Build a UI with Layout Editor

In the Layout Editor, you can quickly build layouts by dragging UI elements into a visual design editor instead of writing the layout XML by hand. The design editor can preview your layout on different Android devices and versions, and you can dynamically resize the layout to be sure it works well on different screen sizes.

The Layout Editor is especially powerful when building a new layout with ConstraintLayout—a layout manager provided in a support library that's compatible with Android 2.3 (API level 9) and higher.

This page provides an overview of the Layout Editor. To learn more about layout fundamentals, see Layouts. To learn more about how to build a layout with ConstraintLayout, see Build a Responsive UI with ConstraintLayout.

Introduction to the Layout Editor

The Layout Editor appears when you open an XML layout file.

Corresponding to the numbers in figure 1, the regions of the editor are as follows:

  1. Palette: List of views and view groups that you can drag into your layout.
  2. Component Tree: View hierarchy for your layout.
  3. Toolbar: Buttons to configure your layout appearance in the editor and to change some layout attributes.
  4. Design editor: Layout in Design or Blueprint view, or both.
  5. Attributes: Controls for the selected view's attributes.

Figure 1. The Layout Editor

When you open an XML layout file, the design editor opens by default (as shown in figure 1).

To edit the layout XML in the text editor, click the Text tab at the bottom of the window. While in the text editor, you can also view the Palette, Component Tree, and design editor by clicking Preview on the right side of the window. The Attributes window is not available from the text editor.

Tip: You can switch between design and text editors by pressing Alt + Shift + Right/Left arrow (Control + Shift + Right/Left arrow on Mac).

Change the preview appearance

The buttons in the top row of the design editor allow you to configure the appearance of your layout in the editor. This toolbar is also available in the text editor's Preview window.

Figure 2. Buttons in the Layout Editor toolbar that configure the layout appearance

Corresponding to the numbers in figure 2, the buttons available are as follows:

  1. Design and blueprint: Select how you'd like to view your layout in the editor; select either the Design view (a real-world preview of your layout), the Blueprint view (only outlines for each view), or Design + Blueprint for both side by side.

    Tip: Press B to cycle through these views.

  2. Screen orientation and layout variants: Select between landscape and portrait screen orientation, or other screen modes for which your app provides alternative layouts, such as night mode. This menu also contains commands for creating a new layout variant.
  3. Device type and size: Select the device type (phone/tablet, Android TV, or Wear OS) and screen configuration (size and density). You can select from several pre-configured device types and your own AVD definitions, or start a new AVD by selecting Add Device Definition from the list.

    Tip: You can resize the device size by dragging the bottom-right corner of the layout.

  4. API version: Select the version of Android on which to preview your layout.
  5. App theme: Select which UI theme to apply to the preview. (This works only for supported layout styles; thus many themes in this list result in an error.)
  6. Language: Select the language to show for your UI strings. This list displays only the languages available in your string resources. If you'd like to edit your translations, click Edit Translations from the drop-down menu (see Localize the UI with Translations Editor).

Note: These configurations have no effect on your app's code or manifest (unless you chose to add a new layout file from Layout Variants); they affect only the layout preview.

Create a new layout

When adding a new layout for your app, begin by creating a layout file in your project's default layout/ directory so that it applies to all device configurations. Once you have a default layout, you can create layout variations for specific device configurations (such as for xlarge screens).

There are a few different ways to create a new layout, depending on your Project window view, but the following procedure is accessible from any view:

  1. In the Project window, click the module (such as app) in which you want to add a layout.
  2. In the main menu, select File > New > XML > Layout XML File.
  3. In the dialog that appears, enter a name for the file, the root layout tag, and the source set in which the layout belongs. Then click Finish.

A couple other ways to start a new layout file (although the dialogs that appear are different) are the following:

  • If you've selected the Project view in the Project window: open the res directory for your app module, right-click the layout directory where you'd like to add the layout and then click New > Layout resource file.
  • If you've selected the Android view in the Project window: right-click the layout folder and then select New > Layout resource file.

Create a layout variant

If you already have a layout and want to create an alternative version to optimize the layout for different screen sizes or orientations, follow these steps:

  1. Open your original layout file and be sure you're viewing the design editor (click the Design tab at the bottom of the window).
  2. Click Orientation for Preview in the toolbar. In the dropdown list, either click a suggested variant such as Create Landscape Variant and you're done, or click Create Other and continue to the next step.
  3. In the dialog that appears, you simply need to define the resource qualifiers for the directory name. You can type it in Directory name or select from the Available qualifiers list, one at a time, and click Add .
  4. Once you've added all your qualifiers, click OK.

When you have multiple variations of the same layout, you can easily switch between them from the list that appears when you click Layout Variants .

For more information about how to create layouts for different screens, see Supporting Different Screen Sizes.

Convert a view or layout

You can convert a view to another kind of view, and you can convert a layout (view group) to another kind of layout.

  1. Click the Design tab at the bottom of the editor window.
  2. In the Component Tree, right-click the view or layout, and then click Convert view.
  3. In the dialog that appears, choose the new type of view or layout, and then click Apply.

Convert a layout to ConstraintLayout

ConstraintLayout is a view group available in the Constraint Layout library, which is included with Android Studio 2.2 and higher. It was built from the ground up along with the Layout Editor, so everything is accessible from the design editor and you never need to edit the XML by hand. Best of all, its constraint-based layout system allows you to build most layouts without any nested view groups.

