GraphicElement  - AS3 Flex

The level of transparency of the graphic element. Valid values are decimal values between 0 (fully transparent) and 1 (fully opaque). For example, a value of .25 means that the element has 25% opacity.

Specifies that this GraphicElement is to be associated with and be rendered to its own DisplayObject.

預設值為 false。

The vertical distance in pixels from the anchor target to the control's baseline position.

By default the anchor target is the top edge of the container's content area. In layouts with advanced constraints, the target can be a constraint row.

Setting the property to a number or to a numerical string like "10" specifies use of the default anchor target.

To specify an anchor target, set the property value to a string in the format: "anchorTargetName:value". For example, "row1:10".

The y-coordinate of the baseline of the first line of text of the component.

A value from the BlendMode class that specifies which blend mode to use.

預設值為 auto。

相關 API 元素

The vertical distance in pixels from the bottom edge of the component to the anchor target's bottom edge.

By default the anchor target is the container's content area. In layouts with advanced constraints, the target can be a constraint row.

Setting the property to a number or to a numerical string like "10" specifies use of the default anchor target.

To specify an anchor target, set the property value to a string in the format: "anchorTargetName:value". For example, "row1:10".

Determines the order in which items inside of containers are rendered. Spark containers order their items based on their depth property, with the lowest depth in the back, and the higher in the front. Items with the same depth value appear in the order they are added to the container.

Specifies the optional DesignLayer instance associated with this visual element.

When a DesignLayer is assigned, a visual element must consider the visibility and alpha of its parent layer when ultimately committing its own effective visibility or alpha to its backing DisplayObject (if applicable).

A visual element must listen for layerPropertyChange notifications from the associated layer parent. When the effectiveAlpha or effectiveVisibility of the layer changes, the element must then compute its own effective visibility (or alpha) and apply it accordingly.

This property should not be set within MXML directly.

The designLayer property is not used for z-order control, please see depth.

The shared DisplayObject where this IGraphicElement is drawn.

Implementers should not create the DisplayObject here, but in the createDisplayObject() method.

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 propertyChange 事件。

Indicates the association between this IGraphicElement and its display objects. The IGraphicElementContainer manages this property and the values are one of the DisplayObjectSharingMode enum class.

• A value of DisplayObjectSharingMode.OWNS_UNSHARED_OBJECT indicates that the IGraphicElement owns exclusively the DisplayObject corresponding to its displayObject property.
• A value of DisplayObjectSharingMode.OWNS_SHARED_OBJECT indicates taht the IGraphicElement owns the DisplayObject corresponding to its displayObject property but other IGraphicElements are using/drawing to that display object as well. Depending on the specific implementation, the IGraphicElement may perform certain management of the display object. For example the base class GraphicElement clears the transform of the display object, reset its visibility, alpha, etc. properties to their default values and additionally clear the graphics on every validateDisplayList() call.
• A value of DisplayObjectSharingMode.USES_SHARED_OBJECT indicates that the IGraphicElement draws into the DisplayObject corresponding to its displayObject property. There are one or more IGraphicElements that draw into that same displayObject, and the first element that draws has its mode set to DisplayObjectMode.OWNS_SHARED_OBJECT

The actual DisplayObject that is drawn into by the GraphicElement. Typically this is equivalent to the displayObject property. Subclasses should perform drawing commands on this property instead of on displayObject.

The x position where the element should be drawn.

The y position where the element should be drawn.

Number that specifies the explicit height of the component, in pixels, in the component's coordinates.

相關 API 元素

The maximum recommended height of the component to be considered by the parent during layout. This value is in the component's coordinates, in pixels.

相關 API 元素

The maximum recommended width of the component to be considered by the parent during layout. This value is in the component's coordinates, in pixels.

相關 API 元素

The minimum recommended height of the component to be considered by the parent during layout. This value is in the component's coordinates, in pixels.

相關 API 元素

The minimum recommended width of the component to be considered by the parent during layout. This value is in the component's coordinates, in pixels.

