// 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/>.
/**
* This class provides the enhancements to the drag-drop marker editing form.
*
* @module qtype_ddmarker/form
* @copyright 2018 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
define(['jquery', 'core/dragdrop', 'qtype_ddmarker/shapes'], function($, dragDrop, Shapes) {
"use strict";
/**
* Create the manager object that deals with keeping everything synchronised for one drop zone.
*
* @param {int} dropzoneNo the index of this drop zone in the form. 0, 1, ....
* @constructor
*/
function DropZoneManager(dropzoneNo) {
this.dropzoneNo = dropzoneNo;
this.svgEl = null;
this.shape = Shapes.make(this.getShapeType(), this.getLabel());
this.updateCoordinatesFromForm();
}
/**
* Update the coordinates from a particular string.
*
* @param {SVGElement} [svg] the SVG element that is the preview.
*/
DropZoneManager.prototype.updateCoordinatesFromForm = function(svg) {
var coordinates = this.getCoordinates(),
currentNumPoints = this.shape.getType() === 'polygon' && this.shape.points.length;
if (this.shape.getCoordinates() === coordinates) {
return;
}
// We don't need to scale the shape for editing form.
if (!this.shape.parse(coordinates, 1)) {
// Invalid coordinates. Don't update the preview.
return;
}
if (this.shape.getType() === 'polygon' && currentNumPoints !== this.shape.points.length) {
// Polygon, and size has changed.
var currentyActive = this.isActive();
this.removeFromSvg();
if (svg) {
this.addToSvg(svg);
if (currentyActive) {
this.setActive();
}
}
} else {
// Simple update.
this.updateSvgEl();
}
// Update the rounded coordinates if needed.
this.setCoordinatesInForm();
};
/**
* Update the label.
*/
DropZoneManager.prototype.updateLabel = function() {
var label = this.getLabel();
if (this.shape.label !== label) {
this.shape.label = label;
this.updateSvgEl();
}
};
/**
* Handle if the type of shape has changed.
*
* @param {SVGElement} [svg] an SVG element to add this new shape to.
*/
DropZoneManager.prototype.changeShape = function(svg) {
var newShapeType = this.getShapeType(),
currentyActive = this.isActive();
if (newShapeType === this.shape.getType()) {
return;
}
// It has really changed.
this.removeFromSvg();
this.shape = Shapes.getSimilar(newShapeType, this.shape);
if (svg) {
this.addToSvg(svg);
if (currentyActive) {
this.setActive();
}
}
this.setCoordinatesInForm();
};
/**
* Add this drop zone to an SVG graphic.
*
* @param {SVGElement} svg the SVG image to which to add this drop zone.
*/
DropZoneManager.prototype.addToSvg = function(svg) {
if (this.svgEl !== null) {
throw new Error('this.svgEl already set');
}
this.svgEl = this.shape.makeSvg(svg);
if (!this.svgEl) {
return;
}
this.svgEl.setAttribute('class', 'dropzone');
this.svgEl.setAttribute('data-dropzone-no', this.dropzoneNo);
// Add handles.
var handles = this.shape.getHandlePositions();
if (handles === null) {
return;
}
var moveHandle = Shapes.createSvgElement(this.svgEl, 'circle');
moveHandle.setAttribute('cx', handles.moveHandle.x);
moveHandle.setAttribute('cy', handles.moveHandle.y);
moveHandle.setAttribute('r', 7);
moveHandle.setAttribute('class', 'handle move');
for (var i = 0; i < handles.editHandles.length; ++i) {
this.makeEditHandle(i, handles.editHandles[i]);
}
};
/**
* Add a new edit handle.
*
* @param {int} index the handle index.
* @param {Point} point the point at which to add the handle.
*/
DropZoneManager.prototype.makeEditHandle = function(index, point) {
var editHandle = Shapes.createSvgElement(this.svgEl, 'rect');
editHandle.setAttribute('x', point.x - 6);
editHandle.setAttribute('y', point.y - 6);
editHandle.setAttribute('width', 11);
editHandle.setAttribute('height', 11);
editHandle.setAttribute('class', 'handle edit');
editHandle.setAttribute('data-edit-handle-no', index);
};
/**
* Remove this drop zone from an SVG image.
