SplitApp Container under ICONTAB Bar - sapui5

Question

Why is It not possible to add a SplitApp Container as an aggregation for ICONTab Bar. I have tried to add the splitApp under ICONTAB Bar and it is working. But it is not working with SplitApp Container.
<mvc:View controllerName="com.sap.controller.Main"
xmlns:html="http://www.w3.org/1999/xhtml" xmlns:mvc="sap.ui.core.mvc"
xmlns="sap.m">
<App>
<pages>
<Page title="{i18n>title}">
<content>
<IconTabBar id="idIconTabBar" select="handleIconTabBarSelect"
class="sapUiResponsiveContentPadding">
<items>
<IconTabFilter>
<content></content>
</IconTabFilter>
<IconTabFilter>
<content>
<SplitApp id="SplitContDemo1" initialDetail="detail" initialMaster="master">
<detailPages>
<Page id="detail" title="Detail 1" class="sapUiStdPage">
<content>
<Label text="Detail page 1"/>
<Button text="Go to Detail page2" press="onPressNavToDetail"/>
</content>
</Page>
</detailPages>
<masterPages>
<Page id="master" title="Master 1" icon="sap-icon://action"
class="sapUiStdPage">
<content>
<List>
<items>
<StandardListItem title="To Master2" type="Navigation"
press="onPressGoToMaster"/>
</items>
</List>
</content>
</Page>
</masterPages>
</SplitApp>
</content>
</IconTabFilter>
</items>
</IconTabBar>
<SplitContainer id="SplitContDemo">
<detailPages>
<Button text="Detailed Button"/>
</detailPages>
<masterPages>
<Button text="Master Button"/>
</masterPages>
</SplitContainer>
</content>
</Page>
</pages>
</App>
</mvc:View>
Regards,
MS

Answer 1

It is not very clear what your problem is exactly. You can put anything inside the content aggregation of an IconTabFilter. In the items aggregation of an IconTabBar you can only put IconTabFilters and IconTabSeparators.
I have checked your example and made it to work by putting the Split Container inside an IconTabFilter: https://jsfiddle.net/enykp4h8/1/.
<IconTabFilter text="Split Container">
<SplitContainer id="SplitContDemo">
<detailPages>
<Button text="Detailed Button" />
</detailPages>
<masterPages>
<Button text="Master Button" />
</masterPages>
</SplitContainer>
</IconTabFilter>
Later update:
If you put the SplitContainer alone in the IconTabBar, it will seem as though it does not work because the tab's content has 0 height. This is because the SplitContainer has a height 100% of its parent element whilst the tab's height is determined based on the height of its children (so they are somehow codependent).
To go around this you can either use some custom CSS to give the container a fixed height or you can ask the IconTabBar to stretch to its parent's height (using stretchContentHeight):
CSS Solution:
.fixContHeight.sapMSplitContainer {
height: 300px
}
<SplitContainer id="SplitContDemo" class="fixContHeight" >
<!-- the pages... -->
</SplitContainer>
Stretch Content Solution:
<IconTabBar id="idIconTabBar" select="handleIconTabBarSelect"
class="sapUiResponsiveContentPadding" stretchContentHeight="true">
<items>
<IconTabFilter text="Split Container">
<SplitContainer id="SplitContDemo">
<detailPages>
<Button text="Detailed Button" />
</detailPages>
<masterPages>
<Button text="Master Button" />
</masterPages>
</SplitContainer>
</IconTabFilter>
<items>
</IconTabBar>