相關 API 元素

Number that specifies the explicit width of the component, in pixels, in the component's coordinates.

相關 API 元素

An indexed array that contains each filter object currently associated with the graphic element. The mx.filters package contains classes that define specific filters you can use.

The getter returns a copy of the filters array. The filters property value can only be changed via the setter.

相關 API 元素

Returns true if the GraphicElement has any non-translation (x,y) transform properties

Contains true if the element has 3D Matrix.

Use hasLayoutMatrix3D instead of calling and examining the return value of getLayoutMatrix3D() because that method returns a valid matrix even when the element is in 2D.

The height of the graphic element.

預設值為 0。

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 propertyChange 事件。

The horizontal distance in pixels from the center of the component to the center of the anchor target's content area.

The default anchor target is the container itself.

In layouts with advanced constraints, the anchor target can be a constraint column. Then the content area is the space between the preceding column (or container side) and the target column.

Setting the property to a number or to a numerical string like "10" specifies use of the default anchor target.

To specify an anchor target, set the property value to a string in the format "constraintColumnId:value". For example, "col1:10".

The identity of the component.

Specifies whether this element is included in the layout of the parent.

預設值為 true。

Contains true when the element is in 3D. The element can be in 3D either because it has 3D transform properties or it has 3D post layout transform offsets or both.

Specifies the desired layout direction for an element: one of LayoutDirection.LTR (left to right), LayoutDirection.RTL (right to left), or null (inherit). This property is typically backed by an inheriting style. If null, the layoutDirection style will be set to undefined. Classes like GraphicElement, which implement ILayoutDirectionElement but do not support styles, must additionally support a null value for this property which means the layoutDirection must be inherited from its parent.

Contain all of the implementation details of how the GraphicElement implements transform and layering support. In most cases, you should not have to modify this property.

The horizontal distance in pixels from the left edge of the component to the anchor target's left edge.

By default the anchor target is the container's content area. In layouts with advanced constraints, the target can be a constraint column.

Setting the property to a number or to a numerical string like "10" specifies use of the default anchor target.

To specify an anchor target, set the property value to a string in the format "anchorTargetName:value". For example, "col1:10".

A property that controls whether the luminosity mask clips the masked content. This property can only have an effect if the graphic element has a mask applied to it that is of type MaskType.LUMINOSITY.

預設值為 false。

相關 API 元素

A property that controls the calculation of the RGB color value of a graphic element being masked by a luminosity mask. If true, the RGB color value of a pixel in the source content is inverted and multipled by the corresponding region in the mask. If false, the source content's pixel's RGB color value is used directly.

預設值為 false。

相關 API 元素

The calling display object is masked by the specified mask object. If, the mask display object is not on the display list, it will be added to the display list as a child of the displayObject. The mask object itself is not drawn. Set mask to null to remove the mask. To use another GraphicElement as a mask, wrap the GraphicElement in a Group or other container.

相關 API 元素

Defines how the mask is applied to the GraphicElement.

The possible values are MaskType.CLIP, MaskType.ALPHA, and MaskType.LUMINOSITY.

Clip Masking

When masking in clip mode, a clipping masks is reduced to 1-bit. This means that a mask will not affect the opacity of a pixel in the source content; it either leaves the value unmodified, if the corresponding pixel in the mask is has a non-zero alpha value, or makes it fully transparent, if the mask pixel value has an alpha value of zero.

When clip masking is used, only the actual path and shape vectors and fills defined by the mask are used to determine the effect on the source content. strokes and bitmap filters defined on the mask are ignored. Any filled region in the mask is considered filled, and renders the source content. The type and parameters of the fill is irrelevant; a solid color fill, gradient fill, or bitmap fill in a mask will all render the underlying source content, regardless of the alpha values of the mask fill.

BitmapGraphics are treated as bitmap filled rectangles when used in a clipping mask. As a result, the alpha channel of the source bitmap is irrelevant when part of a mask -- the bitmap affects the mask in the same manner as solid filled rectangle of equivalent dimensions.

