java.lang.Object | |
↳ | android.graphics.drawable.Drawable |
Known Direct Subclasses |
Known Indirect Subclasses |
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:
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
the getIntrinsicHeight()
and getIntrinsicWidth()
methods.
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.
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(Drawable.Callback)
) so that animations will work. A
simple way to do this is through the system facilities such as
setBackground(Drawable)
and
ImageView
.
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.
Nested Classes | |||||||||||
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Drawable.Callback |
Implement this interface if you want to create an animated drawable that
extends Drawable .
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Drawable.ConstantState |
This abstract class is used by Drawable s to store shared constant state and data
between Drawables.
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Public Constructors | |||||||||||
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Public Methods | |||||||||||
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Applies the specified theme to this Drawable and its children.
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Removes the color filter for this drawable.
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Return a copy of the drawable's bounds in a new Rect.
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Return a copy of the drawable's bounds in the specified Rect (allocated
by the caller).
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Create a drawable from file path name.
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Create a drawable from an inputstream, using the given resources and
value to determine density information.
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Create a drawable from an inputstream, using the given resources and
value to determine density information.
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Create a drawable from an inputstream
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Create a drawable from an XML document using an optional
Resources.Theme .
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Create a drawable from an XML document.
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Create from inside an XML document.
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Create a drawable from inside an XML document using an optional
Resources.Theme .
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Draw in its bounds (set via setBounds) respecting optional effects such
as alpha (set via setAlpha) and color filter (set via setColorFilter).
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Gets the current alpha value for the drawable.
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Return the drawable's bounds Rect.
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Return the current
Drawable.Callback implementation attached to this
Drawable.
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Return a mask of the configuration parameters for which this drawable
may change, requiring that it be re-created.
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Returns the current color filter, or
null if none set.
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Return a
Drawable.ConstantState instance that holds the shared state of this Drawable.
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Return the drawable's dirty bounds Rect.
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Populates
outRect with the hotspot bounds.
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Return the intrinsic height of the underlying drawable object.
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Return the intrinsic width of the underlying drawable object.
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Returns the resolved layout direction for this Drawable.
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Retrieve the current level.
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Returns the minimum height suggested by this Drawable.
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Returns the minimum width suggested by this Drawable.
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Return the opacity/transparency of this Drawable.
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Called to get the drawable to populate the Outline that defines its drawing area.
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Return in padding the insets suggested by this Drawable for placing
content inside the drawable's bounds.
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Describes the current state, as a union of primitve states, such as
state_focused ,
state_selected , etc.
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Returns a Region representing the part of the Drawable that is completely
transparent.
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Inflate this Drawable from an XML resource optionally styled by a theme.
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Inflate this Drawable from an XML resource.
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Use the current
Drawable.Callback implementation to have this Drawable
redrawn.
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Tells if this Drawable will be automatically mirrored when its layout direction is RTL
right-to-left.
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Indicates whether this drawable will change its appearance based on
state.
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If this Drawable does transition animations between states, ask that
it immediately jump to the current state and skip any active animations.
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Make this drawable mutable.
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Called when the drawable's resolved layout direction changes.
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Return the appropriate opacity value for two source opacities.
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Use the current
Drawable.Callback implementation to have this Drawable
scheduled.
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Specify an alpha value for the drawable.
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Set whether this Drawable is automatically mirrored when its layout direction is RTL
(right-to left).
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Specify a bounding rectangle for the Drawable.
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Specify a bounding rectangle for the Drawable.
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Bind a
Drawable.Callback object to this Drawable.
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Set a mask of the configuration parameters for which this drawable
may change, requiring that it be re-created.
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Specify an optional color filter for the drawable.
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Specify a color and Porter-Duff mode to be the color filter for this
drawable.
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This method was deprecated
in API level 23.
This property is ignored.
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Set to true to have the drawable filter its bitmaps with bilinear
sampling when they are scaled or rotated.
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Specifies the hotspot's location within the drawable.
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Sets the bounds to which the hotspot is constrained, if they should be
different from the drawable bounds.
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Set the layout direction for this drawable.
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Specify the level for the drawable.
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Specify a set of states for the drawable.
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Specifies tint color for this drawable.
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Specifies tint color for this drawable as a color state list.
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Specifies a tint blending mode for this drawable.
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Set whether this Drawable is visible.
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Use the current
Drawable.Callback implementation to have this Drawable
unscheduled.
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Protected Methods | |||||||||||
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Override this in your subclass to change appearance if you vary based on
the bounds.
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Override this in your subclass to change appearance if you vary based
on level.
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Override this in your subclass to change appearance if you recognize the
specified state.
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[Expand]
Inherited Methods | |||||||||||
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From class
java.lang.Object
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Applies the specified theme to this Drawable and its children.