*/
DropZoneManager.prototype.removeFromSvg = function() {
if (this.svgEl !== null) {
this.svgEl.parentNode.removeChild(this.svgEl);
this.svgEl = null;
}
};
/**
* Update the shape of this drop zone (but not type) in an SVG image.
*/
DropZoneManager.prototype.updateSvgEl = function() {
if (this.svgEl === null) {
return;
}
this.shape.updateSvg(this.svgEl);
// Adjust handles.
var handles = this.shape.getHandlePositions();
if (handles === null) {
return;
}
// Move handle.
// The shape + its label are the first two children of svgEl.
// Then come the move handle followed by the edit handles.
this.svgEl.childNodes[2].setAttribute('cx', handles.moveHandle.x);
this.svgEl.childNodes[2].setAttribute('cy', handles.moveHandle.y);
// Edit handles.
for (var i = 0; i < handles.editHandles.length; ++i) {
this.svgEl.childNodes[3 + i].setAttribute('x', handles.editHandles[i].x - 6);
this.svgEl.childNodes[3 + i].setAttribute('y', handles.editHandles[i].y - 6);
}
};
/**
* Find out of this drop zone is currently being edited.
*
* @return {boolean} true if it is.
*/
DropZoneManager.prototype.isActive = function() {
return this.svgEl !== null && this.svgEl.getAttribute('class').match(/\bactive\b/);
};
/**
* Set this drop zone as being edited.
*/
DropZoneManager.prototype.setActive = function() {
// Move this one to last, so that it is always on top.
// (Otherwise the handles may not be able to receive events.)
var parent = this.svgEl.parentNode;
parent.removeChild(this.svgEl);
parent.appendChild(this.svgEl);
this.svgEl.setAttribute('class', this.svgEl.getAttribute('class') + ' active');
};
/**
* Set the coordinates in the form to match the current shape.
*/
DropZoneManager.prototype.setCoordinatesInForm = function() {
dragDropForm.form.setFormValue('drops', [this.dropzoneNo, 'coords'], this.shape.getCoordinates());
};
/**
* Returns the coordinates for a drop zone from the text input in the form.
* @returns {string} the coordinates.
*/
DropZoneManager.prototype.getCoordinates = function() {
return dragDropForm.form.getFormValue('drops', [this.dropzoneNo, 'coords']).replace(/\s*/g, '');
};
/**
* Returns the selected marker number from the dropdown in the form.
* @returns {int} choice number.
*/
DropZoneManager.prototype.getChoiceNo = function() {
return dragDropForm.form.getFormValue('drops', [this.dropzoneNo, 'choice']);
};
/**
* Returns the selected marker number from the dropdown in the form.
* @returns {String} marker label text.
*/
DropZoneManager.prototype.getLabel = function() {
return dragDropForm.form.getMarkerText(this.getChoiceNo());
};
/**
* Returns the selected type of shape in the form.
* @returns {String} 'circle', 'rectangle' or 'polygon'.
*/
DropZoneManager.prototype.getShapeType = function() {
return dragDropForm.form.getFormValue('drops', [this.dropzoneNo, 'shape']);
};
/**
* Start responding to dragging the move handle.
* @param {Event} e Event object
*/
DropZoneManager.prototype.handleMove = function(e) {
var info = dragDrop.prepare(e);
if (!info.start) {
return;
}
var movingDropZone = this,
lastX = info.x,
lastY = info.y,
dragProxy = this.makeDragProxy(info.x, info.y),
bgImg = $('fieldset#id_previewareaheader .dropbackground'),
maxX = bgImg.width(),
maxY = bgImg.height();
dragDrop.start(e, $(dragProxy), function(pageX, pageY) {
movingDropZone.shape.move(pageX - lastX, pageY - lastY, maxX, maxY);
lastX = pageX;
lastY = pageY;
movingDropZone.updateSvgEl();
movingDropZone.setCoordinatesInForm();
}, function() {
document.body.removeChild(dragProxy);
});
};
/**
* Start responding to dragging the move handle.
* @param {Event} e Event object
* @param {int} handleIndex
* @param {SVGElement} [svg] an SVG element to add this new shape to.
