#### Adaptive Layouts

Libadwaita provides a number of widgets that change their layout based on the available space. This can be used to make applications adapt their UI between desktop and mobile devices.

# Clamp

`AdwClamp` has one child and constrains its maximum size while still allowing it to shrink. In other words, it allows the child to have padding when there’s enough space, and to remove them otherwise.

This is commonly used for patterns such as boxed lists:

    <object class="AdwClamp">
      <property name="child">
        <object class="GtkBox">
          <property name="orientation">vertical</property>
          <property name="margin-top">24</property>
          <property name="margin-bottom">24</property>
          <property name="margin-start">12</property>
          <property name="margin-end">12</property>
          <property name="spacing">24</property>
          <child>
            <object class="GtkListBox">
              <property name="selection-mode">none</property>
              <style>
                <class name="boxed-list"/>
              </style>
              <!-- rows -->
            </object>
          </child>
          <!-- more lists -->
        </object>
      </property>
    </object>

See also: `AdwClampLayout`, `AdwClampScrollable`.

# Breakpoints

`AdwBreakpoint` allows applications to restructure UI in arbitrary ways depending on available size. Breakpoints can be used with `AdwWindow`, `AdwApplicationWindow`, or `AdwBreakpointBin`.

When using breakpoints, the widget containing them will have no minimum size, and the application must manually set the `GtkWidget:width-request` and `GtkWidget:height-request` properties, indicating the smallest supported size.

All of the examples below use breakpoints.

# View Switcher

The `AdwViewSwitcher` and `AdwViewSwitcherBar` widgets implement an adaptive view switcher.

They are typically used together, providing desktop and mobile UI for the same navigation: a view switcher in the header bar when there’s enough space, or a view switcher in a bottom bar otherwise. An `AdwBreakpoint` is used to switch between them depending on available width.

    <object class="AdwWindow">
      <property name="width-request">360</property>
      <property name="height-request">200</property>
      <child>
        <object class="AdwBreakpoint">
          <condition>max-width: 550sp</condition>
          <setter object="switcher_bar" property="reveal">True</setter>
          <setter object="header_bar" property="title-widget"/>
        </object>
      </child>
      <property name="content">
        <object class="AdwToolbarView">
          <child type="top">
            <object class="AdwHeaderBar" id="header_bar">
              <property name="title-widget">
                <object class="AdwViewSwitcher">
                  <property name="stack">stack</property>
                  <property name="policy">wide</property>
                </object>
              </property>
            </object>
          </child>
          <property name="content">
            <object class="AdwViewStack" id="stack"/>
          </property>
          <child type="bottom">
            <object class="AdwViewSwitcherBar" id="switcher_bar">
              <property name="stack">stack</property>
            </object>
          </child>
        </object>
      </property>
    </object>

You may need to adjust the breakpoint threshold depending on the number of pages in your application, as well as their titles.

# Split Views

Libadwaita provides two containers for creating multi-pane layouts that can collapse on small widths: `AdwNavigationSplitView` and `AdwOverlaySplitView`.

Both widgets have two children: sidebar and content. They are typically used together with a `AdwBreakpoint` toggling their `collapsed` property for narrow widths.

## Navigation Split View

`AdwNavigationSplitView` turns into an `AdwNavigationView` when collapsed, containing the sidebar as the root page and content as its subpage. Only `AdwNavigationPage` can be used for both the sidebar and content.

