// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* JavaScript to make drag-drop into text questions work.
*
* Some vocabulary to help understand this code:
*
* The question text contains 'drops' - blanks into which the 'drags', the missing
* words, can be put.
*
* The thing that can be moved into the drops are called 'drags'. There may be
* multiple copies of the 'same' drag which does not really cause problems.
* Each drag has a 'choice' number which is the value set on the drop's hidden
* input when this drag is placed in a drop.
*
* These may be in separate 'groups', distinguished by colour.
* Things can only interact with other things in the same group.
* The groups are numbered from 1.
*
* The place where a given drag started from is called its 'home'.
*
* @module qtype_ddwtos/ddwtos
* @copyright 2018 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since 3.6
*/
define([
'jquery',
'core/dragdrop',
'core/key_codes',
'core_form/changechecker'
], function(
$,
dragDrop,
keys,
FormChangeChecker
) {
"use strict";
/**
* Object to handle one drag-drop into text question.
*
* @param {String} containerId id of the outer div for this question.
* @param {boolean} readOnly whether the question is being displayed read-only.
* @constructor
*/
function DragDropToTextQuestion(containerId, readOnly) {
this.containerId = containerId;
this.questionAnswer = {};
if (readOnly) {
this.getRoot().addClass('qtype_ddwtos-readonly');
}
this.resizeAllDragsAndDrops();
this.cloneDrags();
this.positionDrags();
}
/**
* In each group, resize all the items to be the same size.
*/
DragDropToTextQuestion.prototype.resizeAllDragsAndDrops = function() {
var thisQ = this;
this.getRoot().find('.answercontainer > div').each(function(i, node) {
thisQ.resizeAllDragsAndDropsInGroup(
thisQ.getClassnameNumericSuffix($(node), 'draggrouphomes'));
});
};
/**
* In a given group, set all the drags and drops to be the same size.
*
* @param {int} group the group number.
*/
DragDropToTextQuestion.prototype.resizeAllDragsAndDropsInGroup = function(group) {
var thisQ = this,
dragHomes = this.getRoot().find('.draggrouphomes' + group + ' span.draghome'),
maxWidth = 0,
maxHeight = 0;
// Find the maximum size of any drag in this groups.
dragHomes.each(function(i, drag) {
maxWidth = Math.max(maxWidth, Math.ceil(drag.offsetWidth));
maxHeight = Math.max(maxHeight, Math.ceil(0 + drag.offsetHeight));
});
// The size we will want to set is a bit bigger than this.
maxWidth += 8;
maxHeight += 2;
// Set each drag home to that size.
dragHomes.each(function(i, drag) {
thisQ.setElementSize(drag, maxWidth, maxHeight);
});
// Set each drop to that size.
this.getRoot().find('span.drop.group' + group).each(function(i, drop) {
thisQ.setElementSize(drop, maxWidth, maxHeight);
});
};
/**
* Set a given DOM element to be a particular size.
*
* @param {HTMLElement} element
* @param {int} width
* @param {int} height
*/
DragDropToTextQuestion.prototype.setElementSize = function(element, width, height) {
$(element).width(width).height(height).css('lineHeight', height + 'px');
};
/**
* Invisible 'drag homes' are output by the renderer. These have the same properties
* as the drag items but are invisible. We clone these invisible elements to make the
* actual drag items.
*/
DragDropToTextQuestion.prototype.cloneDrags = function() {
var thisQ = this;
thisQ.getRoot().find('span.draghome').each(function(index, draghome) {
var drag = $(draghome);
var placeHolder = drag.clone();
placeHolder.removeClass();
placeHolder.addClass('draghome choice' +
thisQ.getChoice(drag) + ' group' +
thisQ.getGroup(drag) + ' dragplaceholder');
drag.before(placeHolder);
});
};
/**
* Update the position of drags.
