ChartElement  - AS3 Flex

Refers to the chart component containing this element.

The data provider assigned to the enclosing chart. Element types can choose to inherit the data provider from the enclosing chart if necessary, or allow developers to assign data providers specifically to the element. Not all elements are necessarily driven by a data provider.

Each ChartElement carries a cursor associated with their dataProvider for their own internal use. ChartElements have sole ownership of this cursor; they can assume no other code will modify its position.

A data provider assigned to the this specific element. In general, elements inherit the dataProvider from the enclosing chart. But individual elements can override with a specific dataProvider of their own.

The DataTransform object that the element is associated with. A DataTransform object represents an association between a set of elements and a set of axis objects used to transform those elements from data space to screen coordinates and back. A chart element uses its associated DataTransform object to calculate how to render its data.

The DisplayObject that displays labels rendered by this element. In most cases, labels displayed in the data area of a chart are rendered on top of all elements rather than interleaved with the data. If an implementing Element has labels to display, it can place them in a Sprite object and return it as the value of the labelContainer property. Enclosing charts will render labelContainers from all enclosed elements and place them in the data area above all other elements.

Constructor.

Adds a child DisplayObject after the end of this child list.

Calling childList.addChild(child) is the same as calling childList.addChild(child, childList.numChildren) After it has been added, its index of the new child will be (child.numChildren - 1)

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Adds a child DisplayObject instance to this DisplayObjectContainer instance. The child is added at the index position specified. An index of 0 represents the back (bottom) of the display list for this DisplayObjectContainer object.

If you add a child object that already has a different display object container as a parent, the object is removed from the child list of the other display object container.

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Called by the enclosing chart to indicate that the current state of the chart has changed. Implementing elements should respond to this method in order to synchronize changes to the data displayed by the element.

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Called by the chart to allow associated elements to claim style selectors from its chartSeriesStyles Array. Each chart has an associated set of selectors that are implicitly assigned to contained elements that require them. Implementing this function gives an element a chance to 'claim' elements out of that set, as necessary. An element that requires N style selectors claims the values from styles[firstAvailable] to styles[firstAvailable + N - 1].

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Called by the enclosing chart to collect any transitions a particular element might play when the chart changes state. The chart collects transitions from all elements and ensures that they play in parallel. It waits until all transitions have completed before advancing to another state. Implementors should append any necessary transitions to the transitions Array parameter.

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Creates a unique id to represent the dataPoint for comparison purposes. Derived classes can call this function with a locally unique data point ID to generate an ID that is unique across the application.

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Indicates the underlying data represented by the element has changed. You should call this method whenever the data your series or element is displaying changes. It gives any associated axes a chance to update their ranges if appropriate.

Converts a tuple of data values to an x-y coordinate on screen. Call this function to transform data on to the screen using the same transform that the individual elements go through. For example, to create a custom highlight for a data region of a chart, you might use this function to determine the on-screen coordinates of the range of interest.

For Cartesian chartelements, you typically pass two values. The first value maps to the horizontal axis, and the second value maps to the vertical axis.

For polar charts, the first value maps to the angular axis, and the second maps to the radial axis.

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Called by the governing DataTransform to obtain a description of the data represented by this IChartElement. Implementors fill out and return an Array of mx.charts.chartClasses.DataDescription objects to guarantee that their data is correctly accounted for by any axes that are autogenerating values from the displayed data (such as minimum, maximum, interval, and unitSize). Most element types return an Array containing a single DataDescription. Aggregate elements, such as BarSet and ColumnSet, might return multiple DataDescription instances that describe the data displayed by their subelements. When called, the implementor describes the data along the axis indicated by the dimension argument. This function might be called for each axis supported by the containing chart.

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Finds the closest data point represented by the element under the given coordinates.

This method returns either an array of HitData structures describing the datapoints within range. Individual ChartElements may choose to only return a single dataPoint if their dataPoints are guaranteed not to overlap.

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Returns an array of HitData of the items of all the underlying ChartElements whose dataTips are to be shown when showAllDataTips is set to true on chart

Converts a coordinate on screen to a tuple of data values. Call this function to determine what data values a particular point on-screen represents.

Individual chart types determine how this transformation occurs. The point should be relative to the chart's coordinate space.

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Called when the mapping of one or more associated axes changes. The DataTransform assigned to this ChartElement will call this method when any of the axes it represents is modified in some way.

Called when a new dataProvider is assigned to the element. Subclasses can override and define custom behavior when a new dataProvider is assigned. This method is called when either the dataProvider property is set, or when the chartDataProvider property is set if no specific dataProvider has been assigned directly.

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