[NavigationRail] Add expanded state

PiperOrigin-RevId: 660106312

Author: imhappi

lib/java/com/google/android/material/appbar/res/values/attrs.xml

@@ -43,7 +43,7 @@
     <attr name="android:background"/>
     <!-- The initial expanded state for the AppBarLayout. This only takes effect when this
          view is a direct child of a CoordinatorLayout. -->
-    <attr name="expanded" format="boolean"/>
+    <attr name="expanded" />
     <attr name="android:keyboardNavigationCluster"/>
     <attr name="android:touchscreenBlocksFocus"/>
     <!-- Whether the {@link AppBarLayout} should lift on scroll. If set to

lib/java/com/google/android/material/navigation/NavigationBarItemView.java

@@ -188,7 +188,8 @@ public NavigationBarItemView(@NonNull Context context) {
           // If item icon gravity is start, we want to update the active indicator width in a layout
           // change listener to keep the active indicator size up to date with the content width.
           if (itemIconGravity == ITEM_ICON_GRAVITY_START
-              && activeIndicatorExpandedDesiredWidth == ACTIVE_INDICATOR_WIDTH_WRAP_CONTENT) {
+              && activeIndicatorExpandedDesiredWidth == ACTIVE_INDICATOR_WIDTH_WRAP_CONTENT
+              && (right - left) != (oldRight - oldLeft)) {
             LayoutParams lp = (LayoutParams) innerContentContainer.getLayoutParams();
             int newWidth = right - left + lp.rightMargin + lp.leftMargin;
             LayoutParams indicatorParams = (LayoutParams) activeIndicatorView.getLayoutParams();

lib/java/com/google/android/material/navigationrail/NavigationRailView.java

@@ -20,6 +20,7 @@
 
 import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT;
 import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;
+import static java.lang.Math.max;
 import static java.lang.Math.min;
 
 import android.content.Context;
@@ -109,11 +110,23 @@ public class NavigationRailView extends NavigationBarView {
 
   private final int contentMarginTop;
   private final int headerMarginBottom;
+  private final int minExpandedWidth;
+  private final int maxExpandedWidth;
   @Nullable private View headerView;
   @Nullable private Boolean paddingTopSystemWindowInsets = null;
   @Nullable private Boolean paddingBottomSystemWindowInsets = null;
   @Nullable private Boolean paddingStartSystemWindowInsets = null;
 
+  private boolean expanded = false;
+  private int collapsedItemSpacing;
+  private int collapsedItemMinHeight = NO_ITEM_MINIMUM_HEIGHT;
+  @ItemIconGravity private int collapsedIconGravity = ITEM_ICON_GRAVITY_TOP;
+  @ItemGravity private int collapsedItemGravity = ITEM_GRAVITY_TOP_CENTER;
+  private int expandedItemMinHeight;
+  @ItemIconGravity private int expandedIconGravity;
+  @ItemGravity private int expandedItemGravity;
+  private int expandedItemSpacing;
+
   public NavigationRailView(@NonNull Context context) {
     this(context, null);
   }
@@ -133,6 +146,24 @@ public NavigationRailView(
 
     // Ensure we are using the correctly themed context rather than the context that was passed in.
     context = getContext();
+    minExpandedWidth =
+        getContext()
+            .getResources()
+            .getDimensionPixelSize(R.dimen.m3_navigation_rail_min_expanded_width);
+    maxExpandedWidth =
+        getContext()
+            .getResources()
+            .getDimensionPixelSize(R.dimen.m3_navigation_rail_max_expanded_width);
+    expandedItemSpacing =
+        getContext()
+            .getResources()
+            .getDimensionPixelSize(R.dimen.m3_navigation_rail_expanded_item_spacing);
+    expandedItemMinHeight =
+        getContext()
+            .getResources()
+            .getDimensionPixelSize(R.dimen.m3_navigation_rail_expanded_item_min_height);
+    expandedItemGravity = ITEM_GRAVITY_START_CENTER;
+    expandedIconGravity = ITEM_ICON_GRAVITY_START;
 
