Vector Asset Studio

Vector Asset Studio helps you add material icons and import Scalable Vector Graphic (SVG) files into your app project as a drawable resource. Compared to raster images, vector drawables can reduce the size of your app and be resized without loss of image quality. They help you to more easily support different Android devices with varying screen sizes and resolutions because you can display one vector drawable on all of them.

About Vector Asset Studio

Vector Asset Studio adds a vector graphic to the project as an XML file that describes the image. Maintaining one XML file can be easier than updating multiple raster graphics at various resolutions.

Android 4.4 (API level 20) and lower doesn't support vector drawables. If your minimum API level is set at one of these API levels, Vector Asset Studio also directs Gradle to generate raster images of the vector drawable for backward-compatibility. You can refer to vector assets as Drawable in Java code or @drawable in XML code; when your app runs, the corresponding vector or raster image displays automatically depending on the API level.

Supported vector graphic types

The Google material design specification provides material icons that you can use in your Android apps. Vector Asset Studio helps you choose, import, and size material icons, as well as define opacity and the Right-to-Left (RTL) mirroring setting.

Vector Asset Studio also helps you to import your own SVG files. SVG is an XML-based open standard of the World Wide Web Consortium (W3C). Vector Asset Studio supports the essential standard, but not all features. When you specify an SVG file, Vector Asset Studio gives immediate feedback about whether the graphics code is supported or not. If the SVG code is supported, it converts the file into an XML file containing VectorDrawable code.

Considerations for SVG files

A vector drawable is appropriate for simple icons. The material icons provide good examples of the types of images that work well as vector drawables in an app. In contrast, many app launch icons do have many details, so they work better as raster images.

The initial loading of a vector graphic can cost more CPU cycles than the corresponding raster image. Afterward, memory use and performance are similar between the two. We recommend that you limit a vector image to a maximum of 200 x 200 dp; otherwise, it can take too long to draw.

Although vector drawables do support one or more colors, in many cases it makes sense to color icons black (android:fillColor="#FF000000"). Using this approach, you can add a tint to the vector drawable that you placed in a layout, and the icon color changes to the tint color. If the icon color isn't black, the icon color might instead blend with the tint color.

Vector drawable support at different API levels

Android 5.0 (API level 21) and higher provides vector drawable support. If your app has a minimum API level that is lower, Vector Asset Studio adds the vector drawable file to your project; also, at build time, Gradle creates Portable Network Graphic (PNG) raster images at various resolutions. Gradle generates the PNG densities specified by the Domain Specific Language (DSL) generatedDensities property in a build.gradle file. To generate PNGs, the build system requires Android Plugin for Gradle 1.5.0 or higher.

For Android 5.0 (API level 21) and higher, Vector Asset Studio supports all of the VectorDrawable elements. For backward compatibility with Android 4.4 (API level 20) and lower, Vector Asset Studio supports the following XML elements:

Only Android 5.0 (API level 21) and higher supports dynamic attributes, for example, android:fillColor="?android:attr/colorControlNormal".

You can change the XML code that Vector Asset Studio generates, although it’s not a best practice. Changing the values in the code should not cause any issues, as long as they’re valid and static. If you want to add XML elements, you need to make sure that they’re supported based on your minimum API level.

For Android 5.0 (API level 21) and higher, you can use the AnimatedVectorDrawable class to animate the properties of VectorDrawable. For more information, see Animating Vector Drawables.

Running Vector Asset Studio

Follow these steps to start Vector Asset Studio:

1. In Android Studio, open an Android app project.
2. In the Project window, select the Android view.
3. Right-click the res folder and select New > Vector Asset.

Some other project views and folders have this menu item as well.

Vector Asset Studio appears.


4. If a Need newer Android plugin for Gradle dialog appears instead, correct your Gradle version as follows:
1. Select File > Project Structure.
2. In the Project Structure dialog, select Project.
3. In the Android Plugin Version field, change the Android Plugin for Gradle version to 1.5.0 or higher, and click OK.

Gradle syncs the project.

4. In the Android view of the Project window, right-click the res folder and select New > Vector Asset.

Vector Asset Studio appears.

5. Continue with Importing a Vector Graphic.

Importing a Vector Graphic

Vector Asset Studio helps you to import a vector graphics file into your app project. Follow one of the following procedures:

• Adding a material icon
• Importing an SVG file

Adding a material icon

After you open Vector Asset Studio, you can add a material icon as follows:

1. In Vector Asset Studio, select Material Icon.
2. Click Choose.
3. Select a material icon and click OK.

The icon appears in the Vector Drawable Preview.

4. Optionally change the resource name, size, opacity, and Right-To-Left (RTL) mirroring setting:
   • Resource name - Type a new name if you don’t want to use the default name. Vector Asset Studio automatically creates a unique name (adds a number to the end of the name) if that resource name already exists in the project. The name can contain lowercase characters, underscores, and digits only.
   • Override default size from material design - Select this option if you want to adjust the size of the image. When you type a new size, the change appears in the preview area.

