Drawable resources

A drawable resource is a general concept for a graphic that can be drawn to the screen and that you can retrieve with APIs such as getDrawable(int) or apply to another XML resource with attributes such as android:drawable and android:icon. There are several types of drawables:

Bitmap file
: A bitmap graphic file (PNG, WEBP, JPG, or GIF). Creates a BitmapDrawable.
Nine-patch file: A PNG file with stretchable regions to let images resize based on content (.9.png). Creates a NinePatchDrawable.
Layer list: A drawable that manages an array of other drawables. These are drawn in array order, so the element with the largest index is drawn on top. Creates a LayerDrawable.
State list: An XML file that references different bitmap graphics for different states—for example, to use a different image when a button is tapped. Creates a StateListDrawable.
Level list: An XML file that defines a drawable that manages a number of alternate drawables, each assigned a maximum numerical value. Creates a LevelListDrawable.
Transition drawable: An XML file that defines a drawable that can cross-fade between two drawable resources. Creates a TransitionDrawable.
Inset drawable: An XML file that defines a drawable that insets another drawable by a specified distance. This is useful when a view needs a background drawable that is smaller than the view's actual bounds.
Clip drawable: An XML file that defines a drawable that clips another drawable based on this drawable's current level value. Creates a ClipDrawable.
Scale drawable: An XML file that defines a drawable that changes the size of another drawable based on its current level value. Creates a ScaleDrawable
Shape drawable.: An XML file that defines a geometric shape, including colors and gradients. Creates a GradientDrawable.

For information about how to create an AnimationDrawable, see the Animation resources document.

Note: A color resource can also be used as a drawable in XML. For example, when creating a state list drawable, you can reference a color resource for the android:drawable attribute (android:drawable="@color/green").

Bitmap

A bitmap image. Android supports bitmap files in the following formats: PNG (preferred), WEBP (preferred, requires API level 17 or higher), JPG (acceptable), GIF (discouraged).

You can reference a bitmap file directly, using the filename as the resource ID, or create an alias resource ID in XML.

Note: Bitmap files might be automatically optimized with lossless image compression by the aapt tool during the build process. For example, a true-color PNG that doesn't require more than 256 colors might be converted to an 8-bit PNG with a color palette. This results in an image of equal quality that requires less memory.

So, be aware that the image binaries placed in this directory can change during the build. If you plan to read an image as a bit stream to convert it to a bitmap, put your images in the res/raw/ folder instead, where they aren't optimized.

Bitmap file

A bitmap file is a PNG, WEBP, JPG, or GIF file. Android creates a Drawable resource for any of these files when you save them in the res/drawable/ directory.

file location:

res/drawable/filename.png (.png, .webp, .jpg, or .gif)
The filename is the resource ID

compiled resource datatype:

Resource pointer to a BitmapDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

example:

With an image saved at res/drawable/myimage.png, this layout XML applies the image to a view:

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

The following application code retrieves the image as a Drawable:

Kotlin

val drawable: Drawable? = ResourcesCompat.getDrawable(resources, R.drawable.myimage, null)

Java

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

see also:

XML bitmap

An XML bitmap is a resource defined in XML that points to a bitmap file. The effect is an alias for a raw bitmap file. The XML can specify additional properties for the bitmap, such as dithering and tiling.

Note: You can use a <bitmap> element as a child of an <item> element. For example, when creating a state list or layer list, you can exclude the android:drawable attribute from an <item> element and nest a <bitmap> inside it that defines the drawable item.

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a BitmapDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<bitmap
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:src="@[package:]drawable/drawable_resource"
    android:antialias=["true" | "false"]
    android:dither=["true" | "false"]
    android:filter=["true" | "false"]
    android:gravity=["top" | "bottom" | "left" | "right" | "center_vertical" |
                      "fill_vertical" | "center_horizontal" | "fill_horizontal" |
                      "center" | "fill" | "clip_vertical" | "clip_horizontal"]
    android:mipMap=["true" | "false"]
    android:tileMode=["disabled" | "clamp" | "repeat" | "mirror"] />

elements:

<bitmap>

Required. Defines the bitmap source and its properties.