    <object class="AdwWindow">
      <property name="width-request">360</property>
      <property name="height-request">200</property>
      <child>
        <object class="AdwBreakpoint">
          <condition>max-width: 400sp</condition>
          <setter object="split_view" property="collapsed">True</setter>
        </object>
      </child>
      <property name="content">
        <object class="AdwNavigationSplitView" id="split_view">
          <property name="sidebar">
            <object class="AdwNavigationPage">
              <property name="title" translatable="yes">Sidebar</property>
              <property name="tag">sidebar</property>
              <property name="child">
                <object class="AdwToolbarView">
                  <child type="top">
                    <object class="AdwHeaderBar"/>
                  </child>
                  <property name="content">
                    <!-- sidebar -->
                  </property>
                </object>
              </property>
            </object>
          </property>
          <property name="content">
            <object class="AdwNavigationPage">
              <property name="title" translatable="yes">Content</property>
              <property name="tag">content</property>
              <property name="child">
                <object class="AdwToolbarView">
                  <child type="top">
                    <object class="AdwHeaderBar"/>
                  </child>
                  <property name="content">
                    <!-- content -->
                  </property>
                </object>
              </property>
            </object>
          </property>
        </object>
      </property>
    </object>

`AdwHeaderBar` will automatically provide a back button, manage window controls and display the title from its `AdwNavigationPage`.

## Overlay Split View

`AdwOverlaySplitView` shows the sidebar as an overlay above the content when collapsed. It’s commonly used to implement utility panes, but can be used with split header bars as well.

    <object class="AdwWindow">
      <property name="width-request">360</property>
      <property name="height-request">200</property>
      <child>
        <object class="AdwBreakpoint">
          <condition>max-width: 400sp</condition>
          <setter object="split_view" property="collapsed">True</setter>
        </object>
      </child>
      <property name="content">
        <object class="AdwToolbarView">
          <property name="top-bar-style">raised</property>
          <child type="top">
            <object class="AdwHeaderBar">
              <child type="start">
                <object class="GtkToggleButton" id="show_sidebar_button">
                  <property name="icon-name">sidebar-show-symbolic</property>
                  <property name="active">True</property>
                </object>
              </child>
            </object>
          </child>
          <property name="content">
            <object class="AdwOverlaySplitView" id="split_view">
              <property name="show-sidebar"
                        bind-source="show_sidebar_button"
                        bind-property="active"
                        bind-flags="sync-create|bidirectional"/>
              <property name="sidebar">
                <!-- utility pane -->
              </property>
              <property name="content">
                <!-- main view -->
              </property>
            </object>
          </property>
        </object>
      </property>
    </object>

To make the utility pane permanently visible on desktop, and only allow to show and hide it on mobile, you can toggle the button’s visibility with your breakpoint:

    <object class="AdwBreakpoint">
      <condition>max-width: 400sp</condition>
      <setter object="split_view" property="collapsed">True</setter>
      <setter object="toggle_pane_button" property="visible">True</setter>
    </object>
    <!-- ... -->
    <object class="GtkToggleButton" id="toggle_pane_button">
      <property name="icon-name">sidebar-show-symbolic</property>
      <property name="active">True</property>
      <property name="visible">False</property>
    </object>

## Triple Pane Layouts

Both split views can be used for creating triple pane layouts, via nesting two of the views within one another. The inner view can be placed as the sidebar or content widget in the outer view, depending on how you want to handle collapsing.

An example of a triple-pane layout with the an `AdwNavigationSplitView` nested within another `AdwNavigationSplitView`‘s sidebar:

    <object class="AdwWindow">
      <property name="width-request">360</property>
      <property name="height-request">200</property>
      <child>
        <object class="AdwBreakpoint">
          <condition>max-width: 860sp</condition>
          <setter object="outer_view" property="collapsed">True</setter>
          <setter object="inner_view" property="sidebar-width-fraction">0.33</setter>
        </object>
      </child>
      <child>
        <object class="AdwBreakpoint">
          <condition>max-width: 500sp</condition>
          <setter object="outer_view" property="collapsed">True</setter>
          <setter object="inner_view" property="sidebar-width-fraction">0.33</setter>
          <setter object="inner_view" property="collapsed">True</setter>
        </object>
      </child>
      <property name="content">
        <object class="AdwNavigationSplitView" id="outer_view">
          <property name="min-sidebar-width">470</property>
          <property name="max-sidebar-width">780</property>
          <property name="sidebar-width-fraction">0.47</property>
          <property name="sidebar">
            <object class="AdwNavigationPage">
              <property name="child">
                <object class="AdwNavigationSplitView" id="inner_view">
                  <property name="max-sidebar-width">260</property>
                  <property name="sidebar-width-fraction">0.38</property>
                  <property name="sidebar">
                    <!-- sidebar -->
                  </property>
                  <property name="content">
                    <!-- middle pane -->
                  </property>
                </object>
              </property>
            </object>
          </property>
          <property name="content">
            <!-- content -->
          </property>
        </object>
      </property>
    </object>

