Determines the baseline y-coordinate of the first line of text of the component. Each component should override this property.

Used by Flex to suggest bitmap caching for the object. If cachePolicy is UIComponentCachePolicy.AUTO, then cacheHeuristic is used to control the object's cacheAsBitmap property.

Specifies the bitmap caching policy for this object. Possible values in MXML are "on", "off" and "auto" (default).

Possible values in ActionScript are UIComponentCachePolicy.ON, UIComponentCachePolicy.OFF and UIComponentCachePolicy.AUTO (default).

• A value of UIComponentCachePolicy.ON means that the object is always cached as a bitmap.
• A value of UIComponentCachePolicy.OFF means that the object is never cached as a bitmap.
• A value of UIComponentCachePolicy.AUTO means that the framework uses heuristics to decide whether the object should be cached as a bitmap.

The default value is UIComponentCachePolicy.AUTO.

The name of this instance's class, such as "Button".

This string does not include the package name. If you need the package name as well, call the getQualifiedClassName() method in the flash.utils package. It will return a string such as "mx.controls::Button".

Returns the x position of the mouse, in the content coordinate system. Content coordinates specify a pixel position relative to the upper left corner of the component's content, and include all of the component's content area, including any regions that are currently clipped and must be accessed by scrolling the component.

Returns the y position of the mouse, in the content coordinate system. Content coordinates specify a pixel position relative to the upper left corner of the component's content, and include all of the component's content area, including any regions that are currently clipped and must be accessed by scrolling the component.

The current view state of the component. Set to "" or null to reset the component back to its base state.

When you use this property to set a component's state, Flex applies any transition you have defined. You can also use the setCurrentState() method to set the current state; this method can optionally change states without applying a transition.

This property can be used as the source for data binding.

See also

Reference to the UIComponentDescriptor, if any, that was used by the createComponentFromDescriptor() method to create this UIComponent instance. If this UIComponent instance was not created from a descriptor, this property is null.

See also

A reference to the document object associated with this UIComponent. A document object is an Object at the top of the hierarchy of a Flex application, MXML component, or AS component.

Specifies whether the UIComponent object receives doubleClick events. The default value is true, which means that the UIComponent object receives doubleClick events.

The mouseEnabled property must also be set to true, its default value, for the object to receive doubleClick events.

The default value is true.

Whether the component can accept user interaction. If you set the enabled property to false for a container, Flex dims the color of the container and of all of its children, and blocks user input to the container and to all of its children.

This property can be used as the source for data binding.

The text that will be displayed by a component's error tip when a component is monitored by a Validator and validation fails.

You can use the errorString property to show a validation error for a component, without actually using a validator class. When you write a String value to the errorString property, Flex draws a red border around the component to indicate the validation error, and the String appears in a tooltip as the validation error message when you move the mouse over the component, just as if a validator detected a validation error.

To clear the validation error, write an empty String, "", to the errorString property.

Note that writing a value to the errorString property does not trigger the valid or invalid events; it only changes the border color and displays the validation error message.

This property can be used as the source for data binding.

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

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 explicitHeight with respect to its parent is affected by the scaleY property.

Setting the height property also sets this property to the specified height value.

This property can be used as the source for data binding.

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

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 will be set to UIComponent.DEFAULT_MAX_HEIGHT.

The default value is NaN.

This property can be used as the source for data binding.

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

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 will be set to UIComponent.DEFAULT_MAX_WIDTH.

The default value is NaN.

This property can be used as the source for data binding.

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

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 default value is NaN.

This property can be used as the source for data binding.

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

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.

The default value is NaN.

This property can be used as the source for data binding.

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

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 explicitWidth with respect to its parent is affected by the scaleX property.

Setting the width property also sets this property to the specified width value.

This property can be used as the source for data binding.

Indicates whether the component can receive focus when clicked on. If this property is false, focus will be transferred to the first parent that is mouseFocusEnable set to true.

The default value is true.

Gets the FocusManager that controls focus for this component and its peers. Each popup has its own focus loop and therefore its own instance of a FocusManager. To make sure you're talking to the right one, use this method.

The focus pane associated with this object. An object has a focus pane when one of its children has focus.

Number that specifies the height of the component, in pixels, in the parent's coordinates. The default value is 0, not the actual height of the control.

Note: You can specify a percentage value in the MXML height attribute, such as height="100%", but you cannot use a percentage value for the height property in ActionScript; use the percentHeight property instead.

Setting this property causes a resize event to be dispatched. See the resize event for details on when this event is dispatched. If the component's scaleY property is not 100, the height of the component from its internal coordinates will not match. Thus a 100 pixel high component with a scaleY of 200 will take 100 pixels in the parent, but will internally think it is 50 pixels high.

This property can be used as the source for data binding.

ID of the component. This value becomes the instance name of the object and should not contain any white space or special characters. Each component throughout an application should have a unique id.

If your application is going to be tested by third party tools, give each component a meaningful id. Testing tools use ids to represent the control in their scripts and having a meaningful name can make scripts more readable. For example, set the value of a button to submit_button rather than b1 or button1.

