Element

java.lang.Object
- ohos.agp.components.element.Element

直接已知子类:

ElementContainer, ElementWrapper, LayerElement, PixelMapElement, ShadowElement, ShapeElement, VectorElement
```
public abstract class Element
extends Object
```
An abstract class of something that can be drawn.
When static images need to be displayed in an application, this class and its child classes can be used to draw shapes and images. These child classes can resolve issues in specific image use situations.

从以下版本开始:

1

嵌套类概要

嵌套类
限定符和类型	类	说明
`static class`	`Element.ConstantState`	An abstract class of `Element` used to store constant states and data shared by `Elements` instances.
`static interface`	`Element.OnBoundsChangeListener`	Provides a callback to listen for changes of element bounds.
`static interface`	`Element.OnChangeListener`	Provides a callback to listen for element changes.
`static interface`	`Element.OnLayoutDirectionChangeListener`	Provides a callback to listen for element layout direction changes.
`protected static interface`	`Element.OnRankChangeListener`	Provides a callback to listen for `Element` rank change.

字段概要

字段
限定符和类型	字段	说明
`static int`	`ALPHA_DEFAULT`	Indicates the default alpha value.
`static int`	`ALPHA_MAX`	Indicates the maximum alpha value.
`static int`	`ALPHA_MIN`	Indicates the minimum alpha value.
`static Rect`	`DEFAULT_BOUNDS_RECT`	Indicates the default bounds in shape of rectangle.
`static int`	`MAX_RANK`	Indicates the maximum rank value.
`static int`	`MIN_RANK`	Indicates the minimum rank value.

构造器概要

构造器
构造器	说明
`Element()`	Default constructor used to create an `Element` object.
`Element(Object source)`	A constructor used to create an `Element` object based on a specified `Object`.
`Element(Resource resource, boolean decodeImmediately)`	A constructor used to create an `Element` object based on a specific `Resource`.

方法概要

所有方法实例方法具体方法已过时的方法
限定符和类型	方法	说明
`void`	`clearColorMatrix()`	Clears the color matrix of this `Element` object.
`void`	`drawToCanvas(Canvas canvas)`	Draws an `Element` object on the canvas.
`int`	`getAlpha()`	Obtains the alpha value of an element object.
`Rect`	`getBounds()`	Obtains the bounds rectangle of an `Element` object.
`Element.OnChangeListener`	`getCallback()`	Obtains the listener for element attribute changes
`ColorMatrix`	`getColorMatrix()`	Obtains the color matrix of this `Element` object.
`Element`	`getCurrentElement()`	Obtains the `Element` object in use.
`int`	`getHeight()`	Obtains the height of this `Element` object.
`Component.LayoutDirection`	`getLayoutDirection()`	Obtains the resolved layout direction for this `Element`.
`int`	`getMinHeight()`	Obtains the minimum `Element` height suitable for the layout.
`int`	`getMinWidth()`	Obtains the minimum `Element` width suitable for the layout.
`Optional<Rect>`	`getPadding()`	Obtains the padding of this `Element`.
`int`	`getRank()`	Obtains the rank of this `Element`.
`BlendMode`	`getStateColorMode()`	Obtains the `BlendMode` instance of this `Element`.
`boolean`	`getVisible()`	已过时。 This change is effective since API version 8. Replaced by `isVisible()`
`int`	`getWidth()`	Obtains the width of this `Element` object.
`boolean`	`isInheritDirection()`	Checks whether an element inherits the layout of the component that uses the element as the background when `layoutDirection` of the component is RTL.
`boolean`	`isStateful()`	Checks whether the state of an `Element` object is changed based on the component state.
`boolean`	`isVisible()`	Checks whether this `Element` is visible.
`void`	`release()`	已过时。 This change is effective since API version 8. Method is no longer used.
`void`	`setAlpha(int alpha)`	Sets the alpha value of an element object.
`void`	`setBounds(int left, int top, int right, int bottom)`	Sets the bounds of an `Element` object using a `Rect` object.
`void`	`setBounds(Rect bounds)`	Sets the bound of rectangle an `Element` object using a `Rect` object.
`void`	`setCallback(Element.OnChangeListener listener)`	Sets a listener for element attribute changes, such as the attributes set by `setVisible(boolean, boolean)`, `setBounds(int, int, int, int)`, and `setColorMatrix(ohos.agp.render.ColorMatrix)`.
`void`	`setColorMatrix(ColorMatrix matrix)`	Sets the color matrix for this `Element` object.
`void`	`setInheritDirection(boolean followRTL)`	Sets whether the element, which is used by a component as the background, inherits the component's layout when `layoutDirection` of the component is RTL (that is, mirror display).
`boolean`	`setLayoutDirection(Component.LayoutDirection layoutDirection)`	Sets the layout direction for this `Element`.
`protected void`	`setOnBoundsChangeListener(Element.OnBoundsChangeListener listener)`	Listens for bounds changes of this `Element`.
`protected void`	`setOnLayoutDirectionChangeListener(Element.OnLayoutDirectionChangeListener listener)`	Listens for layout direction changes of this `Element`.
`protected void`	`setOnRankChangeListener(Element.OnRankChangeListener listener)`	Listens for rank changes of this `Element`.
`boolean`	`setRank(int rank)`	Set the rank value for the `Element`.
`void`	`setStateColor(StateColor color)`	Sets `StateColor` to `Element`.
`void`	`setStateColorList(int[][] colorState, int[] colors)`	已过时。 Please use `setStateColor(ohos.agp.colors.StateColor)`
`void`	`setStateColorMode(BlendMode mode)`	Sets a `BlendMode` object for this `Element` object.
`boolean`	`setVisible(boolean visible, boolean restart)`	This method doesn't change the visibility of an `Element`.
`void`	`skipAnimation()`	Skips the animation of this `Element` object.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - ALPHA_DEFAULT
```
public static final int ALPHA_DEFAULT
```
    Indicates the default alpha value.
    
