| /* |
| * Copyright 2022 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.car.app.model.constraints; |
| |
| import androidx.annotation.NonNull; |
| import androidx.annotation.RestrictTo; |
| import androidx.car.app.annotations.ExperimentalCarApi; |
| import androidx.car.app.annotations.RequiresCarApi; |
| import androidx.car.app.model.Tab; |
| |
| import java.util.List; |
| |
| /** |
| * Encapsulates the constraints to apply when creating {@link TabTemplate}. |
| * |
| * @hide |
| */ |
| @ExperimentalCarApi |
| @RequiresCarApi(6) |
| @RestrictTo(RestrictTo.Scope.LIBRARY) |
| public class TabsConstraints { |
| private static final int MAXIMUM_ALLOWED_TABS = 4; |
| private static final int MINIMUM_REQUIRED_TABS = 2; |
| |
| @NonNull |
| public static final TabsConstraints DEFAULT = |
| new TabsConstraints.Builder() |
| .setMaxTabs(MAXIMUM_ALLOWED_TABS) |
| .setMinTabs(MINIMUM_REQUIRED_TABS) |
| .build(); |
| |
| private final int mMaxTabs; |
| private final int mMinTabs; |
| |
| /** |
| * Validates that the {@link Tab}s satisfies this {@link TabConstraints} instance. |
| * |
| * @throws IllegalArgumentException if the constraints are not met |
| */ |
| public void validateOrThrow(@NonNull List<Tab> tabs) { |
| if (tabs.size() < mMinTabs) { |
| throw new IllegalArgumentException( |
| "Number of tabs set do not meet the minimum requirement of " + mMinTabs |
| + " tabs"); |
| } |
| |
| if (tabs.size() > mMaxTabs) { |
| throw new IllegalArgumentException( |
| "Number of tabs set exceed the maximum allowed size of " + mMaxTabs); |
| } |
| |
| int numOfActiveTabs = 0; |
| for (Tab tab : tabs) { |
| if (tab.isActive()) { |
| numOfActiveTabs++; |
| } |
| } |
| if (numOfActiveTabs == 0) { |
| throw new IllegalArgumentException("An active tab is required"); |
| } |
| if (numOfActiveTabs > 1) { |
| throw new IllegalArgumentException("Only one active tab is allowed"); |
| } |
| } |
| |
| TabsConstraints(Builder builder) { |
| mMaxTabs = builder.mMaxTabs; |
| mMinTabs = builder.mMinTabs; |
| } |
| |
| /** |
| * A builder of {@link TabsConstraints}. |
| */ |
| public static final class Builder { |
| int mMaxTabs = Integer.MAX_VALUE; |
| int mMinTabs = 0; |
| |
| /** Sets the maximum number of tabs allowed to be added. */ |
| @NonNull |
| public TabsConstraints.Builder setMaxTabs(int maxTabs) { |
| mMaxTabs = maxTabs; |
| return this; |
| } |
| |
| /** Sets the minimum number of tabs required to be added. */ |
| @NonNull |
| public TabsConstraints.Builder setMinTabs(int minTabs) { |
| mMinTabs = minTabs; |
| return this; |
| } |
| |
| /** |
| * Constructs the {@link TabsConstraints} defined by this builder. |
| */ |
| @NonNull |
| public TabsConstraints build() { |
| return new TabsConstraints(this); |
| } |
| |
| public Builder() { |
| } |
| } |
| } |