*/
DragDropToTextQuestion.prototype.positionDrags = function() {
var thisQ = this,
root = this.getRoot();
// First move all items back home.
root.find('span.draghome').not('.dragplaceholder').each(function(i, dragNode) {
var drag = $(dragNode),
currentPlace = thisQ.getClassnameNumericSuffix(drag, 'inplace');
drag.addClass('unplaced')
.removeClass('placed');
drag.removeAttr('tabindex');
if (currentPlace !== null) {
drag.removeClass('inplace' + currentPlace);
}
});
// Then place the once that should be placed.
root.find('input.placeinput').each(function(i, inputNode) {
var input = $(inputNode),
choice = input.val(),
place = thisQ.getPlace(input);
// Record the last known position of the drop.
var drop = root.find('.drop.place' + place),
dropPosition = drop.offset();
drop.data('prev-top', dropPosition.top).data('prev-left', dropPosition.left);
if (choice === '0') {
// No item in this place.
return;
}
// Get the unplaced drag.
var unplacedDrag = thisQ.getUnplacedChoice(thisQ.getGroup(input), choice);
// Get the clone of the drag.
var hiddenDrag = thisQ.getDragClone(unplacedDrag);
if (hiddenDrag.length) {
if (unplacedDrag.hasClass('infinite')) {
var noOfDrags = thisQ.noOfDropsInGroup(thisQ.getGroup(unplacedDrag));
var cloneDrags = thisQ.getInfiniteDragClones(unplacedDrag, false);
if (cloneDrags.length < noOfDrags) {
var cloneDrag = unplacedDrag.clone();
hiddenDrag.after(cloneDrag);
questionManager.addEventHandlersToDrag(cloneDrag);
} else {
hiddenDrag.addClass('active');
}
} else {
hiddenDrag.addClass('active');
}
}
// Send the drag to drop.
thisQ.sendDragToDrop(thisQ.getUnplacedChoice(thisQ.getGroup(input), choice), drop);
});
// Save the question answer.
thisQ.questionAnswer = thisQ.getQuestionAnsweredValues();
};
/**
* Get the question answered values.
*
* @return {Object} Contain key-value with key is the input id and value is the input value.
*/
DragDropToTextQuestion.prototype.getQuestionAnsweredValues = function() {
let result = {};
this.getRoot().find('input.placeinput').each((i, inputNode) => {
result[inputNode.id] = inputNode.value;
});
return result;
};
/**
* Check if the question is being interacted or not.
*
* @return {boolean} Return true if the user has changed the question-answer.
*/
DragDropToTextQuestion.prototype.isQuestionInteracted = function() {
const oldAnswer = this.questionAnswer;
const newAnswer = this.getQuestionAnsweredValues();
let isInteracted = false;
// First, check both answers have the same structure or not.
if (JSON.stringify(newAnswer) !== JSON.stringify(oldAnswer)) {
isInteracted = true;
return isInteracted;
}
// Check the values.
Object.keys(newAnswer).forEach(key => {
if (newAnswer[key] !== oldAnswer[key]) {
isInteracted = true;
}
});
return isInteracted;
};
/**
* Handles the start of dragging an item.
*
* @param {Event} e the touch start or mouse down event.
*/
DragDropToTextQuestion.prototype.handleDragStart = function(e) {
var thisQ = this,
drag = $(e.target).closest('.draghome');
var info = dragDrop.prepare(e);
if (!info.start || drag.hasClass('beingdragged')) {
return;
}
drag.addClass('beingdragged');
var currentPlace = this.getClassnameNumericSuffix(drag, 'inplace');
if (currentPlace !== null) {
this.setInputValue(currentPlace, 0);
drag.removeClass('inplace' + currentPlace);
var hiddenDrop = thisQ.getDrop(drag, currentPlace);
if (hiddenDrop.length) {
hiddenDrop.addClass('active');
drag.offset(hiddenDrop.offset());
}
} else {
var hiddenDrag = thisQ.getDragClone(drag);
if (hiddenDrag.length) {
if (drag.hasClass('infinite')) {
var noOfDrags = this.noOfDropsInGroup(this.getGroup(drag));
var cloneDrags = this.getInfiniteDragClones(drag, false);
if (cloneDrags.length < noOfDrags) {
var cloneDrag = drag.clone();
cloneDrag.removeClass('beingdragged');
hiddenDrag.after(cloneDrag);
questionManager.addEventHandlersToDrag(cloneDrag);
drag.offset(cloneDrag.offset());
} else {
hiddenDrag.addClass('active');
drag.offset(hiddenDrag.offset());
}
} else {
hiddenDrag.addClass('active');
drag.offset(hiddenDrag.offset());
}
}
}
dragDrop.start(e, drag, function(x, y, drag) {
thisQ.dragMove(x, y, drag);
}, function(x, y, drag) {
thisQ.dragEnd(x, y, drag);
});
};
/**
* Called whenever the currently dragged items moves.