Attributes:

xmlns:android

String. Defines the XML namespace, which must be "http://schemas.android.com/apk/res/android". This is required only if the <bitmap> is the root element. It isn't needed when the <bitmap> is nested inside an <item>.

android:src

Drawable resource. Required. Reference to a drawable resource.

android:antialias

Boolean. Enables or disables antialiasing.

android:dither

Boolean. Enables or disables dithering of the bitmap if the bitmap doesn't have the same pixel configuration as the screen, such as an ARGB 8888 bitmap on an RGB 565 screen.

android:filter

Boolean. Enables or disables bitmap filtering. Filtering is used when the bitmap is shrunk or stretched to smooth its appearance.

android:gravity

Keyword. Defines the gravity for the bitmap. The gravity indicates where to position the drawable in its container if the bitmap is smaller than the container.

Must be one or more of the following constant values, separated by |:

Value	Description
`top`	Put the object at the top of its container, not changing its size.
`bottom`	Put the object at the bottom of its container, not changing its size.
`left`	Put the object at the left edge of its container, not changing its size.
`right`	Put the object at the right edge of its container, not changing its size.
`center_vertical`	Put the object in the vertical center of its container, not changing its size.
`fill_vertical`	Grow the vertical size of the object if needed so it completely fills its container.
`center_horizontal`	Place object in the horizontal center of its container, not changing its size.
`fill_horizontal`	Grow the horizontal size of the object if needed so it completely fills its container.
`center`	Put the object in the center of its container in both the vertical and horizontal axis, not changing its size.
`fill`	Grow the horizontal and vertical size of the object if needed so it completely fills its container. This is the default.
`clip_vertical`	Additional option that can be set to have the top and/or bottom edges of the child clipped to its container's bounds. The clip is based on the vertical gravity: a top gravity clips the bottom edge, a bottom gravity clips the top edge, and neither clips both edges.
`clip_horizontal`	Additional option that can be set to have the left and/or right edges of the child clipped to its container's bounds. The clip is based on the horizontal gravity: a left gravity clips the right edge, a right gravity clips the left edge, and neither clips both edges.

android:mipMap

Boolean. Enables or disables the mipmap hint. See setHasMipMap() for more information. The default value is false.

android:tileMode

Keyword. Defines the tile mode. When the tile mode is enabled, the bitmap is repeated. Gravity is ignored when the tile mode is enabled.

Must be one of the following constant values:

Value	Description
`disabled`	Don't tile the bitmap. This is the default value.
`clamp`	Replicate the edge color if the shader draws outside its original bounds
`repeat`	Repeat the shader's image horizontally and vertically.
`mirror`	Repeat the shader's image horizontally and vertically, alternating mirror images so that adjacent images always seam.

example:

<?xml version="1.0" encoding="utf-8"?>
<bitmap xmlns:android="http://schemas.android.com/apk/res/android"
    android:src="@drawable/icon"
    android:tileMode="repeat" />

see also:

Nine-patch

A NinePatch is a PNG image in which you can define stretchable regions that Android scales when content within the view exceeds the normal image bounds. You typically assign this type of image as the background of a view that has at least one dimension set to "wrap_content".

When the view grows to accommodate the content, the nine-patch image is also scaled to match the size of the view. An example use of a nine-patch image is the background used by Android's standard Button widget, which must stretch to accommodate the text (or image) inside the button.

As with a normal bitmap, you can reference a nine-patch file directly or from a resource defined by XML.

For a complete discussion about how to create a nine-patch file with stretchable regions, see Create resizable bitmaps (9-patch files).

