ViewGroupKt

public static final boolean contains(@NonNull ViewGroup receiver, @NonNull View view)

Returns true if view is found in this view group.

public static final void forEach(
    @NonNull ViewGroup receiver,
    @NonNull Function1<@NonNull View, Unit> action
)

Performs the given action on each view in this view group.

public static final void forEachIndexed(
    @NonNull ViewGroup receiver,
    @NonNull Function2<@NonNull Integer, @NonNull View, Unit> action
)

Performs the given action on each view in this view group, providing its sequential index.

public static final @NonNull View get(@NonNull ViewGroup receiver, int index)

Returns the view at index.

public static final @NonNull Sequence<@NonNull View> getChildren(@NonNull ViewGroup receiver)

Returns a Sequence over the immediate child views in this view group.

public static final @NonNull Sequence<@NonNull View> getDescendants(@NonNull ViewGroup receiver)

Returns a Sequence over the child views in this view group recursively.

This performs a depth-first traversal. A view with no children will return a zero-element sequence.

For example, to efficiently filter views within the hierarchy using a predicate:

fun ViewGroup.findViewTreeIterator(predicate: (View) -> Boolean): Sequence<View> {
    return sequenceOf(this)
        .plus(descendantsTree)
        .filter { predicate(it) }
}

public static final @NonNull IntRange getIndices(@NonNull ViewGroup receiver)

Returns an IntRange of the valid indices for the children of this view group.

This can be used for looping:

for (i in viewGroup.indices.reversed) {
  if (viewGroup[i] is SomeView) {
    viewGroup.removeViewAt(i)
  }
}

Or to determine if an index is valid:

if (2 in viewGroup.indices) {
  // Do something…
}

public static final int getSize(@NonNull ViewGroup receiver)

Returns the number of views in this view group.

public static final boolean isEmpty(@NonNull ViewGroup receiver)

Returns true if this view group contains no views.

public static final boolean isNotEmpty(@NonNull ViewGroup receiver)

Returns true if this view group contains one or more views.

public static final @NonNull Iterator<@NonNull View> iterator(@NonNull ViewGroup receiver)

Returns a MutableIterator over the views in this view group.

public static final void minusAssign(@NonNull ViewGroup receiver, @NonNull View view)

Removes view from this view group.

public static final void plusAssign(@NonNull ViewGroup receiver, @NonNull View view)

Adds view to this view group.

public static final void setMargins(@NonNull ViewGroup.MarginLayoutParams receiver, @Px int size)

Sets the margins in the ViewGroup's MarginLayoutParams. This version of the method sets all axes to the provided size.

public static final void updateMargins(
    @NonNull ViewGroup.MarginLayoutParams receiver,
    @Px int left,
    @Px int top,
    @Px int right,
    @Px int bottom
)

Updates the margins in the ViewGroup's ViewGroup.MarginLayoutParams. This version of the method allows using named parameters to just set one or more axes.

public static final void updateMarginsRelative(
    @NonNull ViewGroup.MarginLayoutParams receiver,
    @Px int start,
    @Px int top,
    @Px int end,
    @Px int bottom
)

Updates the relative margins in the ViewGroup's MarginLayoutParams. This version of the method allows using named parameters to just set one or more axes.

Note that this inline method references platform APIs added in API 17 and may raise runtime verification warnings on earlier platforms. See Chromium's guide to Class Verification Failures for more information.