In PowerBuilder, there are two ways to display graphs:
-
In a DataWindow, using data retrieved from the DataWindow data source
-
In a graph control in a window or user object, using data supplied by your application code
This chapter discusses the graph control and describes how your application code can supply data for the graph and manipulate its appearance.
For information about graphs in DataWindows, see DataWindow Programmers Guide and DataWindow Reference.
To learn about designing graphs and setting graph properties in the painters, see Working with Graphs in Users Guide.
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 appearance and give it a more sophisticated look.
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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 the following table.
|
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 the following table to manipulate data in a graph.
|
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 |