    另请参阅:
    
    常量字段值
  - ALPHA_MAX
```
public static final int ALPHA_MAX
```
    Indicates the maximum alpha value.
    
    另请参阅:
    
    常量字段值
  - ALPHA_MIN
```
public static final int ALPHA_MIN
```
    Indicates the minimum alpha value.
    
    另请参阅:
    
    常量字段值
  - DEFAULT_BOUNDS_RECT
```
public static final Rect DEFAULT_BOUNDS_RECT
```
    Indicates the default bounds in shape of rectangle.
  - MAX_RANK
```
public static final int MAX_RANK
```
    Indicates the maximum rank value.
    
    另请参阅:
    
    常量字段值
  - MIN_RANK
```
public static final int MIN_RANK
```
    Indicates the minimum rank value.
    
    另请参阅:
    
    常量字段值
- 构造器详细资料
  - Element
```
public Element()
```
    Default constructor used to create an Element object.
  - Element
```
public Element(Object source)
```
    A constructor used to create an Element object based on a specified Object.
    
    参数:
    
    source - Indicates the resources used for native initialization.
    
    从以下版本开始:
    
    4
  - Element
```
public Element(Resource resource,
               boolean decodeImmediately)
```
    A constructor used to create an Element object based on a specific Resource.
    This method is mostly used by PixelMapElement created from Resource.
    
    参数:
    
    resource - Indicates the resource to decode.
    
    decodeImmediately - Specifies whether to decode the resource immediately. The value true means to decode the resource immediately (to start decoding upon the creation), and false means the opposite.
    
    从以下版本开始:
    
    7
- 方法详细资料
  - setAlpha
```
public void setAlpha(int alpha)
```
    Sets the alpha value of an element object.
    Value 0 indicates complete transparency, and value 255 indicates complete opacity.
    
    参数:
    
    alpha - Indicates the alpha value.
    
    另请参阅:
    
    getAlpha()
  - getAlpha
```
public int getAlpha()
```
    Obtains the alpha value of an element object.
    Value 0 indicates complete transparency, and value 255 indicates complete opacity. This method is implemented by Element child classes. The default alpha value is 255.
    
    返回:
    
    Returns the alpha value.
    
    另请参阅:
    
    setAlpha(int)
  - setRank
```
public final boolean setRank(int rank)
```
    Set the rank value for the Element.
    This change an element appearance depending on the rank.
    