   The default is 24 x 24 dp, which is defined in the material design specification. Deselect the checkbox to return to the default.

   • Opacity - Use the slider to adjust the opacity of the image. The change appears in the preview area.
   • Enable auto mirroring for RTL layout - Select this option if you want a mirror image to display when the layout is right to left, instead of left to right. For example, some languages are read right to left; if you have an arrow icon, you might want to display a mirror image of it in this case. Note that if you’re working with an older project, you might also need to add android:supportsRtl="true" to your app manifest. Auto-mirroring is supported on Android 5.0 (API level 21) and higher only.
5. Click Next.
6. Optionally change the module and resource directory:
• Target Module - Select a module in the project where you want to add the resource. For more information, see Creating an Android Module.
• Res Directory - Select the resource source set where you want to add the vector asset: src/main/res, src/debug/res, src/release/res, or a user-defined source set. The main source set applies to all build variants, including debug and release. The debug and release source sets override the main source set and apply to one version of a build. The debug source set is for debugging only. To define a new source set, select File > Project Structure > app > Build Types. For example, you could define a beta source set and create a version of an icon that includes the text "BETA” in the bottom right corner. For more information, see Working with Build Variants.

The Output Directories area displays the vector image and the directory where it will appear.

7. Click Finish.

Vector Asset Studio adds an XML file defining the vector drawable to the project in the app/src/main/res/drawable/ folder. From the Android view of the Project window, you can view the generated vector XML file in the drawable folder.

8. Build the project.

If the minimum API level is Android 4.4 (API level 20) and lower, Vector Asset Studio generates PNG files. From the Project view of the Project window, you can view the generated PNG and XML files in the app/build/generated/res/pngs/debug/ folder.

You should not edit these generated raster files, but instead work with the vector XML file. The build system regenerates the raster files automatically when needed so you don’t need to maintain them.

Importing a Scalable Vector Graphic (SVG)

After you open Vector Asset Studio, you can import an SVG file as follows:

1. In Vector Asset Studio, select Local SVG file.

The file must be on a local drive. If it’s located on the network, for example, you need to download it to a local drive first.

2. Specify an Image file by clicking … .

The image appears in the Vector Drawable Preview.

However, if the SVG file contains unsupported features, an error appears at the bottom left of Vector Asset Studio, as shown in the following figure.



In this case, you can’t use Vector Asset Studio to add the graphics file. Click More to view the errors. For a list of supported elements, see Vector Drawable Support at Different API Levels.

3. Optionally change the resource name, size, opacity, and Right-To-Left (RTL) mirroring setting:
• Resource name - Type a new name if you don’t want to use the default name. Vector Asset Studio automatically creates a unique name (adds a number to the end of the name) if that resource name already exists in the project. The name can contain lowercase characters, underscores, and digits only.
• Override default size from material design - Select this option if you want to adjust the size of the image. After you select it, the size changes to the size of the image itself. Whenever you change the size, the change appears in the preview area.

The default is 24 x 24 dp, which is defined in the material design specification. Deselect the checkbox to return to the default.

• Opacity - Use the slider to adjust the opacity of the image. The change appears in the preview area.
• Enable auto mirroring for RTL layout - Select this option if you want a mirror image to display when the layout is right to left, instead of left to right. For example, some languages are read right to left; if you have an arrow icon, you might want to display a mirror image of it in this case. Note that if you’re working with an older project, you might need to add android:supportsRtl="true" to your app manifest. Auto-mirroring is supported on Android 5.0 (API level 21) and higher only.
4. Click Next.
5. Optionally change the module and resource directory:
• Target Module - Select a module in the project where you want to add the resource. For more information, see Creating an Android Module.
• Res Directory - Select the resource source set where you want to add the vector asset: src/main/res, src/debug/res, src/release/res, or a user-defined source set. The main source set applies to all build variants, including debug and release. The debug and release source sets override the main source set and apply to one version of a build. The debug source set is for debugging only. To define a new source set, select File > Project Structure > app > Build Types. For example, you could define a beta source set and create a version of an icon that includes the text "BETA” in the bottom right corner. For more information, see Working with Build Variants.

The Output Directories area displays the vector image and the directory where it will appear.

6. Click Finish.

Vector Asset Studio adds an XML file defining the vector drawable to the project in the app/src/main/res/drawable/ folder. From the Android view of the Project window, you can view the generated vector XML file in the drawable folder.

7. Build the project.

If the minimum API level is Android 4.4 (API level 20) and lower, Vector Asset Studio generates PNG files. From the Project view of the Project window, you can view the generated PNG and XML files in the app/build/generated/res/pngs/debug/ folder.

You should not edit these generated raster files, but instead work with the vector XML file. The build system regenerates the raster files automatically when needed so you don’t need to maintain them.