     /* Custom attributes */
     TintTypedArray attributes =
@@ -155,7 +186,7 @@ public NavigationRailView(
         attributes.getInt(R.styleable.NavigationRailView_menuGravity, DEFAULT_MENU_GRAVITY));
 
     if (attributes.hasValue(R.styleable.NavigationRailView_itemMinHeight)) {
-      setItemMinimumHeight(
+      setCollapsedItemMinimumHeight(
           attributes.getDimensionPixelSize(
               R.styleable.NavigationRailView_itemMinHeight, NO_ITEM_MINIMUM_HEIGHT));
     }
@@ -189,14 +220,61 @@ public NavigationRailView(
         AnimationUtils.lerp(getItemPaddingBottom(), largeFontBottomPadding, progress);
     setItemPaddingTop(Math.round(topPadding));
     setItemPaddingBottom(Math.round(bottomPadding));
-    setItemSpacing(
+    setCollapsedItemSpacing(
         attributes.getDimensionPixelSize(R.styleable.NavigationRailView_itemSpacing, 0));
 
+    setExpanded(attributes.getBoolean(R.styleable.NavigationRailView_expanded, false));
+
     attributes.recycle();
 
     applyWindowInsets();
   }
 
+  @Override
+  public void setItemIconGravity(int itemIconGravity) {
+    collapsedIconGravity = itemIconGravity;
+    expandedIconGravity = itemIconGravity;
+    super.setItemIconGravity(itemIconGravity);
+  }
+
+  @Override
+  public int getItemIconGravity() {
+    return getNavigationRailMenuView().getItemIconGravity();
+  }
+
+  @Override
+  public void setItemGravity(int itemGravity) {
+    collapsedItemGravity = itemGravity;
+    expandedItemGravity = itemGravity;
+    super.setItemGravity(itemGravity);
+  }
+
+  @Override
+  public int getItemGravity() {
+    return getNavigationRailMenuView().getItemGravity();
+  }
+
+  private void setExpanded(boolean expanded) {
+    if (this.expanded == expanded) {
+      return;
+    }
+    this.expanded = expanded;
+    int iconGravity = collapsedIconGravity;
+    int itemSpacing = collapsedItemSpacing;
+    int itemMinHeight = collapsedItemMinHeight;
+    int itemGravity = collapsedItemGravity;
+    if (expanded) {
+      iconGravity = expandedIconGravity;
+      itemSpacing = expandedItemSpacing;
+      itemMinHeight = expandedItemMinHeight;
+      itemGravity = expandedItemGravity;
+    }
+    getNavigationRailMenuView().setItemGravity(itemGravity);
+    super.setItemIconGravity(iconGravity);
+    getNavigationRailMenuView().setItemSpacing(itemSpacing);
+    getNavigationRailMenuView().setItemMinimumHeight(itemMinHeight);
+  }
+
   private void applyWindowInsets() {
     ViewUtils.doOnApplyWindowInsets(
         this,
@@ -236,11 +314,28 @@ private boolean shouldApplyWindowInsetPadding(Boolean paddingInsetFlag) {
     return paddingInsetFlag != null ? paddingInsetFlag : getFitsSystemWindows();
   }
 
+  private int getMaxChildWidth() {
+    int childCount = getNavigationRailMenuView().getChildCount();
+    int maxChildWidth = 0;
+    for (int i = 0; i < childCount; i++) {
+      View child = getNavigationRailMenuView().getChildAt(i);
+      if (child.getVisibility() != GONE) {
+        maxChildWidth = max(maxChildWidth, child.getMeasuredWidth());
+      }
+    }
+    return maxChildWidth;
+  }
+
   @Override
   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
     int minWidthSpec = makeMinWidthSpec(widthMeasureSpec);
+    if (expanded) {
+      // Try measuring child with no other restrictions than existing measure spec
+      measureChild(getNavigationRailMenuView(), widthMeasureSpec, heightMeasureSpec);
+      // Measure properly with the max child width
+      minWidthSpec = makeExpandedWidthMeasureSpec(widthMeasureSpec, getMaxChildWidth());
+    }
     super.onMeasure(minWidthSpec, heightMeasureSpec);
-
     if (isHeaderViewVisible()) {
       int maxMenuHeight = getMeasuredHeight() - headerView.getMeasuredHeight() - contentMarginTop
           - headerMarginBottom;
@@ -344,10 +439,9 @@ public int getMenuGravity() {
     return getNavigationRailMenuView().getMenuGravity();
   }
 
-  /** Get the minimum height each item in the navigation rail's menu should be. */
+  /** Get the current minimum height each item in the navigation rail's menu should be. */
   public int getItemMinimumHeight() {
-    NavigationRailMenuView menuView = (NavigationRailMenuView) getMenuView();
-    return menuView.getItemMinimumHeight();
+    return getNavigationRailMenuView().getItemMinimumHeight();
   }
 
