/*
 * --- Legend functions ---
 */


function showSubMenu(image, subMenuId) {
    var subMenu = xGetElementById(subMenuId);
    if (!subMenu) return;
    
    var visible = xIsVisible(subMenu);
    
    if (visible) {
        xPosition(subMenu, "absolute");
        xHide(subMenu);
        changeImage(image, plusImage);
    } else {
        xShow(subMenu);
        xPosition(subMenu, "");     
        changeImage(image, minusImage);
    }
}
function changeImage(image, predefinedImagePath) {
    image.src = predefinedImagePath;
}

/*
 * --- Checks/unchecks all group elements ---
 */ 
function checkAllGroup(groupHead, groupId) {
    var check = groupHead.checked;
    checkGroupObjects(groupId, check);
}

/*
 * --- Checks/unchecks all group objects ---
 */ 
function checkGroupObjects(groupId, check) {
        
    var i = 0;
    var objId = groupId + i++;
    var obj = null;
    
    while( (obj = document.getElementById(objId)) != null ) {
        obj.checked = check;
        objId = groupId + i++;
    }
}

function checkGroupHead(groupHeadId) {
    var groupHead = document.getElementById(groupHeadId);
    groupHead.checked = true;
}

function refreshLegend() {
    showLoading();
    var legendForm = document.getElementById("legendForm") ;
    if (legendForm) {
        legendForm.tool.value = MAP_ACTIONS["REFRESH_LEGEND"];
    }
    return true;
}