Slice templates

This document provides details on how to use the template builders in Android Jetpack to construct Slices.

Define your Slice template

Slices are constructed by using a ListBuilder. ListBuilder allows you to add different types of rows that are displayed in a list. This section describes each of those row types and how they are constructed.

SliceAction

The most basic element of a Slice template is a SliceAction. A SliceAction contains a label along with a PendingIntent and is one of the following:

Icon button
Default toggle
Custom toggle (a drawable with an on/off state)

SliceAction is used by the template builders described in the rest of this section. A SliceAction can have an image mode defined that determines how the image is presented for the action:

ICON_IMAGE: tiny size and tintable
SMALL_IMAGE: small size and non-tintable
LARGE_IMAGE: largest size and non-tintable

HeaderBuilder

In most cases, you should set a header for your template using a HeaderBuilder. A header can support the following:

Title
Subtitle
Summary subtitle
Primary action

Some example header configurations are shown below. Note that gray boxes show potential icon and padding locations:

Header rendering on different surfaces

When a Slice is needed, the displaying surface determines how to render the Slice. Note that rendering might differ somewhat between hosting surfaces.

In smaller formats, usually only the header is displayed, if one exists. If you’ve specified a summary for the header, the summary text is shown instead of the subtitle text.

If you have not specified a header in your template, the first row added to your ListBuilder is usually displayed instead.

HeaderBuilder example - Simple list Slice with header

Kotlin

fun createSliceWithHeader(sliceUri: Uri) =
    list(context, sliceUri, ListBuilder.INFINITY) {
        setAccentColor(0xff0F9D) // Specify color for tinting icons
        header {
            title = "Get a ride"
            subtitle = "Ride in 4 min"
            summary = "Work in 1 hour 45 min | Home in 12 min"
        }
        row {
            title = "Home"
            subtitle = "12 miles | 12 min | $9.00"
            addEndItem(
                IconCompat.createWithResource(context, R.drawable.ic_home),
                ListBuilder.ICON_IMAGE
            )
        }
    }

Java

public Slice createSliceWithHeader(Uri sliceUri) {
    if (getContext() == null) {
        return null;
    }

    // Construct the parent.
    ListBuilder listBuilder = new ListBuilder(getContext(), sliceUri, ListBuilder.INFINITY)
            .setAccentColor(0xff0F9D58) // Specify color for tinting icons.
            .setHeader( // Create the header and add to slice.
                    new HeaderBuilder()
                            .setTitle("Get a ride")
                            .setSubtitle("Ride in 4 min.")
                            .setSummary("Work in 1 hour 45 min | Home in 12 min.")
            ).addRow(new RowBuilder() // Add a row.
                    .setPrimaryAction(
                            createActivityAction()) // A slice always needs a SliceAction.
                    .setTitle("Home")
                    .setSubtitle("12 miles | 12 min | $9.00")
                    .addEndItem(IconCompat.createWithResource(getContext(), R.drawable.ic_home),
                            SliceHints.ICON_IMAGE)
            ); // Add more rows if needed...
    return listBuilder.build();
}

SliceActions in headers

Slice headers can also display SliceActions:

Kotlin

fun createSliceWithActionInHeader(sliceUri: Uri): Slice {
    // Construct our slice actions.
    val noteAction = SliceAction.create(
        takeNoteIntent,
        IconCompat.createWithResource(context, R.drawable.ic_pencil),
        ICON_IMAGE,
        "Take note"
    )

    val voiceNoteAction = SliceAction.create(
        voiceNoteIntent,
        IconCompat.createWithResource(context, R.drawable.ic_mic),
        ICON_IMAGE,
        "Take voice note"
    )

    val cameraNoteAction = SliceAction.create(
        cameraNoteIntent,
        IconCompat.createWithResource(context, R.drawable.ic_camera),
        ICON_IMAGE,
        "Create photo note"
    )

    // Construct the list.
    return list(context, sliceUri, ListBuilder.INFINITY) {
        setAccentColor(0xfff4b4) // Specify color for tinting icons
        header {
            title = "Create new note"
            subtitle = "Easily done with this note taking app"
        }
        addAction(noteAction)
        addAction(voiceNoteAction)
        addAction(cameraNoteAction)
    }
}

Java

public Slice createSliceWithActionInHeader(Uri sliceUri) {
    if (getContext() == null) {
        return null;
    }
    // Construct our slice actions.
    SliceAction noteAction = SliceAction.create(takeNoteIntent,
            IconCompat.createWithResource(getContext(), R.drawable.ic_pencil),
            ListBuilder.ICON_IMAGE, "Take note");

