Window Defaults

When using Large Titles with a ScrollView inside a NavigationWindow or TabGroup, three Window properties must work together. Missing any one of them causes visual glitches.

The problem

On iOS, enabling largeTitleEnabled alone can cause two issues:

1. Content overlaps behind the nav bar. The ScrollView starts at y=0, hidden behind the navigation bar.
2. Large title renders with a visible delay. The nav bar area appears empty for a moment before the title draws.

The solution: 3 interdependent properties

Property	Value	What it does
autoAdjustScrollViewInsets	true	iOS adjusts ScrollView insets so content starts below the nav bar
extendEdges	[Ti.UI.EXTEND_EDGE_ALL]	Content extends behind bars, creating the blur/translucent effect
largeTitleEnabled	true	Shows the large title that collapses on scroll

Without autoAdjustScrollViewInsets, extendEdges pushes the content behind the nav bar without compensating the ScrollView insets.

Without extendEdges + autoAdjustScrollViewInsets (using only largeTitleEnabled), the large title renders with a visible delay: the empty nav bar area appears first, then the title draws. With all three properties, iOS calculates the full layout before displaying the window.

Configuring as global defaults

Instead of repeating these properties on every window, set them once in config.cjs:

purgetss/config.cjs

module.exports = {
  theme: {
    Window: {
      ios: {
        apply: 'auto-adjust-scroll-view-insets extend-edges-all large-title-enabled'
      }
    }
  }
}

This generates default styles for all Windows on iOS. Individual windows only need to set largeTitleDisplayMode if they want to override the collapse behavior.

Works with NavigationWindow and TabGroup

On iOS, TabGroup wraps each Tab in an implicit NavigationWindow. The three-property pattern applies equally to both scenarios.

NavigationWindow

app/views/index.xml

<Alloy>
  <NavigationWindow id="navWin">
    <Window title="Home">
      <ScrollView class="vertical content-w-screen content-h-auto">
        <!-- Content starts below the nav bar automatically -->
      </ScrollView>
    </Window>
  </NavigationWindow>
</Alloy>

TabGroup

app/views/index.xml

<Alloy>
  <TabGroup>
    <Tab title="Home">
      <Window title="Home">
        <ScrollView class="vertical content-w-screen content-h-auto">
          <!-- Each tab has its own implicit NavigationWindow -->
        </ScrollView>
      </Window>
    </Tab>
  </TabGroup>
</Alloy>

Controlling Large Title display

largeTitleDisplayMode controls how the title behaves in the navigation stack:

Mode	Constant	Behavior
Automatic	Ti.UI.iOS.LARGE_TITLE_DISPLAY_MODE_AUTOMATIC	Inherits from previous window; collapses on scroll
Always	Ti.UI.iOS.LARGE_TITLE_DISPLAY_MODE_ALWAYS	Title stays large regardless of scroll
Never	Ti.UI.iOS.LARGE_TITLE_DISPLAY_MODE_NEVER	Always uses standard title size

In PurgeTSS, use the utility class large-title-display-mode-never on detail windows to show a standard-size title:

<Window class="large-title-display-mode-never" title="Detail">
  <!-- Standard nav bar title -->
</Window>

tip

Set the three base properties (autoAdjustScrollViewInsets, extendEdges, largeTitleEnabled) as global defaults in config.cjs, and only override largeTitleDisplayMode per-window as needed.