| java.lang.Object | ||
| ↳ | android.graphics.drawable.Drawable | |
| ↳ | android.graphics.drawable.ScaleDrawable | |
A Drawable that changes the size of another Drawable based on its current level value. You can control how much the child Drawable changes in width and height based on the level, as well as a gravity to control where it is placed in its overall container. Most often used to implement things like progress bars.
It can be defined in an XML file with the <scale> element. For more
information, see the guide to Drawable Resources.
| XML Attributes | |||||||||||
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| android:drawable | Reference to a drawable resource to draw with the specified scale. | ||||||||||
| android:scaleGravity | Specifies where the drawable is positioned after scaling. | ||||||||||
| android:scaleHeight | Scale height, expressed as a percentage of the drawable's bound. | ||||||||||
| android:scaleWidth | Scale width, expressed as a percentage of the drawable's bound. | ||||||||||
| Public Constructors | |||||||||||
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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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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. | |||||||||||
Returns the drawable scaled by this ScaleDrawable.
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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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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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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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Specify an optional colorFilter for the drawable.
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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). | |||||||||||
| Protected Methods | |||||||||||
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Override this in your subclass to change appearance if you recognize the
specified state.
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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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Reference to a drawable resource to draw with the specified scale.
Must be a reference to another resource, in the form "@[+][package:]type:name"
or to a theme attribute in the form "?[package:][type:]name".
This corresponds to the global attribute
resource symbol drawable.
Specifies where the drawable is positioned after scaling. The default value is left.
Must be one or more (separated by '|') of the following constant values.
| Constant | Value | Description |
|---|---|---|
top | 0x30 | Push object to the top of its container, not changing its size. |
bottom | 0x50 | Push object to the bottom of its container, not changing its size. |
left | 0x03 | Push object to the left of its container, not changing its size. |
right | 0x05 | Push object to the right of its container, not changing its size. |
center_vertical | 0x10 | Place object in the vertical center of its container, not changing its size. |
fill_vertical | 0x70 | Grow the vertical size of the object if needed so it completely fills its container. |
center_horizontal | 0x01 | Place object in the horizontal center of its container, not changing its size. |
fill_horizontal | 0x07 | Grow the horizontal size of the object if needed so it completely fills its container. |
center | 0x11 | Place the object in the center of its container in both the vertical and horizontal axis, not changing its size. |
fill | 0x77 | Grow the horizontal and vertical size of the object if needed so it completely fills its container. |
clip_vertical | 0x80 | Additional option that can be set to have the top and/or bottom edges of the child clipped to its container's bounds. The clip will be based on the vertical gravity: a top gravity will clip the bottom edge, a bottom gravity will clip the top edge, and neither will clip both edges. |
clip_horizontal | 0x08 | Additional option that can be set to have the left and/or right edges of the child clipped to its container's bounds. The clip will be based on the horizontal gravity: a left gravity will clip the right edge, a right gravity will clip the left edge, and neither will clip both edges. |
start | 0x00800003 | Push object to the beginning of its container, not changing its size. |
end | 0x00800005 | Push object to the end of its container, not changing its size. |
This corresponds to the global attribute
resource symbol scaleGravity.
Scale height, expressed as a percentage of the drawable's bound. The value's format is XX%. For instance: 100%, 12.5%, etc.
Must be a string value, using '\\;' to escape characters such as '\\n' or '\\uxxxx' for a unicode character.
This may also be a reference to a resource (in the form
"@[package:]type:name") or
theme attribute (in the form
"?[package:][type:]name")
containing a value of this type.
This corresponds to the global attribute
resource symbol scaleHeight.
Scale width, expressed as a percentage of the drawable's bound. The value's format is XX%. For instance: 100%, 12.5%, etc.
Must be a string value, using '\\;' to escape characters such as '\\n' or '\\uxxxx' for a unicode character.
This may also be a reference to a resource (in the form
"@[package:]type:name") or
theme attribute (in the form
"?[package:][type:]name")
containing a value of this type.
This corresponds to the global attribute
resource symbol scaleWidth.
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 |
|---|
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 scaled by this ScaleDrawable.
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.
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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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. |
|---|---|
| what | The action to execute. |
| when | The time (in milliseconds) to run. The timebase is
uptimeMillis()
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Specify an alpha value for the drawable. 0 means fully transparent, and 255 means fully opaque.
Specify an optional colorFilter for the drawable. Pass null to remove any filters.
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. |
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. |
|---|---|
| what | The action being unscheduled. |
Override this in your subclass to change appearance if you recognize the specified state.
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.