Specifies whether this component is included in the layout of the parent container. If true, the object is included in its parent container's layout. If false, the object is positioned by its parent container as per its layout rules, but it is ignored for the purpose of computing the position of the next child.

The default value is true.

This property can be used as the source for data binding.

The beginning of this component's chain of inheriting styles. The getStyle() method simply accesses inheritingStyles[styleName] to search the entire prototype-linked chain. This object is set up by initProtoChain(). Developers typically never need to access this property directly.

A flag that determines if an object has been through all three phases of layout: commitment, measurement, and layout (provided that any were required).

The index of a repeated component. If the component is not within a Repeater, the value is -1.

An Array containing the indices required to reference this UIComponent object from its parent document. The Array is empty unless this UIComponent object is within one or more Repeaters. The first element corresponds to the outermost Repeater. For example, if the id is "b" and instanceIndices is [2,4], you would reference it on the parent document as b[2][4].

Determines whether this UIComponent instance is a document object, that is, whether it is at the top of the hierarchy of a Flex application, MXML component, or ActionScript component.

Set to true by the PopUpManager to indicate that component has been popped up.

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

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 will be set to UIComponent.DEFAULT_MAX_HEIGHT.

The default value is 10000.

This property can be used as the source for data binding.

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

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 will be set to UIComponent.DEFAULT_MAX_WIDTH.

The default value is 10000.

This property can be used as the source for data binding.

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

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

The default minimum width 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.

Number that specifies the minimum height of the component, in pixels, in the component's coordinates. The default value depends on the component implementation.

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.

This property can be used as the source for data binding.

Number that specifies the minimum width of the component, in pixels, in the component's coordinates. The default value depends on the component implementation.

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.

This property can be used as the source for data binding.

Whether you can receive focus when clicked on. If false, focus will be transferred to the first parent that is mouseFocusEnable set to true.

The default value is true.

Depth of this object in the containment hierarchy. This number is used by the measurement and layout code. The value is 0 if this component is not on the DisplayList.

The beginning of this component's chain of non-inheriting styles. The getStyle() method simply accesses nonInheritingStyles[styleName] to search the entire prototype-linked chain. This object is set up by initProtoChain(). Developers typically never need to access this property directly.

The owner of this UIComponent. By default, it is the parent of this UIComponent. However, if this UIComponent object is a child component that is popped up by its parent, such as the dropdown list of a ComboBox control, the owner is the component that popped up this UIComponent 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 UIComponent objects should have a parent property. Non-UIComponent objects should use another property to reference the object to which they belong. By convention, non-UIComponent objects use an owner property to reference the object to which they belong.

A reference to the Application object that contains this UIComponent instance. This Application object might exist in a SWFLoader control in another Application, and so on, creating a chain of Application objects that can be walked using parentApplication. The parentApplication property of an Application is never itself; it is either the Application into which it was loaded or null (for the top-level Application). Walking the application chain using the parentApplication property is similar to walking the document chain using the parentDocument property. You can access the top-level application using the application property of the Application class.

This property can be used as the source for data binding.

A reference to the parent document object for this UIComponent. A document object is a UIComponent at the top of the hierarchy of a Flex application, MXML component, or AS component. For the Application object, the parentDocument property is null. This property is useful in MXML scripts to go up a level in the chain of document objects. It can be used to walk this chain using parentDocument.parentDocument, and so on. It is typed as Object so that authors can access properties and methods on ancestor document objects without casting.

This property can be used as the source for data binding.

Number that specifies the height of a component as a percentage of its parent's size. Allowed values are 0-100. The default value is NaN. 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.

This property can be used as the source for data binding.

Number that 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 can be used as the source for data binding.

Set to true after immediate or deferred child creation, depending on which one happens. For a Container object, it is set to true at the end of the createComponentsFromDescriptors() method, meaning after the Container object creates its children from its child descriptors.

For example, if an Accordion container uses deferred instantiation, the processedDescriptors property for the second pane of the Accordion container does not become true until after the user navigates to that pane and the pane creates its children. But, if the Accordion had set the creationPolicy property to "all", the processedDescriptors property for its second pane is set to true during application startup.

For classes that are not containers, which do not have descriptors, it is set to true after the createChildren() method creates any internal component children.

A reference to the Repeater object in the parent document that produced this UIComponent. Use this property, rather than the repeaters property, when the UIComponent is created by a single Repeater object. Use the repeaters property when this UIComponent is created by nested Repeater objects.

The property is set to null when this UIComponent is not created by a Repeater.

The index of the item in the data provider of the Repeater that produced this UIComponent. Use this property, rather than the repeaterIndices property, when the UIComponent is created by a single Repeater object. Use the repeaterIndices property when this UIComponent is created by nested Repeater objects.

This property is set to -1 when this UIComponent is not created by a Repeater.

An Array containing the indices of the items in the data provider of the Repeaters in the parent document that produced this UIComponent. The Array is empty unless this UIComponent is within one or more Repeaters.

