PaneTemplate.java
/*
* Copyright 2020 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;
import static androidx.car.app.model.constraints.ActionsConstraints.ACTIONS_CONSTRAINTS_BODY;
import static androidx.car.app.model.constraints.ActionsConstraints.ACTIONS_CONSTRAINTS_HEADER;
import static androidx.car.app.model.constraints.ActionsConstraints.ACTIONS_CONSTRAINTS_SIMPLE;
import static androidx.car.app.model.constraints.RowListConstraints.ROW_LIST_CONSTRAINTS_PANE;
import static java.util.Objects.requireNonNull;
import androidx.annotation.Keep;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.car.app.annotations.CarProtocol;
import androidx.car.app.model.constraints.CarTextConstraints;
import java.util.Collections;
import java.util.Objects;
/**
* A template that displays a {@link Pane}.
*
* <h4>Template Restrictions</h4>
*
* In regards to template refreshes, as described in
* {@link androidx.car.app.Screen#onGetTemplate()}, this template is considered a refresh of a
* previous one if:
*
* <ul>
* <li>The previous template is in a loading state (see {@link Pane.Builder#setLoading}, or
* <li>The template title has not changed, and the number of rows and the title (not counting
* spans) of each row between the previous and new {@link Pane}s have not changed.
* </ul>
*/
@CarProtocol
public final class PaneTemplate implements Template {
@Keep
@Nullable
private final CarText mTitle;
@Keep
@Nullable
private final Pane mPane;
@Keep
@Nullable
private final Action mHeaderAction;
@Keep
@Nullable
private final ActionStrip mActionStrip;
/**
* Returns the title of the template or {@code null} if not set.
*
* @see Builder#setTitle(CharSequence)
*/
@Nullable
public CarText getTitle() {
return mTitle;
}
/**
* Returns the {@link Action} that is set to be displayed in the header of the template, or
* {@code null} if not set.
*
* @see Builder#setHeaderAction(Action)
*/
@Nullable
public Action getHeaderAction() {
return mHeaderAction;
}
/**
* Returns the {@link ActionStrip} for this template or {@code null} if not set.
*
* @see Builder#setActionStrip(ActionStrip)
*/
@Nullable
public ActionStrip getActionStrip() {
return mActionStrip;
}
/**
* Returns the {@link Pane} to display in the template.
*
* @see Builder#Builder(Pane)
*/
@NonNull
public Pane getPane() {
return requireNonNull(mPane);
}
@NonNull
@Override
public String toString() {
return "PaneTemplate";
}
@Override
public int hashCode() {
return Objects.hash(mTitle, mPane, mHeaderAction, mActionStrip);
}
@Override
public boolean equals(@Nullable Object other) {
if (this == other) {
return true;
}
if (!(other instanceof PaneTemplate)) {
return false;
}
PaneTemplate otherTemplate = (PaneTemplate) other;
return Objects.equals(mTitle, otherTemplate.mTitle)
&& Objects.equals(mPane, otherTemplate.mPane)
&& Objects.equals(mHeaderAction, otherTemplate.mHeaderAction)
&& Objects.equals(mActionStrip, otherTemplate.mActionStrip);
}
PaneTemplate(Builder builder) {
mTitle = builder.mTitle;
mPane = builder.mPane;
mHeaderAction = builder.mHeaderAction;
mActionStrip = builder.mActionStrip;
}
/** Constructs an empty instance, used by serialization code. */
private PaneTemplate() {
mTitle = null;
mPane = null;
mHeaderAction = null;
mActionStrip = null;
}
/** A builder of {@link PaneTemplate}. */
public static final class Builder {
@Nullable
CarText mTitle;
Pane mPane;
@Nullable
Action mHeaderAction;
@Nullable
ActionStrip mActionStrip;
/**
* Sets the title of the template.
*
* <p>Unless set with this method, the template will not have a title.
*
* <p>Only {@link DistanceSpan}s and {@link DurationSpan}s are supported in the input
* string.
*
* @throws NullPointerException if {@code title} is {@code null}
* @throws IllegalArgumentException if {@code title} contains unsupported spans
* @see CarText
*/
@NonNull
public Builder setTitle(@NonNull CharSequence title) {
mTitle = CarText.create(requireNonNull(title));
CarTextConstraints.TEXT_ONLY.validateOrThrow(mTitle);
return this;
}
/**
* Sets the {@link Action} that will be displayed in the header of the template.
*
* <p>Unless set with this method, the template will not have a header action.
*
* <h4>Requirements</h4>
*
* This template only supports either one of {@link Action#APP_ICON} and
* {@link Action#BACK} as a header {@link Action}.
*
* @throws IllegalArgumentException if {@code headerAction} does not meet the template's
* requirements
* @throws NullPointerException if {@code headerAction} is {@code null}
*/
@NonNull
public Builder setHeaderAction(@NonNull Action headerAction) {
ACTIONS_CONSTRAINTS_HEADER.validateOrThrow(
Collections.singletonList(requireNonNull(headerAction)));
mHeaderAction = headerAction;
return this;
}
/**
* Sets the {@link ActionStrip} for this template.
*
* <p>Unless set with this method, the template will not have an action strip.
*
* <h4>Requirements</h4>
*
* This template allows up to 2 {@link Action}s in its {@link ActionStrip}. Of the 2 allowed
* {@link Action}s, one of them can contain a title as set via
* {@link Action.Builder#setTitle}. Otherwise, only {@link Action}s with icons are allowed.
*
* @throws IllegalArgumentException if {@code actionStrip} does not meet the requirements
* @throws NullPointerException if {@code actionStrip} is {@code null}
*/
@NonNull
public Builder setActionStrip(@NonNull ActionStrip actionStrip) {
ACTIONS_CONSTRAINTS_SIMPLE.validateOrThrow(requireNonNull(actionStrip).getActions());
mActionStrip = actionStrip;
return this;
}
/**
* Constructs the template defined by this builder.
*
* <h4>Requirements</h4>
*
* The number of items in the {@link ItemList} should be smaller or equal than the limit
* provided by
* {@link androidx.car.app.constraints.ConstraintManager#CONTENT_LIMIT_TYPE_PANE}. The host
* will ignore any rows over that limit. Each {@link Row}s can add up to 2 lines of texts
* via {@link Row.Builder#addText} and cannot contain either a {@link Toggle} or a {@link
* OnClickListener}.
*
* <p>Up to 2 {@link Action}s are allowed in the {@link Pane}. Each action's title color
* can be customized with {@link ForegroundCarColorSpan} instances. Any other span is not
* supported.
*
* <p>Either a header {@link Action} or title must be set on the template.
*
* @throws IllegalArgumentException if the {@link Pane} does not meet the requirements
* @throws IllegalStateException if the template does not have either a title or header
* {@link Action} set
* @see androidx.car.app.constraints.ConstraintManager#getContentLimit(int)
*/
@NonNull
public PaneTemplate build() {
ROW_LIST_CONSTRAINTS_PANE.validateOrThrow(mPane);
ACTIONS_CONSTRAINTS_BODY.validateOrThrow(mPane.getActions());
if (CarText.isNullOrEmpty(mTitle) && mHeaderAction == null) {
throw new IllegalStateException("Either the title or header action must be set");
}
return new PaneTemplate(this);
}
/**
* Returns a new instance of a @link Builder}.
*
* @throws NullPointerException if {@code pane} is {@code null}
*/
public Builder(@NonNull Pane pane) {
mPane = pane;
}
}
}