Nine-patch file

file location:

res/drawable/filename.9.png
The filename is the resource ID

compiled resource datatype:

Resource pointer to a NinePatchDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

example:

With an image saved at res/drawable/myninepatch.9.png, this layout XML applies the nine-patch to a view:

<Button
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:background="@drawable/myninepatch" />

see also:

XML nine-patch

An XML nine-patch is a resource defined in XML that points to a nine-patch file. The XML can specify dithering for the image.

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a NinePatchDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<nine-patch
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:src="@[package:]drawable/drawable_resource"
    android:dither=["true" | "false"] />

elements:

example:

<?xml version="1.0" encoding="utf-8"?>
<nine-patch xmlns:android="http://schemas.android.com/apk/res/android"
    android:src="@drawable/myninepatch"
    android:dither="false" />

Layer list

A LayerDrawable is a drawable object that manages an array of other drawables. Each drawable in the list is drawn in the order of the list. The last drawable in the list is drawn on top.

Each drawable is represented by an <item> element inside a single <layer-list> element.

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a LayerDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:drawable="@[package:]drawable/drawable_resource"
        android:id="@[+][package:]id/resource_name"
        android:top="dimension"
        android:right="dimension"
        android:bottom="dimension"
        android:left="dimension" />
</layer-list>

elements:

example:

XML file saved at res/drawable/layers.xml:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
      <bitmap android:src="@drawable/android_red"
        android:gravity="center" />
    </item>
    <item android:top="10dp" android:left="10dp">
      <bitmap android:src="@drawable/android_green"
        android:gravity="center" />
    </item>
    <item android:top="20dp" android:left="20dp">
      <bitmap android:src="@drawable/android_blue"
        android:gravity="center" />
    </item>
</layer-list>

This example uses a nested <bitmap> element to define the drawable resource for each item with a "center" gravity. This ensures that none of the images are scaled to fit the size of the container, due to resizing caused by the offset images.

This layout XML applies the drawable to a view:

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

The result is a stack of increasingly offset images:

see also:

LayerDrawable

State list

A StateListDrawable is a drawable object defined in XML that uses multiple images to represent the same graphic, depending on the state of the object. For example, the state of a Button widget can be tapped, focused, or neither; using a state list drawable, you can provide a different background image for each state.

You describe the state list in an XML file. Each graphic is represented by an <item> element inside a single <selector> element. Each <item> uses various attributes to describe the state in which it is used as the graphic for the drawable.

During each state change, the state list is traversed top to bottom, and the first item that matches the current state is used. The selection is not based on the "best match," but rather the first item that meets the minimum criteria of the state.

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a StateListDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android"
    android:constantSize=["true" | "false"]
    android:dither=["true" | "false"]
    android:variablePadding=["true" | "false"] >
    <item
        android:drawable="@[package:]drawable/drawable_resource"
        android:state_pressed=["true" | "false"]
        android:state_focused=["true" | "false"]
        android:state_hovered=["true" | "false"]
        android:state_selected=["true" | "false"]
        android:state_checkable=["true" | "false"]
        android:state_checked=["true" | "false"]
        android:state_enabled=["true" | "false"]
        android:state_activated=["true" | "false"]
        android:state_window_focused=["true" | "false"] />
</selector>

elements:

<selector>

Required. This must be the root element. Contains one or more <item> elements.

Attributes:

xmlns:android: String. Required. Defines the XML namespace, which must be "http://schemas.android.com/apk/res/android".
android:constantSize: Boolean. True if the drawable's reported internal size remains constant as the state changes (the size is the maximum of all of the states); false if the size varies based on the current state. The default is false.
android:dither: Boolean. True to enable dithering of the bitmap if the bitmap doesn't have the same pixel configuration as the screen, such as an ARGB 8888 bitmap on an RGB 565 screen; false to disable dithering. The default is true.
android:variablePadding: Boolean. True if the drawable's padding changes based on the current state that is selected; false if the padding must stay the same, based on the maximum padding of all the states. Enabling this feature requires that you deal with performing layout when the state changes, which is often not supported. The default is false.