*
* @param {Number} pageX the x position.
* @param {Number} pageY the y position.
* @param {jQuery} drag the item being moved.
*/
DragDropToTextQuestion.prototype.dragMove = function(pageX, pageY, drag) {
var thisQ = this;
this.getRoot().find('span.drop.group' + this.getGroup(drag)).each(function(i, dropNode) {
var drop = $(dropNode);
if (thisQ.isPointInDrop(pageX, pageY, drop)) {
drop.addClass('valid-drag-over-drop');
} else {
drop.removeClass('valid-drag-over-drop');
}
});
this.getRoot().find('span.draghome.placed.group' + this.getGroup(drag)).not('.beingdragged').each(function(i, dropNode) {
var drop = $(dropNode);
if (thisQ.isPointInDrop(pageX, pageY, drop) && !thisQ.isDragSameAsDrop(drag, drop)) {
drop.addClass('valid-drag-over-drop');
} else {
drop.removeClass('valid-drag-over-drop');
}
});
};
/**
* Called when user drops a drag item.
*
* @param {Number} pageX the x position.
* @param {Number} pageY the y position.
* @param {jQuery} drag the item being moved.
*/
DragDropToTextQuestion.prototype.dragEnd = function(pageX, pageY, drag) {
var thisQ = this,
root = this.getRoot(),
placed = false;
root.find('span.drop.group' + this.getGroup(drag)).each(function(i, dropNode) {
var drop = $(dropNode);
if (!thisQ.isPointInDrop(pageX, pageY, drop)) {
// Not this drop.
return true;
}
// Now put this drag into the drop.
drop.removeClass('valid-drag-over-drop');
thisQ.sendDragToDrop(drag, drop);
placed = true;
return false; // Stop the each() here.
});
root.find('span.draghome.placed.group' + this.getGroup(drag)).not('.beingdragged').each(function(i, placedNode) {
var placedDrag = $(placedNode);
if (!thisQ.isPointInDrop(pageX, pageY, placedDrag) || thisQ.isDragSameAsDrop(drag, placedDrag)) {
// Not this placed drag.
return true;
}
// Now put this drag into the drop.
placedDrag.removeClass('valid-drag-over-drop');
var currentPlace = thisQ.getClassnameNumericSuffix(placedDrag, 'inplace');
var drop = thisQ.getDrop(drag, currentPlace);
thisQ.sendDragToDrop(drag, drop);
placed = true;
return false; // Stop the each() here.
});
if (!placed) {
this.sendDragHome(drag);
}
};
/**
* Animate a drag item into a given place (or back home).
*
* @param {jQuery|null} drag the item to place. If null, clear the place.
* @param {jQuery} drop the place to put it.
*/
DragDropToTextQuestion.prototype.sendDragToDrop = function(drag, drop) {
// Is there already a drag in this drop? if so, evict it.
var oldDrag = this.getCurrentDragInPlace(this.getPlace(drop));
if (oldDrag.length !== 0) {
var currentPlace = this.getClassnameNumericSuffix(oldDrag, 'inplace');
var hiddenDrop = this.getDrop(oldDrag, currentPlace);
hiddenDrop.addClass('active');
oldDrag.addClass('beingdragged');
oldDrag.offset(hiddenDrop.offset());
this.sendDragHome(oldDrag);
}
if (drag.length === 0) {
this.setInputValue(this.getPlace(drop), 0);
if (drop.data('isfocus')) {
drop.focus();
}
} else {
this.setInputValue(this.getPlace(drop), this.getChoice(drag));
drag.removeClass('unplaced')
.addClass('placed inplace' + this.getPlace(drop));
drag.attr('tabindex', 0);
this.animateTo(drag, drop);
}
};
/**
* Animate a drag back to its home.
*
* @param {jQuery} drag the item being moved.
