Tweaks on symbol layer dialogs (#3945)

* Vertical center alignment for "Offset" label with its corresponding comboboxes
* Vertical center alignment for "Anchor point" label with its comboboxes + consistency in the order of options
* Remove unnecessary horizontal layouts (with single widget) in the dialog
* Fix tab order

Author: DelazJ

src/ui/symbollayer/qgsarrowsymbollayerwidgetbase.ui

@@ -88,7 +88,11 @@
       </widget>
      </item>
      <item>
-      <widget class="QgsUnitSelectionWidget" name="mHeadThicknessUnitWidget" native="true"/>
+      <widget class="QgsUnitSelectionWidget" name="mHeadThicknessUnitWidget" native="true">
+       <property name="focusPolicy">
+        <enum>Qt::TabFocus</enum>
+       </property>
+      </widget>
      </item>
     </layout>
    </item>
@@ -205,7 +209,11 @@
       </widget>
      </item>
      <item>
-      <widget class="QgsUnitSelectionWidget" name="mArrowWidthUnitWidget" native="true"/>
+      <widget class="QgsUnitSelectionWidget" name="mArrowWidthUnitWidget" native="true">
+       <property name="focusPolicy">
+        <enum>Qt::TabFocus</enum>
+       </property>
+      </widget>
      </item>
     </layout>
    </item>
@@ -265,7 +273,11 @@
       </widget>
      </item>
      <item>
-      <widget class="QgsUnitSelectionWidget" name="mHeadLengthUnitWidget" native="true"/>
+      <widget class="QgsUnitSelectionWidget" name="mHeadLengthUnitWidget" native="true">
+       <property name="focusPolicy">
+        <enum>Qt::TabFocus</enum>
+       </property>
+      </widget>
      </item>
     </layout>
    </item>
@@ -330,7 +342,11 @@
       </widget>
      </item>
      <item>
-      <widget class="QgsUnitSelectionWidget" name="mArrowStartWidthUnitWidget" native="true"/>
+      <widget class="QgsUnitSelectionWidget" name="mArrowStartWidthUnitWidget" native="true">
+       <property name="focusPolicy">
+        <enum>Qt::TabFocus</enum>
+       </property>
+      </widget>
      </item>
     </layout>
    </item>
@@ -371,8 +387,27 @@
   </customwidget>
  </customwidgets>
  <tabstops>
+  <tabstop>mHeadTypeCombo</tabstop>
+  <tabstop>mHeadTypeDDBtn</tabstop>
+  <tabstop>mArrowTypeCombo</tabstop>
+  <tabstop>mArrowTypeDDBtn</tabstop>
+  <tabstop>mArrowWidthSpin</tabstop>
+  <tabstop>mArrowWidthUnitWidget</tabstop>
+  <tabstop>mArrowWidthDDBtn</tabstop>
+  <tabstop>mArrowStartWidthSpin</tabstop>
+  <tabstop>mArrowStartWidthUnitWidget</tabstop>
+  <tabstop>mArrowStartWidthDDBtn</tabstop>
+  <tabstop>mHeadLengthSpin</tabstop>
+  <tabstop>mHeadLengthUnitWidget</tabstop>
+  <tabstop>mHeadWidthDDBtn</tabstop>
+  <tabstop>mHeadThicknessSpin</tabstop>
+  <tabstop>mHeadThicknessUnitWidget</tabstop>
+  <tabstop>mHeadHeightDDBtn</tabstop>
   <tabstop>mOffsetSpin</tabstop>
   <tabstop>mOffsetUnitWidget</tabstop>
+  <tabstop>mOffsetDDBtn</tabstop>
+  <tabstop>mCurvedArrowChck</tabstop>
+  <tabstop>mRepeatArrowChck</tabstop>
  </tabstops>
  <resources/>
  <connections/>