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client.js
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103 lines (79 loc) · 2.5 KB
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// Copyright (c) 2012 Titanium I.T. LLC. All rights reserved. See LICENSE.txt for details.
/*global Raphael, $ */
(function() {
"use strict";
var SvgCanvas = require("./svg_canvas.js");
var HtmlElement = require("./html_element.js");
var browser = require("./browser.js");
var failFast = require("./fail_fast.js");
var svgCanvas = null;
var start = null;
var lineDrawn = false;
var drawingArea;
var clearScreenButton;
var documentBody;
var windowElement;
var useSetCaptureApi = false;
exports.initializeDrawingArea = function(elements) {
if (svgCanvas !== null) throw new Error("Client.js is not re-entrant");
drawingArea = elements.drawingAreaDiv;
clearScreenButton = elements.clearScreenButton;
failFast.unlessDefined(drawingArea, "elements.drawingArea");
failFast.unlessDefined(clearScreenButton, "elements.clearScreenButton");
documentBody = new HtmlElement(document.body);
windowElement = new HtmlElement(window);
svgCanvas = new SvgCanvas(drawingArea);
drawingArea.preventBrowserDragDefaults();
handleClearScreenClick();
handleMouseDragEvents();
handleTouchDragEvents();
return svgCanvas;
};
exports.drawingAreaHasBeenRemovedFromDom = function() {
svgCanvas = null;
};
function handleClearScreenClick() {
clearScreenButton.onMouseClick(function() {
svgCanvas.clear();
});
}
function handleMouseDragEvents() {
drawingArea.onMouseDown(startDrag);
documentBody.onMouseMove(continueDrag);
windowElement.onMouseUp(endDrag);
if (browser.doesNotHandlesUserEventsOnWindow()) {
drawingArea.onMouseUp(endDrag);
useSetCaptureApi = true;
}
}
function handleTouchDragEvents() {
drawingArea.onSingleTouchStart(startDrag);
drawingArea.onSingleTouchMove(continueDrag);
drawingArea.onTouchEnd(endDrag);
drawingArea.onTouchCancel(endDrag);
drawingArea.onMultiTouchStart(endDrag);
}
function startDrag(pageOffset) {
start = drawingArea.relativeOffset(pageOffset);
if (useSetCaptureApi) drawingArea.setCapture();
}
function continueDrag(pageOffset) {
if (!isCurrentlyDrawing()) return;
var end = drawingArea.relativeOffset(pageOffset);
if (start.x !== end.x || start.y !== end.y) {
svgCanvas.drawLine(start.x, start.y, end.x, end.y);
start = end;
lineDrawn = true;
}
}
function endDrag() {
if (!isCurrentlyDrawing()) return;
if (!lineDrawn) svgCanvas.drawDot(start.x, start.y);
if (useSetCaptureApi) drawingArea.releaseCapture();
start = null;
lineDrawn = false;
}
function isCurrentlyDrawing() {
return start !== null;
}
}());