[NavigationBar] Add new itemIconGravity attribute

PiperOrigin-RevId: 638866190

docs/components/BottomNavigation.md

@@ -285,6 +285,7 @@ The following is an anatomy diagram for the bottom navigation bar:
 **Size** | `app:itemIconSize` | `setItemIconSize`<br/>`setItemIconSizeRes`<br/>`getItemIconSize` | `24dp`
 **Color (inactive)** | `app:itemIconTint` | `setItemIconTintList`<br/>`getItemIconTintList` | `?attr/colorOnSurfaceVariant` (see all [states](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/bottomnavigation/res/color/m3_navigation_bar_item_with_indicator_icon_tint.xml))
 **Color (active)** | " | " | `?attr/colorOnSecondaryContainer` (see all [states](https://github.com/material-components/material-components-android/tree/master/lib/java/com/google/android/material/bottomnavigation/res/color/m3_navigation_bar_item_with_indicator_icon_tint.xml))
+**Gravity** | `app:itemIconGravity` | `setItemIconGravity`<br/>`getItemIconGravity` | `TOP`
 
 #### Text label attributes
 

docs/components/NavigationRail.md

@@ -342,6 +342,7 @@ for more attributes.
 **Size** | `app:itemIconSize` | `setItemIconSize`<br/>`setItemIconSizeRes`<br/>`getItemIconSize` | `24dp`
 **Color (inactive)** | `app:itemIconTint` | `setItemIconTintList`<br/>`getItemIconTintList` | `?attr/colorOnSurfaceVariant`
 **Color (active)** | `app:itemIconTint` | `setItemIconTintList`<br/>`getItemIconTintList` | `?attr/colorOnSecondaryContainer`
+**Gravity** | `app:itemIconGravity` | `setItemIconGravity`<br/>`getItemIconGravity` | `TOP`
 
 #### Text label attributes
 

lib/java/com/google/android/material/bottomnavigation/BottomNavigationMenuView.java

@@ -19,6 +19,8 @@
 import com.google.android.material.R;
 
 import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;
+import static java.lang.Math.max;
+import static java.lang.Math.min;
 
 import android.content.Context;
 import android.content.res.Resources;
@@ -31,6 +33,7 @@
 import androidx.annotation.RestrictTo;
 import com.google.android.material.navigation.NavigationBarItemView;
 import com.google.android.material.navigation.NavigationBarMenuView;
+import com.google.android.material.navigation.NavigationBarView;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -76,76 +79,101 @@ protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  final int totalCount = getChildCount();
  tempChildWidths.clear();
 
+ int totalWidth = 0;
+ int maxHeight = 0;
+
  int parentHeight = MeasureSpec.getSize(heightMeasureSpec);
  final int heightSpec = MeasureSpec.makeMeasureSpec(parentHeight, MeasureSpec.AT_MOST);
 
