public abstract class Drawable extends Object
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:
setBounds(int, int, int, int)
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
the getIntrinsicHeight()
and getIntrinsicWidth()
methods.
getPadding(android.graphics.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.
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.
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.
Drawable.Callback
interface. All clients should support this
interface (via setCallback(android.graphics.drawable.Drawable.Callback)
) so that animations will work. A
simple way to do this is through the system facilities such as
View.setBackground(Drawable)
and
ImageView
.
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 draw(Canvas)
method to
draw content.
Custom drawables classes may be used in XML in multiple ways:
<com.myapp.MyCustomDrawable xmlns:android="http://schemas.android.com/apk/res/android" android:color="#ffff0000" />
<drawable xmlns:android="http://schemas.android.com/apk/res/android" class="com.myapp.MyTopLevelClass$InnerCustomDrawable" android:color="#ffff0000" />
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.
Modifier and Type | Class and Description |
---|---|
static interface |
Drawable.Callback
Implement this interface if you want to create an animated drawable that
extends
Drawable . |
static class |
Drawable.ConstantState
This abstract class is used by
Drawable s to store shared constant state and data
between Drawables. |
Constructor and Description |
---|
Drawable() |
Modifier and Type | Method and Description |
---|---|
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.
|
void |
clearMutated()
Clears the mutated state, allowing this drawable to be cached and
mutated again.
|
Rect |
copyBounds()
Return a copy of the drawable's bounds in a new Rect.
|
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)
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,
BitmapFactory.Options opts)
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
Resources.Theme . |
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. 0 means fully transparent,
255 means fully opaque.
|
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()
Returns the drawable's intrinsic height.
|
int |
getIntrinsicWidth()
Returns the drawable's intrinsic width.
|
int |
getLayoutDirection()
Returns the resolved layout direction for this Drawable.
|
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.
|
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 primitve states, such as
android.R.attr#state_focused ,
android.R.attr#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)
Inflate this Drawable from an XML resource.
|
void |
inflate(Resources r,
XmlPullParser parser,
AttributeSet attrs,
Resources.Theme theme)
Inflate this Drawable from an XML resource optionally styled by a theme.
|
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 |
isProjected()
Whether this drawable requests projection.
|
boolean |
isStateful()
Indicates whether this drawable will change its appearance based on
state.
|
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.
|
protected static TypedArray |
obtainAttributes(Resources res,
Resources.Theme theme,
AttributeSet set,
int[] attrs)
Obtains styled attributes from the theme, if available, or unstyled
resources if the theme is null.
|
protected 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.
|
protected boolean |
onLevelChange(int level)
Override this in your subclass to change appearance if you vary based
on level.
|
protected boolean |
onStateChange(int[] state)
Override this in your subclass to change appearance if you recognize the
specified state.
|
static PorterDuff.Mode |
parseTintMode(int value,
PorterDuff.Mode defaultMode)
Parses a
PorterDuff.Mode from a tintMode
attribute's enum value. |
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. 0 means fully transparent, and
255 means fully opaque.
|
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.
|
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)
Deprecated.
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.
|
boolean |
setLayoutDirection(int layoutDirection)
Set the layout direction for this drawable.
|
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 |
setXfermode(Xfermode mode) |
void |
unscheduleSelf(Runnable what)
Use the current
Drawable.Callback implementation to have this Drawable
unscheduled. |
public abstract void draw(Canvas canvas)
canvas
- The canvas to draw intopublic void setBounds(int left, int top, int right, int bottom)
public void setBounds(Rect bounds)
public final void copyBounds(Rect bounds)
bounds
- Rect to receive the drawable's bounds (allocated by the
caller).public final Rect copyBounds()
public final Rect getBounds()
copyBounds()
,
copyBounds(android.graphics.Rect)
public Rect getDirtyBounds()
By default, this returns the full drawable bounds. Custom drawables may override this method to perform more precise invalidation.
public void setChangingConfigurations(int configs)
configs
- A mask of the changing configuration parameters, as
defined by ActivityInfo
.ActivityInfo
public int getChangingConfigurations()
setChangingConfigurations(int)
or 0 by default. Subclasses
may extend this to or in the changing configurations of any other
drawables they hold.ActivityInfo
.ActivityInfo
@Deprecated public void setDither(boolean dither)
Paint.setDither(boolean);
public void setFilterBitmap(boolean filter)
This can improve appearance when bitmaps are rotated. If the drawable does not use bitmaps, this call is ignored.
