Working with graph controls in code

Graph controls in a window can be enabled or disabled, visible or invisible, and can be used in drag and drop. You can also write code that uses events of graph controls and additional graph functions.

Properties of graph controls

You can access (and optionally modify) a graph by addressing its properties in code at runtime. There are two kinds of graph properties:

Properties of the graph definition itself These properties are initially set in the painter when you create a graph. They include a graph’s type, title, axis labels, whether axes have major divisions, and so on. For 3D graphs, this includes the Render 3D property that uses transparency rather than overlays to enhance a graph’s appearence and give it a more sophisticated look.

Properties of the data These properties are relevant only at runtime, when data has been loaded into the graph. They include the number of series in a graph (series are created at runtime), colors of bars or columns for a series, whether the series is an overlay, text that identifies the categories (categories are created at runtime), and so on.

Events of graph controls

Graph controls have the events listed in Table 15-1.

**Table 15-1: Graph control events**
Clicked	DragLeave
Constructor	DragWithin
Destructor	GetFocus
DoubleClicked	LoseFocus
DragDrop	Other
DragEnter	RButtonDown

So, for example, you can write a script that is invoked when a user clicks a graph or drags an object on a graph (as long as the graph is enabled).

Functions for graph controls

You use the PowerScript graph functions in Table 15-2 to manipulate data in a graph.

**Table 15-2: PowerScript graph functions**
Function	Action
AddCategory	Adds a category
AddData	Adds a data point
AddSeries	Adds a series
DeleteCategory	Deletes a category
DeleteData	Deletes a data point
DeleteSeries	Deletes a series
ImportClipboard	Copies data from the clipboard to a graph
ImportFile	Copies the data in a text file to a graph
ImportString	Copies the contents of a string to a graph
InsertCategory	Inserts a category before another category
InsertData	Inserts a data point before another data point in a series
InsertSeries	Inserts a series before another series
ModifyData	Changes the value of a data point
Reset	Resets the graph’s data