ScaleDrawable - Android SDK

Added in API level 1

public class

ScaleDrawable

extends DrawableWrapper

java.lang.Object
↳	android.graphics.drawable.Drawable
	↳	android.graphics.drawable.DrawableWrapper
		↳	android.graphics.drawable.ScaleDrawable

Class Overview

A Drawable that changes the size of another Drawable based on its current level value. You can control how much the child Drawable changes 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.

It can be defined in an XML file with the <scale> element. For more information, see the guide to Drawable Resources.

Summary

XML Attributes
Attribute Name	Related Method	Description
android:drawable		Reference to a drawable resource to draw with the specified scale.
android:scaleGravity		Specifies where the drawable is positioned after scaling.
android:scaleHeight		Scale height, expressed as a percentage of the drawable's bound.
android:scaleWidth		Scale width, expressed as a percentage of the drawable's bound.

Public Constructors
	ScaleDrawable(Drawable drawable, int gravity, float scaleWidth, float scaleHeight) Creates a new scale drawable with the specified gravity and scale properties.

Public Methods
void	applyTheme(Resources.Theme t) Applies the specified theme to this Drawable and its children.
void	draw(Canvas canvas) Draw in its bounds (set via setBounds) respecting optional effects such as alpha (set via setAlpha) and color filter (set via setColorFilter).
int	getOpacity() Return the opacity/transparency of this Drawable.
void	inflate(Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme) Inflate this Drawable from an XML resource optionally styled by a theme.

Protected Methods
void	onBoundsChange(Rect bounds) Override this in your subclass to change appearance if you vary based on the bounds.
boolean	onLevelChange(int level) Override this in your subclass to change appearance if you vary based on level.

[Expand]

Inherited Methods

From class android.graphics.drawable.DrawableWrapper

void	applyTheme(Resources.Theme t) Applies the specified theme to this Drawable and its children.
boolean	canApplyTheme()
void	draw(Canvas canvas) Draw in its bounds (set via setBounds) respecting optional effects such as alpha (set via setAlpha) and color filter (set via setColorFilter).
int	getAlpha() Gets the current alpha value for the drawable.
int	getChangingConfigurations() Return a mask of the configuration parameters for which this drawable may change, requiring that it be re-created.
Drawable.ConstantState	getConstantState() Return a `Drawable.ConstantState` instance that holds the shared state of this Drawable.
Drawable	getDrawable()
void	getHotspotBounds(Rect outRect) Populates `outRect` with the hotspot bounds.
int	getIntrinsicHeight() Return the intrinsic height of the underlying drawable object.
int	getIntrinsicWidth() Return the intrinsic width of the underlying drawable object.
int	getOpacity() Return the opacity/transparency of this Drawable.
void	getOutline(Outline outline) Called to get the drawable to populate the Outline that defines its drawing area.
boolean	getPadding(Rect padding) Return in padding the insets suggested by this Drawable for placing content inside the drawable's bounds.
void	invalidateDrawable(Drawable who) Called when the drawable needs to be redrawn.
boolean	isStateful() Indicates whether this drawable will change its appearance based on state.
Drawable	mutate() Make this drawable mutable.
void	onBoundsChange(Rect bounds) Override this in your subclass to change appearance if you vary based on the bounds.
boolean	onLayoutDirectionChanged(int layoutDirection) Called when the drawable's resolved layout direction changes.
boolean	onLevelChange(int level) Override this in your subclass to change appearance if you vary based on level.
boolean	onStateChange(int[] state) Override this in your subclass to change appearance if you recognize the specified state.
void	scheduleDrawable(Drawable who, Runnable what, long when) A Drawable can call this to schedule the next frame of its animation.
void	setAlpha(int alpha) Specify an alpha value for the drawable.
void	setColorFilter(ColorFilter colorFilter) Specify an optional color filter for the drawable.
void	setDrawable(Drawable dr) Sets the wrapped drawable.
void	setHotspot(float x, float y) Specifies the hotspot's location within the drawable.
void	setHotspotBounds(int left, int top, int right, int bottom) Sets the bounds to which the hotspot is constrained, if they should be different from the drawable bounds.
void	setTintList(ColorStateList tint) Specifies tint color for this drawable as a color state list.
void	setTintMode(PorterDuff.Mode tintMode) Specifies a tint blending mode for this drawable.
boolean	setVisible(boolean visible, boolean restart) Set whether this Drawable is visible.
void	unscheduleDrawable(Drawable who, Runnable what) A Drawable can call this to unschedule an action previously scheduled with `scheduleDrawable(Drawable, Runnable, long)`.