<item>

Defines a drawable to use during certain states, as described by its attributes. Must be a child of a <selector> element.

Attributes:

android:drawable: Drawable resource. Required. Reference to a drawable resource.
android:state_pressed: Boolean. True if this item is used when the object is tapped, such as when a button is touched; false if this item is used in the default, non-tapped state.
android:state_focused: Boolean. True if this item is used when the object has input focus, such as when the user selects a text input; false if this item is used in the default, non-focused state.
android:state_hovered: Boolean. True if this item is used when the cursor hovers over the object; false if this item is used in the default, non-hovered state. Often, this drawable can be the same drawable used for the "focused" state.
Introduced in API level 14.
android:state_selected: Boolean. True if this item is used when the object is the current user selection when navigating with a directional control, such as when navigating through a list with a D-pad; false if this item is used when the object isn't selected.
The selected state is used when android:state_focused isn't sufficient, such as when the list view has focus and an item within it is selected with a D-pad.
android:state_checkable: Boolean. True if this item is used when the object is selectable; false if this item is used when the object isn't selectable. Only useful if the object can transition between a selectable and non-selectable widget.
android:state_checked: Boolean. True if this item is used when the object is selected; false if it is used when the object is un-selected.
android:state_enabled: Boolean. True if this item is used when the object is enabled, meaning capable of receiving touch or click events; false if it is used when the object is disabled.
android:state_activated: Boolean. True if this item is used when the object is activated as the persistent selection, such as to "highlight" the previously selected list item in a persistent navigation view; false if it is used when the object isn't activated.
Introduced in API level 11.
android:state_window_focused: Boolean. True if this item is used when the application window has focus, meaning the application is in the foreground; false if this item is used when the application window doesn't have focus, for example, if the notification shade is pulled down or a dialog appears.

Note: Android applies the first item in the state list that matches the current state of the object. So, if the first item in the list contains none of the preceding state attributes, then it is applied every time. This is why you want your default value to always be last, as demonstrated in the following example.

example:

XML file saved at res/drawable/button.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true"
          android:drawable="@drawable/button_pressed" /> <!-- pressed -->
    <item android:state_focused="true"
          android:drawable="@drawable/button_focused" /> <!-- focused -->
    <item android:state_hovered="true"
          android:drawable="@drawable/button_focused" /> <!-- hovered -->
    <item android:drawable="@drawable/button_normal" /> <!-- default -->
</selector>

This layout XML applies the state list drawable to a button:

<Button
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:background="@drawable/button" />

see also:

StateListDrawable

Level list

A drawable that manages a number of alternate drawables, each assigned a maximum numerical value. Setting the level value of the drawable with setLevel() loads the drawable resource in the level list that has an android:maxLevel value greater than or equal to the value passed to the method.

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a LevelListDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<level-list
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:drawable="@drawable/drawable_resource"
        android:maxLevel="integer"
        android:minLevel="integer" />
</level-list>

elements:

example:

<?xml version="1.0" encoding="utf-8"?>
<level-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:drawable="@drawable/status_off"
        android:maxLevel="0" />
    <item
        android:drawable="@drawable/status_on"
        android:maxLevel="1" />
</level-list>

Once this is applied to a View, the level can be changed with setLevel() or setImageLevel().

see also:

LevelListDrawable

Transition drawable

A TransitionDrawable is a drawable object that can cross-fade between two other drawable resources.

Each drawable is represented by an <item> element inside a single <transition> element. No more than two items are supported. To transition forward, call startTransition(). To transition backward, call reverseTransition().

