string>Tab 1</string>
        </attribute>
        <layout class="QVBoxLayout" name="verticalLayout">
         <item>
          <widget class="QScrollArea" name="scrollArea">
           <property name="widgetResizable">
            <bool>true</bool>
           </property>
           <widget class="QWidget" name="scrollAreaWidgetContents">
            <property name="geometry">
             <rect>
              <x>0</x>
              <y>0</y>
              <width>327</width>
              <height>473</height>
             </rect>
            </property>
            <layout class="QGridLayout" name="gridLayout_2">
             <item row="4" column="1">
              <widget class="QLineEdit" name="lineEdit_4"/>
             </item>
             <item row="3" column="1">
              <widget class="QLineEdit" name="lineEdit_3"/>
             </item>
             <item row="0" column="0">
              <widget class="QLabel" name="label">
               <property name="text">
                <string>Eqpt Model:</string>
               </property>
              </widget>
             </item>
             <item row="4" column="0">
              <widget class="QLabel" name="label_5">
               <property name="text">
                <string>Y=</string>
               </property>
              </widget>
             </item>
             <item row="1" column="0">
              <widget class="QLabel" name="label_2">
               <property name="text">
                <string>State:</string>
               </property>
              </widget>
             </item>
             <item row="2" column="0">
              <widget class="QLabel" name="label_3">
               <property name="text">
                <string>Current Position</string>
               </property>
              </widget>
             </item>
             <item row="1" column="1">
              <widget class="QLineEdit" name="lineEdit_2"/>
             </item>
             <item row="3" column="0">
              <widget class="QLabel" name="label_4">
               <property name="text">
                <string>X=</string>
               </property>
              </widget>
             </item>
             <item row="0" column="1">
              <widget class="QLineEdit" name="lineEdit"/>
             </item>
             <item row="5" column="1">
              <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>
            </layout>
           </widget>
          </widget>
         </item>
        </layout>
       </widget>
       <widget class="QWidget" name="tab_2">
        <attribute name="title">
         <string>Tab 2</string>
        </attribute>
       </widget>
      </widget>
     </item>
    </layout>
   </widget>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>