*/
DropZoneManager.prototype.handleEdit = function(e, handleIndex, svg) {
var info = dragDrop.prepare(e);
if (!info.start) {
return;
}
// For polygons, CTRL + drag adds a new point.
if (this.shape.getType() === 'polygon' && (e.ctrlKey || e.metaKey)) {
this.shape.addNewPointAfter(handleIndex);
this.removeFromSvg();
this.addToSvg(svg);
this.setActive();
}
var changingDropZone = this,
lastX = info.x,
lastY = info.y,
dragProxy = this.makeDragProxy(info.x, info.y),
bgImg = $('fieldset#id_previewareaheader .dropbackground'),
maxX = bgImg.width(),
maxY = bgImg.height();
dragDrop.start(e, $(dragProxy), function(pageX, pageY) {
changingDropZone.shape.edit(handleIndex, pageX - lastX, pageY - lastY, maxX, maxY);
lastX = pageX;
lastY = pageY;
changingDropZone.updateSvgEl();
changingDropZone.setCoordinatesInForm();
}, function() {
document.body.removeChild(dragProxy);
changingDropZone.shape.normalizeShape();
changingDropZone.updateSvgEl();
changingDropZone.setCoordinatesInForm();
});
};
/**
* Make an invisible drag proxy.
*
* @param {int} x x position .
* @param {int} y y position.
* @returns {HTMLElement} the drag proxy.
*/
DropZoneManager.prototype.makeDragProxy = function(x, y) {
var dragProxy = document.createElement('div');
dragProxy.style.position = 'absolute';
dragProxy.style.top = y + 'px';
dragProxy.style.left = x + 'px';
dragProxy.style.width = '1px';
dragProxy.style.height = '1px';
document.body.appendChild(dragProxy);
return dragProxy;
};
/**
* Singleton object for managing all the parts of the form.
*/
var dragDropForm = {
/**
* @var {object} for interacting with the file pickers.
*/
fp: null, // Object containing functions associated with the file picker.
/**
* @var {int} the number of drop-zones on the form.
*/
noDropZones: null,
/**
* @var {DropZoneManager[]} the drop zones in the preview, indexed by drop zone number.
*/
dropZones: [],
/**
* Initialise the form.
*/
init: function() {
dragDropForm.fp = dragDropForm.filePickers();
dragDropForm.noDropZones = dragDropForm.form.getFormValue('nodropzone', []);
dragDropForm.setupPreviewArea();
dragDropForm.setOptionsForDragItemSelectors();
dragDropForm.createShapes();
dragDropForm.setupEventHandlers();
dragDropForm.waitForFilePickerToInitialise();
},
/**
* Add html for the preview area.
*/
setupPreviewArea: function() {
$('fieldset#id_previewareaheader div.fcontainer').append(
'<div class="ddarea que ddmarker">' +
' <div id="ddm-droparea" class="droparea">' +
' <img class="dropbackground" />' +
' <div id="ddm-dropzone" class="dropzones">' +
' </div>' +
' </div>' +
'</div>');
},
/**
* When a new marker is added this function updates the Marker dropdown controls in Drop zones.
*/
setOptionsForDragItemSelectors: function() {
var dragItemsOptions = {'0': ''};
var noItems = dragDropForm.form.getFormValue('noitems', []);
var selectedValues = [];
var selector;
var i, label;
for (i = 1; i <= noItems; i++) {
label = dragDropForm.form.getMarkerText(i);
if (label !== "") {
// HTML escape the label.
dragItemsOptions[i] = $('<div/>').text(label).html();
}
}
// Get all the currently selected drags for each drop.
for (i = 0; i < dragDropForm.noDropZones; i++) {
selector = $('#id_drops_' + i + '_choice');
selectedValues[i] = Number(selector.val());
}
for (i = 0; i < dragDropForm.noDropZones; i++) {
selector = $('#id_drops_' + i + '_choice');
// Remove all options for drag choice.
selector.find('option').remove();
// And recreate the options.
for (var value in dragItemsOptions) {
value = Number(value);
var option = '<option value="' + value + '">' + dragItemsOptions[value] + '</option>';
selector.append(option);
var optionnode = selector.find('option[value="' + value + '"]');
if (value === 0) {
continue; // The 'no item' option is always selectable.
}
// Is this the currently selected value?
if (value === selectedValues[i]) {
optionnode.attr('selected', true);
continue; // If it s selected, we must leave it enabled.
}
// Count how many times it is used, and if necessary, disable.
var noofdrags = dragDropForm.form.getFormValue('drags', [value - 1, 'noofdrags']);
if (Number(noofdrags) === 0) { // 'noofdrags === 0' means infinite.
continue; // Nothing to check.
