You can use a canvas control as a background to draw the following dialog elements on it: the rectangle, line and graphictext controls. These dialog elements "visualize" information. You can, for example, create three or four rectangle controls, fill them with color and change their size at runtime. This way, you can build your own bar chart.
Once you have created a canvas control in the dialog, you can go on to create the rectangle, line and graphictext controls in it.
Note:
Graphictext controls do not repaint the background of the rectangle
in which they are located. The background of the rectangle is specified at
creation time of the graphictext control. What they do repaint is only the text
specified in the text attribute.
To create dialog elements on a canvas control
Use the PROCESS GUI statement action
ADD.
The rectangle, line and graphictext controls are then displayed inside the borders of the canvas control; if they exceed the canvas borders, they are clipped.
The following attributes are useful for controlling the behavior of the canvas control and the dialog elements on it:
OFFSET-X and
OFFSET-Y determine the
x and y axis offset of the canvas control's upper border against the upper
border of the area by which the rectangle, line or graphictext control have
exceeded the canvas control's borders.
RECTANGLE-X,
RECTANGLE-Y,
RECTANGLE-W and
RECTANGLE-H determine
the size of a rectangle control and its position relative to the
underlying canvas control.
P1-X,
P1-Y,
P2-X and
P2-Y determine the
start position (P1xx) and the end position
(P2xx) of a
line
control relative to the underlying canvas control.
The following example illustrates how to create a canvas control
/* In the dialog's local data area, the following must be defined: 01 #CNV1 HANDLE OF CANVAS 01 #XAX HANDLE OF LINE 01 #YAX HANDLE OF LINE 01 #H1 HANDLE OF RECTANGLE 01 #H2 HANDLE OF RECTANGLE 01 #H3 HANDLE OF RECTANGLE 01 #H4 HANDLE OF RECTANGLE 01 #RESPONSE (I4) /* In the dialog's AFTER-OPEN event handler, the following must be defined: PROCESS GUI ACTION ADD WITH PARAMETERS PARENT = #DLG$WINDOW TYPE = CANVAS HANDLE-VARIABLE = #CNV1 RECTANGLE-X = 20 RECTANGLE-Y = 20 RECTANGLE-W = 200 RECTANGLE-H = 200 STYLE = 'F' END-PARAMETERS GIVING RESPONSE PROCESS GUI ACTION ADD WITH PARAMETERS PARENT = #CNV1 TYPE = LINE HANDLE-VARIABLE = #YAX STYLE = 'S' P1-X = 20 P1-Y = 20 P2-X = 20 P2-Y = 180 END-PARAMETERS GIVING RESPONSE PROCESS GUI ACTION ADD WITH PARAMETERS PARENT = #CNV1 TYPE = LINE HANDLE-VARIABLE = #XAX P1-X = 180 P1-Y = 180 P2-X = 20 P2-Y = 180 END-PARAMETERS GIVING RESPONSE PROCESS GUI ACTION ADD WITH PARAMETERS PARENT = #CNV1 TYPE = RECTANGLE HANDLE-VARIABLE = #H1 RECTANGLE-X = 20 RECTANGLE-Y = 180 RECTANGLE-H = 20 RECTANGLE-W = -60 FOREGROUND-COLOUR-NAME = BLACK BACKGROUND-COLOUR-NAME = RED END-PARAMETERS GIVING RESPONSE PROCESS GUI ACTION ADD WITH PARAMETERS PARENT = #CNV1 TYPE = RECTANGLE HANDLE-VARIABLE = #H2 RECTANGLE-X = 40 RECTANGLE-Y = 180 RECTANGLE-H = 20 RECTANGLE-W = -40 FOREGROUND-COLOUR-NAME = BLACK BACKGROUND-COLOUR-NAME = BLUE END-PARAMETERS GIVING RESPONSE PROCESS GUI ACTION ADD WITH PARAMETERS PARENT = #CNV1 TYPE = RECTANGLE HANDLE-VARIABLE = #H3 RECTANGLE-X = 60 RECTANGLE-Y = 180 RECTANGLE-H = 20 RECTANGLE-W = -55 FOREGROUND-COLOUR-NAME = BLACK BACKGROUND-COLOUR-NAME = GREEN END-PARAMETERS GIVING RESPONSE PROCESS GUI ACTION ADD WITH PARAMETERS PARENT = #CNV1 TYPE = RECTANGLE HANDLE-VARIABLE = #H4 RECTANGLE-X = 80 RECTANGLE-Y = 180 RECTANGLE-H = 20 RECTANGLE-W = -80 FOREGROUND-COLOUR-NAME = BLACK BACKGROUND-COLOUR-NAME = MAGENTA END-PARAMETERS GIVING RESPONSE