When only the outer split view is collapsed, either the content is visible or the sidebar and middle pane are visible. When both split views are collapsed, only one pane is visible at a time.

An example of a triple-pane layout with the an `AdwNavigationSplitView` nested within an `AdwOverlaySplitView`‘s content:

    <object class="AdwWindow">
      <property name="width-request">360</property>
      <property name="height-request">200</property>
      <child>
        <object class="AdwBreakpoint">
          <condition>max-width: 860sp</condition>
          <setter object="outer_view" property="collapsed">True</setter>
        </object>
      </child>
      <child>
        <object class="AdwBreakpoint">
          <condition>max-width: 500sp</condition>
          <setter object="outer_view" property="collapsed">True</setter>
          <setter object="inner_view" property="collapsed">True</setter>
        </object>
      </child>
      <property name="content">
        <object class="AdwOverlaySplitView" id="outer_view">
          <property name="max-sidebar-width">260</property>
          <property name="sidebar-width-fraction">0.179</property>
          <property name="sidebar">
            <!-- sidebar -->
          </property>
          <property name="content">
            <object class="AdwNavigationSplitView" id="inner_view">
              <property name="min-sidebar-width">290</property>
              <property name="max-sidebar-width">520</property>
              <property name="sidebar-width-fraction">0.355</property>
              <property name="sidebar">
                <!-- middle pane -->
              </property>
              <property name="content">
                <!-- content -->
              </property>
            </object>
          </property>
        </object>
      </property>
    </object>

When only the outer split view is collapsed the middle pane and content are visible, and the sidebar can be overlaid above them.

# Tabs

`AdwTabView` is a dynamic tab container. It doesn’t have a visible tab switcher on its own, leaving that to `AdwTabBar`, `AdwTabButton` and `AdwTabOverview`. When used together with breakpoints, these widgets can provide an adaptive tabbed interface.

    <object class="AdwWindow">
      <property name="width-request">360</property>
      <property name="height-request">200</property>
      <child>
        <object class="AdwBreakpoint">
          <condition>max-width: 500px</condition>
          <setter object="overview_btn" property="visible">True</setter>
          <setter object="new_tab_btn" property="visible">False</setter>
          <setter object="tab_bar" property="visible">False</setter>
        </object>
      </child>
      <property name="content">
        <object class="AdwTabOverview">
          <property name="view">view</property>
          <property name="enable-new-tab">True</property>
          <property name="child">
            <object class="AdwToolbarView">
              <property name="top-bar-style">raised</property>
              <child type="top">
                <object class="AdwHeaderBar">
                  <child type="end">
                    <object class="AdwTabButton" id="overview_btn">
                      <property name="visible">False</property>
                      <property name="view">view</property>
                      <property name="action-name">overview.open</property>
                    </object>
                  </child>
                  <child type="end">
                    <object class="GtkButton" id="new_tab_btn">
                      <property name="icon-name">tab-new-symbolic</property>
                    </object>
                  </child>
                </object>
              </child>
              <child type="top">
                <object class="AdwTabBar" id="tab_bar">
                  <property name="view">view</property>
                </object>
              </child>
              <property name="content">
                <object class="AdwTabView" id="view"/>
              </property>
            </object>
          </property>
        </object>
      </property>
    </object>