isFilterBitmap()
,
Paint.setFilterBitmap(boolean);
public boolean isFilterBitmap()
setFilterBitmap(boolean)
public final void setCallback(Drawable.Callback cb)
Drawable.Callback
object to this Drawable. Required for clients
that want to support animated drawables.cb
- The client's Callback implementation.getCallback()
public Drawable.Callback getCallback()
Drawable.Callback
implementation attached to this
Drawable.Drawable.Callback
instance or null if no callback was set.setCallback(android.graphics.drawable.Drawable.Callback)
public void invalidateSelf()
Drawable.Callback
implementation to have this Drawable
redrawn. Does nothing if there is no Callback attached to the
Drawable.public void scheduleSelf(Runnable what, long when)
Drawable.Callback
implementation to have this Drawable
scheduled. Does nothing if there is no Callback attached to the
Drawable.what
- The action being scheduled.when
- The time (in milliseconds) to run.Drawable.Callback.scheduleDrawable(android.graphics.drawable.Drawable, java.lang.Runnable, long)
public void unscheduleSelf(Runnable what)
Drawable.Callback
implementation to have this Drawable
unscheduled. Does nothing if there is no Callback attached to the
Drawable.what
- The runnable that you no longer want called.Drawable.Callback.unscheduleDrawable(android.graphics.drawable.Drawable, java.lang.Runnable)
public int getLayoutDirection()
View.LAYOUT_DIRECTION_LTR
,
View.LAYOUT_DIRECTION_RTL
setLayoutDirection(int)
public final boolean setLayoutDirection(int layoutDirection)
layoutDirection
- the resolved layout direction for the drawable,
either View.LAYOUT_DIRECTION_LTR
or View.LAYOUT_DIRECTION_RTL
true
if the layout direction change has caused the
appearance of the drawable to change such that it needs to be
re-drawn, false
otherwisegetLayoutDirection()
public boolean onLayoutDirectionChanged(int layoutDirection)
layoutDirection
- the new resolved layout directiontrue
if the layout direction change has caused the
appearance of the drawable to change such that it needs to be
re-drawn, false
otherwisesetLayoutDirection(int)
public abstract void setAlpha(int alpha)
public int getAlpha()
public void setXfermode(Xfermode mode)
public abstract void setColorFilter(ColorFilter colorFilter)
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
.
colorFilter
- The color filter to apply, or null
to remove the
existing color filterpublic void setColorFilter(int color, PorterDuff.Mode mode)
Convenience for setColorFilter(ColorFilter)
which constructs a
PorterDuffColorFilter
.
Note: Setting a color filter disables
tint
.
public void setTint(int tintColor)
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, PorterDuff.Mode)
.
To clear the tint, pass null
to
setTintList(ColorStateList)
.
Note: Setting a color filter via
setColorFilter(ColorFilter)
or
setColorFilter(int, PorterDuff.Mode)
overrides tint.
tintColor
- Color to use for tinting this drawablesetTintList(ColorStateList)
,
setTintMode(PorterDuff.Mode)
public void setTintList(ColorStateList tint)
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, PorterDuff.Mode)
.
Note: Setting a color filter via
setColorFilter(ColorFilter)
or
setColorFilter(int, PorterDuff.Mode)
overrides tint.
tint
- Color state list to use for tinting this drawable, or
null
to clear the tintsetTint(int)
,
setTintMode(PorterDuff.Mode)
public void setTintMode(PorterDuff.Mode tintMode)
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(ColorFilter)
or
setColorFilter(int, PorterDuff.Mode)
overrides tint.
