;--------------------------------------------------------------------------- ; Document name: box_cursor2.pro ; Created by: Liyun Wang, GSFC/ARC, September 9, 1994 ; ; Last Modified: Mon Jun 5 12:02:16 1995 (lwang@achilles.nascom.nasa.gov) ;--------------------------------------------------------------------------- ; PRO box_cursor2, x0, y0, nx, ny, INIT = init, FIXED_SIZE = fixed_size, $ message = message, color = color, anywhere=anywhere, $ event_pro=event_pro, stc4event=event ;+ ; NAME: ; BOX_CURSOR2 ; ; PURPOSE: ; Emulate the operation of a variable-sized box cursor ; ; EXPLANATION: ; This is a better improved version of BOX_CURSOR, a standard procedure ; from the IDL user library. The added keywords are: COLOR, ANYWHERE, ; EVENT_PRO, and STC4EVENT. ; ; CATEGORY: ; Interactive graphics. ; ; CALLING SEQUENCE: ; BOX_CURSOR2, x0, y0, nx, ny [, INIT = init] [, FIXED_SIZE = fixed_size] ; [, COLOR = color] ; INPUTS: ; No required input parameters. ; ; OPTIONAL INPUT PARAMETERS: ; X0, Y0, NX, NY - The initial location (X0, Y0) and size (NX, NY) ; of the box if the keyword INIT is set. Otherwise, ; the box is initially drawn in the center of the ; screen. ; EVENT_PRO - Name of the procedure to be called when the boxed ; cursor is manipulated. This procedure must have one ; and only one positional parameter which is a ; structure. This structure is passed in with the ; keyword STC4EVENT and must have at least two tags ; named X and Y being the cursor position in device ; pixels. ; STC4EVENT - Structure to be processed by the procedure specified ; by EVENT_PRO. It can have any number of tags, but X ; and Y tags are required ones. ; ; KEYWORD PARAMETERS: ; INIT - If this keyword is set, X0, Y0, NX, and NY contain the ; initial parameters for the box. ; FIXED_SIZE - If this keyword is set, nx and ny contain the initial ; size of the box. This size may not be changed by the ; user. ; MESSAGE - If this keyword is set, print a short message describing ; operation of the cursor. ; COLOR - Index of color to be used to draw the cursor. Default: ; !d.n_colors-1 ; ANYWHERE - Set this keyword to allow box to be moved outside the ; window ; ; OUTPUTS: ; x0 - X value of lower left corner of box. ; y0 - Y value of lower left corner of box. ; nx - width of box in pixels. ; ny - height of box in pixels. ; ; The box is also constrained to lie entirely within the window. ; ; COMMON BLOCKS: ; None. ; ; SIDE EFFECTS: ; A box is drawn in the currently active window. It is erased ; on exit. ; ; RESTRICTIONS: ; Works only with window system drivers. ; ; PROCEDURE: ; The graphics function is set to 6 for eXclusive OR. This ; allows the box to be drawn and erased without disturbing the ; contents of the window. ; ; Operation is as follows: ; Left mouse button: Move the box by dragging. ; Middle mouse button: Resize the box by dragging. The corner ; nearest the initial mouse position is moved. ; Right mouse button: Exit this procedure, returning the ; current box parameters. ; ; KNOWN PROBLEM: ; The box can be off the display window when resizing. More ; checking is needed to prevent this. ; ; MODIFICATION HISTORY: ; DMS, April, 1990. ; DMS, April, 1992. Made dragging more intutitive. ; June, 1993 - Bill Thompson ; prevented the box from having a negative size. ; September 1, 1994 -- Liyun Wang ; Added the COLOR keyword ; September 9, 1994 -- Liyun Wang, GSFC/ARC ; Prevented the box from jumpping around ; when resizing ; May 26, 1995 -- Liyun Wang, GSFC/ARC ; Added the ANYWHERE keyword ; June 5, 1995 -- Liyun Wang, GSFC/ARC ; Added EVENT_PRO and STC4EVENT keywords ;- DEVICE, get_graphics = old, set_graphics = 6 ; Set xor IF