- if (isShifting(getLabelVisibilityMode(), visibleCount)
- && isItemHorizontalTranslationEnabled()) {
- final View activeChild = getChildAt(getSelectedItemPosition());
- int activeItemWidth = activeItemMinWidth;
- if (activeChild.getVisibility() != View.GONE) {
- // Do an AT_MOST measure pass on the active child to get its desired width, and resize the
- // active child view based on that width
- activeChild.measure(
- MeasureSpec.makeMeasureSpec(activeItemMaxWidth, MeasureSpec.AT_MOST), heightSpec);
- activeItemWidth = Math.max(activeItemWidth, activeChild.getMeasuredWidth());
+ if (getItemIconGravity() == NavigationBarView.ITEM_ICON_GRAVITY_TOP) {
+ if (isShifting(getLabelVisibilityMode(), visibleCount)
+ && isItemHorizontalTranslationEnabled()) {
+ final View activeChild = getChildAt(getSelectedItemPosition());
+ int activeItemWidth = activeItemMinWidth;
+ if (activeChild.getVisibility() != View.GONE) {
+ // Do an AT_MOST measure pass on the active child to get its desired width, and resize the
+ // active child view based on that width
+ activeChild.measure(
+ MeasureSpec.makeMeasureSpec(activeItemMaxWidth, MeasureSpec.AT_MOST), heightSpec);
+ activeItemWidth = max(activeItemWidth, activeChild.getMeasuredWidth());
+ }
+ final int inactiveCount = visibleCount - (activeChild.getVisibility() != View.GONE ? 1 : 0);
+ final int activeMaxAvailable = width - inactiveCount * inactiveItemMinWidth;
+ final int activeWidth = min(activeMaxAvailable, min(activeItemWidth, activeItemMaxWidth));
+ final int inactiveMaxAvailable =
+ (width - activeWidth) / (inactiveCount == 0 ? 1 : inactiveCount);
+ final int inactiveWidth = min(inactiveMaxAvailable, inactiveItemMaxWidth);
+ int extra = width - activeWidth - inactiveWidth * inactiveCount;
+
+ for (int i = 0; i < totalCount; i++) {
+ int tempChildWidth = 0;
+ if (getChildAt(i).getVisibility() != View.GONE) {
+ tempChildWidth = (i == getSelectedItemPosition()) ? activeWidth : inactiveWidth;
+ // Account for integer division which sometimes leaves some extra pixel spaces.
+ // e.g. If the nav was 10px wide, and 3 children were measured to be 3px-3px-3px, there
+ // would be a 1px gap somewhere, which this fills in.
+ if (extra > 0) {
+ tempChildWidth++;
+ extra--;
+ }
+ }
+ tempChildWidths.add(tempChildWidth);
+ }
+ } else {
+ final int maxAvailable = width / (visibleCount == 0 ? 1 : visibleCount);
+ final int childWidth = min(maxAvailable, activeItemMaxWidth);
+ int extra = width - childWidth * visibleCount;
+ for (int i = 0; i < totalCount; i++) {
+ int tempChildWidth = 0;
+ if (getChildAt(i).getVisibility() != View.GONE) {
+ tempChildWidth = childWidth;
+ if (extra > 0) {
+ tempChildWidth++;
+ extra--;
+ }
+ }
+ tempChildWidths.add(tempChildWidth);
+ }
  }
- final int inactiveCount = visibleCount - (activeChild.getVisibility() != View.GONE ? 1 : 0);
- final int activeMaxAvailable = width - inactiveCount * inactiveItemMinWidth;
- final int activeWidth =
- Math.min(activeMaxAvailable, Math.min(activeItemWidth, activeItemMaxWidth));
- final int inactiveMaxAvailable =
- (width - activeWidth) / (inactiveCount == 0 ? 1 : inactiveCount);
- final int inactiveWidth = Math.min(inactiveMaxAvailable, inactiveItemMaxWidth);
- int extra = width - activeWidth - inactiveWidth * inactiveCount;
 
  for (int i = 0; i < totalCount; i++) {
- int tempChildWidth = 0;
- if (getChildAt(i).getVisibility() != View.GONE) {
- tempChildWidth = (i == getSelectedItemPosition()) ? activeWidth : inactiveWidth;
- // Account for integer division which sometimes leaves some extra pixel spaces.
- // e.g. If the nav was 10px wide, and 3 children were measured to be 3px-3px-3px, there
- // would be a 1px gap somewhere, which this fills in.
- if (extra > 0) {
- tempChildWidth++;
- extra--;
- }
+ final View child = getChildAt(i);
+ if (child.getVisibility() == GONE) {
+ continue;
  }
- tempChildWidths.add(tempChildWidth);
+ child.measure(
+ MeasureSpec.makeMeasureSpec(tempChildWidths.get(i), MeasureSpec.EXACTLY), heightSpec);
+ ViewGroup.LayoutParams params = child.getLayoutParams();
+ params.width = child.getMeasuredWidth();
+ totalWidth += child.getMeasuredWidth();
+ maxHeight = max(maxHeight, child.getMeasuredHeight());
  }
- } else {
- final int maxAvailable = width / (visibleCount == 0 ? 1 : visibleCount);
- final int childWidth = Math.min(maxAvailable, activeItemMaxWidth);
- int extra = width - childWidth * visibleCount;
+ } else { // icon gravity is start
+ int childCount = visibleCount == 0 ? 1 : visibleCount;
+ // Calculate the min nav item width based on the item count and bar width according to
+ // these rules:
+ // 3 items: the items should occupy 60% of the bar's width
+ // 4 items: the items should occupy 70% of the bar's width
+ // 5 items: the items should occupy 80% of the bar's width
+ // 6+ items: the items should occupy 90% of the bar's width
+ int minChildWidth = Math.round((min((childCount + 3) / 10f, 0.9f) * width) / childCount);
+ int maxChildWidth = Math.round((float) width / childCount);
  for (int i = 0; i < totalCount; i++) {
- int tempChildWidth = 0;
- if (getChildAt(i).getVisibility() != View.GONE) {
- tempChildWidth = childWidth;
- if (extra > 0) {
- tempChildWidth++;
- extra--;
+ View child = getChildAt(i);
+ if (child.getVisibility() != View.GONE) {
+ child.measure(
+ MeasureSpec.makeMeasureSpec(maxChildWidth, MeasureSpec.AT_MOST), heightSpec);
+ if (child.getMeasuredWidth() < minChildWidth) {
+ child.measure(
+ MeasureSpec.makeMeasureSpec(minChildWidth, MeasureSpec.EXACTLY), heightSpec);
+ }
+ totalWidth += child.getMeasuredWidth();
+ maxHeight = max(maxHeight, child.getMeasuredHeight());
  }
  }
- tempChildWidths.add(tempChildWidth);
- }
- }
-
- int totalWidth = 0;
- int maxHeight = 0;
- for (int i = 0; i < totalCount; i++) {
- final View child = getChildAt(i);
- if (child.getVisibility() == GONE) {
- continue;
- }
- child.measure(
- MeasureSpec.makeMeasureSpec(tempChildWidths.get(i), MeasureSpec.EXACTLY), heightSpec);
- ViewGroup.LayoutParams params = child.getLayoutParams();
- params.width = child.getMeasuredWidth();
- totalWidth += child.getMeasuredWidth();
- maxHeight = Math.max(maxHeight, child.getMeasuredHeight());
  }
 