Alpha Masking

In alpha mode, the opacity of each pixel in the source content is multiplied by the opacity of the corresponding region of the mask. i.e., a pixel in the source content with an opacity of 1 that is masked by a region of opacity of .5 will have a resulting opacity of .5. A source pixel with an opacity of .8 masked by a region with opacity of .5 will have a resulting opacity of .4.

Conceptually, alpha masking is equivalent to rendering the transformed mask and source content into separate RGBA surfaces, and multiplying the alpha channel of the mask content into the alpha channel of the source content. All of the mask content is rendered into its surface before compositing into the source content's surface. As a result, all FXG features, such as strokes, bitmap filters, and fill opacity will affect the final composited content.

When in alpha mode, the alpha channel of any bitmap data is composited normally into the mask alpha channel, and will affect the final rendered content. This holds true for both BitmapGraphics and bitmap filled shapes and paths.

Luminosity Masking

A luminosity mask, sometimes called a 'soft mask', works very similarly to an alpha mask except that both the opacity and RGB color value of a pixel in the source content is multiplied by the opacity and RGB color value of the corresponding region in the mask.

Conceptually, luminosity masking is equivalent to rendering the transformed mask and source content into separate RGBA surfaces, and multiplying the alpha channel and the RGB color value of the mask content into the alpha channel and RGB color value of the source content. All of the mask content is rendered into its surface before compositing into the source content's surface. As a result, all FXG features, such as strokes, bitmap filters, and fill opacity will affect the final composited content.

Luminosity masking is not native to Flash but is common in Adobe Creative Suite tools like Adobe Illustrator and Adobe Photoshop. In order to accomplish the visual effect of a luminosity mask in Flash-rendered content, a graphic element specifying a luminosity mask actually instantiates a shader filter that mimics the visual look of a luminosity mask as rendered in Adobe Creative Suite tools.

Objects being masked by luminosity masks can set properties to control the RGB color value and clipping of the mask. See the luminosityInvert and luminosityClip attributes.

預設值為 MaskType.CLIP。

相關 API 元素

The maximum recommended height of the component to be considered by the parent during layout. This value is in the component's coordinates, in pixels. The default value of this property is set by the component developer.

The component developer uses this property to set an upper limit on the height of the component.

If the application developer overrides the default value of maxHeight, the new value is stored in explicitMaxHeight. The default value of maxHeight does not change. As a result, at layout time, if maxHeight was explicitly set by the application developer, then the value of explicitMaxHeight is used for the component's maximum recommended height. If maxHeight is not set explicitly by the user, then the default value is used.

This value is used by the container in calculating the size and position of the component. It is not used by the component itself in determining its default size. Thus this property may not have any effect if parented by Container, or containers that don't factor in this property. Because the value is in component coordinates, the true maxHeight with respect to its parent is affected by the scaleY property. Some components have no theoretical limit to their height. In those cases their maxHeight is set to UIComponent.DEFAULT_MAX_HEIGHT.

The maximum recommended width of the component to be considered by the parent during layout. This value is in the component's coordinates, in pixels. The default value of this property is set by the component developer.

The component developer uses this property to set an upper limit on the width of the component.

If the application developer overrides the default value of maxWidth, the new value is stored in explicitMaxWidth. The default value of maxWidth does not change. As a result, at layout time, if maxWidth was explicitly set by the application developer, then the value of explicitMaxWidth is used for the component's maximum recommended width. If maxWidth is not set explicitly by the user, then the default value is used.

This value is used by the container in calculating the size and position of the component. It is not used by the component itself in determining its default size. Thus this property may not have any effect if parented by Container, or containers that don't factor in this property. Because the value is in component coordinates, the true maxWidth with respect to its parent is affected by the scaleX property. Some components have no theoretical limit to their width. In those cases their maxWidth is set to UIComponent.DEFAULT_MAX_WIDTH.

The default height of the component, in pixels. This value is set by the measure() method.

The default width of the component, in pixels. This value is set by the measure() method.

The default measured bounds top-left corner relative to the origin of the element.

