When you define a graph in the DataWindow painter, you specify its behavior and appearance. For example, you might define a graph as a column graph with a certain title, divide its Value axis into four major divisions, and so on. Each of these entries corresponds to a property of a graph. For example, all graphs have a property GraphType, which specifies the type of graph.
When dynamically changing the graph type
If you change the graph type, be sure also to change the other properties as needed to properly define the new graph.
You can change these graph properties at execution time by assigning values to the graph's properties in code.
Property expressions
PowerBuilder
You can modify properties using property expressions. For example, to change the type of the graph gr_emp to Column, you could code:
dw_empinfo.Object.gr_emp.GraphType = ColGraph!
To change the title of the graph at execution time, you could code:
dw_empinfo.Object.gr_emp.Title = "New title"
Modify method
You can use the Modify method to reference parts of a graph.
Example for PowerBuilder
For example, to change the title of graph gr_emp in DataWindow control dw_empinfo, you could code:
dw_empinfo.Modify("gr_emp.Title = 'New title'")For a complete list of graph properties, see the section called “Properties for Graph controls in DataWindow objects” in DataWindow Reference.
Graphs consist of parts: a title, a legend, and axes. Each of these parts has a set of display properties. These display properties are themselves stored as properties in a subobject (structure) of Graph called grDispAttr.
For example, graphs have a Title property, which specifies the text for the title. Graphs also have a property TitleDispAttr, of type grDispAttr, which itself contains properties that specify all the characteristics of the title text, such as the font, size, whether the text is italicized, and so on.
Similarly, graphs have axes, each of which also has a set of properties. These properties are stored in a subobject (structure) of Graph called grAxis. For example, graphs have a property Values, of type grAxis, which specifies the properties of the Value axis, such as whether to use autoscaling of values, the number of major and minor divisions, the axis label, and so on.
Here is a representation of the properties of a graph:
Graph int Height int Depth grGraphType GraphType boolean Border string Title ... grDispAttr TitleDispAttr, LegendDispAttr, PieDispAttr string FaceName int TextSize boolean Italic ... grAxis Values, Category, Series boolean AutoScale int MajorDivisions int MinorDivisions string Label ...
You use dot notation or the Describe and Modify methods to reference the display properties of the various parts of a graph. For example, one of the properties of a graph's title is whether the text is italicized or not. That information is stored in the boolean Italic property in the TitleDispAttr property of the graph.
This example changes the label text for the Value axis of graph gr_emp in the DataWindow control dw_empinfo:
dw_empinfo.Object.gr_emp.Values.Label="New label"
For a complete list of graph properties, see the section called “Properties for Graph controls in DataWindow objects” in DataWindow Reference.
You can use the PowerBuilder Browser to examine the properties of a DataWindow object that contains a graph. For more information, see the Users Guide.
