java.lang.Object | ||
↳ | android.graphics.drawable.Drawable | |
↳ | android.graphics.drawable.LayerDrawable |
Known Direct Subclasses |
A Drawable that manages an array of other Drawables. These are drawn in array order, so the element with the largest index will be drawn on top.
It can be defined in an XML file with the
<layer-list>
element.
Each Drawable in the layer is defined in a nested
<item>
. For more
information, see the guide to
Drawable Resources
.
XML Attributes | |||||||||||
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android:bottom | Bottom coordinate of the layer. | ||||||||||
android:drawable | Drawable used to render the layer. | ||||||||||
android:id | Identifier of the layer. | ||||||||||
android:left | Left coordinate of the layer. | ||||||||||
android:right | Right coordinate of the layer. | ||||||||||
android:top | Top coordinate of the layer. |
Public Constructors | |||||||||||
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Create a new layer drawable with the list of specified layers.
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Public Methods | |||||||||||
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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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Look for a layer with the given id, and returns its
Drawable
.
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Gets the current alpha value for the 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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Return a
Drawable.ConstantState
instance that holds the shared state of this Drawable.
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Returns the drawable at the specified layer index.
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Returns the id of the specified layer.
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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 number of layers contained within this.
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Return the opacity/transparency of this Drawable.
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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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Inflate this Drawable from an XML resource.
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Called when the drawable needs to be 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 view will change its appearance based on state.
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Make this drawable mutable.
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A Drawable can call this to schedule the next frame of its
animation.
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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 an optional colorFilter for the drawable.
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Set to true to have the drawable dither its colors when drawn to a device
with fewer than 8-bits per color component.
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Sets (or replaces) the
Drawable
for the layer with the given id.
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Sets the ID of a layer.
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Specify modifiers to the bounds for the drawable[index].
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Sets the opacity of this drawable directly, instead of collecting the states from
the layers
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Set whether this Drawable is visible.
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A Drawable can call this to unschedule an action previously
scheduled with
scheduleDrawable(Drawable, Runnable, long)
.
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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
android.graphics.drawable.Drawable
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From class
java.lang.Object
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From interface
android.graphics.drawable.Drawable.Callback
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Bottom coordinate of the layer.
Must be a dimension value, which is a floating point number appended with a unit such as "
14.5sp
".
Available units are: px (pixels), dp (density-independent pixels), sp (scaled pixels based on preferred font size),
in (inches), mm (millimeters).
This may also be a reference to a resource (in the form
"
@[
package
:]
type
:
name
") or
theme attribute (in the form
"
?[
package
:][
type
:]
name
")
containing a value of this type.
This corresponds to the global attribute
resource symbol
bottom
.
Drawable used to render the layer.
Must be a reference to another resource, in the form "
@[+][
package
:]
type
:
name
"
or to a theme attribute in the form "
?[
package
:][
type
:]
name
".
This corresponds to the global attribute
resource symbol
drawable
.
Identifier of the layer. This can be used to retrieve the layer from a drawbable container.
Must be a reference to another resource, in the form "
@[+][
package
:]
type
:
name
"
or to a theme attribute in the form "
?[
package
:][
type
:]
name
".
This corresponds to the global attribute
resource symbol
id
.
Left coordinate of the layer.
Must be a dimension value, which is a floating point number appended with a unit such as "
14.5sp
".
Available units are: px (pixels), dp (density-independent pixels), sp (scaled pixels based on preferred font size),
in (inches), mm (millimeters).
This may also be a reference to a resource (in the form
"
@[
package
:]
type
:
name
") or
theme attribute (in the form
"
?[
package
:][
type
:]
name
")
containing a value of this type.
This corresponds to the global attribute
resource symbol
left
.
Right coordinate of the layer.
Must be a dimension value, which is a floating point number appended with a unit such as "
14.5sp
".
Available units are: px (pixels), dp (density-independent pixels), sp (scaled pixels based on preferred font size),
in (inches), mm (millimeters).
This may also be a reference to a resource (in the form
"
@[
package
:]
type
:
name
") or
theme attribute (in the form
"
?[
package
:][
type
:]
name
")
containing a value of this type.
This corresponds to the global attribute
resource symbol
right
.
Top coordinate of the layer.
Must be a dimension value, which is a floating point number appended with a unit such as "
14.5sp
".
Available units are: px (pixels), dp (density-independent pixels), sp (scaled pixels based on preferred font size),
in (inches), mm (millimeters).
This may also be a reference to a resource (in the form
"
@[
package
:]
type
:
name
") or
theme attribute (in the form
"
?[
package
:][
type
:]
name
")
containing a value of this type.
This corresponds to the global attribute
resource symbol
top
.
Create a new layer drawable with the list of specified layers.
layers | A list of drawables to use as layers in this new drawable. |
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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).
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 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.
Configuration
.
Return a
Drawable.ConstantState
instance that holds the shared state of this Drawable.
q
Returns the drawable at the specified layer index.
index | The layer index of the drawable to retrieve. |
---|
Drawable
at the specified layer index.
Returns the id of the specified layer.
index | The index of the layer. |
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NO_ID
if the layer has no id.
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 number of layers contained within this.
Return the opacity/transparency of this Drawable. The returned value is
one of the abstract format constants in
PixelFormat
:
UNKNOWN
,
TRANSLUCENT
,
TRANSPARENT
, or
OPAQUE
.
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
take into account a
custom alpha or color filter that has been applied by the client through
the
setAlpha(int)
or
setColorFilter(ColorFilter)
methods.
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). Returns true if this drawable actually has a padding, else false. When false is returned, the padding is always set to 0.
Inflate this Drawable from an XML resource.
Called when the drawable needs to be redrawn. A view at this point should invalidate itself (or at least the part of itself where the drawable appears).
who | The drawable that is requesting the update. |
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Tells if this Drawable will be automatically mirrored when its layout direction is RTL
right-to-left. See
LayoutDirection
.
Indicates whether this view will change its appearance based on state. Clients can use this to determine whether it is necessary to calculate their state and call setState.
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.
A Drawable can call this to schedule the next frame of its
animation. An implementation can generally simply call
postAtTime(Runnable, Object, long)
with
the parameters
(what, who, when)
to perform the
scheduling.
who | The drawable being scheduled. |
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what | The action to execute. |
when |
The time (in milliseconds) to run. The timebase is
uptimeMillis()
|
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 an optional colorFilter for the drawable. Pass null to remove any filters.
Set to true to have the drawable dither its colors when drawn to a device with fewer than 8-bits per color component. This can improve the look on those devices, but can also slow down the drawing a little.
Sets the ID of a layer.
index | The index of the layer which will received the ID. |
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id | The ID to assign to the layer. |
Specify modifiers to the bounds for the drawable[index]. left += l top += t; right -= r; bottom -= b;
Sets the opacity of this drawable directly, instead of collecting the states from the layers
opacity |
The opacity to use, or
PixelFormat.UNKNOWN
for the default behavior
|
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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. |
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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. |
A Drawable can call this to unschedule an action previously
scheduled with
scheduleDrawable(Drawable, Runnable, long)
. An implementation can
generally simply call
removeCallbacks(Runnable, Object)
with
the parameters
(what, who)
to unschedule the drawable.
who | The drawable being unscheduled. |
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what | The action being unscheduled. |
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.