The default measured bounds top-left corner relative to the origin of the element.

The minimum recommended height of the component to be considered by the parent during layout. This value is in the component's coordinates, in pixels. The default value depends on the component's implementation.

If the application developer sets the value of minHeight, the new value is stored in explicitMinHeight. The default value of minHeight does not change. As a result, at layout time, if minHeight was explicitly set by the application developer, then the value of explicitMinHeight is used for the component's minimum recommended height. If minHeight is not set explicitly by the application developer, then the value of measuredMinHeight is used.

This value is used by the container in calculating the size and position of the component. It is not used by the component itself in determining its default size. Thus this property may not have any effect if parented by Container, or containers that don't factor in this property. Because the value is in component coordinates, the true minHeight with respect to its parent is affected by the scaleY property.

The minimum recommended width of the component to be considered by the parent during layout. This value is in the component's coordinates, in pixels. The default value depends on the component's implementation.

If the application developer sets the value of minWidth, the new value is stored in explicitMinWidth. The default value of minWidth does not change. As a result, at layout time, if minWidth was explicitly set by the application developer, then the value of explicitMinWidth is used for the component's minimum recommended width. If minWidth is not set explicitly by the application developer, then the value of measuredMinWidth is used.

This value is used by the container in calculating the size and position of the component. It is not used by the component itself in determining its default size. Thus this property may not have any effect if parented by Container, or containers that don't factor in this property. Because the value is in component coordinates, the true minWidth with respect to its parent is affected by the scaleX property.

True if the element requires an exclusive DisplayObject. Developers don't usually call this method directly, but override it in their subclasses to indicate that an exclusive DisplayObject is needed. Usually a subclass needs a DisplayObject when it has to set its properties. Some examples of such DisplayObject properties are filters, blendMode, mask, rotation, alpha.

The owner of this IVisualElement object. By default, it is the parent of this IVisualElement object. However, if this IVisualElement object is a child component that is popped up by its parent, such as the drop-down list of a ComboBox control, the owner is the component that popped up this IVisualElement object.

This property is not managed by Flex, but by each component. Therefore, if you use the PopUpManger.createPopUp() or PopUpManger.addPopUp() method to pop up a child component, you should set the owner property of the child component to the component that popped it up.

The default value is the value of the parent property.

The parent container or component for this component. Only visual elements should have a parent property. Non-visual items should use another property to reference the object to which they belong. By convention, non-visual objects use an owner property to reference the object to which they belong.

Specifies the height of a component as a percentage of its parent's size. Allowed values are 0-100. Setting the height or explicitHeight properties resets this property to NaN.

This property returns a numeric value only if the property was previously set; it does not reflect the exact size of the component in percent.

Specifies the width of a component as a percentage of its parent's size. Allowed values are 0-100. The default value is NaN. Setting the width or explicitWidth properties resets this property to NaN.

This property returns a numeric value only if the property was previously set; it does not reflect the exact size of the component in percent.

This property is always set to NaN for the UITextField control.

When used with Spark layouts, this property is used to calculate the width of the component's bounds after scaling and rotation. For example if the component is rotated at 90 degrees, then specifying percentWidth will affect the component's height.

Defines a set of adjustments that can be applied to the object's transform in a way that is invisible to its parent's layout.

For example, if you want a layout to adjust for an object that is rotated 90 degrees, set the object's rotation property. If you want the layout to not adjust for the object being rotated, set its postLayoutTransformOffsets.rotationZ property.

The horizontal distance in pixels from the right edge of the component to the anchor target's right edge.

By default the anchor target is the container's content area. In layouts with advanced constraints, the target can be a constraint column.

Setting the property to a number or to a numerical string like "10" specifies use of the default anchor target.

To specify an anchor target, set the property value to a string in the format "anchorTargetName:value". For example, "col1:10".

Indicates the rotation of the element, in degrees, from the transform point.

Indicates the x-axis rotation of the element instance, in degrees, from its original orientation relative to the 3D parent container. Values from 0 to 180 represent clockwise rotation; values from 0 to -180 represent counterclockwise rotation. Values outside this range are added to or subtracted from 360 to obtain a value within the range. This property is ignored during calculation by any of Flex's 2D layouts.