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a TransitionDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<transition
xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:drawable="@[package:]drawable/drawable_resource"
        android:id="@[+][package:]id/resource_name"
        android:top="dimension"
        android:right="dimension"
        android:bottom="dimension"
        android:left="dimension" />
</transition>

elements:

example:

XML file saved at res/drawable/transition.xml:

<?xml version="1.0" encoding="utf-8"?>
<transition xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/on" />
    <item android:drawable="@drawable/off" />
</transition>

This layout XML applies the drawable to a view:

<ImageButton
    android:id="@+id/button"
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:src="@drawable/transition" />

And the following code performs a 500 ms transition from the first item to the second:

Kotlin

val button: ImageButton = findViewById(R.id.button)
val drawable: Drawable = button.drawable
if (drawable is TransitionDrawable) {
    drawable.startTransition(500)
}

Java

ImageButton button = (ImageButton) findViewById(R.id.button);
Drawable drawable = button.getDrawable();
if (drawable instanceof TransitionDrawable) {
    ((TransitionDrawable) drawable).startTransition(500);
}

see also:

TransitionDrawable

Inset drawable

A drawable defined in XML that insets another drawable by a specified distance. This is useful when a view needs a background that is smaller than the view's actual bounds.

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a InsetDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<inset
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/drawable_resource"
    android:insetTop="dimension"
    android:insetRight="dimension"
    android:insetBottom="dimension"
    android:insetLeft="dimension" />

elements:

example:

<?xml version="1.0" encoding="utf-8"?>
<inset xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/background"
    android:insetTop="10dp"
    android:insetLeft="10dp" />

see also:

InsetDrawable

Clip drawable

A drawable defined in XML that clips another drawable based on this drawable's current level. You can control how much the child drawable gets clipped in width and height based on the level, as well as a gravity to control where it is placed in its overall container. Most often used to implement things like progress bars.

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a ClipDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<clip
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/drawable_resource"
    android:clipOrientation=["horizontal" | "vertical"]
    android:gravity=["top" | "bottom" | "left" | "right" | "center_vertical" |
                     "fill_vertical" | "center_horizontal" | "fill_horizontal" |
                     "center" | "fill" | "clip_vertical" | "clip_horizontal"] />

elements:

<clip>

Required. Defines the clip drawable. This must be the root element.

Attributes:

xmlns:android

String. Required. Defines the XML namespace, which must be "http://schemas.android.com/apk/res/android".

android:drawable

Drawable resource. Required. Reference to a drawable resource to be clipped.

android:clipOrientation

Keyword. The orientation for the clip.

Must be one of the following constant values:

Value	Description
`horizontal`	Clip the drawable horizontally.
`vertical`	Clip the drawable vertically.

android:gravity

Keyword. Specifies where to clip within the drawable.

Must be one or more of the following constant values, separated by |:

Value	Description
`top`	Put the object at the top of its container, not changing its size. When `clipOrientation` is `"vertical"`, clipping occurs at the bottom of the drawable.
`bottom`	Put the object at the bottom of its container, not changing its size. When `clipOrientation` is `"vertical"`, clipping occurs at the top of the drawable.
`left`	Put the object at the left edge of its container, not changing its size. This is the default. When `clipOrientation` is `"horizontal"`, clipping occurs at the right side of the drawable.
`right`	Put the object at the right edge of its container, not changing its size. When `clipOrientation` is `"horizontal"`, clipping occurs at the left side of the drawable.
`center_vertical`	Put the object in the vertical center of its container, not changing its size. Clipping behaves the same as when gravity is `"center"`.
`fill_vertical`	Grow the vertical size of the object if needed so it completely fills its container. When `clipOrientation` is `"vertical"`, no clipping occurs because the drawable fills the vertical space (unless the drawable level is 0, in which case it's not visible).
`center_horizontal`	Put the object in the horizontal center of its container, not changing its size. Clipping behaves the same as when gravity is `"center"`.
`fill_horizontal`	Grow the horizontal size of the object if needed so it completely fills its container. When `clipOrientation` is `"horizontal"`, no clipping occurs because the drawable fills the horizontal space (unless the drawable level is 0, in which case it's not visible).
`center`	Put the object in the center of its container in both the vertical and horizontal axis, not changing its size. When `clipOrientation` is `"horizontal"`, clipping occurs on the left and right. When `clipOrientation` is `"vertical"`, clipping occurs on the top and bottom.
`fill`	Grow the horizontal and vertical size of the object if needed so it completely fills its container. No clipping occurs because the drawable fills the horizontal and vertical space (unless the drawable level is 0, in which case it's not visible).
`clip_vertical`	Additional option that can be set to have the top and/or bottom edges of the child clipped to its container's bounds. The clip is based on the vertical gravity: a top gravity clips the bottom edge, a bottom gravity clips the top edge, and neither clips both edges.
`clip_horizontal`	Additional option that can be set to have the left and/or right edges of the child clipped to its container's bounds. The clip is based on the horizontal gravity: a left gravity clips the right edge, a right gravity clips the left edge, and neither clips both edges.