*/
DragDropToTextQuestion.prototype.sendDragHome = function(drag) {
var currentPlace = this.getClassnameNumericSuffix(drag, 'inplace');
if (currentPlace !== null) {
drag.removeClass('inplace' + currentPlace);
}
drag.data('unplaced', true);
this.animateTo(drag, this.getDragHome(this.getGroup(drag), this.getChoice(drag)));
};
/**
* Handles keyboard events on drops.
*
* Drops are focusable. Once focused, right/down/space switches to the next choice, and
* left/up switches to the previous. Escape clear.
*
* @param {KeyboardEvent} e
*/
DragDropToTextQuestion.prototype.handleKeyPress = function(e) {
var drop = $(e.target).closest('.drop');
if (drop.length === 0) {
var placedDrag = $(e.target);
var currentPlace = this.getClassnameNumericSuffix(placedDrag, 'inplace');
if (currentPlace !== null) {
drop = this.getDrop(placedDrag, currentPlace);
}
}
var currentDrag = this.getCurrentDragInPlace(this.getPlace(drop)),
nextDrag = $();
switch (e.keyCode) {
case keys.space:
case keys.arrowRight:
case keys.arrowDown:
nextDrag = this.getNextDrag(this.getGroup(drop), currentDrag);
break;
case keys.arrowLeft:
case keys.arrowUp:
nextDrag = this.getPreviousDrag(this.getGroup(drop), currentDrag);
break;
case keys.escape:
break;
default:
questionManager.isKeyboardNavigation = false;
return; // To avoid the preventDefault below.
}
if (nextDrag.length) {
nextDrag.data('isfocus', true);
nextDrag.addClass('beingdragged');
var hiddenDrag = this.getDragClone(nextDrag);
if (hiddenDrag.length) {
if (nextDrag.hasClass('infinite')) {
var noOfDrags = this.noOfDropsInGroup(this.getGroup(nextDrag));
var cloneDrags = this.getInfiniteDragClones(nextDrag, false);
if (cloneDrags.length < noOfDrags) {
var cloneDrag = nextDrag.clone();
cloneDrag.removeClass('beingdragged');
cloneDrag.removeAttr('tabindex');
hiddenDrag.after(cloneDrag);
questionManager.addEventHandlersToDrag(cloneDrag);
nextDrag.offset(cloneDrag.offset());
} else {
hiddenDrag.addClass('active');
nextDrag.offset(hiddenDrag.offset());
}
} else {
hiddenDrag.addClass('active');
nextDrag.offset(hiddenDrag.offset());
}
}
} else {
drop.data('isfocus', true);
}
e.preventDefault();
this.sendDragToDrop(nextDrag, drop);
};
/**
* Choose the next drag in a group.
*
* @param {int} group which group.
* @param {jQuery} drag current choice (empty jQuery if there isn't one).
* @return {jQuery} the next drag in that group, or null if there wasn't one.
*/
DragDropToTextQuestion.prototype.getNextDrag = function(group, drag) {
var choice,
numChoices = this.noOfChoicesInGroup(group);
if (drag.length === 0) {
choice = 1; // Was empty, so we want to select the first choice.
} else {
choice = this.getChoice(drag) + 1;
}
var next = this.getUnplacedChoice(group, choice);
while (next.length === 0 && choice < numChoices) {
choice++;
next = this.getUnplacedChoice(group, choice);
}
return next;
};
/**
* Choose the previous drag in a group.
*
* @param {int} group which group.
* @param {jQuery} drag current choice (empty jQuery if there isn't one).
* @return {jQuery} the next drag in that group, or null if there wasn't one.
*/
DragDropToTextQuestion.prototype.getPreviousDrag = function(group, drag) {
var choice;
if (drag.length === 0) {
choice = this.noOfChoicesInGroup(group);
} else {
choice = this.getChoice(drag) - 1;
}
var previous = this.getUnplacedChoice(group, choice);
while (previous.length === 0 && choice > 1) {
choice--;
previous = this.getUnplacedChoice(group, choice);
}
// Does this choice exist?
return previous;
};
/**
* Animate an object to the given destination.
*
* @param {jQuery} drag the element to be animated.
* @param {jQuery} target element marking the place to move it to.