   /**
@@ -356,20 +450,38 @@ public int getItemMinimumHeight() {
    * <p>If this is unset (-1), each item will be at least as tall as the navigation rail is wide.
    */
   public void setItemMinimumHeight(@Px int minHeight) {
+    collapsedItemMinHeight = minHeight;
+    expandedItemMinHeight = minHeight;
     NavigationRailMenuView menuView = (NavigationRailMenuView) getMenuView();
     menuView.setItemMinimumHeight(minHeight);
   }
 
+  // TODO: b/356407064 - Make public once expanded state is public
+  private void setCollapsedItemMinimumHeight(@Px int minHeight) {
+    collapsedItemMinHeight = minHeight;
+    if (!expanded) {
+      ((NavigationRailMenuView) getMenuView()).setItemMinimumHeight(minHeight);
+    }
+  }
+
   /**
    * Set the padding in between the navigation rail menu items.
    */
   public void setItemSpacing(@Px int itemSpacing) {
+    this.collapsedItemSpacing = itemSpacing;
+    this.expandedItemSpacing = itemSpacing;
     getNavigationRailMenuView().setItemSpacing(itemSpacing);
   }
 
-  /**
-   * Get the padding in between the navigation rail menu items.
-   */
+  // TODO: b/356407064 - Make public once expanded state is public
+  private void setCollapsedItemSpacing(@Px int itemSpacing) {
+    this.collapsedItemSpacing = itemSpacing;
+    if (!expanded) {
+      getNavigationRailMenuView().setItemSpacing(itemSpacing);
+    }
+  }
+
+  /** Get the current padding in between the navigation rail menu items. */
   public int getItemSpacing() {
     return getNavigationRailMenuView().getItemSpacing();
   }
@@ -399,6 +511,17 @@ private int makeMinWidthSpec(int measureSpec) {
       return MeasureSpec.makeMeasureSpec(
           min(MeasureSpec.getSize(measureSpec), minWidth), MeasureSpec.EXACTLY);
     }
+    return measureSpec;
+  }
+
+  private int makeExpandedWidthMeasureSpec(int measureSpec, int measuredWidth) {
+    int minWidth = min(minExpandedWidth, MeasureSpec.getSize(measureSpec));
+
+    if (MeasureSpec.getMode(measureSpec) != MeasureSpec.EXACTLY) {
+      int newWidth = max(measuredWidth, minWidth);
+      newWidth = max(getSuggestedMinimumWidth(), min(newWidth, maxExpandedWidth));
+      return MeasureSpec.makeMeasureSpec(newWidth, MeasureSpec.EXACTLY);
+    }
 
     return measureSpec;
   }

lib/java/com/google/android/material/navigationrail/res/values/attrs.xml

@@ -57,6 +57,8 @@
     <!-- Shape appearance overlay style reference for NavigationRail. To be used to augment
          attributes declared in the shapeAppearance. Attribute declaration is in the Shape package. -->
     <attr name="shapeAppearanceOverlay"/>
+    <!-- Whether or not to start the NavigationRailView in its expanded state. -->
+    <attr name="expanded" />
   </declare-styleable>
 
 </resources>

lib/java/com/google/android/material/navigationrail/res/values/dimens.xml

@@ -43,4 +43,9 @@
   <dimen name="m3_navigation_rail_expanded_active_indicator_height">56dp</dimen>
   <dimen name="m3_navigation_rail_expanded_leading_trailing_space">20dp</dimen>
 
+  <dimen name="m3_navigation_rail_min_expanded_width">220dp</dimen>
+  <dimen name="m3_navigation_rail_max_expanded_width">360dp</dimen>
+  <dimen name="m3_navigation_rail_expanded_item_spacing">0dp</dimen>
+  <dimen name="m3_navigation_rail_expanded_item_min_height">56dp</dimen>
+
 </resources>

lib/java/com/google/android/material/resources/res/values/attrs.xml

@@ -26,6 +26,7 @@
   <attr name="ensureMinTouchTargetSize" format="boolean" />
   <attr name="trackColor" format="color" />
   <attr name="navigationIconTint" format="color"/>
+  <attr name="expanded" format="boolean" />
 
   <!-- Navigation and Pickers -->
   <attr name="headerLayout" format="reference"/>