Indicates the y-axis rotation of the DisplayObject instance, in degrees, from its original orientation relative to the 3D parent container. Values from 0 to 180 represent clockwise rotation; values from 0 to -180 represent counterclockwise rotation. Values outside this range are added to or subtracted from 360 to obtain a value within the range. This property is ignored during calculation by any of Flex's 2D layouts.

Indicates the rotation of the element, in degrees, from the transform point.

The horizontal scale (percentage) of the element as applied from the transform point.

The vertical scale (percentage) of the element as applied from the transform point.

The z scale (percentage) of the element as applied from the transform point.

The vertical distance in pixels from the top edge of the component to the anchor target's top edge.

By default the anchor target is the container's content area. In layouts with advanced constraints, the target can be a constraint row.

Setting the property to a number or to a numerical string like "10" specifies use of the default anchor target.

To specify an anchor target, set the property value to a string in the format "anchorTargetName:value". For example, "row1:10".

這是一個物件，具有和顯示物件的矩陣、顏色轉換和像素邊界有關的屬性。 特定屬性，包括 matrix、colorTransform 以及三個唯讀屬性 (concatenatedMatrix、concatenatedColorTransform 和 pixelBounds)，將在 Transform 類別項目中說明。

每個變形物件的屬性其本身就是一個物件。 這一點很重要，因為要設定矩陣或 colorTransform 物件的新值，唯一的方式就是建立新物件並將該物件複製到 transform.matrix 或 transform.colorTransform 屬性。

例如，若要增加顯示物件矩陣的 tx 值，必須為整個矩陣物件建立副本，然後將此新物件複製到變形物件的矩陣屬性：

    var myMatrix:Matrix = myDisplayObject.transform.matrix;  
    myMatrix.tx += 10; 
    myDisplayObject.transform.matrix = myMatrix;  
    

您不能直接設定 tx 屬性。 下列程式碼不會影響 myDisplayObject：

    myDisplayObject.transform.matrix.tx += 10;
    

您也可以複製整個變形物件，再將它指定給另一個顯示物件的變形屬性。 例如，下列程式碼會將整個變形物件從 myOldDisplayObj 複製到 myNewDisplayObj：

產生的顯示物件 myNewDisplayObj 現在和原有的顯示物件 myOldDisplayObj，都具有相同的矩陣、顏色轉換和像素邊界值。

請注意，若有硬體加速可供使用，AIR for TV 裝置會自動為顏色變化使用硬體加速。

The x position transform point of the element.

The y position transform point of the element.

The z position transform point of the element.

The vertical distance in pixels from the center of the component to the center of the anchor target's content area.

The default anchor target is the container itself.

In layouts with advanced constraints, the anchor target can be a constraint row. Then the content area is the space between the preceding row (or container side) and the target row.

Setting the property to a number or to a numerical string like "10" specifies use of the default anchor target.

To specify an anchor target, set the property value to a string in the format "constraintColumnId:value". For example, "row1:10".

Controls the visibility of this visual element. If true, the object is visible.

If an object is not visible, but the includeInLayout property is set to true, then the object takes up space in the container, but is invisible.

If visible is set to true, the object may not necessarily be visible due to its size and whether container clipping is enabled.

Setting visible to false, prevents the component from getting focus.

The width of the graphic element.

預設值為 0。

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 propertyChange 事件。

The x position of the graphic element.

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 propertyChange 事件。

The y position of the graphic element.

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 propertyChange 事件。

The z position of the graphic element.

此屬性可以做為資料繫結的來源。一旦修改此屬性，將傳送 propertyChange 事件。

Returns true if this IGraphicElement is compatible and can share display objects with the next IGraphicElement in the sequence.

參數

Returns true if this IGraphicElement is compatible and can share display objects with the previous IGraphicElement in the sequence.

In certain cases the element might be passed to the IGraphicElementContainer in a call to the setSharedDisplayObject() method. In those cases, this method is not called.

