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client.js
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112 lines (83 loc) · 2.49 KB
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// Copyright (c) 2012 Titanium I.T. LLC. All rights reserved. See LICENSE.txt for details.
/*global dump, Raphael, $, wwp:true, Event*/
wwp = {};
(function() {
"use strict";
var paper = null;
var start = null;
wwp.initializeDrawingArea = function(drawingAreaElement) {
if (paper !== null) throw new Error("Client.js is not re-entrant");
paper = new Raphael(drawingAreaElement);
handleDragEvents(drawingAreaElement);
return paper;
};
wwp.drawingAreaHasBeenRemovedFromDom = function() {
paper = null;
};
function handleDragEvents(drawingAreaElement) {
var drawingArea = $(drawingAreaElement);
drawingArea.on("selectstart", function(event) {
// This event handler is needed so IE 8 doesn't select text when you drag outside drawing area
event.preventDefault();
});
drawingArea.mousedown(function(event) {
event.preventDefault();
startDrag(drawingArea, event.pageX, event.pageY);
});
drawingArea.mousemove(function(event) {
continueDrag(drawingArea, event.pageX, event.pageY);
});
drawingArea.mouseleave(function(event) {
endDrag();
});
drawingArea.mouseup(function(event) {
endDrag();
});
drawingArea.on("touchstart", function(event) {
event.preventDefault();
var originalEvent = event.originalEvent;
if (originalEvent.touches.length !== 1) {
start = null;
return;
}
var pageX = originalEvent.touches[0].pageX;
var pageY = originalEvent.touches[0].pageY;
startDrag(drawingArea, pageX, pageY);
});
drawingArea.on("touchmove", function(event) {
var originalEvent = event.originalEvent;
var pageX = originalEvent.touches[0].pageX;
var pageY = originalEvent.touches[0].pageY;
continueDrag(drawingArea, pageX, pageY);
});
drawingArea.on("touchend", function(event) {
endDrag();
});
drawingArea.on("touchcancel", function(event) {
endDrag();
});
}
function startDrag(drawingArea, pageX, pageY) {
var offset = relativeOffset(drawingArea, pageX, pageY);
start = offset;
}
function continueDrag(drawingArea, pageX, pageY) {
if (start === null) return;
var end = relativeOffset(drawingArea, pageX, pageY);
drawLine(start.x, start.y, end.x, end.y);
start = end;
}
function endDrag() {
start = null;
}
function drawLine(startX, startY, endX, endY) {
paper.path("M" + startX + "," + startY + "L" + endX + "," + endY);
}
function relativeOffset(element, pageX, pageY) {
var pageOffset = element.offset();
return {
x: pageX - pageOffset.left,
y: pageY - pageOffset.top
};
}
}());