From class android.graphics.drawable.Drawable

void	applyTheme(Resources.Theme t) Applies the specified theme to this Drawable and its children.
boolean	canApplyTheme()
void	clearColorFilter() Removes the color filter for this drawable.
final Rect	copyBounds() Return a copy of the drawable's bounds in a new Rect.
final void	copyBounds(Rect bounds) Return a copy of the drawable's bounds in the specified Rect (allocated by the caller).
static Drawable	createFromPath(String pathName) Create a drawable from file path name.
static Drawable	createFromResourceStream(Resources res, TypedValue value, InputStream is, String srcName, BitmapFactory.Options opts) Create a drawable from an inputstream, using the given resources and value to determine density information.
static Drawable	createFromResourceStream(Resources res, TypedValue value, InputStream is, String srcName) Create a drawable from an inputstream, using the given resources and value to determine density information.
static Drawable	createFromStream(InputStream is, String srcName) Create a drawable from an inputstream
static Drawable	createFromXml(Resources r, XmlPullParser parser, Resources.Theme theme) Create a drawable from an XML document using an optional `Resources.Theme`.
static Drawable	createFromXml(Resources r, XmlPullParser parser) Create a drawable from an XML document.
static Drawable	createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs) Create from inside an XML document.
static Drawable	createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme) Create a drawable from inside an XML document using an optional `Resources.Theme`.
abstract void	draw(Canvas canvas) Draw in its bounds (set via setBounds) respecting optional effects such as alpha (set via setAlpha) and color filter (set via setColorFilter).
int	getAlpha() Gets the current alpha value for the drawable.
final Rect	getBounds() Return the drawable's bounds Rect.
Drawable.Callback	getCallback() Return the current `Drawable.Callback` implementation attached to this Drawable.
int	getChangingConfigurations() Return a mask of the configuration parameters for which this drawable may change, requiring that it be re-created.
ColorFilter	getColorFilter() Returns the current color filter, or `null` if none set.
Drawable.ConstantState	getConstantState() Return a `Drawable.ConstantState` instance that holds the shared state of this Drawable.
Drawable	getCurrent()
Rect	getDirtyBounds() Return the drawable's dirty bounds Rect.
void	getHotspotBounds(Rect outRect) Populates `outRect` with the hotspot bounds.
int	getIntrinsicHeight() Return the intrinsic height of the underlying drawable object.
int	getIntrinsicWidth() Return the intrinsic width of the underlying drawable object.
int	getLayoutDirection() Returns the resolved layout direction for this Drawable.
final int	getLevel() Retrieve the current level.
int	getMinimumHeight() Returns the minimum height suggested by this Drawable.
int	getMinimumWidth() Returns the minimum width suggested by this Drawable.
abstract int	getOpacity() Return the opacity/transparency of this Drawable.
void	getOutline(Outline outline) Called to get the drawable to populate the Outline that defines its drawing area.
boolean	getPadding(Rect padding) Return in padding the insets suggested by this Drawable for placing content inside the drawable's bounds.
int[]	getState() Describes the current state, as a union of primitve states, such as `state_focused`, `state_selected`, etc.
Region	getTransparentRegion() Returns a Region representing the part of the Drawable that is completely transparent.
void	inflate(Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme) Inflate this Drawable from an XML resource optionally styled by a theme.
void	inflate(Resources r, XmlPullParser parser, AttributeSet attrs) Inflate this Drawable from an XML resource.
void	invalidateSelf() Use the current `Drawable.Callback` implementation to have this Drawable redrawn.
boolean	isAutoMirrored() Tells if this Drawable will be automatically mirrored when its layout direction is RTL right-to-left.
boolean	isFilterBitmap()
boolean	isStateful() Indicates whether this drawable will change its appearance based on state.
final boolean	isVisible()
void	jumpToCurrentState() If this Drawable does transition animations between states, ask that it immediately jump to the current state and skip any active animations.
Drawable	mutate() Make this drawable mutable.
void	onBoundsChange(Rect bounds) Override this in your subclass to change appearance if you vary based on the bounds.
boolean	onLayoutDirectionChanged(int layoutDirection) Called when the drawable's resolved layout direction changes.
boolean	onLevelChange(int level) Override this in your subclass to change appearance if you vary based on level.
boolean	onStateChange(int[] state) Override this in your subclass to change appearance if you recognize the specified state.
static int	resolveOpacity(int op1, int op2) Return the appropriate opacity value for two source opacities.
void	scheduleSelf(Runnable what, long when) Use the current `Drawable.Callback` implementation to have this Drawable scheduled.
abstract void	setAlpha(int alpha) Specify an alpha value for the drawable.
void	setAutoMirrored(boolean mirrored) Set whether this Drawable is automatically mirrored when its layout direction is RTL (right-to left).
void	setBounds(Rect bounds) Specify a bounding rectangle for the Drawable.
void	setBounds(int left, int top, int right, int bottom) Specify a bounding rectangle for the Drawable.
final void	setCallback(Drawable.Callback cb) Bind a `Drawable.Callback` object to this Drawable.
void	setChangingConfigurations(int configs) Set a mask of the configuration parameters for which this drawable may change, requiring that it be re-created.
abstract void	setColorFilter(ColorFilter colorFilter) Specify an optional color filter for the drawable.
void	setColorFilter(int color, PorterDuff.Mode mode) Specify a color and Porter-Duff mode to be the color filter for this drawable.
void	setDither(boolean dither) This method was deprecated in API level 23. This property is ignored.
void	setFilterBitmap(boolean filter) Set to true to have the drawable filter its bitmaps with bilinear sampling when they are scaled or rotated.
void	setHotspot(float x, float y) Specifies the hotspot's location within the drawable.
void	setHotspotBounds(int left, int top, int right, int bottom) Sets the bounds to which the hotspot is constrained, if they should be different from the drawable bounds.
final boolean	setLayoutDirection(int layoutDirection) Set the layout direction for this drawable.
final boolean	setLevel(int level) Specify the level for the drawable.
boolean	setState(int[] stateSet) Specify a set of states for the drawable.
void	setTint(int tintColor) Specifies tint color for this drawable.
void	setTintList(ColorStateList tint) Specifies tint color for this drawable as a color state list.
void	setTintMode(PorterDuff.Mode tintMode) Specifies a tint blending mode for this drawable.
boolean	setVisible(boolean visible, boolean restart) Set whether this Drawable is visible.
void	unscheduleSelf(Runnable what) Use the current `Drawable.Callback` implementation to have this Drawable unscheduled.

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

From interface android.graphics.drawable.Drawable.Callback

XML Attributes

android:drawable

Reference to a drawable resource to draw with the specified scale.

Must be a reference to another resource, in the form "@[+][package:]type:name" or to a theme attribute in the form "?[package:][type:]name".

This corresponds to the global attribute resource symbol drawable.

Related Methods

android:scaleGravity

Specifies where the drawable is positioned after scaling. The default value is left.

Must be one or more (separated by '|') of the following constant values.

Constant	Value	Description
`top`	0x30	Push object to the top of its container, not changing its size.
`bottom`	0x50	Push object to the bottom of its container, not changing its size.
`left`	0x03	Push object to the left of its container, not changing its size.
`right`	0x05	Push object to the right of its container, not changing its size.
`center_vertical`	0x10	Place object in the vertical center of its container, not changing its size.
`fill_vertical`	0x70	Grow the vertical size of the object if needed so it completely fills its container.
`center_horizontal`	0x01	Place object in the horizontal center of its container, not changing its size.
`fill_horizontal`	0x07	Grow the horizontal size of the object if needed so it completely fills its container.
`center`	0x11	Place the object in the center of its container in both the vertical and horizontal axis, not changing its size.
`fill`	0x77	Grow the horizontal and vertical size of the object if needed so it completely fills its container.
`clip_vertical`	0x80	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 will be based on the vertical gravity: a top gravity will clip the bottom edge, a bottom gravity will clip the top edge, and neither will clip both edges.
`clip_horizontal`	0x08	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 will be based on the horizontal gravity: a left gravity will clip the right edge, a right gravity will clip the left edge, and neither will clip both edges.
`start`	0x00800003	Push object to the beginning of its container, not changing its size.
`end`	0x00800005	Push object to the end of its container, not changing its size.

This corresponds to the global attribute resource symbol scaleGravity.