    SliceAction voiceNoteAction = SliceAction.create(voiceNoteIntent,
            IconCompat.createWithResource(getContext(), R.drawable.ic_mic),
            ListBuilder.ICON_IMAGE,
            "Take voice note");

    SliceAction cameraNoteAction = SliceAction.create(cameraNoteIntent,
            IconCompat.createWithResource(getContext(), R.drawable.ic_camera),
            ListBuilder.ICON_IMAGE,
            "Create photo note");


    // Construct the list.
    ListBuilder listBuilder = new ListBuilder(getContext(), sliceUri, ListBuilder.INFINITY)
            .setAccentColor(0xfff4b400) // Specify color for tinting icons
            .setHeader(new HeaderBuilder() // Construct the header.
                    .setTitle("Create new note")
                    .setSubtitle("Easily done with this note taking app")
            )
            .addRow(new RowBuilder()
                    .setTitle("Enter app")
                    .setPrimaryAction(createActivityAction())
            )
            // Add the actions to the ListBuilder.
            .addAction(noteAction)
            .addAction(voiceNoteAction)
            .addAction(cameraNoteAction);
    return listBuilder.build();
}

RowBuilder

You can construct a row of content by using a RowBuilder. A row can support any of the following:

Title
Subtitle
Start item: SliceAction, Icon, or a timestamp
End items: SliceAction, Icon, or a timestamp
Primary action

You can combine row content in a number of ways, subject to the following restrictions:

Start items will not show in the first row of a Slice
End items cannot be a mix of SliceAction objects and Icon objects
A row can contain only one timestamp

Example rows of content are shown in the following images. Note that gray boxes show potential icon and padding locations:

RowBuilder example - Wi-Fi toggle

The example below demonstrates a row with a primary action and a default toggle.

Kotlin

fun createActionWithActionInRow(sliceUri: Uri): Slice {
    // Primary action - open wifi settings.
    val wifiAction = SliceAction.create(
        wifiSettingsPendingIntent,
        IconCompat.createWithResource(context, R.drawable.ic_wifi),
        ICON_IMAGE,
        "Wi-Fi Settings"
    )

    // Toggle action - toggle wifi.
    val toggleAction = SliceAction.createToggle(
        wifiTogglePendingIntent,
        "Toggle Wi-Fi",
        isConnected /* isChecked */
    )

    // Create the parent builder.
    return list(context, wifiUri, ListBuilder.INFINITY) {
        setAccentColor(0xff4285) // Specify color for tinting icons / controls.
        row {
            title = "Wi-Fi"
            primaryAction = wifiAction
            addEndItem(toggleAction)
        }
    }
}

Java

public Slice createActionWithActionInRow(Uri sliceUri) {
    if (getContext() == null) {
        return null;
    }
    // Primary action - open wifi settings.
    SliceAction primaryAction = SliceAction.create(wifiSettingsPendingIntent,
            IconCompat.createWithResource(getContext(), R.drawable.ic_wifi),
            ListBuilder.ICON_IMAGE,
            "Wi-Fi Settings"
    );

    // Toggle action - toggle wifi.
    SliceAction toggleAction = SliceAction.createToggle(wifiTogglePendingIntent,
            "Toggle Wi-Fi", isConnected /* isChecked */);

    // Create the parent builder.
    ListBuilder listBuilder = new ListBuilder(getContext(), wifiUri, ListBuilder.INFINITY)
            // Specify color for tinting icons / controls.
            .setAccentColor(0xff4285f4)
            // Create and add a row.
            .addRow(new RowBuilder()
                    .setTitle("Wi-Fi")
                    .setPrimaryAction(primaryAction)
                    .addEndItem(toggleAction));
    // Build the slice.
    return listBuilder.build();
}

GridBuilder

You can construct a grid of content by using a GridBuilder. A grid can support the following image types:

ICON_IMAGE: tiny size and tintable
SMALL_IMAGE: small size and non-tintable
LARGE_IMAGE: largest size and non-tintable

A grid cell is constructed by using a CellBuilder. A cell can support up to two lines of text and one image. A cell cannot be empty.

Grid examples are shown in the following images:

GridRowBuilder example - Nearby restaurants

The example below demonstrates a grid row that contains images and text.

