yjs/Examples/Drawing/index.js
2016-09-20 18:29:19 +02:00

85 lines
2.1 KiB
JavaScript

/* globals Y, d3 */
'strict mode'
Y({
db: {
name: 'memory'
},
connector: {
name: 'websockets-client',
room: 'drawing-example'
// url: 'localhost:1234'
},
sourceDir: '/bower_components',
share: {
drawing: 'Array'
}
}).then(function (y) {
window.yDrawing = y
var drawing = y.share.drawing
var renderPath = d3.svg.line()
.x(function (d) { return d[0] })
.y(function (d) { return d[1] })
.interpolate('basis')
var svg = d3.select('#drawingCanvas')
.call(d3.behavior.drag()
.on('dragstart', dragstart)
.on('drag', drag)
.on('dragend', dragend))
// create line from a shared array object and update the line when the array changes
function drawLine (yarray) {
var line = svg.append('path').datum(yarray.toArray())
line.attr('d', renderPath)
yarray.observe(function (event) {
// we only implement insert events that are appended to the end of the array
event.values.forEach(function (value) {
line.datum().push(value)
})
line.attr('d', renderPath)
})
}
// call drawLine every time an array is appended
y.share.drawing.observe(function (event) {
if (event.type === 'insert') {
event.values.forEach(drawLine)
} else {
// just remove all elements (thats what we do anyway)
svg.selectAll('path').remove()
}
})
// draw all existing content
for (var i = 0; i < drawing.length; i++) {
drawLine(drawing.get(i))
}
// clear canvas on request
document.querySelector('#clearDrawingCanvas').onclick = function () {
drawing.delete(0, drawing.length)
}
var sharedLine = null
function dragstart () {
drawing.insert(drawing.length, [Y.Array])
sharedLine = drawing.get(drawing.length - 1)
}
// After one dragged event is recognized, we ignore them for 33ms.
var ignoreDrag = null
function drag () {
if (sharedLine != null && ignoreDrag == null) {
ignoreDrag = window.setTimeout(function () {
ignoreDrag = null
}, 33)
sharedLine.push([d3.mouse(this)])
}
}
function dragend () {
sharedLine = null
window.clearTimeout(ignoreDrag)
ignoreDrag = null
}
})