}
// Go through all selected values in drop downs.
for (var k in selectedValues) {
if (Number(selectedValues[k]) !== value) {
continue;
}
// Count down 'noofdrags' and if reach zero then set disabled option for this drag item.
if (Number(noofdrags) === 1) {
optionnode.attr('disabled', true);
break;
} else {
noofdrags--;
}
}
}
if (dragDropForm.dropZones.length > 0) {
dragDropForm.dropZones[i].updateLabel();
}
}
},
/**
* Create the shape representation of each dropZone.
*/
createShapes: function() {
for (var dropzoneNo = 0; dropzoneNo < dragDropForm.noDropZones; dropzoneNo++) {
dragDropForm.dropZones[dropzoneNo] = new DropZoneManager(dropzoneNo);
}
},
/**
* Events linked to form actions.
*/
setupEventHandlers: function() {
// Changes to labels in the Markers section.
$('fieldset#id_draggableitemheader').on('change input', 'input, select', function() {
dragDropForm.setOptionsForDragItemSelectors();
});
// Changes to Drop zones section: shape, coordinates and marker.
$('fieldset#id_dropzoneheader').on('change input', 'input, select', function(e) {
var ids = e.currentTarget.name.match(/^drops\[(\d+)]\[([a-z]*)]$/);
if (!ids) {
return;
}
var dropzoneNo = ids[1],
inputType = ids[2],
dropZone = dragDropForm.dropZones[dropzoneNo];
switch (inputType) {
case 'shape':
dropZone.changeShape(dragDropForm.form.getSvg());
break;
case 'coords':
dropZone.updateCoordinatesFromForm(dragDropForm.form.getSvg());
break;
case 'choice':
dropZone.updateLabel();
break;
}
});
// Click to toggle graphical editing.
var previewArea = $('fieldset#id_previewareaheader');
previewArea.on('click', 'g.dropzone', function(e) {
var dropzoneNo = $(e.currentTarget).data('dropzone-no'),
currentlyActive = dragDropForm.dropZones[dropzoneNo].isActive();
$(dragDropForm.form.getSvg()).find('.dropzone.active').removeClass('active');
if (!currentlyActive) {
dragDropForm.dropZones[dropzoneNo].setActive();
}
});
// Drag start on a move handle.
previewArea.on('mousedown touchstart', '.dropzone .handle.move', function(e) {
var dropzoneNo = $(e.currentTarget).closest('g').data('dropzoneNo');
dragDropForm.dropZones[dropzoneNo].handleMove(e);
});
// Drag start on a move handle.
previewArea.on('mousedown touchstart', '.dropzone .handle.edit', function(e) {
var dropzoneNo = $(e.currentTarget).closest('g').data('dropzoneNo'),
handleIndex = e.currentTarget.getAttribute('data-edit-handle-no');
dragDropForm.dropZones[dropzoneNo].handleEdit(e, handleIndex, dragDropForm.form.getSvg());
});
},
/**
* Prevents adding drop zones until the preview background image is ready to load.
*/
waitForFilePickerToInitialise: function() {
if (dragDropForm.fp.file('bgimage').href === null) {
// It would be better to use an onload or onchange event rather than this timeout.
// Unfortunately attempts to do this early are overwritten by filepicker during its loading.
setTimeout(dragDropForm.waitForFilePickerToInitialise, 1000);
return;
}
// From now on, when a new file gets loaded into the filepicker, update the preview.
// This is not in the setupEventHandlers section as it needs to be delayed until
// after filepicker's javascript has finished.
$('form.mform[data-qtype="ddmarker"]').on('change', '#id_bgimage', dragDropForm.loadPreviewImage);
dragDropForm.loadPreviewImage();
},
/**
* Loads the preview background image.
*/
loadPreviewImage: function() {
$('fieldset#id_previewareaheader .dropbackground')
.one('load', dragDropForm.afterPreviewImageLoaded)
.attr('src', dragDropForm.fp.file('bgimage').href);
},
/**
* Functions to run after background image loaded.
*/
afterPreviewImageLoaded: function() {
var bgImg = $('fieldset#id_previewareaheader .dropbackground');
// Place the dropzone area over the background image (adding one to account for the border).
$('#ddm-dropzone').css('position', 'relative').css('top', (bgImg.height() + 1) * -1);
$('#ddm-droparea').css('height', bgImg.height() + 20);
dragDropForm.updateSvgDisplay();
},
/**
* Draws or re-draws all dropzones in the preview area based on form data.
* Call this function when there is a change in the form data.
*/
updateSvgDisplay: function() {
var bgImg = $('fieldset#id_previewareaheader .dropbackground'),
dropzoneNo;
if (dragDropForm.form.getSvg()) {
// Already exists, just need to be updated.
for (dropzoneNo = 0; dropzoneNo < dragDropForm.noDropZones; dropzoneNo++) {
dragDropForm.dropZones[dropzoneNo].updateSvgEl();
}
} else {
// Create.
$('#ddm-dropzone').html('<svg xmlns="http://www.w3.org/2000/svg" class="dropzones" ' +
'width="' + bgImg.outerWidth() + '" ' +
'height="' + bgImg.outerHeight() + '"></svg>');
for (dropzoneNo = 0; dropzoneNo < dragDropForm.noDropZones; dropzoneNo++) {
dragDropForm.dropZones[dropzoneNo].addToSvg(dragDropForm.form.getSvg());
}
}
},
/**
* Helper to make it easy to work with form elements with names like "drops[0][shape]".
*/
form: {
/**
* Returns the label text for a marker.
* @param {int} markerNo
* @returns {string} Marker text
*/
getMarkerText: function(markerNo) {
if (Number(markerNo) !== 0) {
var label = dragDropForm.form.getFormValue('drags', [markerNo - 1, 'label']);
return label.replace(new RegExp("^\\s*(.*)\\s*$"), "$1");
} else {
return '';
}
},
/**
* Get the SVG element, if there is one, otherwise return null.
*
* @returns {SVGElement|null} the SVG element or null.
*/
getSvg: function() {
var svg = $('fieldset#id_previewareaheader svg');
if (svg.length === 0) {
return null;
} else {
return svg[0];
}
},
toNameWithIndex: function(name, indexes) {
var indexString = name;
for (var i = 0; i < indexes.length; i++) {
indexString = indexString + '[' + indexes[i] + ']';
}
return indexString;
},
getEl: function(name, indexes) {
var form = $('form.mform[data-qtype="ddmarker"]')[0];
return form.elements[this.toNameWithIndex(name, indexes)];
},
/**
* Helper to get the value of a form elements with name like "drops[0][shape]".
*
* @param {String} name the base name, e.g. 'drops'.
* @param {String[]} indexes the indexes, e.g. ['0', 'shape'].
* @return {String} the value of that field.
*/
getFormValue: function(name, indexes) {
var el = this.getEl(name, indexes);
if (el.type === 'checkbox') {
return el.checked;
} else {
return el.value;
}
},
/**
* Helper to get the value of a form elements with name like "drops[0][shape]".
*
* @param {String} name the base name, e.g. 'drops'.
* @param {String[]} indexes the indexes, e.g. ['0', 'shape'].
* @param {String} value the value to set.
*/
setFormValue: function(name, indexes, value) {
var el = this.getEl(name, indexes);
if (el.type === 'checkbox') {
el.checked = value;
} else {
el.value = value;
}
}
},
/**
* Utility to get the file name and url from the filepicker.
* @returns {Object} object containing functions {file, name}
*/
filePickers: function() {
var draftItemIdsToName;
var nameToParentNode;
if (draftItemIdsToName === undefined) {
draftItemIdsToName = {};
nameToParentNode = {};
$('form.mform input.filepickerhidden').each(function(key, filepicker) {
draftItemIdsToName[filepicker.value] = filepicker.name;
nameToParentNode[filepicker.name] = filepicker.parentNode;
});
}
return {
file: function(name) {
var fileAnchor = $(nameToParentNode[name]).find('div.filepicker-filelist a');
if (fileAnchor.length) {
return {href: fileAnchor.get(0).href, name: fileAnchor.get(0).innerHTML};
} else {
return {href: null, name: null};
}
},
name: function(draftitemid) {
return draftItemIdsToName[draftitemid];
}
};
}
};
/**
* @alias module:qtype_ddmarker/form
*/
return {
/**
* Initialise the form javascript features.
* @param {Object} maxBgimageSize object with two properties: width and height.
*/
init: dragDropForm.init
};
});