The first element in the Array corresponds to the outermost Repeater. For example, if repeaterIndices is [2,4] it means that the outer repeater used item dataProvider[2] and the inner repeater used item dataProvider[4].

Note that this property differs from the instanceIndices property if the startingIndex property of any of the Repeaters is not 0. For example, even if a Repeater starts at dataProvider[4], the document reference of the first repeated object is b[0], not b[4].

An Array containing references to the Repeater objects in the parent document that produced this UIComponent. The Array is empty unless this UIComponent is within one or more Repeaters. The first element corresponds to the outermost Repeater object.

Number that specifies the horizontal scaling factor.

The default value is 1.0, which means that the object is not scaled. A scaleX of 2.0 means the object has been magnified by a factor of 2, and a scaleX of 0.5 means the object has been reduced by a factor of 2.

A value of 0.0 is an invalid value. Rather than setting it to 0.0, set it to a small value, or set the visible property to false to hide the component.

The default value is 1.0.

This property can be used as the source for data binding.

Number that specifies the vertical scaling percentage.

The default value is 1.0, which means that the object is not scaled. A scaleY of 2.0 means the object has been magnified by a factor of 2, and a scaleY of 0.5 means the object has been reduced by a factor of 2.

A value of 0.0 is an invalid value. Rather than setting it to 0.0, set it to a small value, or set the visible property to false to hide the component.

The default value is 1.0.

This property can be used as the source for data binding.

Returns an object that contains the size and position of the base drawing surface for this object.

The view states that are defined for this component. You can specify the states property only on the root of the application or on the root tag of an MXML component. The compiler generates an error if you specify it on any other control.

Storage for the inline inheriting styles on this object. This CSSStyleDeclaration is created the first time that the setStyle() method is called on this component to set an inheriting style. Developers typically never need to access this property directly.

The class style used by this component. This can be a String, CSSStyleDeclaration or an IStyleClient.

If this is a String, it is the name of a class declaration in an mx:Style tag or CSS file. You do not include the period in the styleName. For example, if you have a class style named ".bigText", set the styleName property to "bigText" (no period).

If this is an IStyleClient (typically a UIComponent), all styles in the styleName ojbect are used by this component.

The default value is null.

Returns the SystemManager object used by this component.

Text to display in the ToolTip.

The default value is null.

This property can be used as the source for data binding.

An Array of Transition objects, where each Transition object defines a set of effects to play when a view state change occurs.

See also

Array of properties that are currently being tweened on this object.

Used to alert the EffectManager that certain properties of this object are being tweened, so that the EffectManger doesn't attempt to animate the same properties.

A unique identifier for the object. Flex data-driven controls, including all controls that are subclasses of List class, use a UID to track data provider items.

Flex can automatically create and manage UIDs. However, there are circumstances when you must supply your own uid property by implementing the IUID interface, or when supplying your own uid property improves processing efficiency. UIDs do not need to be universally unique for most uses in Flex. One exception is for messages sent by data services.

See also

A convenience method for determining the unscaled height of the component All of a component's drawing and child layout should be done within a bounding rectangle of this height, which is also passed as an argument to updateDisplayList().

A convenience method for determining the unscaled width of the component All of a component's drawing and child layout should be done within a bounding rectangle of this width, which is also passed as an argument to updateDisplayList().

A flag that determines if an object has been through all three phases of layout validation (provided that any were required).

Used by a validator to associate a subfield with this component.

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

When setting to true, the object will dispatch a show event. When setting to false, the object will dispatch a hide event. In either case the children of the object will not emit a show or hide event unless the object has specifically written an implementation to do so.

The default value is true.

This property can be used as the source for data binding.

Number that specifies the width of the component, in pixels, in the parent's coordinates. The default value is 0, not the actual width of the control.

Note: You can specify a percentage value in the MXML width attribute, such as width="100%", but you cannot use a percentage value in the width property in ActionScript. Use the percentWidth property instead.

Setting this property causes a resize event to be dispatched. See the resize event for details on when this event is dispatched. If the component's scaleX property is not 1.0, the width of the component from its internal coordinates will not match. Thus a 100 pixel wide component with a scaleX of 2 will take 100 pixels in the parent, but will internally think it is 50 pixels wide.

This property can be used as the source for data binding.

Number that specifies the component's horizontal position, in pixels, within its parent container.

Setting this property directly or calling move() will have no effect -- or only a temporary effect -- if the component is parented by a layout container such as HBox, Grid, or Form, because the layout calculations of those containers set the x position to the results of the calculation. However, the x property must almost always be set when the parent is a Canvas or other absolute-positioning container because the default value is 0.

The default value is 0.

This property can be used as the source for data binding.

Number that specifies the component's vertical position, in pixels, within its parent container.

Setting this property directly or calling move() will have no effect -- or only a temporary effect -- if the component is parented by a layout container such as HBox, Grid, or Form, because the layout calculations of those containers set the x position to the results of the calculation. However, the x property must almost always be set when the parent is a Canvas or other absolute-positioning container because the default value is 0.