Adding a Vector Drawable to a Layout

In a layout file, you can set any icon-related widget, such as ImageButton, ImageView, and so on, to point to a vector asset. For example, the following layout shows a vector asset displayed on a button:

Follow these steps to display a vector asset on a widget, as shown in the figure:

1. Open a project and import a vector asset.
2. In the Android view of the Project window, double-click a layout XML file, such as content_main.xml.
3. Click the Design tab to display the Layout Editor.
4. Drag the ImageButton widget from the Palette window onto the Layout Editor.
5. In the Properties window, locate the src property of the ImageButton instance and click … .
6. In the Resources dialog, select the Project tab, navigate to the Drawable folder, and select a vector asset. Click OK.

The vector asset appears on the ImageButton in the layout.

7. To change the color of the image to the accent color defined in the theme, locate the tint property in the Properties window and click … .
8. In the Resources dialog, select the Project tab, navigate to the Color folder, and select colorAccent. Click OK.

The color of the image changes to the accent color in the layout.

The ImageButton code should be similar to the following:

<ImageButton
  android:id="@+id/imageButton"
  android:src="@drawable/ic_build_24dp"
  android:tint="@color/colorAccent"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_below="@+id/textView2"
  android:layout_marginTop="168dp" />

Referring to a Vector Drawable in Code

You can normally refer to a vector drawable resource in a generic way in your code, and when your app runs, the corresponding vector or raster image displays automatically depending on the API level:

• In most cases, you can refer to vector assets as @drawable in XML code or Drawable in Java code.

For example, the following layout XML code applies the image to a view:

<ImageView
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:src="@drawable/myimage" />

The following Java code retrieves the image as a Drawable:

Resources res = getResources();
Drawable drawable = res.getDrawable(R.drawable.myimage);

• Occasionally, you might need to typecast the drawable resource to its exact class, such as when you need to use specific features of the VectorDrawable class. To do so, you could use Java code such as the following:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
   VectorDrawable vectorDrawable =  (VectorDrawable) drawable;
} else {
   BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
}

Modifying XML Code Generated by Vector Asset Studio

You can modify the vector asset XML code, but not the PNGs and corresponding XML code generated at build time. However, we don't recommended it. Vector Asset Studio makes sure that the vector drawable and the PNGs match, and that the manifest contains the proper code. If you add code that's not supported on Android 4.4 (API level 20) and lower, your vector and PNG images might differ. You also need to make sure that the manifest contains the code to support your changes.

Follow these steps to modify the vector XML file:

1. In the Project window, double-click the generated vector XML file in the drawable folder.

The XML file appears in the editor and Preview windows.


2. Edit the XML code based on what’s supported by the minimum API level:
• Android 5.0 (API level 21) and higher - Vector Asset Studio supports all of the Drawable and VectorDrawable elements. You can add XML elements and change values.
• Android 4.4 (API level 20) and lower - Vector Asset Studio supports all of the Drawable elements and a subset of the VectorDrawable elements. See Support at Different API Levels for a list. You can change values in the generated code and add XML elements that are supported. Dynamic attributes aren't supported.

For example, if you didn’t select the RTL option in Vector Asset Studio but realize you now need it, you can add the autoMirrored attribute later. To view the RTL version, select Preview Right-to-Left Layout in the menu of the Preview window. (Select None to remove the RTL preview.)



Note: If you’re working with an older project, you might need to add android:supportsRtl="true" to your app manifest. Also, because autoMirrored is a dynamic attribute, it's supported on Android 5.0 (API level 21) and higher only.

3. Build the project and check that the vector and raster images look the same.

Remember that the generated PNGs could display differently in the Preview window than in the app due to different rendering engines and any changes made to the vector drawable before a build. If you add code to the vector XML file created by Vector Asset Studio, any features unsupported in Android 4.4 (API level 20) and lower don't appear in the generated PNG files. As a result, when you add code, you should always check that the generated PNGs match the vector drawable. To do so, you could double-click the PNG in the Project view of the Project window; the left margin of the code editor also displays the PNG image when your code refers to the drawable.

Deleting a Vector Asset from a Project

Follow these steps to remove a vector asset from a project:

1. In the Project window, delete the generated vector XML file by selecting the file and pressing the Delete key (or select Edit > Delete).

The Safe Delete dialog appears.

2. Optionally select options to find where the file is used in the project, and click OK.

Android Studio deletes the file from the project and the drive. However, if you chose to search for places in the project where the file is used and some usages are found, you can view them and decide whether to delete the file.

3. Select Build > Clean Project.

Any auto-generated PNG and XML files corresponding to the deleted vector asset are removed from the project and the drive.

Delivering an App Containing Vector Drawables

When your minimum API level includes Android 4.4 (API level 20) or lower, you have corresponding vector and raster images in your project. In this case, you have two options for delivering your APK files:

• Create one APK that includes both the vector images and the corresponding raster representations. This solution is the simplest to implement.
• Create separate APKs for different API levels. When you don’t include the corresponding raster images in the APK for Android 5.0 (API level 21) and higher, the APK can be much smaller in size. For more information, see Multiple APK Support.