*/
DragDropToTextQuestion.prototype.animateTo = function(drag, target) {
var currentPos = drag.offset(),
targetPos = target.offset(),
thisQ = this;
M.util.js_pending('qtype_ddwtos-animate-' + thisQ.containerId);
// Animate works in terms of CSS position, whereas locating an object
// on the page works best with jQuery offset() function. So, to get
// the right target position, we work out the required change in
// offset() and then add that to the current CSS position.
drag.animate(
{
left: parseInt(drag.css('left')) + targetPos.left - currentPos.left,
top: parseInt(drag.css('top')) + targetPos.top - currentPos.top
},
{
duration: 'fast',
done: function() {
$('body').trigger('qtype_ddwtos-dragmoved', [drag, target, thisQ]);
M.util.js_complete('qtype_ddwtos-animate-' + thisQ.containerId);
}
}
);
};
/**
* Detect if a point is inside a given DOM node.
*
* @param {Number} pageX the x position.
* @param {Number} pageY the y position.
* @param {jQuery} drop the node to check (typically a drop).
* @return {boolean} whether the point is inside the node.
*/
DragDropToTextQuestion.prototype.isPointInDrop = function(pageX, pageY, drop) {
var position = drop.offset();
return pageX >= position.left && pageX < position.left + drop.width()
&& pageY >= position.top && pageY < position.top + drop.height();
};
/**
* Set the value of the hidden input for a place, to record what is currently there.
*
* @param {int} place which place to set the input value for.
* @param {int} choice the value to set.
*/
DragDropToTextQuestion.prototype.setInputValue = function(place, choice) {
this.getRoot().find('input.placeinput.place' + place).val(choice);
};
/**
* Get the outer div for this question.
*
* @returns {jQuery} containing that div.
*/
DragDropToTextQuestion.prototype.getRoot = function() {
return $(document.getElementById(this.containerId));
};
/**
* Get drag home for a given choice.
*
* @param {int} group the group.
* @param {int} choice the choice number.
* @returns {jQuery} containing that div.
*/
DragDropToTextQuestion.prototype.getDragHome = function(group, choice) {
if (!this.getRoot().find('.draghome.dragplaceholder.group' + group + '.choice' + choice).is(':visible')) {
return this.getRoot().find('.draggrouphomes' + group +
' span.draghome.infinite' +
'.choice' + choice +
'.group' + group);
}
return this.getRoot().find('.draghome.dragplaceholder.group' + group + '.choice' + choice);
};
/**
* Get an unplaced choice for a particular group.
*
* @param {int} group the group.
* @param {int} choice the choice number.
* @returns {jQuery} jQuery wrapping the unplaced choice. If there isn't one, the jQuery will be empty.
*/
DragDropToTextQuestion.prototype.getUnplacedChoice = function(group, choice) {
return this.getRoot().find('.draghome.group' + group + '.choice' + choice + '.unplaced').slice(0, 1);
};
/**
* Get the drag that is currently in a given place.
*
* @param {int} place the place number.
* @return {jQuery} the current drag (or an empty jQuery if none).
*/
DragDropToTextQuestion.prototype.getCurrentDragInPlace = function(place) {
return this.getRoot().find('span.draghome.inplace' + place);
};
/**
* Return the number of blanks in a given group.
*
* @param {int} group the group number.
* @returns {int} the number of drops.
*/
DragDropToTextQuestion.prototype.noOfDropsInGroup = function(group) {
return this.getRoot().find('.drop.group' + group).length;
};
/**
* Return the number of choices in a given group.
*
* @param {int} group the group number.
* @returns {int} the number of choices.
*/
DragDropToTextQuestion.prototype.noOfChoicesInGroup = function(group) {
return this.getRoot().find('.draghome.group' + group).length;
};
/**
* Return the number at the end of the CSS class name with the given prefix.
*
* @param {jQuery} node
* @param {String} prefix name prefix
* @returns {Number|null} the suffix if found, else null.
*/
DragDropToTextQuestion.prototype.getClassnameNumericSuffix = function(node, prefix) {
var classes = node.attr('class');
if (classes !== '') {
var classesArr = classes.split(' ');
for (var index = 0; index < classesArr.length; index++) {
var patt1 = new RegExp('^' + prefix + '([0-9])+$');
if (patt1.test(classesArr[index])) {
var patt2 = new RegExp('([0-9])+$');
var match = patt2.exec(classesArr[index]);
return Number(match[0]);
}
}
}
return null;
};
/**
* Get the choice number of a drag.