參數

Determines if the call to the measure() method can be skipped.

Processes the properties set on the element. This is an advanced method that you might override when creating a subclass.

You do not call this method directly. Flex calls the commitProperties() method when you use the addElement() method to add an element to an IGraphicElementContainer container such as Group, or when you call the invalidateProperties() method of the element. Calls to the commitProperties() method occur before calls to the measure() method. This lets you set property values that might be used by the measure() method.

Some elements have properties that interact with each other. It is often best at startup time to process all of these properties at one time to avoid duplicating work.

Creates a new DisplayObject where this IGraphicElement is drawn.

Subsequent calls to the getter of the displayObject property must return the same display object.

After the DisplayObject is created, the parent IGraphicElementContainer will pass along the display objects to the rest of the elements in the sequence.

The IGraphicElementContainer ensures that this method is called only when needed.

If the element wants to participate in the DisplayObject sharing, then the new DisplayObject must implement IShareableDisplayObject. This interface is being used by the IGraphicElementContainer to manage invalidation and redrawing of the graphic element sequence and typically is not directly used by the developer.

To reevaluate the shared sequences, call the invalidateGraphicElementSharing() method on the IGraphicElementContainer.

To force the IGraphicElementContainer to remove the element's current DisplayObject from its display list and recalculate the display object sharing, call the discardDisplayObject() method on the IGraphicElementContainer.

Returns the x coordinate of the element's bounds at the specified element size.

This method is typically used by layouts during a call to the measure() method to predict what the element position will be, if the element is resized to particular dimensions.

參數

Returns the y coordinate of the element's bounds at the specified element size. This method is typically used by layouts during a call to the measure() to predict what the element position will be, if the element is resized to particular dimensions.

參數

Returns the element's layout height. This is the size that the element uses to draw on screen.

參數

Returns the element's layout width. This is the size that the element uses to draw on screen.

參數

Returns the x coordinate that the element uses to draw on screen.

參數

Returns the y coordinate that the element uses to draw on screen.

參數

Returns the transform matrix that is used to calculate the component's layout relative to its siblings.

This matrix is typically defined by the component's 2D properties such as x, y, rotation, scaleX, scaleY, transformX, and transformY. Some components may have additional transform properties that are applied on top of the layout matrix to determine the final, computed matrix. For example UIComponent defines the offsets property.

Returns the layout transform Matrix3D for this element.

This matrix is typically defined by the component's transform properties such as x, y, z, rotationX, rotationY, rotationZ, scaleX, scaleY, scaleZ, transformX, and transformY. Some components may have additional transform properties that are applied on top of the layout matrix to determine the final, computed matrix. For example UIComponent defines the offsets property.

Returns the element's maximum height.

參數

Returns the element's maximum width.

參數

Returns the element's minimum height.

參數

Returns the element's minimum width.

參數

Returns the element's preferred height.

參數

Returns the element's preferred width.

參數

Returns the amount of pixels occupied by the stroke on each side of the element's bounds.

參數

Called automatically by the MXML compiler when the GraphicElement is created using an MXML tag. If you create the GraphicElement through ActionScript you must set the id property manually.

參數

Calling this method results in a call to the elements's validateDisplayList() method before the display list is rendered.

Subclasses should override and do their work in updateDisplayList().

Utility method that notifies the host that this element has changed and needs its layer to be updated.

An element must call this method when its layoutDirection changes or when its parent's layoutDirection changes. If they differ, this method is responsible for mirroring the element’s contents and for updating the element’s post-layout transform so that descendants inherit a mirrored coordinate system. IVisualElements typically implement mirroring by using postLayoutTransformOffsets to scale the X axis by -1 and to translate the x coordinate of the origin by the element's width. The net effect of this "mirror" transform is to reverse the direction in which the X axis increases without changing the element's location relative to its parent's origin.

Helper method to invalidate parent size and display list if this object affects its layout (includeInLayout is true).

Calling this method results in a call to the elements's validateProperties() method before the display list is rendered.

