h5p-php-library/js/h5p-resizer.js

125 lines
3.1 KiB
JavaScript
Raw Blame History

This file contains invisible Unicode characters!

This file contains invisible Unicode characters that may be processed differently from what appears below. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to reveal hidden characters.

// H5P iframe Resizer
(function () {
if (!window.postMessage || !window.addEventListener) {
return; // Not supported
}
// Map actions to handlers
var actionHandlers = {};
/**
* Prepare iframe resize.
*
* @private
* @param {Object} iframe Element
* @param {Object} data Payload
* @param {Function} respond Send a response to the iframe
*/
actionHandlers.hello = function (iframe, data, respond) {
// Make iframe responsive
iframe.style.width = '100%';
// Tell iframe that it needs to resize when our window resizes
var resize = function (event) {
if (iframe.contentWindow) {
// Limit resize calls to avoid flickering
respond('resize');
}
else {
// Frame is gone, unregister.
window.removeEventListener('resize', resize);
}
};
window.addEventListener('resize', resize, false);
// Respond to let the iframe know we can resize it
respond('hello');
};
/**
* Prepare iframe resize.
*
* @private
* @param {Object} iframe Element
* @param {Object} data Payload
* @param {Function} respond Send a response to the iframe
*/
actionHandlers.prepareResize = function (iframe, data, respond) {
responseData = {};
// Reset iframe height, in case content has shrinked.
iframe.style.height = '1px';
respond('resizePrepared');
};
/**
* Resize parent and iframe to desired height.
*
* @private
* @param {Object} iframe Element
* @param {Object} data Payload
* @param {Function} respond Send a response to the iframe
*/
actionHandlers.resize = function (iframe, data, respond) {
// Resize iframe so all content is visible.
iframe.style.height = data.height + 'px';
};
/**
* Keyup event handler. Exits full screen on escape.
*
* @param {Event} event
*/
var escape = function (event) {
if (event.keyCode === 27) {
exitFullScreen();
}
};
// Listen for messages from iframes
window.addEventListener('message', function receiveMessage(event) {
if (event.data.context !== 'h5p') {
return; // Only handle h5p requests.
}
// Find out who sent the message
var iframe, iframes = document.getElementsByTagName('iframe');
for (var i = 0; i < iframes.length; i++) {
if (iframes[i].contentWindow === event.source) {
iframe = iframes[i];
break;
}
}
if (!iframe) {
return; // Cannot find sender
}
// Find action handler handler
if (actionHandlers[event.data.action]) {
actionHandlers[event.data.action](iframe, event.data, function respond(action, data) {
if (data === undefined) {
data = {};
}
data.action = action;
data.context = 'h5p';
event.source.postMessage(data, event.origin);
});
}
}, false);
// Let h5p iframes know we're ready!
var iframes = document.getElementsByTagName('iframe');
var ready = {
context: 'h5p',
action: 'ready'
};
for (var i = 0; i < iframes.length; i++) {
if (iframes[i].src.indexOf('h5p') !== -1) {
iframes[i].contentWindow.postMessage(ready, '*');
}
}
})();