The default value is 0.

This property can be used as the source for data binding.

Constructor.

Adjust the focus rectangle.

This is an internal method used by the Flex framework to support the Dissolve effect. You should not need to call it or override it.

Queues a function to be called later.

Before each update of the screen, the Flash Player calls the set of functions that are scheduled for the update. Sometimes, a function should be called in the next update to allow the rest of the code scheduled for the current update to be executed. Some features, like effects, can cause queued functions to be delayed until the feature completes.

Performs any final processing after child objects are created. This is an advanced method that you might override when creating a subclass of UIComponent.

Deletes a style property from this component instance.

This does not necessarily cause the getStyle() method to return undefined.

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

You do not call this method directly. Flex calls the commitProperties() method when you use the addChild() method to add a component to a container, or when you call the invalidateProperties() method of the component. 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 components have properties that affect the number or kinds of child objects that they need to create, or have properties that interact with each other, such as the horizontalScrollPolicy and horizontalScrollPosition properties. It is often best at startup time to process all of these properties at one time to avoid duplicating work.

See also

Converts a Point object from content coordinates to global coordinates. Content coordinates specify a pixel position relative to the upper left corner of the component's content, and include all of the component's content area, including any regions that are currently clipped and must be accessed by scrolling the component. You use the content coordinate system to set and get the positions of children of a container that uses absolute positioning. Global coordinates specify a pixel position relative to the upper-left corner of the Stage in Flash Player, that is, the outermost edge of the application.

See also

Converts a Point object from content to local coordinates. Content coordinates specify a pixel position relative to the upper left corner of the component's content, and include all of the component's content area, including any regions that are currently clipped and must be accessed by scrolling the component. You use the content coordinate system to set and get the positions of children of a container that uses absolute positioning. Local coordinates specify a pixel position relative to the upper left corner of the component.

See also

Create child objects of the component. This is an advanced method that you might override when creating a subclass of UIComponent.

A component that creates other components or objects within it is called a composite component. For example, the Flex ComboBox control is actually made up of a TextInput control to define the text area of the ComboBox, and a Button control to define the ComboBox arrow. Components implement the createChildren() method to create child objects (such as other components) within the component.

From within an override of the createChildren() method, you call the addChild() method to add each child object.

You do not call this method directly. Flex calls the createChildren() method in response to the call to the addChild() method to add the component to its parent.

See also

Creates an id reference to this IUIComponent object on its parent document object. This function can create multidimensional references such as b[2][4] for objects inside one or more repeaters. If the indices are null, it creates a simple non-Array reference.

Deletes the id reference to this IUIComponent object on its parent document object. This function can delete from multidimensional references such as b[2][4] for objects inside one or more Repeaters. If the indices are null, it deletes the simple non-Array reference.

Returns a UITextFormat object corresponding to the text styles for this UIComponent.

Shows or hides the focus indicator around this component.

UIComponent implements this by creating an instance of the class specified by the focusSkin style and positioning it appropriately.

Programatically draws a rectangle into this skin's Graphics object.

The rectangle can have rounded corners. Its edges are stroked with the current line style of the Graphics object. It can have a solid color fill, a gradient fill, or no fill. A solid fill can have an alpha transparency. A gradient fill can be linear or radial. You can specify up to 15 colors and alpha values at specified points along the gradient, and you can specify a rotation angle or transformation matrix for the gradient. Finally, the rectangle can have a rounded rectangular hole carved out of it.

This versatile rectangle-drawing routine is used by many skins. It calls the drawRect() or drawRoundRect() methods (in the flash.display.Graphics class) to draw into this skin's Graphics object.

Called by the effect instance when it stops playing on the component. You can use this method to restore a modification to the component made by the effectStarted() method when the effect started, or perform some other action when the effect ends.

Called by the effect instance when it starts playing on the component. You can use this method to perform a modification to the component as part of an effect. You can use the effectFinished() method to restore the modification when the effect ends.

Ends all currently playing effects on the component.

Executes the data bindings into this UIComponent object.

Called after printing is complete. For the UIComponent class, the method performs no action. Flex containers override the method to restore the container after printing.

This method is normally not used by application developers.

See also

The event handler called when a UIComponent object gets focus. If you override this method, make sure to call the base class version.

The event handler called when a UIComponent object loses focus. If you override this method, make sure to call the base class version.

Finds the type selectors for this UIComponent instance. The algorithm walks up the superclass chain. For example, suppose that class MyButton extends Button. A MyButton instance will first look for a MyButton type selector then, it will look for a Button type selector. then, it will look for a UIComponent type selector. (The superclass chain is considered to stop at UIComponent, not Object.)

A convenience method for determining whether to use the explicit or measured height

A convenience method for determining whether to use the explicit or measured width

Gets the object that currently has focus. It might not be this object. Note that this method does not necessarily return the component that has focus. It may return the internal subcomponent of the component that has focus. To get the component that has focus, use the focusManager.focus property.