- setMeasuredDimension(totalWidth, Math.max(maxHeight, getSuggestedMinimumHeight()));
+ setMeasuredDimension(totalWidth, max(maxHeight, getSuggestedMinimumHeight()));
  }
 
  @Override

lib/java/com/google/android/material/bottomnavigation/res/layout/design_bottom_navigation_item.xml

@@ -15,34 +15,45 @@
  ~ limitations under the License.
  -->
 <merge xmlns:android="http://schemas.android.com/apk/res/android">
+
  <LinearLayout
  android:id="@id/navigation_bar_item_content_container"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_gravity="top|center_horizontal"
+ android:layout_marginTop="@dimen/design_bottom_navigation_margin"
  android:clipChildren="false"
  android:duplicateParentState="true"
- android:gravity="center"
- android:layout_marginTop="@dimen/design_bottom_navigation_margin"
  android:orientation="vertical">
  <FrameLayout
  android:id="@id/navigation_bar_item_icon_container"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
+ android:clipChildren="false"
  android:layout_gravity="center"
  android:duplicateParentState="true">
  <View
  android:id="@id/navigation_bar_item_active_indicator_view"
  android:layout_width="0dp"
  android:layout_height="0dp"
  android:layout_gravity="center" />
- <ImageView
- android:id="@id/navigation_bar_item_icon_view"
- android:layout_width="@dimen/design_bottom_navigation_icon_size"
- android:layout_height="@dimen/design_bottom_navigation_icon_size"
+ <LinearLayout
+ android:id="@id/navigation_bar_item_inner_content_container"
+ android:layout_width="wrap_content"
+ android:layout_height="wrap_content"
  android:layout_gravity="center"
- android:contentDescription="@null"
- android:duplicateParentState="true" />
+ android:clipChildren="false"
+ android:duplicateParentState="true"
+ android:gravity="center"
+ android:orientation="horizontal">
+ <ImageView
+ android:id="@id/navigation_bar_item_icon_view"
+ android:layout_width="@dimen/design_bottom_navigation_icon_size"
+ android:layout_height="@dimen/design_bottom_navigation_icon_size"
+ android:layout_gravity="center"
+ android:contentDescription="@null"
+ android:duplicateParentState="true" />
+ </LinearLayout>
  </FrameLayout>
  <com.google.android.material.internal.BaselineLayout
  android:id="@id/navigation_bar_item_labels_group"

lib/java/com/google/android/material/bottomnavigation/res/values/styles.xml

@@ -30,6 +30,7 @@
  <item name="activeIndicatorLabelPadding">1dp</item>
  <item name="itemActiveIndicatorStyle">@null</item>
  <item name="android:minHeight">@dimen/design_bottom_navigation_height</item>
+ <item name="itemIconGravity">top</item>
  </style>
 
  <!-- Default style for BottomNavigationViews.