How to automatically resize a child element in Qt Designer?

Question

I am making the GUI of my software with QT Designer.

My GUI has some tabs which I successfully managed to auto-resize in full width when the user makes fullscreen the GUI on his computer.

Then inside each tab, I need to insert a Toolbox. But this time, I didn't succeed in auto-resize this toolbox when the user makes the GUI full screen.

I think the best way to explain to you my issue is to have a look at my screenshots: My GUI in QT designer:

The preview with the issue:

You can see on the preview that the toolbox is keeping the same size when I go for fullscreen.

Answer 1

Solution

You need to add a layout to tab_Run, e.g. by selecting tabWidget and pressing Ctrl+L (on Windows), so your tree would look like this:

Note: In general, you have to set a layout for every widget, the size of whos children you want to be managed automatically by Qt.

Example

As a reference, here is the ui-file I have created:

<?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>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <layout class="QVBoxLayout" name="verticalLayout">
    <item>
     <widget class="QTabWidget" name="tabWidget">
      <property name="currentIndex">
       <number>0</number>
      </property>
      <widget class="QWidget" name="tab_Run">
       <attribute name="title">
        <string>Run</string>
       </attribute>
       <layout class="QVBoxLayout" name="verticalLayout_2">
        <item>
         <widget class="QToolBox" name="toolBox">
          <property name="currentIndex">
           <number>0</number>
          </property>
          <widget class="QWidget" name="page">
           <property name="geometry">
            <rect>
             <x>0</x>
             <y>0</y>
             <width>758</width>
             <height>443</height>
            </rect>
           </property>
           <attribute name="label">
            <string>Page 1</string>
           </attribute>
          </widget>
          <widget class="QWidget" name="page_2">
           <property name="geometry">
            <rect>
             <x>0</x>
             <y>0</y>
             <width>758</width>
             <height>443</height>
            </rect>
           </property>
           <attribute name="label">
            <string>Page 2</string>
           </attribute>
          </widget>
         </widget>
        </item>
       </layout>
      </widget>
      <widget class="QWidget" name="tab_Campaigns">
       <attribute name="title">
        <string>Campaigns</string>
       </attribute>
      </widget>
      <widget class="QWidget" name="tab_Settings">
       <attribute name="title">
        <string>Settings</string>
       </attribute>
      </widget>
      <widget class="QWidget" name="tab_Help">
       <attribute name="title">
        <string>Help</string>
       </attribute>
      </widget>
     </widget>
    </item>
   </layout>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>21</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

Result

Here is the produced result: