Drawable
public
abstract
class
Drawable
extends Object
java.lang.Object | |
↳ | android.graphics.drawable.Drawable |
A Drawable is a general abstraction for "something that can be drawn." Most
often you will deal with Drawable as the type of resource retrieved for
drawing things to the screen; the Drawable class provides a generic API for
dealing with an underlying visual resource that may take a variety of forms.
Unlike a View
, a Drawable does not have any facility to
receive events or otherwise interact with the user.
In addition to simple drawing, Drawable provides a number of generic mechanisms for its client to interact with what is being drawn:
- The
setBounds(Rect)
method must be called to tell the Drawable where it is drawn and how large it should be. All Drawables should respect the requested size, often simply by scaling their imagery. A client can find the preferred size for some Drawables with thegetIntrinsicHeight()
andgetIntrinsicWidth()
methods. - The
getPadding(Rect)
method can return from some Drawables information about how to frame content that is placed inside of them. For example, a Drawable that is intended to be the frame for a button widget would need to return padding that correctly places the label inside of itself. - The
setState(int)
method allows the client to tell the Drawable in which state it is to be drawn, such as "focused", "selected", etc. Some drawables may modify their imagery based on the selected state. - The
setLevel(int)
method allows the client to supply a single continuous controller that can modify the Drawable is displayed, such as a battery level or progress level. Some drawables may modify their imagery based on the current level. - A Drawable can perform animations by calling back to its client
through the
Callback
interface. All clients should support this interface (viasetCallback(Callback)
) so that animations will work. A simple way to do this is through the system facilities such asView.setBackground(Drawable)
andImageView
.
- Bitmap: the simplest Drawable, a PNG or JPEG image.
- Nine Patch: an extension to the PNG format allows it to specify information about how to stretch it and place things inside of it.
- Vector: a drawable defined in an XML file as a set of points, lines, and curves along with its associated color information. This type of drawable can be scaled without loss of display quality.
- Shape: contains simple drawing commands instead of a raw bitmap, allowing it to resize better in some cases.
- Layers: a compound drawable, which draws multiple underlying drawables on top of each other.
- States: a compound drawable that selects one of a set of drawables based on its state.
- Levels: a compound drawable that selects one of a set of drawables based on its level.
- Scale: a compound drawable with a single child drawable, whose overall size is modified based on the current level.
Custom drawables
All versions of Android allow the Drawable class to be extended and used at
run time in place of framework-provided drawable classes. Starting in
API 24
, custom drawables classes
may also be used in XML.
Note: Custom drawable classes are only accessible from within your application package. Other applications will not be able to load them.
At a minimum, custom drawable classes must implement the abstract methods on
Drawable and should override the Drawable#draw(Canvas)
method to
draw content.
Custom drawables classes may be used in XML in multiple ways:
-
Using the fully-qualified class name as the XML element name. For
this method, the custom drawable class must be a public top-level
class.
<com.myapp.MyCustomDrawable xmlns:android="http://schemas.android.com/apk/res/android" android:color="#ffff0000" />
-
Using drawable as the XML element name and specifying the
fully-qualified class name from the class attribute. This
method may be used for both public top-level classes and public
static inner classes.
<drawable xmlns:android="http://schemas.android.com/apk/res/android" class="com.myapp.MyTopLevelClass$InnerCustomDrawable" android:color="#ffff0000" />
Developer Guides
For more information about how to use drawables, read the Canvas and Drawables developer guide. For information and examples of creating drawable resources (XML or bitmap files that can be loaded in code), read the Drawable Resources document.
Summary
Nested classes | |
---|---|
interface |
Drawable.Callback
Implement this interface if you want to create an animated drawable that
extends |
class |
Drawable.ConstantState
This abstract class is used by |
Public constructors | |
---|---|
Drawable()
|
Public methods | |
---|---|
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)
This method was deprecated in API level 28. Prefer the version without an Options object. |
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)
Create a drawable from an XML document. |
static
Drawable
|
createFromXml(Resources r, XmlPullParser parser, Resources.Theme theme)
Create a drawable from an XML document using an optional |
static
Drawable
|
createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme)
Create a drawable from inside an XML document using an optional
|
static
Drawable
|
createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs)
Create from inside an XML document. |
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 |
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 |
Drawable.ConstantState
|
getConstantState()
Return a |
Drawable
|
getCurrent()
|
Rect
|
getDirtyBounds()
Return the drawable's dirty bounds Rect. |
void
|
getHotspotBounds(Rect outRect)
Populates |
int
|
getIntrinsicHeight()
Returns the drawable's intrinsic height. |
int
|
getIntrinsicWidth()
Returns the drawable's intrinsic width. |
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()
This method was deprecated in API level 29. This method is no longer used in graphics optimizations |
Insets
|
getOpticalInsets()
Return in insets the layout insets suggested by this Drawable for use with alignment operations during layout. |
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 primitive states, such as
|
Region
|
getTransparentRegion()
Returns a Region representing the part of the Drawable that is completely transparent. |
boolean
|
hasFocusStateSpecified()
Indicates whether this drawable has at least one state spec explicitly
specifying |
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 |
boolean
|
isAutoMirrored()
Tells if this Drawable will be automatically mirrored when its layout direction is RTL right-to-left. |
boolean
|
isFilterBitmap()
|
boolean
|
isProjected()
Whether this drawable requests projection. |
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. |
boolean
|
onLayoutDirectionChanged(int layoutDirection)
Called when the drawable's resolved layout direction changes. |
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 |
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(int left, int top, int right, int bottom)
Specify a bounding rectangle for the Drawable. |
void
|
setBounds(Rect bounds)
Specify a bounding rectangle for the Drawable. |
final
void
|
setCallback(Drawable.Callback cb)
Bind a |
void
|
setChangingConfigurations(int configs)
Set a mask of the configuration parameters for which this drawable may change, requiring that it be re-created. |
void
|
setColorFilter(int color, PorterDuff.Mode mode)
This method was deprecated
in API level 29.
use |
abstract
void
|
setColorFilter(ColorFilter colorFilter)
Specify an optional color filter for the 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
|
setTintBlendMode(BlendMode blendMode)
Specifies a tint blending mode 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 |
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. |
boolean
|
onStateChange(int[] state)
Override this in your subclass to change appearance if you recognize the specified state. |
Inherited methods | |
---|---|
Public constructors
Drawable
public Drawable ()
Public methods
applyTheme
public void applyTheme (Resources.Theme t)
Applies the specified theme to this Drawable and its children.
Parameters | |
---|---|
t |
Resources.Theme : the theme to apply
This value cannot be null . |
clearColorFilter
public void clearColorFilter ()
Removes the color filter for this drawable.
copyBounds
public final Rect copyBounds ()
Return a copy of the drawable's bounds in a new Rect. This returns the same values as getBounds(), but the returned object is guaranteed to not be changed later by the drawable (i.e. it retains no reference to this rect). If the caller already has a Rect allocated, call copyBounds(rect).
Returns | |
---|---|
Rect |
A copy of the drawable's bounds
This value cannot be null . |
copyBounds
public final void copyBounds (Rect bounds)
Return a copy of the drawable's bounds in the specified Rect (allocated by the caller). The bounds specify where this will draw when its draw() method is called.
Parameters | |
---|---|
bounds |
Rect : Rect to receive the drawable's bounds (allocated by the
caller).
This value cannot be null . |
createFromPath
public static Drawable createFromPath (String pathName)
Create a drawable from file path name.
Parameters | |
---|---|
pathName |
String |
Returns | |
---|---|
Drawable |
This value may be null . |
createFromResourceStream
public static Drawable createFromResourceStream (Resources res, TypedValue value, InputStream is, String srcName, BitmapFactory.Options opts)
This method was deprecated
in API level 28.
Prefer the version without an Options object.
Create a drawable from an inputstream, using the given resources and value to determine density information.
Parameters | |
---|---|
res |
Resources : This value may be null . |
value |
TypedValue : This value may be null . |
is |
InputStream : This value may be null . |
srcName |
String : This value may be null . |
opts |
BitmapFactory.Options : This value may be null . |
Returns | |
---|---|
Drawable |
This value may be null . |
createFromResourceStream
public 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.
Parameters | |
---|---|
res |
Resources : This value may be null . |
value |
TypedValue : This value may be null . |
is |
InputStream : This value may be null . |
srcName |
String : This value may be null . |
Returns | |
---|---|
Drawable |
This value may be null . |
createFromStream
public static Drawable createFromStream (InputStream is, String srcName)
Create a drawable from an inputstream
Parameters | |
---|---|
is |
InputStream : This value may be null . |
srcName |
String : This value may be null . |
Returns | |
---|---|
Drawable |
This value may be null . |
createFromXml
public static Drawable createFromXml (Resources r, XmlPullParser parser)
Create a drawable from an XML document. For more information on how to create resources in XML, see Drawable Resources.
Parameters | |
---|---|
r |
Resources : This value cannot be null . |
parser |
XmlPullParser : This value cannot be null . |
Returns | |
---|---|
Drawable |
This value cannot be null . |
Throws | |
---|---|
IOException |
|
XmlPullParserException |
createFromXml
public static Drawable createFromXml (Resources r, XmlPullParser parser, Resources.Theme theme)
Create a drawable from an XML document using an optional Theme
.
For more information on how to create resources in XML, see
Drawable Resources.
Parameters | |
---|---|
r |
Resources : This value cannot be null . |
parser |
XmlPullParser : This value cannot be null . |
theme |
Resources.Theme : This value may be null . |
Returns | |
---|---|
Drawable |
This value cannot be null . |
Throws | |
---|---|
IOException |
|
XmlPullParserException |
createFromXmlInner
public static Drawable createFromXmlInner (Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme)
Create a drawable from inside an XML document using an optional
Theme
. Called on a parser positioned at a tag in an XML
document, tries to create a Drawable from that tag. Returns null
if the tag is not a valid drawable.
Parameters | |
---|---|
r |
Resources : This value cannot be null . |
parser |
XmlPullParser : This value cannot be null . |
attrs |
AttributeSet : This value cannot be null . |
theme |
Resources.Theme : This value may be null . |
Returns | |
---|---|
Drawable |
Throws | |
---|---|
IOException |
|
XmlPullParserException |
createFromXmlInner
public static Drawable createFromXmlInner (Resources r, XmlPullParser parser, AttributeSet attrs)
Create from inside an XML document. Called on a parser positioned at a tag in an XML document, tries to create a Drawable from that tag. Returns null if the tag is not a valid drawable.
Parameters | |
---|---|
r |
Resources : This value cannot be null . |
parser |
XmlPullParser : This value cannot be null . |
attrs |
AttributeSet : This value cannot be null . |
Returns | |
---|---|
Drawable |
Throws | |
---|---|
IOException |
|
XmlPullParserException |
draw
public 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).
Parameters | |
---|---|
canvas |
Canvas : The canvas to draw into
This value cannot be null . |
getAlpha
public int getAlpha ()
Gets the current alpha value for the drawable. 0 means fully transparent, 255 means fully opaque. This method is implemented by Drawable subclasses and the value returned is specific to how that class treats alpha. The default return value is 255 if the class does not override this method to return a value specific to its use of alpha.
Returns | |
---|---|
int |
Value is between 0 and 255 inclusive |
getBounds
public final Rect getBounds ()
Return the drawable's bounds Rect. Note: for efficiency, the returned object may be the same object stored in the drawable (though this is not guaranteed), so if a persistent copy of the bounds is needed, call copyBounds(rect) instead. You should also not change the object returned by this method as it may be the same object stored in the drawable.
Returns | |
---|---|
Rect |
The bounds of the drawable (which may change later, so caller
beware). DO NOT ALTER the returned object as it may change the
stored bounds of this drawable.
This value cannot be null . |
getCallback
public Drawable.Callback getCallback ()
Return the current Callback
implementation attached to this
Drawable.
Returns | |
---|---|
Drawable.Callback |
A Callback instance or null if no callback was set. |
getChangingConfigurations
public int getChangingConfigurations ()
Return a mask of the configuration parameters for which this drawable
may change, requiring that it be re-created. The default implementation
returns whatever was provided through
setChangingConfigurations(int)
or 0 by default. Subclasses
may extend this to or in the changing configurations of any other
drawables they hold.
Returns | |
---|---|
int |
Returns a mask of the changing configuration parameters, as
defined by ActivityInfo .
Value is either 0 or a combination of ActivityInfo.CONFIG_MCC , ActivityInfo.CONFIG_MNC , ActivityInfo.CONFIG_LOCALE , ActivityInfo.CONFIG_TOUCHSCREEN , ActivityInfo.CONFIG_KEYBOARD , ActivityInfo.CONFIG_KEYBOARD_HIDDEN , ActivityInfo.CONFIG_NAVIGATION , ActivityInfo.CONFIG_ORIENTATION , ActivityInfo.CONFIG_SCREEN_LAYOUT , ActivityInfo.CONFIG_UI_MODE , ActivityInfo.CONFIG_SCREEN_SIZE , ActivityInfo.CONFIG_SMALLEST_SCREEN_SIZE , ActivityInfo.CONFIG_DENSITY , ActivityInfo.CONFIG_LAYOUT_DIRECTION , ActivityInfo.CONFIG_COLOR_MODE , ActivityInfo.CONFIG_FONT_SCALE , and ActivityInfo.CONFIG_GRAMMATICAL_GENDER |
See also:
getColorFilter
public ColorFilter getColorFilter ()
Returns the current color filter, or null
if none set.
Returns | |
---|---|
ColorFilter |
the current color filter, or null if none set |
getConstantState
public Drawable.ConstantState getConstantState ()
Return a ConstantState
instance that holds the shared state of this Drawable.
Returns | |
---|---|
Drawable.ConstantState |
The ConstantState associated to that Drawable.
This value may be null . |
See also:
getCurrent
public Drawable getCurrent ()
Returns | |
---|---|
Drawable |
The current drawable that will be used by this drawable. For simple drawables, this
is just the drawable itself. For drawables that change state like
StateListDrawable and LevelListDrawable this will be the child drawable
currently in use.
This value cannot be null . |
getDirtyBounds
public Rect getDirtyBounds ()
Return the drawable's dirty bounds Rect. Note: for efficiency, the returned object may be the same object stored in the drawable (though this is not guaranteed).
By default, this returns the full drawable bounds. Custom drawables may override this method to perform more precise invalidation.
Returns | |
---|---|
Rect |
The dirty bounds of this drawable
This value cannot be null . |
getHotspotBounds
public void getHotspotBounds (Rect outRect)
Populates outRect
with the hotspot bounds.
Parameters | |
---|---|
outRect |
Rect : the rect to populate with the hotspot bounds
This value cannot be null . |
See also:
getIntrinsicHeight
public int getIntrinsicHeight ()
Returns the drawable's intrinsic height.
Intrinsic height is the height at which the drawable would like to be laid out, including any inherent padding. If the drawable has no intrinsic height, such as a solid color, this method returns -1.
Returns | |
---|---|
int |
the intrinsic height, or -1 if no intrinsic height |
getIntrinsicWidth
public int getIntrinsicWidth ()
Returns the drawable's intrinsic width.
Intrinsic width is the width at which the drawable would like to be laid out, including any inherent padding. If the drawable has no intrinsic width, such as a solid color, this method returns -1.
Returns | |
---|---|
int |
the intrinsic width, or -1 if no intrinsic width |
getLayoutDirection
public int getLayoutDirection ()
Returns the resolved layout direction for this Drawable.
Returns | |
---|---|
int |
One of View.LAYOUT_DIRECTION_LTR ,
View.LAYOUT_DIRECTION_RTL
Value is View.LAYOUT_DIRECTION_LTR , or View.LAYOUT_DIRECTION_RTL |
See also:
getLevel
public final int getLevel ()
Retrieve the current level.
Returns | |
---|---|
int |
int Current level, from 0 (minimum) to 10000 (maximum). Value is between 0 and 10000 inclusive |
getMinimumHeight
public int getMinimumHeight ()
Returns the minimum height suggested by this Drawable. If a View uses this Drawable as a background, it is suggested that the View use at least this value for its height. (There will be some scenarios where this will not be possible.) This value should INCLUDE any padding.
Returns | |
---|---|
int |
The minimum height suggested by this Drawable. If this Drawable doesn't have a suggested minimum height, 0 is returned. |
getMinimumWidth
public int getMinimumWidth ()
Returns the minimum width suggested by this Drawable. If a View uses this Drawable as a background, it is suggested that the View use at least this value for its width. (There will be some scenarios where this will not be possible.) This value should INCLUDE any padding.
Returns | |
---|---|
int |
The minimum width suggested by this Drawable. If this Drawable doesn't have a suggested minimum width, 0 is returned. |
getOpacity
public abstract int getOpacity ()
This method was deprecated
in API level 29.
This method is no longer used in graphics optimizations
Return the opacity/transparency of this Drawable. The returned value is
one of the abstract format constants in
PixelFormat
:
PixelFormat.UNKNOWN
,
PixelFormat.TRANSLUCENT
,
PixelFormat.TRANSPARENT
, or
PixelFormat.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 |
int The opacity class of the Drawable.
Value is PixelFormat.UNKNOWN , PixelFormat.TRANSLUCENT , PixelFormat.TRANSPARENT , or PixelFormat.OPAQUE |
See also:
getOpticalInsets
public Insets getOpticalInsets ()
Return in insets the layout insets suggested by this Drawable for use with alignment operations during layout.
Returns | |
---|---|
Insets |
This value cannot be null . |
getOutline
public void getOutline (Outline outline)
Called to get the drawable to populate the Outline that defines its drawing area.
This method is called by the default ViewOutlineProvider
to define
the outline of the View.
The default behavior defines the outline to be the bounding rectangle of 0 alpha. Subclasses that wish to convey a different shape or alpha value must override this method.
Parameters | |
---|---|
outline |
Outline : This value cannot be null . |
getPadding
public boolean getPadding (Rect padding)
Return in padding the insets suggested by this Drawable for placing content inside the drawable's bounds. Positive values move toward the center of the Drawable (set Rect.inset).
Parameters | |
---|---|
padding |
Rect : This value cannot be null . |
Returns | |
---|---|
boolean |
true if this drawable actually has a padding, else false. When false is returned, the padding is always set to 0. |
getState
public int[] getState ()
Describes the current state, as a union of primitive states, such as
R.attr.state_focused
,
R.attr.state_selected
, etc.
Some drawables may modify their imagery based on the selected state.
Returns | |
---|---|
int[] |
An array of resource Ids describing the current state.
This value cannot be null . |
getTransparentRegion
public Region getTransparentRegion ()
Returns a Region representing the part of the Drawable that is completely transparent. This can be used to perform drawing operations, identifying which parts of the target will not change when rendering the Drawable. The default implementation returns null, indicating no transparent region; subclasses can optionally override this to return an actual Region if they want to supply this optimization information, but it is not required that they do so.
Returns | |
---|---|
Region |
Returns null if the Drawables has no transparent region to report, else a Region holding the parts of the Drawable's bounds that are transparent. |
hasFocusStateSpecified
public boolean hasFocusStateSpecified ()
Indicates whether this drawable has at least one state spec explicitly
specifying R.attr.state_focused
.
Note: A View uses a Drawable
instance as its background and it
changes its appearance based on a state. On keyboard devices, it should
specify its R.attr.state_focused
to make sure the user
knows which view is holding the focus.
Returns | |
---|---|
boolean |
true if R.attr.state_focused is specified
for this drawable. |
inflate
public void inflate (Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme)
Inflate this Drawable from an XML resource optionally styled by a theme. This can't be called more than once for each Drawable. Note that framework may have called this once to create the Drawable instance from XML resource.
Parameters | |
---|---|
r |
Resources : Resources used to resolve attribute values
This value cannot be null . |
parser |
XmlPullParser : XML parser from which to inflate this Drawable
This value cannot be null . |
attrs |
AttributeSet : Base set of attribute values
This value cannot be null . |
theme |
Resources.Theme : Theme to apply, may be null |
Throws | |
---|---|
|
org.xmlpull.v1.XmlPullParserException |
|
java.io.IOException |
IOException |
|
XmlPullParserException |
inflate
public void inflate (Resources r, XmlPullParser parser, AttributeSet attrs)
Inflate this Drawable from an XML resource. Does not apply a theme.
Parameters | |
---|---|
r |
Resources : This value cannot be null . |
parser |
XmlPullParser : This value cannot be null . |
attrs |
AttributeSet : This value cannot be null . |
Throws | |
---|---|
IOException |
|
XmlPullParserException |
invalidateSelf
public void invalidateSelf ()
Use the current Callback
implementation to have this Drawable
redrawn. Does nothing if there is no Callback attached to the
Drawable.
isAutoMirrored
public boolean isAutoMirrored ()
Tells if this Drawable will be automatically mirrored when its layout direction is RTL
right-to-left. See LayoutDirection
.
Returns | |
---|---|
boolean |
boolean Returns true if this Drawable will be automatically mirrored. |
isFilterBitmap
public boolean isFilterBitmap ()
Returns | |
---|---|
boolean |
whether this drawable filters its bitmaps |
See also:
isProjected
public boolean isProjected ()
Whether this drawable requests projection. Indicates that the
RenderNode
this Drawable will draw into should be drawn immediately
after the closest ancestor RenderNode containing a projection receiver.
Returns | |
---|---|
boolean |
See also:
isStateful
public boolean isStateful ()
Indicates whether this drawable will change its appearance based on state. Clients can use this to determine whether it is necessary to calculate their state and call setState.
Returns | |
---|---|
boolean |
True if this drawable changes its appearance based on state, false otherwise. |
See also:
jumpToCurrentState
public void jumpToCurrentState ()
If this Drawable does transition animations between states, ask that it immediately jump to the current state and skip any active animations.
mutate
public Drawable mutate ()
Make this drawable mutable. This operation cannot be reversed. A mutable drawable is guaranteed to not share its state with any other drawable. This is especially useful when you need to modify properties of drawables loaded from resources. By default, all drawables instances loaded from the same resource share a common state; if you modify the state of one instance, all the other instances will receive the same modification. Calling this method on a mutable Drawable will have no effect.
Returns | |
---|---|
Drawable |
This drawable.
This value cannot be null . |
See also:
onLayoutDirectionChanged
public boolean onLayoutDirectionChanged (int layoutDirection)
Called when the drawable's resolved layout direction changes.
Parameters | |
---|---|
layoutDirection |
int : the new resolved layout direction
Value is View.LAYOUT_DIRECTION_LTR , or View.LAYOUT_DIRECTION_RTL |
Returns | |
---|---|
boolean |
true if the layout direction change has caused the
appearance of the drawable to change such that it needs to be
re-drawn, false otherwise |
See also:
resolveOpacity
public static int resolveOpacity (int op1, int op2)
Return the appropriate opacity value for two source opacities. If either is UNKNOWN, that is returned; else, if either is TRANSLUCENT, that is returned; else, if either is TRANSPARENT, that is returned; else, OPAQUE is returned.
This is to help in implementing getOpacity()
.
Parameters | |
---|---|
op1 |
int : One opacity value.
Value is PixelFormat.UNKNOWN , PixelFormat.TRANSLUCENT , PixelFormat.TRANSPARENT , or PixelFormat.OPAQUE |
op2 |
int : Another opacity value.
Value is PixelFormat.UNKNOWN , PixelFormat.TRANSLUCENT , PixelFormat.TRANSPARENT , or PixelFormat.OPAQUE |
Returns | |
---|---|
int |
int The combined opacity value.
Value is PixelFormat.UNKNOWN , PixelFormat.TRANSLUCENT , PixelFormat.TRANSPARENT , or PixelFormat.OPAQUE |
See also:
scheduleSelf
public void scheduleSelf (Runnable what, long when)
Use the current Callback
implementation to have this Drawable
scheduled. Does nothing if there is no Callback attached to the
Drawable.
Parameters | |
---|---|
what |
Runnable : The action being scheduled.
This value cannot be null . |
when |
long : The time (in milliseconds) to run. |
setAlpha
public abstract void setAlpha (int alpha)
Specify an alpha value for the drawable. 0 means fully transparent, and 255 means fully opaque.
Parameters | |
---|---|
alpha |
int : Value is between 0 and 255 inclusive |
setAutoMirrored
public void setAutoMirrored (boolean mirrored)
Set whether this Drawable is automatically mirrored when its layout direction is RTL
(right-to left). See LayoutDirection
.
Parameters | |
---|---|
mirrored |
boolean : Set to true if the Drawable should be mirrored, false if not. |
setBounds
public void setBounds (int left, int top, int right, int bottom)
Specify a bounding rectangle for the Drawable. This is where the drawable will draw when its draw() method is called.
Parameters | |
---|---|
left |
int |
top |
int |
right |
int |
bottom |
int |
setBounds
public void setBounds (Rect bounds)
Specify a bounding rectangle for the Drawable. This is where the drawable will draw when its draw() method is called.
Parameters | |
---|---|
bounds |
Rect : This value cannot be null . |
setCallback
public final void setCallback (Drawable.Callback cb)
Bind a Callback
object to this Drawable. Required for clients
that want to support animated drawables.
Parameters | |
---|---|
cb |
Drawable.Callback : The client's Callback implementation.
This value may be null . |
See also:
setChangingConfigurations
public void setChangingConfigurations (int configs)
Set a mask of the configuration parameters for which this drawable may change, requiring that it be re-created.
Parameters | |
---|---|
configs |
int : A mask of the changing configuration parameters, as
defined by ActivityInfo .
Value is either 0 or a combination of ActivityInfo.CONFIG_MCC , ActivityInfo.CONFIG_MNC , ActivityInfo.CONFIG_LOCALE , ActivityInfo.CONFIG_TOUCHSCREEN , ActivityInfo.CONFIG_KEYBOARD , ActivityInfo.CONFIG_KEYBOARD_HIDDEN , ActivityInfo.CONFIG_NAVIGATION , ActivityInfo.CONFIG_ORIENTATION , ActivityInfo.CONFIG_SCREEN_LAYOUT , ActivityInfo.CONFIG_UI_MODE , ActivityInfo.CONFIG_SCREEN_SIZE , ActivityInfo.CONFIG_SMALLEST_SCREEN_SIZE , ActivityInfo.CONFIG_DENSITY , ActivityInfo.CONFIG_LAYOUT_DIRECTION , ActivityInfo.CONFIG_COLOR_MODE , ActivityInfo.CONFIG_FONT_SCALE , and ActivityInfo.CONFIG_GRAMMATICAL_GENDER |
See also:
setColorFilter
public void setColorFilter (int color, PorterDuff.Mode mode)
This method was deprecated
in API level 29.
use setColorFilter(android.graphics.ColorFilter)
with an instance
of BlendModeColorFilter
Specify a color and Porter-Duff mode to be the color filter for this drawable.
Convenience for setColorFilter(android.graphics.ColorFilter)
which constructs a
PorterDuffColorFilter
.
Note: Setting a color filter disables
tint
.
Parameters | |
---|---|
color |
int |
mode |
PorterDuff.Mode : This value cannot be null . |
See also:
setColorFilter
public abstract void setColorFilter (ColorFilter colorFilter)
Specify an optional color filter for the drawable.
If a Drawable has a ColorFilter, each output pixel of the Drawable's drawing contents will be modified by the color filter before it is blended onto the render target of a Canvas.
Pass null
to remove any existing color filter.
Note: Setting a non-null
color
filter disables tint
.
Parameters | |
---|---|
colorFilter |
ColorFilter : The color filter to apply, or null to remove the
existing color filter |
setDither
public void setDither (boolean dither)
This method was deprecated
in API level 23.
This property is ignored.
Set to true to have the drawable dither its colors when drawn to a device with fewer than 8-bits per color component.
Parameters | |
---|---|
dither |
boolean |
See also:
setFilterBitmap
public void setFilterBitmap (boolean filter)
Set to true to have the drawable filter its bitmaps with bilinear sampling when they are scaled or rotated.
This can improve appearance when bitmaps are rotated. If the drawable does not use bitmaps, this call is ignored.
Parameters | |
---|---|
filter |
boolean |
setHotspot
public void setHotspot (float x, float y)
Specifies the hotspot's location within the drawable.
Parameters | |
---|---|
x |
float : The X coordinate of the center of the hotspot |
y |
float : The Y coordinate of the center of the hotspot |
setHotspotBounds
public 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.
Parameters | |
---|---|
left |
int : position in pixels of the left bound |
top |
int : position in pixels of the top bound |
right |
int : position in pixels of the right bound |
bottom |
int : position in pixels of the bottom bound |
See also:
setLayoutDirection
public final boolean setLayoutDirection (int layoutDirection)
Set the layout direction for this drawable. Should be a resolved layout direction, as the Drawable has no capacity to do the resolution on its own.
Parameters | |
---|---|
layoutDirection |
int : the resolved layout direction for the drawable,
either View.LAYOUT_DIRECTION_LTR
or View.LAYOUT_DIRECTION_RTL
Value is View.LAYOUT_DIRECTION_LTR , or View.LAYOUT_DIRECTION_RTL |
Returns | |
---|---|
boolean |
true if the layout direction change has caused the
appearance of the drawable to change such that it needs to be
re-drawn, false otherwise |
See also:
setLevel
public final boolean setLevel (int level)
Specify the level for the drawable. This allows a drawable to vary its imagery based on a continuous controller, for example to show progress or volume level.
If the new level you are supplying causes the appearance of the
Drawable to change, then it is responsible for calling
invalidateSelf()
in order to have itself redrawn, and
true will be returned from this function.
Parameters | |
---|---|
level |
int : The new level, from 0 (minimum) to 10000 (maximum).
Value is between 0 and 10000 inclusive |
Returns | |
---|---|
boolean |
Returns true if this change in level has caused the appearance of the Drawable to change (hence requiring an invalidate), otherwise returns false. |
setState
public boolean setState (int[] stateSet)
Specify a set of states for the drawable. These are use-case specific,
so see the relevant documentation. As an example, the background for
widgets like Button understand the following states:
[R.attr.state_focused
,
R.attr.state_pressed
].
If the new state you are supplying causes the appearance of the
Drawable to change, then it is responsible for calling
invalidateSelf()
in order to have itself redrawn, and
true will be returned from this function.
Note: The Drawable holds a reference on to stateSet until a new state array is given to it, so you must not modify this array during that time.
Parameters | |
---|---|
stateSet |
int : The new set of states to be displayed.
This value cannot be null . |
Returns | |
---|---|
boolean |
Returns true if this change in state has caused the appearance of the Drawable to change (hence requiring an invalidate), otherwise returns false. |
setTint
public void setTint (int tintColor)
Specifies tint color for this drawable.
A Drawable's drawing content will be blended together with its tint
before it is drawn to the screen. This functions similarly to
setColorFilter(int, android.graphics.PorterDuff.Mode)
.
To clear the tint, pass null
to
setTintList(android.content.res.ColorStateList)
.
Note: Setting a color filter via
setColorFilter(android.graphics.ColorFilter)
or
setColorFilter(int, android.graphics.PorterDuff.Mode)
overrides tint.
Parameters | |
---|---|
tintColor |
int : Color to use for tinting this drawable |
setTintBlendMode
public void setTintBlendMode (BlendMode blendMode)
Specifies a tint blending mode for this drawable.
Defines how this drawable's tint color should be blended into the drawable
before it is drawn to screen. Default tint mode is BlendMode#SRC_IN
.
Note: Setting a color filter via
setColorFilter(android.graphics.ColorFilter)
Parameters | |
---|---|
blendMode |
BlendMode : BlendMode to apply to the drawable, a value of null sets the default
blend mode value of BlendMode#SRC_IN |
See also:
setTintList
public void setTintList (ColorStateList tint)
Specifies tint color for this drawable as a color state list.
A Drawable's drawing content will be blended together with its tint
before it is drawn to the screen. This functions similarly to
setColorFilter(int, android.graphics.PorterDuff.Mode)
.
Note: Setting a color filter via
setColorFilter(android.graphics.ColorFilter)
or
setColorFilter(int, android.graphics.PorterDuff.Mode)
overrides tint.
Parameters | |
---|---|
tint |
ColorStateList : Color state list to use for tinting this drawable, or
null to clear the tint |
setTintMode
public void setTintMode (PorterDuff.Mode tintMode)
Specifies a tint blending mode for this drawable.
Defines how this drawable's tint color should be blended into the drawable
before it is drawn to screen. Default tint mode is PorterDuff.Mode#SRC_IN
.
Note: Setting a color filter via
setColorFilter(android.graphics.ColorFilter)
or
setColorFilter(int, android.graphics.PorterDuff.Mode)
overrides tint.
Parameters | |
---|---|
tintMode |
PorterDuff.Mode : A Porter-Duff blending mode to apply to the drawable, a value of null sets
the default Porter-Diff blending mode value
of PorterDuff.Mode#SRC_IN |
See also:
setVisible
public boolean setVisible (boolean visible, boolean restart)
Set whether this Drawable is visible. This generally does not impact the Drawable's behavior, but is a hint that can be used by some Drawables, for example, to decide whether run animations.
Parameters | |
---|---|
visible |
boolean : Set to true if visible, false if not. |
restart |
boolean : You can supply true here to force the drawable to behave
as if it has just become visible, even if it had last
been set visible. Used for example to force animations
to restart. |
Returns | |
---|---|
boolean |
boolean Returns true if the new visibility is different than its previous state. |
unscheduleSelf
public void unscheduleSelf (Runnable what)
Use the current Callback
implementation to have this Drawable
unscheduled. Does nothing if there is no Callback attached to the
Drawable.
Parameters | |
---|---|
what |
Runnable : The runnable that you no longer want called.
This value cannot be null . |
Protected methods
onBoundsChange
protected void onBoundsChange (Rect bounds)
Override this in your subclass to change appearance if you vary based on the bounds.
Parameters | |
---|---|
bounds |
Rect : This value cannot be null . |
onLevelChange
protected boolean onLevelChange (int level)
Override this in your subclass to change appearance if you vary based on level.
Parameters | |
---|---|
level |
int |
Returns | |
---|---|
boolean |
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. |
onStateChange
protected boolean onStateChange (int[] state)
Override this in your subclass to change appearance if you recognize the specified state.
Parameters | |
---|---|
state |
int : This value cannot be null . |
Returns | |
---|---|
boolean |
Returns true if the state 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 state. |
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Last updated 2024-06-18 UTC.