Children collapsible should be false

widegraph.cpp

@@ -40,6 +40,9 @@ WideGraph::WideGraph(QSettings * settings, QWidget *parent) :
   setMaximumWidth (MAX_SCREENSIZE);
   setMaximumHeight (880);
 
+  ui->splitter->setChildrenCollapsible(false);
+  ui->splitter->updateGeometry();
+
   auto filterEscapeEater = new KeyPressEater();
   connect(filterEscapeEater, &KeyPressEater::keyPressed, this, [this](QObject */*obj*/, QKeyEvent *e, bool *pProcessed){
       if(e->key() != Qt::Key_Escape){

widegraph.ui

@@ -101,6 +101,12 @@
         <verstretch>0</verstretch>
        </sizepolicy>
       </property>
+      <property name="minimumSize">
+       <size>
+        <width>100</width>
+        <height>0</height>
+       </size>
+      </property>
       <layout class="QGridLayout" name="gridLayout">
        <property name="leftMargin">
         <number>0</number>