Related Methods

android:scaleHeight

Scale height, expressed as a percentage of the drawable's bound. The value's format is XX%. For instance: 100%, 12.5%, etc.

Must be a string value, using '\\;' to escape characters such as '\\n' or '\\uxxxx' for a unicode character.

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol scaleHeight.

Related Methods

android:scaleWidth

Scale width, expressed as a percentage of the drawable's bound. The value's format is XX%. For instance: 100%, 12.5%, etc.

Must be a string value, using '\\;' to escape characters such as '\\n' or '\\uxxxx' for a unicode character.

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol scaleWidth.

Related Methods

Public Constructors

public ScaleDrawable (Drawable drawable, int gravity, float scaleWidth, float scaleHeight)

Added in API level 1

Creates a new scale drawable with the specified gravity and scale properties.

Parameters

drawable	the drawable to scale
gravity	gravity constant (see `Gravity` used to position the scaled drawable within the parent container
scaleWidth	width scaling factor [0...1] to use then the level is at the maximum value, or -1 to not scale width
scaleHeight	height scaling factor [0...1] to use then the level is at the maximum value, or -1 to not scale height

Public Methods

public void applyTheme (Resources.Theme t)

Added in API level 21

Applies the specified theme to this Drawable and its children.

public void draw (Canvas canvas)

Added in API level 1

Draw in its bounds (set via setBounds) respecting optional effects such as alpha (set via setAlpha) and color filter (set via setColorFilter).

Parameters

canvas	The canvas to draw into

public int getOpacity ()

Added in API level 1

Return the opacity/transparency of this Drawable. The returned value is one of the abstract format constants in PixelFormat: UNKNOWN, TRANSLUCENT, TRANSPARENT, or OPAQUE.

An OPAQUE drawable is one that draws all all content within its bounds, completely covering anything behind the drawable. A TRANSPARENT drawable is one that draws nothing within its bounds, allowing everything behind it to show through. A TRANSLUCENT drawable is a drawable in any other state, where the drawable will draw some, but not all, of the content within its bounds and at least some content behind the drawable will be visible. If the visibility of the drawable's contents cannot be determined, the safest/best return value is TRANSLUCENT.

Generally a Drawable should be as conservative as possible with the value it returns. For example, if it contains multiple child drawables and only shows one of them at a time, if only one of the children is TRANSLUCENT and the others are OPAQUE then TRANSLUCENT should be returned. You can use the method resolveOpacity(int, int) to perform a standard reduction of two opacities to the appropriate single output.

Note that the returned value does not necessarily take into account a custom alpha or color filter that has been applied by the client through the setAlpha(int) or setColorFilter(ColorFilter) methods. Some subclasses, such as BitmapDrawable, ColorDrawable, and GradientDrawable, do account for the value of setAlpha(int), but the general behavior is dependent upon the implementation of the subclass.

Returns

int The opacity class of the Drawable.

public void inflate (Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme)

Added in API level 21

Inflate this Drawable from an XML resource optionally styled by a theme.

Parameters

r	Resources used to resolve attribute values
parser	XML parser from which to inflate this Drawable
attrs	Base set of attribute values
theme	Theme to apply, may be null

Throws

XmlPullParserException
IOException

Protected Methods

protected void onBoundsChange (Rect bounds)

Added in API level 1

Override this in your subclass to change appearance if you vary based on the bounds.

protected boolean onLevelChange (int level)

Added in API level 1

Override this in your subclass to change appearance if you vary based on level.

Returns

Returns true if the level change has caused the appearance of the Drawable to change (that is, it needs to be drawn), else false if it looks the same and there is no need to redraw it since its last level.

Results

Interfaces

Classes

Enums

ScaleDrawable

Class Overview

Summary

XML Attributes

android:drawable

Related Methods

android:scaleGravity

Related Methods

android:scaleHeight

Related Methods

android:scaleWidth

Related Methods

Public Constructors

public ScaleDrawable (Drawable drawable, int gravity, float scaleWidth, float scaleHeight)

Parameters

Public Methods

public void applyTheme (Resources.Theme t)

public void draw (Canvas canvas)

Parameters

public int getOpacity ()

Returns

public void inflate (Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme)

Parameters

Throws

Protected Methods

protected void onBoundsChange (Rect bounds)

protected boolean onLevelChange (int level)

Returns