Returns the item in the dataProvider that was used by the specified Repeater to produce this Repeater, or null if this Repeater isn't repeated. The argument whichRepeater is 0 for the outermost Repeater, 1 for the next inner Repeater, and so on. If whichRepeater is not specified, the innermost Repeater is used.

Gets a style property that has been set anywhere in this component's style lookup chain.

This same method is used to get any kind of style property, so the value returned may be a Boolean, String, Number, int, uint (for an RGB color), Class (for a skin), or any kind of object. Therefore the return type is simply specified as

If you are getting a particular style property, you will know its type and will often want to store the result in a variable of that type. No casting from to that type is necessary:

var backgroundColor:uint = getStyle("backgroundColor");

If the style property has not been set anywhere in the style lookup chain, the value returned by getStyle() will be undefined. Note that undefined is a special value that is not the same as false, "", NaN, 0, or null. No valid style value is ever undefined. You can use the static method StyleManager.isValidStyleValue() to test whether the value was set.

See also

Converts a Point object from global to content coordinates. Global coordinates specify a pixel position relative to the upper-left corner of the Stage in Flash Player, that is, the outermost edge of the application. Content coordinates specify a pixel position relative to the upper left corner of the component's content, and include all of the component's content area, including any regions that are currently clipped and must be accessed by scrolling the component. You use the content coordinate system to set and get the positions of children of a container that uses absolute positioning.

See also

Returns a box Matrix which can be passed to the drawRoundRect() method as the rot parameter when drawing a horizontal gradient.

For performance reasons, the Matrix is stored in a static variable which is reused by all calls to horizontalGradientMatrix() and verticalGradientMatrix(). Therefore, you should pass the resulting Matrix to drawRoundRect() before calling horizontalGradientMatrix() or verticalGradientMatrix() again.

Finalizes the initialization of this component.

This method is the last code that executes when you add a component to a parent for the first time using addChild() or addChildAt(). It handles some housekeeping related to dispatching the initialize event. If you are writing a component, you should not need to override this method.

Initializes the internal structure of this component.

Initializing a UIComponent is the fourth step in the creation of a visual component instance, and happens automatically the first time that the instance is added to a parent. Therefore, you do not generally need to call initialize(); the Flex framework calls it for you from UIComponent's override of the addChild() and addChildAt() methods.

The first step in the creation of a visual component instance is construction, with the new operator:

   var okButton:Button = new Button();

After construction, the new Button instance is a solitary DisplayObject; it does not yet have a UITextField as a child to display its label, and it doesn't have a parent.

The second step is configuring the newly-constructed instance with the appropriate properties, styles, and event handlers:

   okButton.label = "OK";
   okButton.setStyle("cornerRadius", 0);
   okButton.addEventListener(MouseEvent.CLICK, clickHandler);

The third step is adding the instance to a parent:

   someContainer.addChild(okButton);

A side effect of calling addChild() or addChildAt(), when adding a component to a parent for the first time, is that initialize gets automatically called.

This method first dispatches a preinitialize event, giving developers using this component a chance to affect it before its internal structure has been created. Next it calls the createChildren() method to create the component's internal structure; for a Button, this method creates and adds the UITextField for the label. Then it dispatches an initialize event, giving developers a chance to affect the component after its internal structure has been created.

Note that it is the act of attaching a component to a parent for the first time that triggers the creation of its internal structure. If its internal structure includes other UIComponents, then this is a recursive process in which the tree of DisplayObjects grows by one leaf node at a time.

If you are writing a component, you should not need to override this method.

Initializes this component's accessibility code.

This method is called by the initialize() method to hook in the component's accessibility code, which resides in a separate class in the mx.accessibility package. Each subclass that supports accessibility must override this method because the hook-in process uses a different static variable in each subclass.

Initializes various properties which keep track of repeated instances of this component.

An MXML <mx:Repeater/> tag can cause repeated instances of a component to be created, one instance for each item in the Repeater's data provider. The instanceIndices, repeaters, and repeaterIndices properties of UIComponent keep track of which instance came from which data item and which Repeater.

This method is an internal method which is automatically called by the Flex framework. You should not have to call it or override it.

Marks a component so that its updateDisplayList() method gets called during a later screen update.

Invalidation is a useful mechanism for eliminating duplicate work by delaying processing of changes to a component until a later screen update. For example, if you want to change the width and height, it would be wasteful to update the component immediately after you change the width and then update again with the new height. It is more efficient to change both properties and then render the component with its new size once.

Invalidation methods rarely get called. In general, setting a property on a component automatically calls the appropriate invalidation method.

Marks a component so that its commitProperties() method gets called during a later screen update.

Invalidation is a useful mechanism for eliminating duplicate work by delaying processing of changes to a component until a later screen update. For example, if you want to change the text color and size, it would be wasteful to update the color immediately after you change it and then update the size when it gets set. It is more efficient to change both properties and then render the text with its new size and color once.