    参数:
    
    rank - Indicates the rank to set, ranging from 0 to 10000.
    
    返回:
    
    Returns true if the change is applied and OnRankChangeListener is set; returns false otherwise.
    
    从以下版本开始:
    
    7
  - getRank
```
public final int getRank()
```
    Obtains the rank of this Element.
    
    返回:
    
    Returns the rank, ranging from 0 to 10000.
    
    从以下版本开始:
    
    6
    
    另请参阅:
    
    setRank(int)
  - setOnRankChangeListener
```
protected void setOnRankChangeListener(Element.OnRankChangeListener listener)
```
    Listens for rank changes of this Element.
    
    参数:
    
    listener - Indicates the listener to be used.
    
    从以下版本开始:
    
    6
    
    另请参阅:
    
    Element.OnRankChangeListener
  - drawToCanvas
```
public void drawToCanvas(Canvas canvas)
```
    Draws an Element object on the canvas.
    
    参数:
    
    canvas - Indicates the canvas on which to draw the element.
    
    从以下版本开始:
    
    3
  - setVisible
```
public boolean setVisible(boolean visible,
                          boolean restart)
```
    This method doesn't change the visibility of an Element. Mostly used for Elements which supports animation to pause/resume their animation.
    
    参数:
    
    visible - Specifies whether the Element object is playing animation or not. Value true indicates that the animation will be resumed and false indicates that the animation will be paused.
    
    restart - Specifies whether to restart the animation of the Element object. Value true indicates that the animation will be restarted from the first frame and false indicates the animation will be resumed from the most recent frame.
    
    返回:
    
    boolean Returns true if the latest visible state is different from the previous state; returns false otherwise.
    
    另请参阅:
    
    isVisible()
  - getVisible
```
@Deprecated
public boolean getVisible()
```
    已过时。 This change is effective since API version 8. Replaced by isVisible()
    
    Obtains the visible state of a public Element object.
    
    返回:
    
    boolean Returns the visible state of the Element object.
    
    另请参阅:
    
    setVisible(boolean, boolean)
  - isVisible
```
public boolean isVisible()
```
    Checks whether this Element is visible.
    
    返回:
    
    Returns true if the Element is visible; returns false otherwise.
    
    从以下版本开始:
    
    7
    
    另请参阅:
    
    setVisible(boolean, boolean)
  - isStateful
```
public boolean isStateful()
```
    Checks whether the state of an Element object is changed based on the component state.
    
    返回:
    
    Returns true if the Element object state is changed; returns false otherwise.
  - getCurrentElement
```
public Element getCurrentElement()
```
    Obtains the Element object in use.
    
    返回:
    
    Returns the Element object in use in normal cases; returns the child Element object in use if an ElementContainer is used.
  - release
```
@Deprecated
public void release()
```
    已过时。 This change is effective since API version 8. Method is no longer used.
    
    Releases all resources.
    If a component is using the Element object, a runtime exception is thrown. When a ElementContainer object is released, all child Element objects are released.
  - setBounds
```
public void setBounds(int left,
                      int top,
                      int right,
                      int bottom)
```
    Sets the bounds of an Element object using a Rect object.
    NOTE: Bound values could be ignored by some components and Element object can be adjusted to fill container for it.
    
    参数:
    
    left - Indicates the left bound of the Element object, in pixels.
    
    top - Indicates the top bound of the Element object, in pixels.
    
    right - Indicates the right bound of the Element object, in pixels.
    
    bottom - Indicates the bottom bound of the Element object, in pixels.
    
    另请参阅:
    
    getBounds(), setBounds(Rect)
  - setBounds
```
public void setBounds(Rect bounds)
```
    Sets the bound of rectangle an Element object using a Rect object.
    NOTE: bounds value could be ignored by some components and Element object can be adjusted to fill container for it.
    
    参数:
    
    bounds - Indicates the bounds.
    
    另请参阅:
    
    getBounds(), setBounds(int, int, int, int)
  - getBounds
```
public final Rect getBounds()
```
    Obtains the bounds rectangle of an Element object.
    NOTE: Bounds value could be ignored by some components and Element object can be adjusted to fill container for it.
    
