I was playing the example code of the widget_window in the IDL documentation (See below). Works ok, but the user can rotate and zoom on the image in the widget window. For this sort application, I would want to lock down the graphic so the user could not zoom or rotate. Is there anyway to lock certain properties so they cannot be changed?
;+
; The event handler called when any mouse button is pressed.
;-
FUNCTION WIDGET_WINDOW_EX_MOUSE_DOWN_EVENT, $
win, x, y, button, keymods, clicks
COMPILE_OPT idl2
state = win.uvalue
IF(button eq 1 && keymods eq 2) then begin
state['drag'] = 1
state['start'] = [x,y]
; Do not do the default handling.
RETURN, 0
ENDIF
; Continue with the default handling.
return, 1
END
;+
; The event handler called when any mouse button is released.
;-
FUNCTION WIDGET_WINDOW_EX_MOUSE_UP_EVENT, win, x, y, button
COMPILE_OPT idl2
state = win.uvalue
state['drag'] = 0
RETURN, 1
END
;+
; The event handler called when the mouse is moved.
;-
FUNCTION WIDGET_WINDOW_EX_MOUSE_MOTION_EVENT, win, x, y, keymods
COMPILE_OPT idl2
state = win.uvalue
IF(state['drag']) then begin
difference = [x,y] - state['start']
new_center = state['center'] + difference[0]
new_width = state['width'] + difference[1]
new_brain = SET_WINDOW(state['image'], new_center, new_width)
win['display'].setdata, new_brain
return, 0
ENDIF
RETURN, 1
END
;+
; Helper routine. Sets window center and width for an image.
;-
FUNCTION SET_WINDOW, image, center, width
COMPILE_OPT idl2
lo = center - 0.5*width
hi = center + 0.5*width
RETURN, BYTSCL((image > lo) < hi)
END
;+
; The launch routine. Sets up UI & state variable, loads data.
;-
PRO WIDGET_WINDOW_EX
COMPILE_OPT idl2
; An MR image with center and width.
brain = READ_IMAGE(FILE_WHICH('mr_brain.dcm'))
center = 1011 ; from file
width = 2021 ; from file
brain_scaled = SET_WINDOW(brain, center, width)
wtop = WIDGET_BASE(/COLUMN, $
TITLE='Graphics event handling with IDL widgets')
wdraw = WIDGET_WINDOW(wtop, $
MOUSE_DOWN_HANDLER='widget_window_ex_mouse_down_event', $
MOUSE_UP_HANDLER='widget_window_ex_mouse_up_event', $
MOUSE_MOTION_HANDLER='widget_window_ex_mouse_motion_event')
WIDGET_CONTROL, wtop, /REALIZE
; Extract the window reference from the draw widget,
; and display the first image resampled to 150% original size.
WIDGET_CONTROL, wdraw, GET_VALUE=w
g = IMAGE(brain_scaled, /CURRENT, TITLE='MR: Brain', NAME='display')
g.SCALE, 1.5, 1.5, 1.0
t = TEXT(0.5,0.02, $
['Hold <Ctrl> and drag horizontally to change brightness,', $
'drag vertically to change contrast'], $
ALIGNMENT='center')
; Make a state variable.
state = HASH()
state['image'] = brain_scaled
state['drag'] = 0
state['start'] = [0,0]
state['center'] = center
state['width'] = width
; Attach the state variable to the window's user value. Attach the
; window to the top-level base's user value. This ensures that state
; information can be communicated to both the widget and event handlers.
w.uvalue = state
WIDGET_CONTROL, wtop, SET_UVALUE=w
XMANAGER, 'widget_window_ex', wtop, /NO_BLOCK
END
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