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).
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.
bounds | Rect to receive the drawable's bounds (allocated by the caller). |
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Create a drawable from file path name.
Create a drawable from an inputstream, using the given resources and value to determine density information.
Create a drawable from an inputstream, using the given resources and value to determine density information.
Create a drawable from an inputstream
Create a drawable from an XML document using an optional Resources.Theme
.
For more information on how to create resources in XML, see
Drawable Resources.
Create a drawable from an XML document. For more information on how to create resources in XML, see Drawable Resources.
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.
Create a drawable from inside an XML document using an optional
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.
Draw in its bounds (set via setBounds) respecting optional effects such as alpha (set via setAlpha) and color filter (set via setColorFilter).
canvas | The canvas to draw into |
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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.
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.
Return the current Drawable.Callback
implementation attached to this
Drawable.
Drawable.Callback
instance or null if no callback was set.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.
ActivityInfo
.Returns the current color filter, or null
if none set.
null
if none set
Return a Drawable.ConstantState
instance that holds the shared state of this Drawable.
StateListDrawable
and LevelListDrawable
this will be the child drawable
currently in use.
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.
Populates outRect
with the hotspot bounds.
outRect | the rect to populate with the hotspot bounds |
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Return the intrinsic height of the underlying drawable object. Returns -1 if it has no intrinsic height, such as with a solid color.
Return the intrinsic width of the underlying drawable object. Returns -1 if it has no intrinsic width, such as with a solid color.
Returns the resolved layout direction for this Drawable.
Retrieve the current level.
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 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.
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.
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.
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).
Describes the current state, as a union of primitve states, such as
state_focused
,
state_selected
, etc.
Some drawables may modify their imagery based on the selected state.
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.
Inflate this Drawable from an XML resource optionally styled by a theme.
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 |
XmlPullParserException | |
IOException | |
XmlPullParserException |
Inflate this Drawable from an XML resource. Does not apply a theme.
Use the current Drawable.Callback
implementation to have this Drawable
redrawn. Does nothing if there is no Callback attached to the
Drawable.
Tells if this Drawable will be automatically mirrored when its layout direction is RTL
right-to-left. See LayoutDirection
.
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.
If this Drawable does transition animations between states, ask that it immediately jump to the current state and skip any active animations.
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.
Called when the drawable's resolved layout direction changes.
layoutDirection | the new resolved layout direction |
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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()
.
op1 | One opacity value. |
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op2 | Another opacity value. |
Use the current 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. |
Specify an alpha value for the drawable. 0 means fully transparent, and 255 means fully opaque.
Set whether this Drawable is automatically mirrored when its layout direction is RTL
(right-to left). See LayoutDirection
.
mirrored | Set to true if the Drawable should be mirrored, false if not. |
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Specify a bounding rectangle for the Drawable. This is where the drawable will draw when its draw() method is called.
Specify a bounding rectangle for the Drawable. This is where the drawable will draw when its draw() method is called.
Bind a Drawable.Callback
object to this Drawable. Required for clients
that want to support animated drawables.
cb | The client's Callback implementation. |
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Set a mask of the configuration parameters for which this drawable may change, requiring that it be re-created.
configs | A mask of the changing configuration parameters, as
defined by ActivityInfo . |
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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
.
colorFilter | The color filter to apply, or null to remove the
existing color filter
|
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Specify a color and Porter-Duff mode to be the color filter for this drawable.
Convenience for setColorFilter(ColorFilter)
which constructs a
PorterDuffColorFilter
.
Note: Setting a color filter disables
tint
.
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.
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.
Specifies the hotspot's location within the drawable.
x | The X coordinate of the center of the hotspot |
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y | The Y coordinate of the center of the hotspot |
Sets the bounds to which the hotspot is constrained, if they should be different from the drawable bounds.
left | position in pixels of the left bound |
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top | position in pixels of the top bound |
right | position in pixels of the right bound |
bottom | position in pixels of the bottom bound |
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.
layoutDirection | the resolved layout direction for the drawable,
either LAYOUT_DIRECTION_LTR
or LAYOUT_DIRECTION_RTL |
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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.
level | The new level, from 0 (minimum) to 10000 (maximum). |
---|
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:
[state_focused
,
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. |
---|
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, 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 drawable |
---|
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, 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 tint |
---|
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 SRC_IN
.
Note: Setting a color filter via
setColorFilter(ColorFilter)
or
setColorFilter(int, PorterDuff.Mode)
overrides tint.
tintMode | A Porter-Duff blending mode |
---|
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.
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. |
Use the current 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. |
---|
Override this in your subclass to change appearance if you vary based on the bounds.
Override this in your subclass to change appearance if you vary based on level.
Override this in your subclass to change appearance if you recognize the specified state.