blockly/apps/blockfactory/preview.js
/**
* Blockly Apps: Block Factory
*
* Copyright 2013 Google Inc.
* https://blockly.googlecode.com/
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @fileoverview JavaScript for Blockly's Block Factory preview.
* @author fraser@google.com (Neil Fraser)
*/
'use strict';
/**
* The uneditable preview block.
* @type {Blockly.Block}
*/
var previewBlock = null;
/**
* Create the specified block in this preview pane.
* @param {string} type Name of block.
* @param {string} code JavaScript code to create a block.
*/
function updateFunc(type, code) {
if (previewBlock) {
previewBlock.dispose();
previewBlock = null;
}
eval(code);
// Create the preview block.
previewBlock = Blockly.Block.obtain(Blockly.mainWorkspace, type);
previewBlock.initSvg();
previewBlock.render();
previewBlock.setMovable(false);
previewBlock.setDeletable(false);
}
/**
* Initialize Blockly. Called on page load.
*/
function init() {
var rtl = (document.location.search == '?rtl');
Blockly.inject(document.body, {path: '../../', rtl: rtl});
if (window.parent.initPreview) {
// Let the top-level application know that Blockly is ready.
window.parent.initPreview(updateFunc);
} else {
// Attempt to diagnose the problem.
var msg = 'Error: Unable to communicate between frames.\n' +
'The preview frame will not be functional.\n\n';
if (window.parent == window) {
msg += 'Try loading index.html instead of preview.html';
} else if (window.location.protocol == 'file:') {
msg += 'This may be due to a security restriction preventing\n' +
'access when using the file:// protocol.\n' +
'http://code.google.com/p/chromium/issues/detail?id=47416';
}
alert(msg);
}
}
window.addEventListener('load', init);