example:

XML file saved at res/drawable/clip.xml:

<?xml version="1.0" encoding="utf-8"?>
<clip xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/android"
    android:clipOrientation="horizontal"
    android:gravity="left" />

The following layout XML applies the clip drawable to a view:

<ImageView
    android:id="@+id/image"
    android:src="@drawable/clip"
    android:layout_height="wrap_content"
    android:layout_width="wrap_content" />

The following code gets the drawable and increases the amount of clipping to progressively reveal the image:

Kotlin

val imageview: ImageView = findViewById(R.id.image)
val drawable: Drawable = imageview.background
if (drawable is ClipDrawable) {
    drawable.level = drawable.level + 1000
}

Java

ImageView imageview = (ImageView) findViewById(R.id.image);
Drawable drawable = imageview.getBackground();
if (drawable instanceof ClipDrawable) {
    ((ClipDrawable)drawable).setLevel(drawable.getLevel() + 1000);
}

Increasing the level reduces the amount of clipping and slowly reveals the image. Here it is at a level of 7000:

Note: The default level is 0, which is fully clipped so the image isn't visible. When the level is 10,000, the image isn't clipped and is completely visible.

see also:

ClipDrawable

Scale drawable

A drawable defined in XML that changes the size of another drawable based on its current level.

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a ScaleDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<scale
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/drawable_resource"
    android:scaleGravity=["top" | "bottom" | "left" | "right" | "center_vertical" |
                          "fill_vertical" | "center_horizontal" | "fill_horizontal" |
                          "center" | "fill" | "clip_vertical" | "clip_horizontal"]
    android:scaleHeight="percentage"
    android:scaleWidth="percentage" />

elements:

<scale>

Required. Defines the scale drawable. This must be the root element.

Attributes:

xmlns:android

String. Required. Defines the XML namespace, which must be "http://schemas.android.com/apk/res/android".

android:drawable

Drawable resource. Required. Reference to a drawable resource.

android:scaleGravity

Keyword. Specifies the gravity position after scaling.

Must be one or more of the following constant values, separated by |:

Value	Description
`top`	Put the object at the top of its container, not changing its size.
`bottom`	Put the object at the bottom of its container, not changing its size.
`left`	Put the object at the left edge of its container, not changing its size. This is the default.
`right`	Put the object at the right edge of its container, not changing its size.
`center_vertical`	Put the object in the vertical center of its container, not changing its size.
`fill_vertical`	Grow the vertical size of the object if needed so it completely fills its container.
`center_horizontal`	Put the object in the horizontal center of its container, not changing its size.
`fill_horizontal`	Grow the horizontal size of the object if needed so it completely fills its container.
`center`	Put the object in the center of its container in both the vertical and horizontal axis, not changing its size.
`fill`	Grow the horizontal and vertical size of the object if needed so it completely fills its container.
`clip_vertical`	Additional option that can be set to have the top and/or bottom edges of the child clipped to its container's bounds. The clip is based on the vertical gravity: a top gravity clips the bottom edge, a bottom gravity clips the top edge, and neither clips both edges.
`clip_horizontal`	Additional option that can be set to have the left and/or right edges of the child clipped to its container's bounds. The clip is based on the horizontal gravity: a left gravity clips the right edge, a right gravity clips the left edge, and neither clips both edges.