Subclasses should do their work in commitProperties().

Calling this method results in a call to the elements's validateSize() method before the display list is rendered.

Subclasses should override and do their measurement in measure(). By default when explicitWidth and explicitHeight are set, measure() will not be called. To override this default behavior subclasses should override skipMeasure().

Converts the point object from the object's (local) coordinates to the Stage (global) coordinates.

This method allows you to convert any given x and y coordinates from values that are relative to the origin (0,0) of a specific object (local coordinates) to values that are relative to the origin of the Stage (global coordinates).

To use this method, first create an instance of the Point class. The x and y values that you assign represent local coordinates because they relate to the origin of the object.

You then pass the Point instance that you created as the parameter to the localToGlobal() method. The method returns a new Point object with x and y values that relate to the origin of the Stage instead of the origin of the object.

參數

相關 API 元素

Calculates the default size of the element. This is an advanced method that you might override when creating a subclass of GraphicElement.

You do not call this method directly. Flex calls the measure() method when the element is added to an IGraphicElementContainer container such as Group using the addElement() method, and when the element's invalidateSize() method is called.

By default you set both explicit height and explicit width of an element, Flex does not call the measure() method, even if you explicitly call the invalidateSize() method. To override this behavior, override skipMeasure() method.

In your override of this method, you must set the measuredWidth and measuredHeight properties to define the default size. You can optionally set the measuredX and measuredY properties to define the default measured bounds top-left corner relative to the origin of the element.

The conceptual point of measure() is for the element to provide its own natural or intrinsic bounds as a default. Therefore, the measuredWidth and measuredHeight properties should be determined by factors such as:

• The amount of text the component needs to display.
• The size of a JPEG image that the component displays.

In some cases, there is no intrinsic way to determine default values. For example, a simple GreenCircle element might simply set measuredWidth = 100 and measuredHeight = 100 in its measure() method to provide a reasonable default size. In other cases, such as a TextArea, an appropriate computation (such as finding the right width and height that would just display all the text and have the aspect ratio of a Golden Rectangle) might be too time-consuming to be worthwhile.

The default implementation of measure() sets the values of the measuredWidth, measuredHeight, measuredX, and measuredY properties to 0.

Called by IGraphicElementContainer when an IGraphicElement is added to or removed from the host component.

You typically never need to call this method.

參數

Used for the implementation of the ILayoutElement interface, returns the explicit measured height pre-transform.

Used for the implementation of the ILayoutElement interface, returns the explicit of measured width pre-transform.

Sets the coordinates that the element uses to draw on screen.

Note that calls to the setLayoutBoundSize() method can affect the layout position, so call setLayoutBoundPosition() after calling setLayoutBoundSize().

參數

Sets the layout size of the element. This is the size that the element uses to draw on screen.

If the width and/or height parameters are left unspecified (NaN), Flex sets the element's layout size to its preferred width and/or preferred height.

Note that calls to the setLayoutBoundSize() method can affect the layout position, so call setLayoutBoundPosition() after calling setLayoutBoundSize().

參數

Sets the transform Matrix that is used to calculate the component's layout size and position relative to its siblings.

The matrix is typically defined by the component's 2D properties such as x, y, rotation, scaleX, scaleY, transformX, and transformY. Some components may have additional transform properties that are applied on top of the layout matrix to determine the final, computed matrix. For example UIComponent defines the offsets.

Note that layout Matrix is factored in the getPreferredSize(), getMinSize(), getMaxSize(), getLayoutSize() methods when computed in parent coordinates as well as in getLayoutPosition() in both parent and child coordinates. Layouts that calculate the transform matrix explicitly typically call this method and work with sizes in child coordinates. Layouts calling this method pass false to the invalidateLayout() method so that a subsequent layout pass is not triggered.

參數

Sets the transform Matrix3D that is used to calculate the component's layout size and position relative to its siblings.