Kotlin

fun createSliceWithGridRow(sliceUri: Uri): Slice {
    // Create the parent builder.
    return list(context, sliceUri, ListBuilder.INFINITY) {
        header {
            title = "Famous restaurants"
            primaryAction = SliceAction.create(
                pendingIntent, icon, ListBuilder.ICON_IMAGE, "Famous restaurants"
            )
        }
        gridRow {
            cell {
                addImage(image1, LARGE_IMAGE)
                addTitleText("Top Restaurant")
                addText("0.3 mil")
                contentIntent = intent1
            }
            cell {
                addImage(image2, LARGE_IMAGE)
                addTitleText("Fast and Casual")
                addText("0.5 mil")
                contentIntent = intent2
            }
            cell {
                addImage(image3, LARGE_IMAGE)
                addTitleText("Casual Diner")
                addText("0.9 mi")
                contentIntent = intent3
            }
            cell {
                addImage(image4, LARGE_IMAGE)
                addTitleText("Ramen Spot")
                addText("1.2 mi")
                contentIntent = intent4
            }
        }
    }
}

Java

public Slice createSliceWithGridRow(Uri sliceUri) {
    if (getContext() == null) {
        return null;
    }
    // Create the parent builder.
    ListBuilder listBuilder = new ListBuilder(getContext(), sliceUri, ListBuilder.INFINITY)
            .setHeader(
                    // Create the header.
                    new HeaderBuilder()
                            .setTitle("Famous restaurants")
                            .setPrimaryAction(SliceAction
                                    .create(pendingIntent, icon, ListBuilder.ICON_IMAGE,
                                            "Famous restaurants"))
            )
            // Add a grid row to the list.
            .addGridRow(new GridRowBuilder()
                    // Add cells to the grid row.
                    .addCell(new CellBuilder()
                            .addImage(image1, ListBuilder.LARGE_IMAGE)
                            .addTitleText("Top Restaurant")
                            .addText("0.3 mil")
                            .setContentIntent(intent1)
                    ).addCell(new CellBuilder()
                            .addImage(image2, ListBuilder.LARGE_IMAGE)
                            .addTitleText("Fast and Casual")
                            .addText("0.5 mil")
                            .setContentIntent(intent2)
                    )
                    .addCell(new CellBuilder()
                            .addImage(image3, ListBuilder.LARGE_IMAGE)
                            .addTitleText("Casual Diner")
                            .addText("0.9 mi")
                            .setContentIntent(intent3))
                    .addCell(new CellBuilder()
                            .addImage(image4, ListBuilder.LARGE_IMAGE)
                            .addTitleText("Ramen Spot")
                            .addText("1.2 mi")
                            .setContentIntent(intent4))
                    // Every slice needs a primary action.
                    .setPrimaryAction(createActivityAction())
            );
    return listBuilder.build();
}

RangeBuilder

With a RangeBuilder, you can create a row that contains either a progress bar or an input range, such as a slider.

Progress and slider examples are shown in the following images:

RangeBuilder example - Slider

The example below demonstrates how to build a Slice that contains a volume slider by using an InputRangeBuilder. To construct a progress row, use addRange().

Kotlin

fun createSliceWithRange(sliceUri: Uri): Slice {
    return list(context, sliceUri, ListBuilder.INFINITY) {
        inputRange {
            title = "Ring Volume"
            inputAction = volumeChangedPendingIntent
            max = 100
            value = 30
        }
    }
}

Java

public Slice createSliceWithRange(Uri sliceUri) {
    if (getContext() == null) {
        return null;
    }
    // Construct the parent.
    ListBuilder listBuilder = new ListBuilder(getContext(), sliceUri, ListBuilder.INFINITY)
            .addRow(new RowBuilder() // Every slice needs a row.
                    .setTitle("Enter app")
                     // Every slice needs a primary action.
                    .setPrimaryAction(createActivityAction())
            )
            .addInputRange(new InputRangeBuilder() // Create the input row.
                    .setTitle("Ring Volume")
                    .setInputAction(volumeChangedPendingIntent)
                    .setMax(100)
                    .setValue(30)
            );
    return listBuilder.build();
}

Delayed content

You should return a Slice as quickly as possible from SliceProvider#onBindSlice. Time-consuming calls can lead to display issues, such as flickering and abrupt resizing.

If you have Slice content that cannot be loaded quickly, you can construct your Slice with null or placeholder content while noting in the builder that the content is loading. Once the content is ready to be displayed, call getContentResolver().notifyChange(sliceUri, null) using your Slice URI. This results in another call to SliceProvider#onBindSlice, where you can construct the Slice again with fresh content.