    返回:
    
    Returns the bounds rectangle.
    
    另请参阅:
    
    setBounds(Rect), setBounds(int, int, int, int)
  - setOnBoundsChangeListener
```
protected void setOnBoundsChangeListener(Element.OnBoundsChangeListener listener)
```
    Listens for bounds changes of this Element.
    
    参数:
    
    listener - Indicates the listener to be used. (Bounds changes are the result of setBounds(ohos.agp.utils.Rect).)
    
    从以下版本开始:
    
    7
    
    另请参阅:
    
    getBounds(), setBounds(Rect), setBounds(int, int, int, int)
  - getWidth
```
public int getWidth()
```
    Obtains the width of this Element object.
    
    返回:
    
    Returns the element width; returns -1 if the element width was not set.
    
    从以下版本开始:
    
    3
  - getHeight
```
public int getHeight()
```
    Obtains the height of this Element object.
    
    返回:
    
    Returns the element height; returns -1 if the element height was not set.
    
    从以下版本开始:
    
    3
  - getMinWidth
```
public int getMinWidth()
```
    Obtains the minimum Element width suitable for the layout. If the element is used as the background of a component,the width of the component must be greater than or equal to the obtained width.
    
    返回:
    
    Returns the suitable element width; returns 0 if the element width was not set.
    
    从以下版本开始:
    
    3
  - getMinHeight
```
public int getMinHeight()
```
    Obtains the minimum Element height suitable for the layout. If the element is used as the background of a component,the height of the component must be greater than or equal to the obtained height.
    
    返回:
    
    Returns the suitable element height; returns 0 if the element height was not set.
    
    从以下版本开始:
    
    3
  - setColorMatrix
```
public void setColorMatrix(ColorMatrix matrix)
```
    Sets the color matrix for this Element object.
    Element colors and the alpha value can be changed by using the color matrix.
    
    参数:
    
    matrix - Indicates the color matrix used as a filter.
    
    从以下版本开始:
    
    3
  - getColorMatrix
```
public ColorMatrix getColorMatrix()
```
    Obtains the color matrix of this Element object.
    
    返回:
    
    Returns the color matrix.
    
    从以下版本开始:
    
    3
  - clearColorMatrix
```
public void clearColorMatrix()
```
    Clears the color matrix of this Element object.
    
    从以下版本开始:
    
    3
  - setStateColorList
```
@Deprecated
public void setStateColorList(int[][] colorState,
                              int[] colors)
```
    已过时。 Please use setStateColor(ohos.agp.colors.StateColor)
    
    Sets Element states and their corresponding colors.
    The length of the state list must equal that of the color list.
    
    参数:
    
    colorState - Indicates a list of element states. The value can be obtained from the ComponentState class.
    
    colors - Indicates a list of colors corresponding to the element states. The value can be obtained from the Color class.
    
    从以下版本开始:
    
    4
    
    另请参阅:
    
    ComponentState, Color
  - setStateColor
```
public void setStateColor(StateColor color)
```
    Sets StateColor to Element. Note: When this function is called content of StateColor object is copied and any later changes of this object will not affect Element. If you need to apply these changes, call this function again.
    
    参数:
    
    color - Indicates a StateColor to set.
    
    从以下版本开始:
    
    7
  - setStateColorMode
```
public void setStateColorMode(BlendMode mode)
```
    Sets a BlendMode object for this Element object.
    This method applies the colors listed in BlendMode to this Element object.
    
    参数:
    
    mode - Indicates the BlendMode object to set.
    
    从以下版本开始:
    
    4
  - getStateColorMode
```
public BlendMode getStateColorMode()
```
    Obtains the BlendMode instance of this Element.
    
    返回:
    
    Returns the BlendMode instance.
    
    从以下版本开始:
    
    7
  - setCallback
```
public void setCallback(Element.OnChangeListener listener)
```
    Sets a listener for element attribute changes, such as the attributes set by setVisible(boolean, boolean), setBounds(int, int, int, int), and setColorMatrix(ohos.agp.render.ColorMatrix).
    