tintMode
- A Porter-Duff blending modesetTint(int)
,
setTintList(ColorStateList)
public ColorFilter getColorFilter()
null
if none set.null
if none setpublic void clearColorFilter()
public void setHotspot(float x, float y)
x
- The X coordinate of the center of the hotspoty
- The Y coordinate of the center of the hotspotpublic void setHotspotBounds(int left, int top, int right, int bottom)
left
- position in pixels of the left boundtop
- position in pixels of the top boundright
- position in pixels of the right boundbottom
- position in pixels of the bottom boundgetHotspotBounds(android.graphics.Rect)
public void getHotspotBounds(Rect outRect)
outRect
with the hotspot bounds.outRect
- the rect to populate with the hotspot boundssetHotspotBounds(int, int, int, int)
public boolean isProjected()
public boolean isStateful()
setState(int[])
public boolean setState(int[] stateSet)
android.R.attr#state_focused
,
android.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.
stateSet
- The new set of states to be displayed.public int[] getState()
android.R.attr#state_focused
,
android.R.attr#state_selected
, etc.
Some drawables may modify their imagery based on the selected state.public void jumpToCurrentState()
public Drawable getCurrent()
StateListDrawable
and LevelListDrawable
this will be the child drawable
currently in use.public final boolean setLevel(int 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.
level
- The new level, from 0 (minimum) to 10000 (maximum).public final int getLevel()
public boolean setVisible(boolean visible, boolean restart)
visible
- Set to true if visible, false if not.restart
- 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.public final boolean isVisible()
public void setAutoMirrored(boolean mirrored)
LayoutDirection
.mirrored
- Set to true if the Drawable should be mirrored, false if not.public boolean isAutoMirrored()
LayoutDirection
.public void applyTheme(Resources.Theme t)
t
- the theme to applypublic boolean canApplyTheme()
public abstract int getOpacity()
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(android.graphics.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.
PixelFormat
public static int resolveOpacity(int op1, int op2)
This is to help in implementing getOpacity()
.
op1
- One opacity value.op2
- Another opacity value.getOpacity()
public Region getTransparentRegion()
protected boolean onStateChange(int[] state)
protected boolean onLevelChange(int level)
protected void onBoundsChange(Rect bounds)
public int getIntrinsicWidth()
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.
public int getIntrinsicHeight()
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.
public int getMinimumWidth()
public int getMinimumHeight()
public boolean getPadding(Rect padding)
public Insets getOpticalInsets()
public void getOutline(Outline outline)
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.
public Drawable mutate()
Drawable.ConstantState
,
getConstantState()
public void clearMutated()
This is hidden because only framework drawables can be cached, so custom drawables don't need to support constant state, mutate(), or clearMutated().
public static Drawable createFromStream(InputStream is, String srcName)
public static Drawable createFromResourceStream(Resources res, TypedValue value, InputStream is, String srcName)
public static Drawable createFromResourceStream(Resources res, TypedValue value, InputStream is, String srcName, BitmapFactory.Options opts)
public static Drawable createFromXml(Resources r, XmlPullParser parser) throws XmlPullParserException, IOException
XmlPullParserException
IOException
public static Drawable createFromXml(Resources r, XmlPullParser parser, Resources.Theme theme) throws XmlPullParserException, IOException
Resources.Theme
.
For more information on how to create resources in XML, see
Drawable Resources.XmlPullParserException
IOException
public static Drawable createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs) throws XmlPullParserException, IOException
XmlPullParserException
IOException
public static Drawable createFromXmlInner(Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme) throws XmlPullParserException, IOException
Resources.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.XmlPullParserException
IOException
public static Drawable createFromPath(String pathName)
public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs) throws XmlPullParserException, IOException
XmlPullParserException
IOException
#inflate(Resources, XmlPullParser, AttributeSet, Theme)
public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs, Resources.Theme theme) throws XmlPullParserException, IOException
r
- Resources used to resolve attribute valuesparser
- XML parser from which to inflate this Drawableattrs
- Base set of attribute valuestheme
- Theme to apply, may be nullXmlPullParserException
IOException
public Drawable.ConstantState getConstantState()
Drawable.ConstantState
instance that holds the shared state of this Drawable.Drawable.ConstantState
,
mutate()
protected static TypedArray obtainAttributes(Resources res, Resources.Theme theme, AttributeSet set, int[] attrs)
public static PorterDuff.Mode parseTintMode(int value, PorterDuff.Mode defaultMode)
PorterDuff.Mode
from a tintMode
attribute's enum value.