android:scaleHeight

Percentage. The scale height, expressed as a percentage of the drawable's bound. The value's format is XX%, such as 100% or 12.5%.

android:scaleWidth

Percentage. The scale width, expressed as a percentage of the drawable's bound. The value's format is XX%, such as 100% or 12.5%.

example:

<?xml version="1.0" encoding="utf-8"?>
<scale xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/logo"
    android:scaleGravity="center_vertical|center_horizontal"
    android:scaleHeight="80%"
    android:scaleWidth="80%" />

see also:

ScaleDrawable

Shape drawable

This is a generic shape defined in XML.

file location:

res/drawable/filename.xml
The filename is the resource ID

compiled resource datatype:

Resource pointer to a GradientDrawable

resource reference:

In Java: R.drawable.filename
In XML: @[package:]drawable/filename

syntax:

<?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape=["rectangle" | "oval" | "line" | "ring"] >
    <corners
        android:radius="integer"
        android:topLeftRadius="integer"
        android:topRightRadius="integer"
        android:bottomLeftRadius="integer"
        android:bottomRightRadius="integer" />
    <gradient
        android:angle="integer"
        android:centerX="float"
        android:centerY="float"
        android:centerColor="integer"
        android:endColor="color"
        android:gradientRadius="integer"
        android:startColor="color"
        android:type=["linear" | "radial" | "sweep"]
        android:useLevel=["true" | "false"] />
    <padding
        android:left="integer"
        android:top="integer"
        android:right="integer"
        android:bottom="integer" />
    <size
        android:width="integer"
        android:height="integer" />
    <solid
        android:color="color" />
    <stroke
        android:width="integer"
        android:color="color"
        android:dashWidth="integer"
        android:dashGap="integer" />
</shape>

elements:

<shape>

Required. The shape drawable. This must be the root element.

Attributes:

xmlns:android

String. Required. Defines the XML namespace, which must be "http://schemas.android.com/apk/res/android".

android:shape

Keyword. Defines the type of shape. Valid values are:

Value	Description
`"rectangle"`	A rectangle that fills the containing view. This is the default shape.
`"oval"`	An oval shape that fits the dimensions of the containing view.
`"line"`	A horizontal line that spans the width of the containing view. This shape requires the `<stroke>` element to define the width of the line.
`"ring"`	A ring shape.

The following attributes are used only when android:shape="ring":

android:innerRadius: Dimension. The radius for the inner part of the ring (the hole in the middle), as a dimension value or dimension resource.
android:innerRadiusRatio: Float. The radius for the inner part of the ring, expressed as a ratio of the ring's width. For instance, if android:innerRadiusRatio="5", then the inner radius equals the ring's width divided by 5. This value is overridden by android:innerRadius. The default value is 9.
android:thickness: Dimension. The thickness of the ring, as a dimension value or dimension resource.
android:thicknessRatio: Float. The thickness of the ring expressed as a ratio of the ring's width. For instance, if android:thicknessRatio="2", then the thickness equals the ring's width divided by 2. This value is overridden by android:innerRadius. The default value is 3.
android:useLevel: Boolean. True if this is used as a LevelListDrawable. This normally is false, or else your shape might not appear.

<corners>

Creates rounded corners for the shape. Applies only when the shape is a rectangle.

Attributes:

android:radius: Dimension. The radius for all corners, as a dimension value or dimension resource. This is overridden for each corner by the following attributes.
android:topLeftRadius: Dimension. The radius for the top-left corner, as a dimension value or dimension resource.
android:topRightRadius: Dimension. The radius for the top-right corner, as a dimension value or dimension resource.
android:bottomLeftRadius: Dimension. The radius for the bottom-left corner, as a dimension value or dimension resource.
android:bottomRightRadius: Dimension. The radius for the bottom-right corner, as a dimension value or dimension resource.