    参数:
    
    listener - Indicates the listener to set.
    
    从以下版本开始:
    
    3
  - getCallback
```
public Element.OnChangeListener getCallback()
```
    Obtains the listener for element attribute changes
    
    返回:
    
    Returns the listener; returns null if the listener was not set.
    
    从以下版本开始:
    
    4
  - skipAnimation
```
public void skipAnimation()
```
    Skips the animation of this Element object.
    
    从以下版本开始:
    
    3
  - setLayoutDirection
```
public final boolean setLayoutDirection(Component.LayoutDirection layoutDirection)
```
    Sets the layout direction for this Element.
    
    参数:
    
    layoutDirection - Indicates the layout direction to set.
    
    返回:
    
    Returns true if the Element needs invalidation (re-drawing); returns false otherwise.
    
    抛出:
    
    IllegalArgumentException - Throws this exception if layoutDirection is not Component.LayoutDirection#LTR or Component.LayoutDirection#RTL.
    
    从以下版本开始:
    
    7
    
    另请参阅:
    
    getLayoutDirection(), Element.OnLayoutDirectionChangeListener, Component.LayoutDirection
  - getLayoutDirection
```
public Component.LayoutDirection getLayoutDirection()
```
    Obtains the resolved layout direction for this Element.
    
    返回:
    
    Returns the resolved layout direction.
    
    从以下版本开始:
    
    7
    
    另请参阅:
    
    setLayoutDirection(LayoutDirection), Element.OnLayoutDirectionChangeListener, Component.LayoutDirection
  - setOnLayoutDirectionChangeListener
```
protected void setOnLayoutDirectionChangeListener(Element.OnLayoutDirectionChangeListener listener)
```
    Listens for layout direction changes of this Element.
    
    参数:
    
    listener - Indicates the listener to be used. (Layout direction changes are the result of setLayoutDirection(ohos.agp.components.Component.LayoutDirection).)
    
    从以下版本开始:
    
    7
    
    另请参阅:
    
    getLayoutDirection(), setLayoutDirection(LayoutDirection), Component.LayoutDirection
  - setInheritDirection
```
public void setInheritDirection(boolean followRTL)
```
    Sets whether the element, which is used by a component as the background, inherits the component's layout when layoutDirection of the component is RTL (that is, mirror display).
    
    参数:
    
    followRTL - Indicates whether the element inherits the component's layout when layoutDirection of the component is RTL. Value true indicates that the element inherits the component's layout; value false indicates the opposite.
    
    从以下版本开始:
    
    4
    
    另请参阅:
    
    Component.LayoutDirection
  - isInheritDirection
```
public boolean isInheritDirection()
```
    Checks whether an element inherits the layout of the component that uses the element as the background when layoutDirection of the component is RTL.
    
    返回:
    
    Returns true if the element inherits the layout of the component that uses the element as the background; returns false otherwise.
    
    从以下版本开始:
    
    4
    
    另请参阅:
    
    Component.LayoutDirection
  - getPadding
```
public Optional<Rect> getPadding()
```
    Obtains the padding of this Element.
    
    返回:
    
    Returns the Optional object with the padding inside of Rect if the Element has padding.
    
    从以下版本开始:
    
    7
    
    另请参阅:
    
    setBounds(Rect), getBounds()

类 Element

嵌套类概要

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

ALPHA_DEFAULT

ALPHA_MAX

ALPHA_MIN

DEFAULT_BOUNDS_RECT

MAX_RANK

MIN_RANK

构造器详细资料

Element

Element

Element

方法详细资料

setAlpha

getAlpha

setRank

getRank

setOnRankChangeListener

drawToCanvas

setVisible

getVisible

isVisible

isStateful

getCurrentElement

release

setBounds

setBounds

getBounds

setOnBoundsChangeListener

getWidth

getHeight

getMinWidth

getMinHeight

setColorMatrix

getColorMatrix

clearColorMatrix

setStateColorList

setStateColor

setStateColorMode

getStateColorMode

setCallback

getCallback

skipAnimation

setLayoutDirection

getLayoutDirection

setOnLayoutDirectionChangeListener

setInheritDirection

isInheritDirection

getPadding