draw_rectangle1π
Short descriptionπ
draw_rectangle1 β Draw a rectangle parallel to the coordinate axis.
Signatureπ
draw_rectangle1( window WindowHandle, out rectangle.origin.y Row1, out rectangle.origin.x Column1, out rectangle.corner.y Row2, out rectangle.corner.x Column2 )
Descriptionπ
draw_rectangle1 returns the parameter for a rectangle parallel
to the coordinate axes, which has been created interactively by the user
in the window.
To create a rectangle you have to press the left mouse button determining a corner of the rectangle. While keeping the button pressed you may βdragβ the rectangle in any direction. After another mouse click in the middle of the created rectangle you can move it. A click close to one side βgripsβ it to modify the rectangleβs dimension in perpendicular direction to this side. If you click on one corner of the created rectangle, you may move this corner. Pressing the right mouse button terminates the procedure.
After terminating the procedure the rectangle is not visible in the window any longer.
Attentionπ
If used in a buffer window, mouse events have to be supplied by the application, while the draw operator must be run in another thread.
Execution informationπ
Execution information
-
Multithreading type: reentrant (runs in parallel with non-exclusive operators).
-
Multithreading scope: global (may be called from any thread).
-
Processed without parallelization.
Parametersπ
WindowHandle (input_control) window β (handle)
Window handle.
Row1 (output_control) rectangle.origin.y β (real)
Row index of the left upper corner.
Column1 (output_control) rectangle.origin.x β (real)
Column index of the left upper corner.
Row2 (output_control) rectangle.corner.y β (real)
Row index of the right lower corner.
Column2 (output_control) rectangle.corner.x β (real)
Column index of the right lower corner.
Exampleπ
(HDevelop)
read_image(Image,'monkey')
get_image_size (Image, Width, Height)
dev_display (Image)
draw_rectangle1(WindowHandle,Row1,Column1,Row2,Column2)
dev_set_part (Row1, Column1, Row2, Column2)
dev_display (Image)
read_image(&Image,"monkey")\;
get_image_size(Image,&Width,&Height)\;
disp_image(Image,WindowHandle)\;
draw_rectangle1(WindowHandle,&Row1,&Column1,&Row2,&Column2)\;
set_part(WindowHandle,Row1,Column1,Row2,Column2)\;
disp_image(Image,WindowHandle)\;
Resultπ
draw_rectangle1 returns 2 (H_MSG_TRUE) if the window is valid.
If necessary, an exception is raised.
Combinations with other operatorsπ
Combinations
Possible predecessors
Possible successors
reduce_domain, disp_region, set_colored, set_line_width, set_draw
Alternatives
draw_rectangle1_mod, draw_rectangle2, draw_region
See also
Moduleπ
Foundation