*
* @param {jQuery} drag the drag.
* @returns {Number} the choice number.
*/
DragDropToTextQuestion.prototype.getChoice = function(drag) {
return this.getClassnameNumericSuffix(drag, 'choice');
};
/**
* Given a DOM node that is significant to this question
* (drag, drop, ...) get the group it belongs to.
*
* @param {jQuery} node a DOM node.
* @returns {Number} the group it belongs to.
*/
DragDropToTextQuestion.prototype.getGroup = function(node) {
return this.getClassnameNumericSuffix(node, 'group');
};
/**
* Get the place number of a drop, or its corresponding hidden input.
*
* @param {jQuery} node the DOM node.
* @returns {Number} the place number.
*/
DragDropToTextQuestion.prototype.getPlace = function(node) {
return this.getClassnameNumericSuffix(node, 'place');
};
/**
* Get drag clone for a given drag.
*
* @param {jQuery} drag the drag.
* @returns {jQuery} the drag's clone.
*/
DragDropToTextQuestion.prototype.getDragClone = function(drag) {
return this.getRoot().find('.draggrouphomes' +
this.getGroup(drag) +
' span.draghome' +
'.choice' + this.getChoice(drag) +
'.group' + this.getGroup(drag) +
'.dragplaceholder');
};
/**
* Get infinite drag clones for given drag.
*
* @param {jQuery} drag the drag.
* @param {Boolean} inHome in the home area or not.
* @returns {jQuery} the drag's clones.
*/
DragDropToTextQuestion.prototype.getInfiniteDragClones = function(drag, inHome) {
if (inHome) {
return this.getRoot().find('.draggrouphomes' +
this.getGroup(drag) +
' span.draghome' +
'.choice' + this.getChoice(drag) +
'.group' + this.getGroup(drag) +
'.infinite').not('.dragplaceholder');
}
return this.getRoot().find('span.draghome' +
'.choice' + this.getChoice(drag) +
'.group' + this.getGroup(drag) +
'.infinite').not('.dragplaceholder');
};
/**
* Get drop for a given drag and place.
*
* @param {jQuery} drag the drag.
* @param {Integer} currentPlace the current place of drag.
* @returns {jQuery} the drop's clone.
*/
DragDropToTextQuestion.prototype.getDrop = function(drag, currentPlace) {
return this.getRoot().find('.drop.group' + this.getGroup(drag) + '.place' + currentPlace);
};
/**
* Check that the drag is drop to it's clone.
*
* @param {jQuery} drag The drag.
* @param {jQuery} drop The drop.
* @returns {boolean}
*/
DragDropToTextQuestion.prototype.isDragSameAsDrop = function(drag, drop) {
return this.getChoice(drag) === this.getChoice(drop) && this.getGroup(drag) === this.getGroup(drop);
};
/**
* Singleton that tracks all the DragDropToTextQuestions on this page, and deals
* with event dispatching.
*
* @type {Object}
*/
var questionManager = {
/**
* {boolean} used to ensure the event handlers are only initialised once per page.
*/
eventHandlersInitialised: false,
/**
* {Object} ensures that the drag event handlers are only initialised once per question,
* indexed by containerId (id on the .que div).
*/
dragEventHandlersInitialised: {},
/**
* {boolean} is keyboard navigation or not.
*/
isKeyboardNavigation: false,
/**
* {DragDropToTextQuestion[]} all the questions on this page, indexed by containerId (id on the .que div).
*/
questions: {},
/**
* Initialise questions.
*
* @param {String} containerId id of the outer div for this question.
* @param {boolean} readOnly whether the question is being displayed read-only.