This matrix is typically defined by the component's transform properties such as x, y, z, rotationX, rotationY, rotationZ, scaleX, scaleY, scaleZ, transformX, and transformY. Some components may have additional transform properties that are applied on top of the layout matrix to determine the final, computed matrix. For example UIComponent defines the offsets property.

Note that layout Matrix3D is factored in the getPreferredSize(), getMinSize(), getMaxSize(), getLayoutSize() when computed in parent coordinates as well as in getLayoutPosition() in both parent and child coordinates. Layouts that calculate the transform matrix explicitly typically call this method and work with sizes in child coordinates. Layouts calling this method pass false to the invalidateLayout() method so that a subsequent layout pass is not triggered.

參數

Determines whether this element can draw itself to the sharedDisplayObject of the sequence.

Typically implementers return true when this IGraphicElement can cumulatively draw in the shared DisplayObject graphics property. In all cases where this IGraphicElement needs to set properties on the DisplayObjects that don't apply to the rest of the elements in the sequence, this method must return false. Examples for such properties are rotation, scale, transform, mask, alpha, filters, color transform, 3D, and layer.

When this method returns true, subsequent calls to the getter of the displayObject property must return the same display object.

In certain cases, the sharedDisplayObject property might be the IGraphicElementContainer itself. In the rest of the cases, the DisplayObject is created by the first element in the sequence.

When this IGraphicElement needs to rebuild its sequence, it notifies the IGraphicElementContainer by calling its invalidateGraphicElementSharing() method.

參數

A utility method to update the rotation, scale, and translation of the transform while keeping a particular point, specified in the component's own coordinate space, fixed in the parent's coordinate space. This function will assign the rotation, scale, and translation values provided, then update the x/y/z properties as necessary to keep the transform center fixed.

參數

Transform the element's size.

This method calculates the bounding box of the graphic element as if the element’s width/height properties were set to the passed in values. The method returns the height of the bounding box.

In general, this method is not for use by developers. Instead, you should implement or override the methods defined by the ILayoutElement interface.

參數

A utility method to transform a point specified in the local coordinates of this object to its location in the object's parent's coordinates. The pre-layout and post-layout result will be set on the position and postLayoutPosition parameters, if they are non-null.

參數

Transform the element's size.

This method calculates the bounding box of the graphic element as if the element’s width/height properties were set to the passed in values. The method returns the width of the bounding box.

In general, this method is not for use by developers. Instead, you should implement or override the methods defined by the ILayoutElement interface.

參數

Draws the element and/or sizes and positions its content. This is an advanced method that you might override when creating a subclass of GraphicElement.

You do not call this method directly. Flex calls the updateDisplayList() method when the component is added to an IGraphicElementContainer container such as Group using the addElement() method, and when the element's invalidateDisplayList() method is called.

This method is where you would do programmatic drawing using methods on the elements's displayObject such as graphics.drawRect().

參數

Called by the IGraphicElementContainer to redraw this element in its displayObject property.

If the element is the first in the sequence (displayObjectSharingMode is set to DisplayObjectSharingMode.OWNS_SHARED_OBJECT) then it must clear the displayObject graphics and set it up as necessary for drawing the rest of the elements.

The element must alway redraw even if it itself has not changed since the last time the validateDisplayList() method was called. The parent IGraphicElementContainer will redraw the whole sequence if any of its elements need to be redrawn.

To ensure this method is called, notify the IGraphicElementContainer by calling its invalidateGraphicElementSize() method.

This method might be called even if this element has not notified the IGraphicElementContainer.

Validates and updates the properties and layout of this object by immediately calling validateProperties(), validateSize(), and validateDisplayList(), if necessary.

Used by layout logic to validate the properties of a component by calling the commitProperties() method. In general, subclasses should override the commitProperties() method and not this method.

Called by the IGraphicElementContainer to validate the size of this element.

When the size of the element changes and is going to affect the IGraphicElementContainer layout, the implementer is responsible for invalidating the parent's size and display list.

To ensure that this method is called, notify the IGraphicElementContainer by calling its invalidateGraphicElementSize() method.

This method might be called even if this element has not notified the IGraphicElementContainer.