FUNCTION qTool_Zoom, state, event_id, zoom_low=zoom_low, zoom_high=zoom_high

;+
; NAME:
;	qTool_Zoom
; PURPOSE:
;	Handles event related to zooming operations
; CATEGORY:
;	
; CALLING SEQUENCE:
;	R = qTool_Zoom(state, event_id)
; INPUTS:
;	state			array[1]; type: structure
;						qImage_cw state structure
;	event_id		scalar; type: long integer
;						widget ID of widget generating the zoom event
; OUTPUTS:
;	R				scalar; type: integer
;						0: screen needs to be redrawn
;						1: screen does not need to be redrawn
; INCLUDE:
	@compile_opt.pro			; On error, return to caller
; CALLS:
; PROCEDURE:
; MODIFICATION HISTORY:
;	FEB-2001, Paul Hick (UCSD/CASS)
;	JUL-2003, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
;		Minor bug fix in update of cw_field containing zoom factor
;-

InitVar, zoom_low , -30
InitVar, zoom_high,  30

CASE event_id OF

state.wid_zoom: BEGIN
	widget_control, state.wid_zoom, get_value=zoom_new, get_uvalue=zoom_current
	IF zoom_current LT 1 THEN zoom_current = -round(1.0/zoom_current)
	zoom_new = (zoom_new > zoom_low) < zoom_high
	IF zoom_new EQ -1 OR zoom_new EQ 0 THEN zoom_new =  1
	set = zoom_new NE zoom_current
	widget_control, state.wid_zoom, set_value=zoom_new
END

state.wid_zoomin : BEGIN
	widget_control, state.wid_zoom, get_value=zoom_current
	zoom_new = (zoom_current+1) < zoom_high
	IF zoom_new EQ -1 OR zoom_new EQ 0 THEN zoom_new =  1
	set = zoom_new NE zoom_current
	IF set THEN widget_control, state.wid_zoom, set_value=zoom_new
END

state.wid_zoomout: BEGIN
	widget_control, state.wid_zoom, get_value=zoom_current
	zoom_new = (zoom_current-1) > zoom_low
	IF zoom_new EQ -1 OR zoom_new EQ 0 THEN zoom_new = -2
	set = zoom_new NE zoom_current
	IF set THEN widget_control, state.wid_zoom, set_value=zoom_new
END

;state.wid_maxzoom : BEGIN

;	screen_size = qImage_cw_Property(state, /screen_size)

;	IF screen_size[0]*screen_size[1] NE 0 THEN BEGIN
;		qImage_cw_Box, state, /get, box

;		widget_control, state.wid_zoom, get_value=zoom_current

;		zoom_new = floor( min( float(screen_size)/(box[*,1]-box[*,0]+1)) )
;		zoom_new = (zoom_new > zoom_low) < zoom_high

;		set = 1
		;set = zoom_new ne zoom_current

		;IF set THEN BEGIN
;			widget_control, state.wid_zoom   , set_value =zoom_new
;			widget_control, state.wid_maxzoom, set_uvalue=1 ; Forces centering of box
		;ENDIF

;	ENDIF
;END

ENDCASE

RETURN, set  &  END