Delayed content example - Ride to work

In the Ride to work row below, the distance to work is determined dynamically and might not be available immediately. The example code demonstrates using a null subtitle as a placeholder while the content loads:

Kotlin

fun createSliceShowingLoading(sliceUri: Uri): Slice {
    // We’re waiting to load the time to work so indicate that on the slice by
    // setting the subtitle with the overloaded method and indicate true.
    return list(context, sliceUri, ListBuilder.INFINITY) {
        row {
            title = "Ride to work"
            setSubtitle(null, true)
            addEndItem(IconCompat.createWithResource(context, R.drawable.ic_work), ICON_IMAGE)
        }
    }
}

Java

public Slice createSliceShowingLoading(Uri sliceUri) {
    if (getContext() == null) {
        return null;
    }
    // Construct the parent.
    ListBuilder listBuilder = new ListBuilder(getContext(), sliceUri, ListBuilder.INFINITY)
            // Construct the row.
            .addRow(new RowBuilder()
                    .setPrimaryAction(createActivityAction())
                    .setTitle("Ride to work")
                    // We’re waiting to load the time to work so indicate that on the slice by
                    // setting the subtitle with the overloaded method and indicate true.
                    .setSubtitle(null, true)
                    .addEndItem(IconCompat.createWithResource(getContext(), R.drawable.ic_work),
                            ListBuilder.ICON_IMAGE)
            );
    return listBuilder.build();
}

private SliceAction createActivityAction() {
    return SliceAction.create(
            PendingIntent.getActivity(
                    getContext(),
                    0,
                    new Intent(getContext(), MainActivity.class),
                    0
            ),
            IconCompat.createWithResource(getContext(), R.drawable.ic_home),
            ListBuilder.ICON_IMAGE,
            "Enter app"
    );
}

Handle disabled scrolling within your Slice

The surface presenting your Slice template may not support scrolling within the template. In this case, some of your content might not be displayed.

As an example, consider a Slice showing a list of WiFi networks:

If the WiFi list is long, and if scrolling is disabled, you can add a See more button to ensure that users have a way to see all items in the list. You can add this button by using addSeeMoreAction(), as shown in the following example:

Kotlin

fun seeMoreActionSlice(sliceUri: Uri) =
    list(context, sliceUri, ListBuilder.INFINITY) {
        // ...
        setSeeMoreAction(seeAllNetworksPendingIntent)
        // ...
    }

Java

public Slice seeMoreActionSlice(Uri sliceUri) {
    if (getContext() == null) {
        return null;
    }
    ListBuilder listBuilder = new ListBuilder(getContext(), sliceUri, ListBuilder.INFINITY);
    // ...
    listBuilder.setSeeMoreAction(seeAllNetworksPendingIntent);
    // ...
    return listBuilder.build();
}

This displays as shown in the following image:

Tapping on See more sends seeAllNetworksPendingIntent.

Alternatively, if you’d like to provide a custom message or row, consider adding a RowBuilder:

Kotlin

fun seeMoreRowSlice(sliceUri: Uri) =
    list(context, sliceUri, ListBuilder.INFINITY) {
        // ...
        seeMoreRow {
            title = "See all available networks"
            addEndItem(
                IconCompat.createWithResource(context, R.drawable.ic_right_caret), ICON_IMAGE
            )
            primaryAction = SliceAction.create(
                seeAllNetworksPendingIntent,
                IconCompat.createWithResource(context, R.drawable.ic_wifi),
                ListBuilder.ICON_IMAGE,
                "Wi-Fi Networks"
            )
        }
    }

Java

public Slice seeMoreRowSlice(Uri sliceUri) {
    if (getContext() == null) {
        return null;
    }
    ListBuilder listBuilder = new ListBuilder(getContext(), sliceUri, ListBuilder.INFINITY)
            // ...
            .setSeeMoreRow(new RowBuilder()
                    .setTitle("See all available networks")
                    .addEndItem(IconCompat
                                    .createWithResource(getContext(), R.drawable
                                            .ic_right_caret),
                            ListBuilder.ICON_IMAGE)
                    .setPrimaryAction(SliceAction.create(seeAllNetworksPendingIntent,
                            IconCompat.createWithResource(getContext(), R.drawable.ic_wifi),
                            ListBuilder.ICON_IMAGE,
                            "Wi-Fi Networks"))
            );
    // ...
    return listBuilder.build();
}

The row or action added via this method is displayed only when one of the following conditions is met:

The presenter of your Slice has disabled scrolling on the view
Not all of your rows can be displayed in the space available

Combine templates

You can create a rich, dynamic Slice by combining multiple row types. For example, a Slice can contain a header row, a grid with a single image, and a grid with two cells of text.

Here's a Slice with a header row along with a grid that contains three cells.