// JavaScript Document for /art2/exhibits/default.aspx

ERR_MSG_1 = 'Your browser does not support this page.';

PATH_PREFIX = 'gallery_samples/graphics/'; //path to image files relative to .aspx file
PRELOADED = false;  //indicates if preloading images is activated

IMG1 = 'leftImg';  		//id attribute of an xhtml IMG element
IMG2 = 'centerImg';  	//id attribute of an xhtml IMG element
IMG3 = 'rightImg';  	//id attribute of an xhtml IMG element
LAST_IMG_SUBSCRIPT = 2; //total images minus one

IMG_INTERVAL = 4000; //delay between rotating images

DELAY_2 = 1000;	//delay to start rotating image 2
DELAY_3 = 2000; //delay to start rotating image 3



function init() {
	var temp = null;
	if(document.getElementById) {
		//preloadGallery();
		for(var i = 0; i < CURRENT_s.length; i++) CURRENT_s[i] = -1;
		setInterval('rotateMainPhotos(IMG1, 0);', IMG_INTERVAL);
		setTimeout("setInterval('rotateMainPhotos(IMG2, 1);', IMG_INTERVAL);", DELAY_2);
		setTimeout("setInterval('rotateMainPhotos(IMG3, 2);',IMG_INTERVAL);", DELAY_3 );
	}
	else alert(ERR_MSG_1);
}

/*	function rotates images into an IMG element by generating a random number subscript
 *	into an Array of image file path names.
 *
 *		input: the string name of the IMG element's id attribute,
 *			and the subscript of the IMG element's position in the Current_s Array.
 *
 *		output: the changing of the input image's src property.
*/
function rotateMainPhotos(imgElemStr, saveIndex) {
	var img = document.getElementById(imgElemStr);
	var done = false;
	var s = 0;
	while(!done) {
		s = Math.round(Math.random() * (PATH.length - 1));
		done = checkDups(s);
	}
	if(PRELOADED) img.src = PIX[s].src
	else img.src = PATH[s];
	
	CURRENT_s[saveIndex] = s; //save the current image subscript

	/* function checks the array of currently displayed images          *
	 *		input:  is the random number subscript to the PATHS array
	 *		oput:	TRUE if the randomNum is not found in the saved Array
	 *				FALSE if the randomNum is found in the saved Array
	*/
	function checkDups(randomNum){
		var flag = true;
		var i = 0;
		while(flag && (i < CURRENT_s.length) ){
			if(randomNum == CURRENT_s[i]) flag = false;
			i++;
		}
		return flag;
	}//end func checkDups
}//end func rotateMainPhotos



function preloadGallery() {
	for (var i = 0; i < PIX.length; i++ ) {
		PIX[i] = new Image();
		PIX[i].src = PATH[i];
	}
	PRELOADED = true;
}//end func preloadGallery


// Array of path names to image files
PATH = new Array();
PATH[0] = PATH_PREFIX + '12years_old_sch.jpg';
PATH[1] = PATH_PREFIX + 'african_queen_stu.jpg';
PATH[2] = PATH_PREFIX + 'age_kali_alb.jpg ';
PATH[3] = PATH_PREFIX + 'anemones_pen.jpg';
PATH[4] = PATH_PREFIX + 'angels_pie.jpg';
PATH[5] = PATH_PREFIX + 'anthuriums_set.jpg';
PATH[6] = PATH_PREFIX + 'art_life3_mcc.jpg';
PATH[7] = PATH_PREFIX + 'autumn_crocus_pen.jpg';
PATH[8] = PATH_PREFIX + 'awaiting_boy.jpg';
PATH[9] = PATH_PREFIX + 'ballad_mcwinches_wad.jpg';

PATH[10] = PATH_PREFIX + 'bandon_beach_bro.jpg';
PATH[11] = PATH_PREFIX + 'beachcombers_encroachment_wat.jpg';
PATH[12] = PATH_PREFIX + 'birth_stjohn_rad.jpg';
PATH[13] = PATH_PREFIX + 'blue_mouse_bea.jpg';
PATH[14] = PATH_PREFIX + 'boy_horse_mil.jpg';
PATH[15] = PATH_PREFIX + 'butterfly_flower_kha.jpg';
PATH[16] = PATH_PREFIX + 'bx5_mcc.jpg';
PATH[17] = PATH_PREFIX + 'calligraphy_tra.jpg';
PATH[18] = PATH_PREFIX + 'cardboard_purse_stu.jpg';
PATH[19] = PATH_PREFIX + 'caterpillar_issue37.jpg';

PATH[20] = PATH_PREFIX + 'caterpillar_issue55.jpg';
PATH[21] = PATH_PREFIX + 'clematis_cirrhosaIII_rie.jpg';
PATH[22] = PATH_PREFIX + 'coolcar_rainy_har.jpg';
PATH[23] = PATH_PREFIX + 'cornelius_roadhouse_bra.jpg';
PATH[24] = PATH_PREFIX + 'country_house_bar.jpg';
PATH[25] = PATH_PREFIX + 'creative_judgemental_mar.jpg';
PATH[26] = PATH_PREFIX + 'dads_guineas_gou.jpg';
PATH[27] = PATH_PREFIX + 'day_dream_eva.jpg';
PATH[28] = PATH_PREFIX + 'fig_tree_ken.jpg';
PATH[29] = PATH_PREFIX + 'flamingo_violets_mil.jpg';

PATH[30] = PATH_PREFIX + 'follows_path_sch.jpg';
PATH[31] = PATH_PREFIX + 'game_backgammon_rad.jpg';
PATH[32] = PATH_PREFIX + 'girl_hats_bra.jpg';
PATH[33] = PATH_PREFIX + 'grasses_hel.jpg';
PATH[34] = PATH_PREFIX + 'hawaiian_foliage_tee.jpg';
PATH[35] = PATH_PREFIX + 'hillary_field_sno.jpg';
PATH[36] = PATH_PREFIX + 'hotel_baudy3_cud.jpg';
PATH[37] = PATH_PREFIX + 'inner_person_gab.jpg';
PATH[38] = PATH_PREFIX + 'isle_capri_hel.jpg';
PATH[39] = PATH_PREFIX + 'jewels_sea_alo.jpg';

PATH[40] = PATH_PREFIX + 'ladies_pepperpatch_cha.jpg';
PATH[41] = PATH_PREFIX + 'last_leaves_cle.jpg';
PATH[42] = PATH_PREFIX + 'light_colors_set.jpg';
PATH[43] = PATH_PREFIX + 'lizard_del.jpg';
PATH[44] = PATH_PREFIX + 'martinique_getaway_tee.jpg';
PATH[45] = PATH_PREFIX + 'meridian_homes_eva.jpg';
PATH[46] = PATH_PREFIX + 'mirror_pond_wat.jpg';
PATH[47] = PATH_PREFIX + 'mm1_ste.jpg';
PATH[48] = PATH_PREFIX + 'moonlight_laundry_wal.jpg';
PATH[49] = PATH_PREFIX + 'musa_coccinea_lee.jpg';

//Array of currently displayed PATH subscripts
CURRENT_s = new Array(LAST_IMG_SUBSCRIPT);

//Array of preloaded images pointed to by PATH
PIX = new Array(PATH.length - 1);