For improved layout performance, you should convert older layouts to ConstraintLayout.

To convert an existing layout to ConstraintLayout, do the following:

  1. Open your existing layout in Android Studio and click the Design tab at the bottom of the editor window.
  2. In the Component Tree window, right-click the layout and then click Convert layout to ConstraintLayout.

The command to specifically convert a layout to ConstraintLayout is more intelligent about inferring constraints and preserving layout than the simple Convert view command described in the previous section.

To learn more about how to build a layout with ConstraintLayout, see Build a Responsive UI with ConstraintLayout.

Find items in the Palette

To search for a view or view group by name in the Palette, click the Search button at the top of the palette, or just start typing the name of the item when the Palette window is active.

You can find frequently used items in the Common category in the Palette. To add an item to this category, right-click on a view or view group in the Palette and click Favorite in the context menu.

Open documentation from the Palette

To open the Android Developers reference documentation for a view or view group, select the UI element in the Palette and press Shift+F1.

To open the Material Guidelines documentation for a view or view group, right-click the UI element in the Palette and select Material Guidelines from the context menu. If no specific entry exists for the item, then this command opens the home page of the Material Guidelines documentation.

Add views to your layout

To start building your layout, simply drag views and view groups from the Palette into the design editor. As you place a view in the layout, the editor displays information about the view's relationship with the rest of the layout.

If you are using ConstraintLayout, you can automatically create constraints using the Infer Constraints and Autoconnect features.

Edit view attributes

Figure 3. The Attributes window

Instead of editing your view attributes in XML, you can do so from the Attributes window (on the right side of the Layout Editor). This window is available only when the design editor is open, so be sure you've selected the Design tab at the bottom of the window.

When you select a view—whether by clicking it in the Component Tree or in the design editor—the Attributes window shows the following, as indicated in figure 3:

  1. The Declared Attributes section, which lists attributes specified in the layout file. To add an attribute, click Add at the top right of the section.
  2. View inspector with controls for width/height style. For views in a ConstraintLayout, this section also shows constraint bias and lists the constraints that the view uses. For more information, see Build a Responsive UI with ConstraintLayout.
  3. A list of common attributes for the selected view. To see all available attributes, expand the All Attributes section at the bottom of the window.
  4. The Search button. Click this to search for a specific view attribute.
  5. The indicator to the right of each attribute value is solid when the value is a resource reference, and empty when it is not. This allows you to recognize hard-coded values at a glance. Clicking this indicator in either state opens the Resources dialog window, where you can select a resource reference for the corresponding attribute.
  6. Attributes with errors or warnings are highlighted, with red highlights for errors and orange highlights for warnings. One example of an error is an invalid entry in a layout-defining attribute (as pictured). One example of a warning is use of a hard-coded value when a resource reference is expected (as pictured).

Add sample data to your view

Because many Android layouts rely on runtime data, it can be difficult to visualize the look and feel of a layout while designing your app. In Android Studio 3.2 and later, you can add sample preview data to a TextView, an ImageView, or a RecyclerView from within the Layout Editor.

You can right-click on one of these view types and choose Set Sample Data to display the Design-time View Attributes window, as shown in figure 4.

Figure 4. The Design-time View Attributes window

In a TextView, you can choose between different sample text categories. When using sample text, Android Studio populates the text attribute of the TextView with your chosen sample data. Note that you can choose sample text via the Design-time View Attributes window only if the text attribute is empty.

Figure 5. A TextView with sample data

In an ImageView, you can choose between different sample images. When you choose a sample image, Android Studio populates the tools:src attribute of the ImageView (or tools:srcCompat if using the Support Library).

Figure 6. An ImageView with sample data

In a RecyclerView, you can choose between a set of templates that contain sample images and texts. When using these templates, Android Studio adds a file to your res/layout directory, recycler_view_item.xml, that contains the layout for the sample data. Android Studio also adds metadata to the RecyclerView to properly display the sample data.

Figure 7. A RecyclerView with sample data

Show layout warnings and errors

If any issues are detected in your layout, they are indicated in the Component Tree with an exclamation icon ( or ) next to the corresponding view. To view the error details, click the icon.

To see all known issues in a window below the editor, click Show Warnings and Errors ( or ) in the toolbar.

From this window you can also enable Show issues on the preview, which adds a warning or error icon to each corresponding view in the preview (in the design view only, not the blueprint view).

Download fonts and apply them to text

When using Android 8.0 (API level 26) or Android Support Library 26.0.0 or higher, you can select from hundreds of fonts by following these steps:

  1. In the Layout Editor, click the Design tab to view your layout in the design editor.
  2. Click a text view.
  3. In the Attributes window, expand textAppearance and then click to expand the fontFamily box.
  4. Scroll to the bottom of the list and click More Fonts to open the Resources dialog.
  5. In the Resources dialog, select a font by browsing the list or typing into the search bar at the top. If you select one listed under Downloadable, then you can either click Create downloadable font to load the font at runtime (as a downloadable font), or click Add font to project to package the TTF font file in your APK. (The fonts listed under Android are provided in the Android system, so they do not need to be downloaded or bundled in your APK.)
  6. Click OK.