Invalidation methods rarely get called. In general, setting a property on a component automatically calls the appropriate invalidation method.

Marks a component so that its measure() method gets called during a later screen update.

Invalidation is a useful mechanism for eliminating duplicate work by delaying processing of changes to a component until a later screen update. For example, if you want to change the text and font size, it would be wasteful to update the text immediately after you change it and then update the size when it gets set. It is more efficient to change both properties and then render the text with its new size once.

Invalidation methods rarely get called. In general, setting a property on a component automatically calls the appropriate invalidation method.

Typically overridden by components containing UITextField objects, where the UITextField object gets focus.

The event handler called for a keyDown event. If you override this method, make sure to call the base class version.

The event handler called for a keyUp event. If you override this method, make sure to call the base class version.

Converts a Point object from local to content coordinates. Local coordinates specify a pixel position relative to the upper left corner of the component. Content coordinates specify a pixel position relative to the upper left corner of the component's content, and include all of the component's content area, including any regions that are currently clipped and must be accessed by scrolling the component. You use the content coordinate system to set and get the positions of children of a container that uses absolute positioning.

See also

Calculates the default size, and optionally the default minimum size, of the component. This is an advanced method that you might override when creating a subclass of UIComponent.

You do not call this method directly. Flex calls the measure() method when the component is added to a container using the addChild() method, and when the component's invalidateSize() method is called.

When you set a specific height and width of a component, Flex does not call the measure() method, even if you explicitly call the invalidateSize() method. That is, Flex only calls the measure() method if the explicitWidth property or the explicitHeight property of the component is NaN.

In your override of this method, you must set the measuredWidth and measuredHeight properties to define the default size. You may optionally set the measuredMinWidth and measuredMinHeight properties to define the default minimum size.

Most components calculate these values based on the content they are displaying, and from the properties that affect content display. A few components simply have hard-coded default values.

The conceptual point of measure() is for the component to provide its own natural or intrinsic size 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 styles, such as fontSize, for that text.
• The size of a JPEG image that the component displays.
• The measured or explicit sizes of the component's children.
• Any borders, margins, and gaps.

In some cases, there is no intrinsic way to determine default values. For example, a simple GreenCircle component 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() is to set the default size to the current size of the component.

See also

Measures the specified HTML text, which may contain HTML tags such as <font> and <b>, assuming that it is displayed in a single-line UITextField using a UITextFormat determined by the styles of this UIComponent.

Measures the specified text, assuming that it is displayed in a single-line UITextField using a UITextFormat determined by the styles of this UIComponent.

Moves the component to a specified position within its parent. Calling this method is exactly the same as setting the component's x and y properties.

If you are overriding the updateDisplayList() method in a custom component, you should call the move() method rather than setting the x and y properties. The difference is that the move() method changes the location of the component and then dispatches a move event when you call the method, while setting the x and y properties changes the location of the component and dispatches the event on the next screen refresh.

Propagate style changes to the children. You typically never need to call this method.

Returns true if the chain of owner properties points from child to this UIComponent.

Called by Flex when a UIComponent object is added to or removed from a parent. Developers typically never need to call this method.

Prepares an IFlexDisplayObject for printing. For the UIComponent class, the method performs no action. Flex containers override the method to prepare for printing; for example, by removing scroll bars from the printed output.

This method is normally not used by application developers.

See also

Builds or rebuilds the CSS style cache for this component and, if the recursive parameter is true, for all descendants of this component as well.

The Flex framework calls this method in the following situations:

• When you add a UIComponent to a parent using the addChild() or addChildAt( methods.
• When you change the styleName property of a UIComponent.
• When you set a style in a CSS selector using the setStyle() method of CSSStyleDeclaration.

Building the style cache is a computation-intensive operation, so you should avoid changing styleName or or setting selector styles unnecessarily.

This method is not called when you set an instance style by calling the setStyle() method of UIComponent. Setting an instance style is a relatively fast operation compared with setting a selector style.

You should not need to call or override this method.

For each effect event, register the EffectManager as one of the event listeners. You typically never need to call this method.

Resumes the background processing of methods queued by callLater(), after a call to suspendBackgroundProcessing().

Refer to the description of suspendBackgroundProcessing() for more information.

Sizes the object. Unlike directly setting the width and height properties, calling the setActualSize() method does not set the explictWidth and explicitHeight properties, so a future layout calculation may result in the object returning to its previous size. This method is used primarily by component developers implementing the updateDisplayList() method, by Effects, and by the LayoutManager.

Set the current state.

See also

Sets the focus to this component. The component may in turn pass focus to a subcomponent.

Note: Only the TextInput and TextArea controls show a highlight when this method sets the focus. All controls show a highlight when the user tabs to the control.

Sets a style property on this component instance.

This may override a style that was set globally.

Calling the setStyle() method can result in decreased performance. Use it only when necessary.

See also

Called when the visible property changes. You should set the visible property to show or hide a component instead of calling this method directly.

Detects changes to style properties. When any style property is set, Flex calls the styleChanged() method, passing to it the name of the style being set.

