attach_background_to_window🔗
Short description🔗
attach_background_to_window — Attach a background image to a HALCON window.
Signature🔗
attach_background_to_window( image Image, window WindowHandle )
Description🔗
This operator attaches the background image passed in Image
to a HALCON window defined in WindowHandle. The input image is
copied. Thus it can be freed safely.
The background image is instantly displayed in the HALCON window
when calling attach_background_to_window. All HALCON objects
that were previously displayed in the window will still be displayed
when calling this operator. Thus the previous window content will
not be overwritten.
The window contents are displayed in the following order: first the
background image, then HALCON objects, and finally the drawing objects.
Thus, the drawing object is displayed always on top.
Note that the window will be redrawn for each user interaction within
the window and each call of set_part. HALCON objects can be
deleted from the window with clear_window.
The background image can be removed from the window with the
operator detach_background_from_window.
Attention🔗
Note that using any synchronous operator which actively probe the event
queue, e.g., get_mbutton or read_char, will conflict with the
interaction with the drawing objects. In case the state of the cursor has to
be read, please refer to the documentation of your framework of choice for an
appropriate, non-invasive alternative.
Furthermore, the event based functionality should not be used together with
the former blocking operators draw_rectangle1,
draw_rectangle2, draw_region, draw_xld or
draw_circle. They conflict with the event based functionality, since
they actively fetch all events sent to the HALCON window.
Execution information🔗
Execution information
-
Multithreading type: reentrant (runs in parallel with non-exclusive operators).
-
Multithreading scope: global (may be called from any thread).
-
Processed without parallelization.
Parameters🔗
Image (input_object) singlechannelimage → object (byte / direction / cyclic / int1 / int2 / uint2 / int4 / int8 / real / complex / vector_field)
Background image.
WindowHandle (input_control) window → (handle)
Window handle.
Result🔗
If the window exists and the specified parameters are correct
attach_background_to_window returns 2 (H_MSG_TRUE). If necessary an exception
is raised.
Combinations with other operators🔗
Module🔗
Foundation