*/
init: function(containerId, readOnly) {
questionManager.questions[containerId] = new DragDropToTextQuestion(containerId, readOnly);
if (!questionManager.eventHandlersInitialised) {
questionManager.setupEventHandlers();
questionManager.eventHandlersInitialised = true;
}
if (!questionManager.dragEventHandlersInitialised.hasOwnProperty(containerId)) {
questionManager.dragEventHandlersInitialised[containerId] = true;
// We do not use the body event here to prevent the other event on Mobile device, such as scroll event.
var questionContainer = document.getElementById(containerId);
if (questionContainer.classList.contains('ddwtos') &&
!questionContainer.classList.contains('qtype_ddwtos-readonly')) {
// TODO: Convert all the jQuery selectors and events to native Javascript.
questionManager.addEventHandlersToDrag($(questionContainer).find('span.draghome'));
}
}
},
/**
* Set up the event handlers that make this question type work. (Done once per page.)
*/
setupEventHandlers: function() {
$('body')
.on('keydown',
'.que.ddwtos:not(.qtype_ddwtos-readonly) span.drop',
questionManager.handleKeyPress)
.on('keydown',
'.que.ddwtos:not(.qtype_ddwtos-readonly) span.draghome.placed:not(.beingdragged)',
questionManager.handleKeyPress)
.on('qtype_ddwtos-dragmoved', questionManager.handleDragMoved);
},
/**
* Binding the drag/touch event again for newly created element.
*
* @param {jQuery} element Element to bind the event
*/
addEventHandlersToDrag: function(element) {
// Unbind all the mousedown and touchstart events to prevent double binding.
element.unbind('mousedown touchstart');
element.on('mousedown touchstart', questionManager.handleDragStart);
},
/**
* Handle mouse down / touch start on drags.
* @param {Event} e the DOM event.
*/
handleDragStart: function(e) {
e.preventDefault();
var question = questionManager.getQuestionForEvent(e);
if (question) {
question.handleDragStart(e);
}
},
/**
* Handle key down / press on drops.
* @param {KeyboardEvent} e
*/
handleKeyPress: function(e) {
if (questionManager.isKeyboardNavigation) {
return;
}
questionManager.isKeyboardNavigation = true;
var question = questionManager.getQuestionForEvent(e);
if (question) {
question.handleKeyPress(e);
}
},
/**
* Given an event, work out which question it affects.
*
* @param {Event} e the event.
* @returns {DragDropToTextQuestion|undefined} The question, or undefined.
*/
getQuestionForEvent: function(e) {
var containerId = $(e.currentTarget).closest('.que.ddwtos').attr('id');
return questionManager.questions[containerId];
},
/**
* Handle when drag moved.
*
* @param {Event} e the event.
* @param {jQuery} drag the drag
* @param {jQuery} target the target
* @param {DragDropToTextQuestion} thisQ the question.
*/
handleDragMoved: function(e, drag, target, thisQ) {
drag.removeClass('beingdragged');
drag.css('top', '').css('left', '');
target.after(drag);
target.removeClass('active');
if (typeof drag.data('unplaced') !== 'undefined' && drag.data('unplaced') === true) {
drag.removeClass('placed').addClass('unplaced');
drag.removeAttr('tabindex');
drag.removeData('unplaced');
if (drag.hasClass('infinite') && thisQ.getInfiniteDragClones(drag, true).length > 1) {
thisQ.getInfiniteDragClones(drag, true).first().remove();
}
}
if (typeof drag.data('isfocus') !== 'undefined' && drag.data('isfocus') === true) {
drag.focus();
drag.removeData('isfocus');
}
if (typeof target.data('isfocus') !== 'undefined' && target.data('isfocus') === true) {
target.removeData('isfocus');
}
if (questionManager.isKeyboardNavigation) {
questionManager.isKeyboardNavigation = false;
}
if (thisQ.isQuestionInteracted()) {
// The user has interacted with the draggable items. We need to mark the form as dirty.
questionManager.handleFormDirty();
// Save the new answered value.
thisQ.questionAnswer = thisQ.getQuestionAnsweredValues();
}
},
/**
* Handle when the form is dirty.
*/
handleFormDirty: function() {
const responseForm = document.getElementById('responseform');
FormChangeChecker.markFormAsDirty(responseForm);
}
};
/**
* @alias module:qtype_ddwtos/ddwtos
*/
return {
/**
* Initialise one drag-drop into text question.
*
* @param {String} containerId id of the outer div for this question.
* @param {boolean} readOnly whether the question is being displayed read-only.
*/
init: questionManager.init
};
});