StateListDrawable
public
class
StateListDrawable
extends DrawableContainer
java.lang.Object | |||
↳ | android.graphics.drawable.Drawable | ||
↳ | android.graphics.drawable.DrawableContainer | ||
↳ | android.graphics.drawable.StateListDrawable |
Lets you assign a number of graphic images to a single Drawable and swap out the visible item by a string ID value.
It can be defined in an XML file with the <selector>
element.
Each state Drawable is defined in a nested <item>
element. For more
information, see the guide to Drawable Resources.
Summary
XML attributes | |
---|---|
android:constantSize |
If true, the drawable's reported internal size will remain constant as the state changes; the size is the maximum of all of the states. |
android:state_activated |
State value for StateListDrawable ,
set when a view or its parent has been "activated" meaning the user has currently
marked it as being of interest.
|
android:state_active |
State value for StateListDrawable ,
set when a view or drawable is considered "active" by its host.
|
android:state_checkable |
State identifier indicating that the object may display a check mark. |
android:state_checked |
State identifier indicating that the object is currently checked. |
android:state_enabled |
State value for StateListDrawable ,
set when a view is enabled.
|
android:state_first |
State value for StateListDrawable ,
set when a view or drawable is in the first position in an ordered set.
|
android:state_focused |
State value for StateListDrawable ,
set when a view has input focus.
|
android:state_last |
State value for StateListDrawable ,
set when a view or drawable is in the last position in an ordered set.
|
android:state_middle |
State value for StateListDrawable ,
set when a view or drawable is in the middle position in an ordered set.
|
android:state_pressed |
State value for StateListDrawable ,
set when the user is pressing down in a view.
|
android:state_selected |
State value for StateListDrawable ,
set when a view (or one of its parents) is currently selected.
|
android:state_single |
State value for StateListDrawable ,
set when a view or drawable is considered "single" by its host.
|
android:state_window_focused |
State value for StateListDrawable ,
set when a view's window has input focus.
|
android:variablePadding |
If true, allows the drawable's padding to change based on the current state that is selected. |
android:visible |
Indicates whether the drawable should be initially visible. |
Public constructors | |
---|---|
StateListDrawable()
|
Public methods | |
---|---|
void
|
addState(int[] stateSet, Drawable drawable)
Add a new image/string ID to the set of images. |
void
|
applyTheme(Resources.Theme theme)
Applies the specified theme to this Drawable and its children. |
int
|
findStateDrawableIndex(int[] stateSet)
Gets the index of the drawable with the provided state set. |
int
|
getStateCount()
Gets the number of states contained in this drawable. |
Drawable
|
getStateDrawable(int index)
Gets the drawable at an index. |
int[]
|
getStateSet(int index)
Gets the state set at an index. |
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. |
boolean
|
isStateful()
Indicates whether this drawable will change its appearance based on state. |
Drawable
|
mutate()
Make this drawable mutable. |
Protected methods | |
---|---|
boolean
|
onStateChange(int[] stateSet)
Override this in your subclass to change appearance if you recognize the specified state. |
void
|
setConstantState(DrawableContainer.DrawableContainerState state)
|
Inherited methods | |
---|---|
XML attributes
android:constantSize
If true, the drawable's reported internal size will remain constant as the state changes; the size is the maximum of all of the states. If false, the size will vary based on the current state.
May be a boolean value, such as "true
" or
"false
".
android:state_activated
State value for StateListDrawable
,
set when a view or its parent has been "activated" meaning the user has currently
marked it as being of interest. This is an alternative representation of
state_checked for when the state should be propagated down the view hierarchy.
May be a boolean value, such as "true
" or
"false
".
android:state_active
State value for StateListDrawable
,
set when a view or drawable is considered "active" by its host. Actual usage may vary
between views. Consult the host view documentation for details.
May be a boolean value, such as "true
" or
"false
".
android:state_checkable
State identifier indicating that the object may display a check mark. See
R.attr.state_checked
for the identifier that indicates whether it is
actually checked.
May be a boolean value, such as "true
" or
"false
".
android:state_checked
State identifier indicating that the object is currently checked. See
R.attr.state_checkable
for an additional identifier that can indicate
if any object may ever display a check, regardless of whether state_checked is
currently set.
