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|Home ChartPack RChart Class TContourPlot Events OnScalesRendered|
|See also: OnBeforeRenderData, OnDataRendered, OnScaleTickDrawn, OnBeforeRenderChartItem, TBeforeRenderCItemEvent, OnDataRendered|
The events OnBeforeRenderData, OnDataRendered and OnScalesRendered provide hooks for adding user defined graphics to the contour plot. Internally, a chart is constructed in three phases before the result is copied to the screen: in the first phase the scales are drawn, then the data is drawn and finally the crosshairs are rendered. The OnScalesRendered event is triggered after the scales are drawn giving access to the non-data areas of the contour plot (i.e. the areas where the scales and captions are drawn). The events OnBeforeRenderData and OnDataRendered are triggered before and after drawing the chart. Note that the latter two events give access to the chart canvas (the area where the chart elements are is drawn).
The event OnScalesRendered occurs after the scales of the chart has been drawn and before the data is drawn. The variable parameter Canvas provides access to the canvas of the data area. Please note that the state of the canvas (e.g. the color of its pen, or the fill mode of the brush) depends on the graphics elements drawn before. The parameters Top and Left are always zero.