Graphical panels

Overview

The support of SCADE Display or SCADE Rapid Prototyper is possible and is partially automated: the SCADE Display DLLs are built and loaded at run time, and the DLL exports all the required functions to access the displays. However, the Python ctype structures corresponding to the layers’ contexts must be written manually for now.

Note

The graphical panels are accessed independently from Python and thus, existing mappings between SCADE Suite and SCADE Display are not considered.

Rationale: Although the proxy considers a single instance of each graphical panel, the current design allows several instances of SCADE root operators. The mapping cannot be applied.

Usage

The wrapper generates the file sdy_xxx.py where xxx is the name of the module generated for SCADE Suite. This file defines one global variable sdy_yyy per graphical panel Yyy with the following members:

• reset(): Reset the graphical panel, automatically called when the Python module is imported

• draw(): Render the image

• lockio(): Lock the contexts before accessing any I/O

• unlockio(): Release the lock on the contexts

• cancelled() -> bool: Return True when the window is closed

• One member per layer in the graphical panels, corresponding to the contexts: The name of the variable is the name of the layer.

The type of these contexts must be written manually in a file called usr_xxx.py. The class defining these contexts must inherit from SdyLayer, defined in the sdyproxy.py resource file and must be named XxxLayer, where Xxx is the name of the corresponding layer.

Example

Consider a SCADE Suite project application.etp containing a SCADE Display project with a graphical specification Panel.sgfx defining a layer Symbology with the following interface:

Variable	Type
active	bool
speed	float64

SCADE KCG Display generates the following C context:

/* Context type */
typedef struct SDY1_Panel_typ_Symbology_ {
  /* ------------------------- inputs --------------------------- */
  SGLbool active;
  SGLdouble speed;
} SDY1_Panel_typ_Symbology;

You must provide the corresponding Python structure in usr_application.py:

import ctypes
from sdyproxy import SdyLayer
class SymbologyLayer(SdyLayer):
    _fields_ = [
        ('active', ctypes.c_uint8),  # provide the C type corresponding to SGLbool
        ('speed', ctypes.c_double),
    ]

Note

No consistency check is performed between the structure you define and the one generated by SCADE Display KCG.

The Python code to access the graphical panel is rather straightforward:

from sdy_application import sdy_panel
...
# run until the window is closed
while not sdy_panel.cancelled():
    ...
    active = True
    speed = 42
    ...
    # update the display
    sdy_panel.lockio()
    sdy_panel.Symbology.active = active
    sdy_panel.Symbology.speed = speed
    sdy_panel.unlockio()
    sdy_panel.draw()
    ...