May be a boolean value, such as "true
" or
"false
".
android:state_enabled
State value for StateListDrawable
,
set when a view is enabled.
May be a boolean value, such as "true
" or
"false
".
android:state_first
State value for StateListDrawable
,
set when a view or drawable is in the first position in an ordered set. Actual usage
may vary between views. Consult the host view documentation for details.
May be a boolean value, such as "true
" or
"false
".
android:state_focused
State value for StateListDrawable
,
set when a view has input focus.
May be a boolean value, such as "true
" or
"false
".
android:state_last
State value for StateListDrawable
,
set when a view or drawable is in the last position in an ordered set. Actual usage
may vary between views. Consult the host view documentation for details.
May be a boolean value, such as "true
" or
"false
".
android:state_middle
State value for StateListDrawable
,
set when a view or drawable is in the middle position in an ordered set. Actual usage
may vary between views. Consult the host view documentation for details.
May be a boolean value, such as "true
" or
"false
".
android:state_pressed
State value for StateListDrawable
,
set when the user is pressing down in a view.
May be a boolean value, such as "true
" or
"false
".
android:state_selected
State value for StateListDrawable
,
set when a view (or one of its parents) is currently selected.
May be a boolean value, such as "true
" or
"false
".
android:state_single
State value for StateListDrawable
,
set when a view or drawable is considered "single" by its host. Actual usage may vary
between views. Consult the host view documentation for details.
May be a boolean value, such as "true
" or
"false
".
android:state_window_focused
State value for StateListDrawable
,
set when a view's window has input focus.
May be a boolean value, such as "true
" or
"false
".
android:variablePadding
If true, allows the drawable's padding to change based on the current state that is selected. If false, the padding will stay the same (based on the maximum padding of all the states). Enabling this feature requires that the owner of the drawable deal with performing layout when the state changes, which is often not supported.
May be a boolean value, such as "true
" or
"false
".
android:visible
Indicates whether the drawable should be initially visible.
May be a boolean value, such as "true
" or
"false
".
Public constructors
Public methods
addState
public void addState (int[] stateSet, Drawable drawable)
Add a new image/string ID to the set of images.
Parameters | |
---|---|
stateSet |
int : An array of resource Ids to associate with the image.
Switch to this image by calling setState(). |
drawable |
Drawable : The image to show. Note this must be a unique Drawable that is not shared
between any other View or Drawable otherwise the results are
undefined and can lead to unexpected rendering behavior |
applyTheme
public void applyTheme (Resources.Theme theme)
Applies the specified theme to this Drawable and its children.
Parameters | |
---|---|
theme |
Resources.Theme : the theme to apply
This value cannot be null . |
findStateDrawableIndex
public int findStateDrawableIndex (int[] stateSet)
Gets the index of the drawable with the provided state set.
Parameters | |
---|---|
stateSet |
int : the state set to look up
This value cannot be null . |
Returns | |
---|---|
int |
the index of the provided state set, or -1 if not found |
See also:
getStateCount
public int getStateCount ()
Gets the number of states contained in this drawable.
Returns | |
---|---|
int |
The number of states contained in this drawable. |
See also:
getStateDrawable
public Drawable getStateDrawable (int index)
Gets the drawable at an index.
Parameters | |
---|---|
index |
int : The index of the drawable. |
Returns | |
---|---|
Drawable |
The drawable at the index.
This value may be null . |
See also:
getStateSet
public int[] getStateSet (int index)
Gets the state set at an index.
Parameters | |
---|---|
index |
int : The index of the state set. |
Returns | |
---|---|
int[] |
The state set at the index.
This value cannot be null . |
See also:
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 | |
---|---|
IOException |
|
XmlPullParserException |
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. |
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 . |
Protected methods
onStateChange
protected boolean onStateChange (int[] stateSet)
Override this in your subclass to change appearance if you recognize the specified state.
Parameters | |
---|---|
stateSet |
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. |
setConstantState
protected void setConstantState (DrawableContainer.DrawableContainerState state)
Parameters | |
---|---|
state |
DrawableContainer.DrawableContainerState : This value cannot be null . |
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Last updated 2024-06-18 UTC.