// These styles need to be added dynamically because we only want them
// when JS is turned on
addCss(".datagrid td.drilldown, .datagrid th.drilldown { display: none; }");

// We should only invoke datagrid actions when selection is empty
function initiateActionOnEmptySelection(actionCode, sessionString) {
    if(selectionEmpty()) {
	initiateAction(actionCode, sessionString);
	return false;
    }
}

// Keyboard
function clearNavigatableHighlight() {
    if(selectedNavigatableRowIndex != undefined) {
	var row = navigatableTableRows[selectedNavigatableRowIndex];
	if(row) {
	    if(!row.hasClassName('drilled-down')) {
		row.removeClassName('hover');
	    }
	} else {
	    selectedNavigatableRowIndex = undefined;
	}
    }
}

function setNavigatableHighlight() {
    if(selectedNavigatableRowIndex != undefined) {
	var row = navigatableTableRows[selectedNavigatableRowIndex];
	if(row) {
	    row.addClassName('hover');
	}
    }
}

function initializeNavigatableRows() {
    navigatableTableRows = $$('tr').select(function(e) { return e.readAttribute('onclick'); });
    selectedNavigatableRowIndex = undefined;
    for(var i = 0; i < navigatableTableRows.length; i++) {
	if(navigatableTableRows[i].hasClassName('drilled-down')) {
	    selectedNavigatableRowIndex = i;
	    break;
	}
    }
    navigatableTableRows.each(function(row) {
	    Event.observe(row, 'mouseover', function(event) {
		    clearNavigatableHighlight();
		    selectedNavigatableRowIndex = undefined;
		});
	});
}

Event.observe(window, 'load', initializeNavigatableRows);

Ajax.Responders.register({
	onComplete: function() {
	    clearNavigatableHighlight();
	    initializeNavigatableRows();
	}
});

shortcut.add("j", function() {
	if(selectedNavigatableRowIndex == undefined) {
	    selectedNavigatableRowIndex = 0;
	} else {
	    clearNavigatableHighlight();
	    selectedNavigatableRowIndex++;
	    if(selectedNavigatableRowIndex == navigatableTableRows.length) {
		selectedNavigatableRowIndex = undefined;
	    }
	}
	setNavigatableHighlight();
    },
    { 'disable_in_input' : true });

shortcut.add("k", function() {
	if(selectedNavigatableRowIndex == undefined) {
	    selectedNavigatableRowIndex = navigatableTableRows.length - 1;
	} else {
	    clearNavigatableHighlight();
	    selectedNavigatableRowIndex--;
	    if(selectedNavigatableRowIndex == -1) {
		selectedNavigatableRowIndex = undefined;
	    }
	}
	setNavigatableHighlight();
    },
    { 'disable_in_input' : true })

shortcut.add("Return", function() {
	if(selectedNavigatableRowIndex != undefined) {
	    navigatableTableRows[selectedNavigatableRowIndex].onclick();
	}
    },
    { 'disable_in_input' : true })