Note: Every corner must initially be provided a corner radius greater than 1, or else no corners are rounded. If you want specific corners to not be rounded, a workaround is to use android:radius to set a default corner radius greater than 1 and then override every corner with the values you really want, providing 0 ("0dp") where you don't want rounded corners.

<gradient>

Specifies a gradient color for the shape.

Attributes:

android:angle

Integer. The angle for the gradient, in degrees. 0 is left to right, 90 is bottom to top. It must be a multiple of 45. The default is 0.

android:centerX

Float. The relative X-position for the center of the gradient (0 - 1.0).

android:centerY

Float. The relative Y-position for the center of the gradient (0 - 1.0).

android:centerColor

Color. Optional color that comes between the start and end colors, as a hexadecimal value or color resource.

android:endColor

Color. The ending color, as a hexadecimal value or color resource.

android:gradientRadius

Float. The radius for the gradient. Only applied when android:type="radial".

android:startColor

Color. The starting color, as a hexadecimal value or color resource.

android:type

Keyword. The type of gradient pattern to apply. Valid values are:

Value	Description
`"linear"`	A linear gradient. This is the default.
`"radial"`	A radial gradient. The start color is the center color.
`"sweep"`	A sweeping line gradient.

android:useLevel

Boolean. True if this is used as a LevelListDrawable.

<padding>

Padding to apply to the containing view element. This pads the position of the view content, not the shape.

Attributes:

android:left: Dimension. Left padding, as a dimension value or dimension resource.
android:top: Dimension. Top padding, as a dimension value or dimension resource.
android:right: Dimension. Right padding, as a dimension value or dimension resource.
android:bottom: Dimension. Bottom padding, as a dimension value or dimension resource.

<size>

The size of the shape.

Attributes:

android:height: Dimension. The height of the shape, as a dimension value or dimension resource.
android:width: Dimension. The width of the shape, as a dimension value or dimension resource.

Note: By default, the shape scales to the size of the container view proportionate to the dimensions defined here. When you use the shape in an ImageView, you can restrict scaling by setting the android:scaleType to "center".

<solid>

A solid color to fill the shape.

Attributes:

android:color: Color. The color to apply to the shape, as a hexadecimal value or color resource.

<stroke>

A stroke line for the shape.

Attributes:

android:width: Dimension. The thickness of the line, as a dimension value or dimension resource.
android:color: Color. The color of the line, as a hexadecimal value or color resource.
android:dashGap: Dimension. The distance between line dashes, as a dimension value or dimension resource. Only valid if android:dashWidth is set.
android:dashWidth: Dimension. The size of each dash line, as a dimension value or dimension resource. Only valid if android:dashGap is set.

example:

XML file saved at res/drawable/gradient_box.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <gradient
        android:startColor="#FFFF0000"
        android:endColor="#80FF00FF"
        android:angle="45"/>
    <padding android:left="7dp"
        android:top="7dp"
        android:right="7dp"
        android:bottom="7dp" />
    <corners android:radius="8dp" />
</shape>

This layout XML applies the shape drawable to a view:

<TextView
    android:background="@drawable/gradient_box"
    android:layout_height="wrap_content"
    android:layout_width="wrap_content" />

This application code gets the shape drawable and applies it to a view:

Kotlin

val shape: Drawable? = getDrawable(resources, R.drawable.gradient_box, getTheme())

val tv: TextView = findViewById(R.id.textview)
tv.background = shape

Java

Resources res = getResources();
Drawable shape = ResourcesCompat.getDrawable(res, R.drawable.gradient_box, getTheme());

TextView tv = (TextView)findViewById(R.id.textview);
tv.setBackground(shape);

see also:

ShapeDrawable

Color state list

Layout