N_ELEMENTS(color) EQ 0 THEN color = !d.n_colors -1 IF N_ELEMENTS(event_pro) NE 0 THEN BEGIN ok = datatype(event_pro) EQ 'STR' IF NOT ok THEN MESSAGE, 'Error in compiling the event procedure.', /cont ENDIF ELSE ok = 0 IF KEYWORD_SET(MESSAGE) THEN BEGIN IF KEYWORD_SET(fixed_size) THEN BEGIN PRINT, "Drag Left button to move box." PRINT, "Right button when done." ENDIF ELSE BEGIN PRINT, "Drag Left button to move box." PRINT, "Drag Middle button near a corner to resize box." PRINT, "Right button when done." ENDELSE ENDIF IF KEYWORD_SET(init) EQ 0 THEN BEGIN ;Supply default values for box: IF KEYWORD_SET(fixed_size) EQ 0 THEN BEGIN nx = !d.x_size/8 ;no fixed size. ny = !d.x_size/8 ENDIF x0 = !d.x_size/2-nx/2 y0 = !d.y_size/2-ny/2 ENDIF button = 0 GOTO, middle WHILE 1 DO BEGIN old_button = button cursor, x, y, 2, /dev ;Wait for a button button = !err IF (old_button EQ 0) AND (button NE 0) THEN BEGIN mx0 = x ;For dragging, mouse locn... my0 = y x00 = x0 ;Orig start of ll corner y00 = y0 ENDIF IF !err EQ 1 THEN BEGIN ;Drag entire box? x0 = x00 + x - mx0 y0 = y00 + y - my0 ENDIF IF (!err EQ 2) AND (KEYWORD_SET(fixed_size) EQ 0) THEN BEGIN ;New size? IF old_button EQ 0 THEN BEGIN ;Find closest corner min_d = 1e6 FOR i = 0,3 DO BEGIN d = FLOAT(px(i)-x)^2 + FLOAT(py(i)-y)^2 IF d LT min_d THEN BEGIN min_d = d corner = i ENDIF ENDFOR nx0 = nx ;Save sizes. ny0 = ny ENDIF dx = x-mx0 & dy = y-my0 ;Distance dragged... ;--------------------------------------------------------------------------- ; The major change was made here. After the closest corner is ; found, the opposite corner is fixed. This prevents the box ; from jumping around -- Liyun Wang, GSFC/ARC ;--------------------------------------------------------------------------- CASE corner OF 0: BEGIN IF (dx GT nx0) THEN BEGIN x0 = x00+nx0 nx = dx-nx0 ENDIF ELSE BEGIN x0 = x00+dx nx = nx0-dx ENDELSE IF (dy GT ny0) THEN BEGIN y0 = y00+ny0 ny = dy-ny0 ENDIF ELSE BEGIN y0 = y00+dy ny = ny0-dy ENDELSE END 1: BEGIN IF (dx LE -nx0) THEN BEGIN nx = -(nx0+dx) x0 = x00-nx ENDIF ELSE BEGIN nx = nx0+dx x0 = x00 ENDELSE IF (dy GT ny0) THEN BEGIN y0 = y00+ny0 ny = dy-ny0 ENDIF ELSE BEGIN y0 = y00+dy ny = ny0-dy ENDELSE END 2: BEGIN IF (dx LE -nx0) THEN BEGIN nx = -(nx0+dx) x0 = x00-nx ENDIF ELSE BEGIN nx = nx0+dx x0 = x00 ENDELSE IF (dy LE -ny0) THEN BEGIN ny = -(ny0+dy) y0 = y00-ny ENDIF ELSE BEGIN ny = ny0+dy y0 = y00 ENDELSE END 3: BEGIN IF (dx GT nx0) THEN BEGIN x0 = x00+nx0 nx = dx-nx0 ENDIF ELSE BEGIN x0 = x00+dx nx = nx0-dx ENDELSE IF (dy LE -ny0) THEN BEGIN ny = -(ny0+dy) y0 = y00-ny ENDIF ELSE BEGIN ny = ny0+dy y0 = y00 ENDELSE END ENDCASE ENDIF PLOTS, px, py, col=color, /dev, thick=1, lines=0 ;Erase previous box EMPTY ;Decwindow bug IF !err EQ 4 THEN BEGIN ;Quitting? DEVICE,set_graphics = old RETURN ENDIF middle: IF NOT KEYWORD_SET(anywhere) THEN BEGIN ;--------------------------------------------------------------------------- ; Never allow the box to be outside window ;--------------------------------------------------------------------------- x0 = x0 > 0 y0 = y0 > 0 x0 = x0 < (!d.x_size-1 - nx) y0 = y0 < (!d.y_size-1 - ny) ENDIF ELSE BEGIN x0 = x0 > (-nx) y0 = y0 > (-ny) x0 = x0 < (!d.x_size-1) y0 = y0 < (!d.y_size-1) ENDELSE IF ok THEN BEGIN event.x = x0 event.y = y0 CALL_PROCEDURE, event_pro, event ENDIF px = [x0, x0 + nx, x0 + nx, x0, x0] ;X points py = [y0, y0, y0 + ny, y0 + ny, y0] ;Y values PLOTS,px, py, col=color, /dev, thick=1, lines=0 ;Draw the box wait, .1 ;Dont hog it all ENDWHILE END ;--------------------------------------------------------------------------- ; End of 'box_cursor2.pro'. ;---------------------------------------------------------------------------