This is an advanced method that you might override when creating a subclass of UIComponent. When you create a custom component, you can override the styleChanged() method to check the style name passed to it, and handle the change accordingly. This lets you override the default behavior of an existing style, or add your own custom style properties.

If you handle the style property, your override of the styleChanged() method should call the invalidateDisplayList() method to cause Flex to execute the component's updateDisplayList() method at the next screen update.

Flex calls the stylesInitialized() method when the styles for a component are first initialized.

This is an advanced method that you might override when creating a subclass of UIComponent. Flex guarantees that your component's styles will be fully initialized before the first time your component's measure and updateDisplayList methods are called. For most components, that is sufficient. But if you need early access to your style values, you can override the stylesInitialized() function to access style properties as soon as they are initialized the first time.

Blocks the background processing of methods queued by callLater(), until resumeBackgroundProcessing() is called.

These methods can be useful when you have time-critical code which needs to execute without interruption. For example, when you set the suspendBackgroundProcessing property of an Effect to true, suspendBackgroundProcessing() is automatically called when it starts playing, and resumeBackgroundProcessing is called when it stops, in order to ensure that the animation is smooth.

Since the LayoutManager uses callLater(), this means that commitProperties(), measure(), and updateDisplayList() will not get called in between calls to suspendBackgroundProcessing() and resumeBackgroundProcessing().

It is safe for both an outer method and an inner method (i.e., one that the outer methods calls) to call suspendBackgroundProcessing() and resumeBackgroundProcessing(), because these methods actually increment and decrement a counter which determines whether background processing occurs.

Draws the object and/or sizes and positions its children. This is an advanced method that you might override when creating a subclass of UIComponent.

You do not call this method directly. Flex calls the updateDisplayList() method when the component is added to a container using the addChild() method, and when the component's invalidateDisplayList() method is called.

If the component has no children, this method is where you would do programmatic drawing using methods on the component's Graphics object such as graphics.drawRect().

If the component has children, this method is where you would call the move() and setActualSize() methods on its children.

Components may do programmatic drawing even if they have children. In doing either, you should use the component's unscaledWidth and unscaledHeight as its bounds.

It is important to use unscaledWidth and unscaledHeight instead of the width and height properties.

See also

Validates the position and size of children and draws other visuals. If the LayoutManager.invalidateDisplayList() method is called with this ILayoutManagerClient, then the validateDisplayList() method is called when it's time to update the display list.

Validate and update the properties and layout of this object and redraw it, if necessary. Processing properties that require substantial computation are normally not processed until the script finishes executing. For example setting the width property is delayed, because it may require recalculating the widths of the objects children or its parent. Delaying the processing prevents it from being repeated multiple times if the script sets the width property more than once. This method lets you manually override this behavior.

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

Validates the measured size of the component If the LayoutManager.invalidateSize() method is called with this ILayoutManagerClient, then the validateSize() method is called when it's time to do measurements.

Handles both the valid and invalid events from a validator assigned to this component.

You typically handle the valid and invalid events dispatched by a validator by assigning event listeners to the validators. If you want to handle validation events directly in the component that is being validated, you can override this method to handle the valid and invalid events. You typically call super.validationResultHandler(event) in your override.

See also

Returns a box Matrix which can be passed to drawRoundRect() as the rot parameter when drawing a vertical gradient.

For performance reasons, the Matrix is stored in a static variable which is reused by all calls to horizontalGradientMatrix() and verticalGradientMatrix(). Therefore, you should pass the resulting Matrix to drawRoundRect() before calling horizontalGradientMatrix() or verticalGradientMatrix() again.

Dispatched when the component is added to a container as a content child by using the addChild() or addChildAt() method. If the component is added to the container as a noncontent child by using the rawChildren.addChild() or rawChildren.addChildAt() method, the event is not dispatched.

The FlexEvent.ADD constant defines the value of the type property of the event object for an add event.

The properties of the event object have the following values:

Dispatched when the component has finished its construction, property processing, measuring, layout, and drawing.

At this point, depending on its visible property, the component may not be visible even though it has been drawn.

The FlexEvent.CREATION_COMPLETE constant defines the value of the type property of the event object for a creationComplete event.

The properties of the event object have the following values:

Dispatched after the view state has changed.

The StateChangeEvent.CURRENT_STATE_CHANGE constant defines the value of the type property of the event that is dispatched when the view state has changed. The value of this constant is "currentStateChange".

The properties of the event object have the following values:

Dispatched after the currentState property changes, but before the view state changes.

The StateChangeEvent.CURRENT_STATE_CHANGING constant defines the value of the type property of the event that is dispatched when the view state is about to change. The value of this constant is "currentStateChanging".

The properties of the event object have the following values:

Dispatched by the drag initiator (the component that is the source of the data being dragged) when the drag operation completes, either when you drop the dragged data onto a drop target or when you end the drag-and-drop operation without performing a drop.

You can use this event to perform any final cleanup of the drag-and-drop operation. For example, if you drag a List control item from one list to another, you can delete the List control item from the source if you no longer need it.

