RtTrend
RtTrend — A graph for displaying real-time trends (in QNX 4).
Synopsis
class RtTrend PtBasic
{
rttrend_data; // array of arrays of integer (Rt_ARG_TREND_DATA)
rttrend_flags; // flag (Rt_ARG_TREND_FLAGS)
trend_attributes; // integer array (Rt_ARG_TREND_ATTRIBUTES)
trend_color_list; // color array (Rt_ARG_TREND_COLOR_LIST)
trend_count; // integer (Rt_ARG_TREND_COUNT)
trend_grid_color; // color (Rt_ARG_TREND_GRID_COLOR)
trend_grid_x; // short (Rt_ARG_TREND_GRID_X)
trend_grid_y; // short (Rt_ARG_TREND_GRID_Y)
trend_inc; // short (Rt_ARG_TREND_INC)
trend_max; // short (Rt_ARG_TREND_MAX)
trend_min; // short (Rt_ARG_TREND_MIN)
}
Description
This widget is a real-time
trend display that can plot multiple trends and display them
in a moving format, to show changes over time. The
QNX 6 version of this widget is PtTrend.
![[Note]](images/note.gif) | For detailed information, please refer to RtTrend
in the Photon documentation.
|
Instance Variables
- rttrend_data
- An array of data arrays. Each data array
corresponds to one trend line on the display.
- rttrend_flags
Flags that specify grid characteristics and
direction. If any of these flags is set incorrectly,
the widget will not display any trends.
| The grid options are only supported by
8-bit graphics environments, and only on some
graphics cards. |
This instance variable may be a combination of
zero or more of the following flags:
- trend_attributes
- An array that indexes the
trend_color_list. Index numbers are
consecutive integers starting with 0, and each number points
to an element of the trend_color_list.
Default is nil.
- trend_color_list
- An array of colors to be used for plotting
trend lines. Default array has a single number:
[16711680], which equals 0xff0000 (red).
- trend_count
- An integer specifying the number of trends.
- trend_grid_color
- A number specifying the color of the grid to be used if
the Rt_GRID flag is set in the
rttrend_flags variable. Default is
0xc0c0c0 (grey).
- trend_grid_x
- A number specifying the number of vertical grid lines
to be used if the Rt_GRID flag is set
in the rttrend_flags variable. Default
is 5.
- trend_grid_y
- A number specifying the number of horizontal grid lines
to be used if the Rt_GRID flag is set
in the rttrend_flags variable. Default
is 5.
- trend_inc
- A number specifying the spacing of the plotted points
along the moving axis. Default is
1.
- trend_max
- A number specifying the maximum value for the display.
Default is 32,767.
- trend_min
- A number specifying the maximum value for the
display. Default is -32,768.
Example
Here is a very simple example of an
RtTrend widget. For more complex examples,
see the Gamma demos cpumem and
trend. This example,
ex_Trend.g, is included in the product distribution.
#!/usr/cogent/bin/phgamma
/*
* This example illustrates an RtTrend in QNX 4, or a PtTrend in QNX 6,
* by creating and displaying a sine function.
*/
require_lisp("PhotonWidgets.lsp");
require_lisp("PhabTemplate.lsp");
PtInit(nil);
wfile = PhabReadWidgetFile (string(_os_, "-WidgetFiles/wgt/trend.wgtw"));
window = PhabCreateWidgets(wfile, nil, nil);
win = PhabLookupWidget(window,#trend,nil);
tr = PhabLookupWidget(window,#Trend,nil);
ebut = PhabLookupWidget(window,#TrendExitButton,nil);
PtAttachCallback(ebut, Pt_CB_ACTIVATE, #exit_program(1));
Values := make_array (1);
valarray = make_array (1);
/*
* Make a function to generate a trend.
*/
Sinex = 0;
function Sine (inc, max, min)
{
local temp = sin (Sinex), diff = (max - min) / 2;
Sinex = Sinex + inc;
temp * diff + min + diff;
}
Trend = list (Sine, 0.07, 550, 250);
/*
* Make a function to evaluate the trend.
*/
function FillTrend ()
{
valarray[0] = eval(Trend);
Values[0] = valarray;
if (_os_ == "QNX4")
tr.rttrend_data = Values;
else if (_os_ == "QNX6")
tr.trend_data = Values;
}
/*
* Set up the trend.
*/
tr.trend_max = 800;
tr.trend_min = 0;
/*
* Start an update timer, and loop forever.
*/
every (.03, #FillTrend());
PtRealizeWidget(win);
PtMainLoop();