The DragEvent.DRAG_COMPLETE constant defines the value of the type property of the event object for a dragComplete event.

The properties of the event object have the following values:

Dispatched by the drop target when the user releases the mouse over it.

You use this event handler to add the drag data to the drop target.

The DragEvent.DRAG_DROP constant defines the value of the type property of the event object for a dragDrop event.

The properties of the event object have the following values:

Dispatched by a component when the user moves the mouse over the component during a drag operation.

In order to be a valid drop target, you must define a handler for this event. In the handler, you can change the appearance of the drop target to provide visual feedback to the user that the component can accept the drag. For example, you could draw a border around the drop target, or give focus to the drop target.

If you want to accept the drag, you must call the DragManager.acceptDragDrop() method. If you don't call acceptDragDrop(), you will not get any of the other drag events.

The value of the action property is always DragManager.MOVE, even if you are doing a copy. This is because the dragEnter event occurs before the control recognizes that the Control key is pressed to signal a copy. The action property of the event object for the dragOver event does contain a value that signifies the type of drag operation.

You may change the type of drag action by calling the DragManager.showFeedback() method.

The DragEvent.DRAG_ENTER constant defines the value of the type property of the event object for a dragEnter event.

The properties of the event object have the following values:

See also

Dispatched by the component when the user drags outside the component, but does not drop the data onto the target.

You use this event to restore the drop target to its normal appearance if you modified its appearance as part of handling the dragEnter or dragOver event.

The DragEvent.DRAG_EXIT constant defines the value of the type property of the event object for a dragExit event.

The properties of the event object have the following values:

Dispatched by a component when the user moves the mouse while over the component during a drag operation.

In the handler, you can change the appearance of the drop target to provide visual feedback to the user that the component can accept the drag. For example, you could draw a border around the drop target, or give focus to the drop target.

You should handle this event to perform additional logic before allowing the drop, such as dropping data to various locations in the drop target, reading keyboard input to determine if the drag-and-drop action is a move or copy of the drag data, or providing different types of visual feedback based on the type of drag-and-drop action.

You may also change the type of drag action by changing the DragManager.showFeedback() method. The default value of the action property is DragManager.MOVE.

The DragEvent.DRAG_OVER constant defines the value of the type property of the event object for a dragOver event.

The properties of the event object have the following values:

See also

Dispatched after an effect ends.

The effect will have made the last set of visual changes before this event is fired, but those changes will not have been rendered on the screen. Thus, you might have to use the callLater() method to delay any other changes that you want to make until after the changes have been rendered onscreen.

The EffectEvent.EFFECT_END constant defines the value of the type property of the event object for an effectEnd event.

The properties of the event object have the following values:

Dispatched just before an effect starts.

The effect does not start changing any visuals until after this event is fired.

The EffectEvent.EFFECT_START constant defines the value of the type property of the event object for an effectStart event.

The properties of the event object have the following values:

Dispatched after the component has returned to the root view state.

The FlexEvent.ENTER_STATE constant defines the value of the type property of the event object for a enterState event.

The properties of the event object have the following values:

Dispatched before the component exits from the root view state.

The FlexEvent.EXIT_STATE constant defines the value of the type property of the event object for a exitState event.

The properties of the event object have the following values:

Dispatched when an object's state changes from visible to invisible.

The FlexEvent.HIDE constant defines the value of the type property of the event object for a hide event.

The properties of the event object have the following values:

Dispatched when the component has finished its construction and has all initialization properties set.

After the initialization phase, properties are processed, the component is measured, laid out, and drawn, after which the creationComplete event is dispatched.

The FlexEvent.INITIALIZE constant defines the value of the type property of the event object for a initialize event.

The properties of the event object have the following values:

Dispatched when a component is monitored by a Validator and the validation failed.

The FlexEvent.INVALID constant defines the value of the type property of the event object for a invalid event.

The properties of the event object have the following values:

Dispatched from a component opened using the PopUpManager when the user clicks outside it.

The FlexMouseEvent.MOUSE_DOWN_OUTSIDE constant defines the value of the type property of the event object for a mouseDownOutside event.

The properties of the event object have the following values:

Dispatched from a component opened using the PopUpManager when the user scrolls the mouse wheel outside it.

The FlexMouseEvent.MOUSE_WHEEL_OUTSIDE constant defines the value of the type property of the event object for a mouseWheelOutside event.

The properties of the event object have the following values:

Dispatched when the object has moved.

You can move the component by setting the x or y properties, by calling the move() method, by setting one of the following properties either on the component or on other components such that the LayoutManager needs to change the x or y properties of the component:

• minWidth
• minHeight
• maxWidth
• maxHeight
• explicitWidth
• explicitHeight

When you call the move() method, the move event is dispatched before the method returns. In all other situations, the move event is not dispatched until after the property changes.

The MoveEvent.MOVE constant defines the value of the type property of the event object for a move event.

The properties of the event object have the following values: