refactored the snapshot generation code.

snapshot/getsnap.js

@@ -0,0 +1,87 @@
+var app = require('app');
+var BrowserWindow = require('browser-window');
+var argv = require('yargs').argv;
+var fs = require('fs');
+var cp = require('child_process');
+
+var mainWindow = null;
+var allWindowClosed = false;
+var pendingTasks = 0;
+var zoom = 2
+
+function checkQuit(){
+	if(allWindowClosed && pendingTasks == 0) app.quit();
+}
+
+app.on('window-all-closed', function() {
+	allWindowClosed = true;
+	checkQuit()
+});
+
+function combineImages(images, outfile, width, height, background, padding){
+	var command = 'convert ' + images.join(' ') + ' -append -crop ' + width + 'x' + height + '+0+0 +repage -bordercolor rgb(52,52,53) -trim  ' + outfile;
+	console.log(command);
+	cp.exec(command, function(err, stdout, stderr){
+		images.forEach(function(file){
+			fs.unlinkSync(file);
+		});
+		pendingTasks -= 1;
+		checkQuit();
+	})
+};
+
+var ipc = require('electron').ipcMain;
+function GOTO(phase){ currentPhase = phase };
+var phases = {
+	prepare : function(event, arg){
+		console.log(arg);
+		GOTO(phases['receive-rect']);
+	},
+	'receive-rect' : function(event, rect){
+		pendingTasks += 1
+		rect = JSON.parse(JSON.stringify(rect));
+		var file = argv.dir + '/' + rect.name + '.png';
+		var j = 0;
+		var totalFiles = Math.ceil(rect.height / rect.windowHeight);
+		var pendingFiles = totalFiles;
+		function doneFileWrite(){
+			pendingFiles -= 1;
+			if(pendingFiles <= 0) {
+				var images = [];
+				for(var k = 0; k < j; k++){
+					images.push(argv.dir + '/' + rect.name + '.' + k + '.png')
+				}
+				combineImages(images, file, rect.windowWidth * rect.dpi, rect.height * rect.dpi, rect.background, rect.padding);
+			}
+		}
+		function step(){
+			event.sender.send('scroll', rect.y + j * rect.windowHeight);
+			GOTO(function(event){
+				mainWindow.capturePage(function(image){
+					fs.writeFile(argv.dir + '/' + rect.name + '.' + j + '.png', image.toPng(), doneFileWrite);
+					j += 1;
+					if(j >= totalFiles) { // Move to next image
+						event.sender.send('complete', file);
+						GOTO(phases['receive-rect']);
+					} else {
+						step()
+					}
+				})
+			})
+		};
+		step()
+	}
+};
+var currentPhase = phases['prepare'];
+ipc.on('snapshot', function(){
+	currentPhase.apply(this, arguments)
+});
+ipc.on('log', function(event, arg){
+	console.log(arg);
+})
+
+app.on('ready', function() {
+	mainWindow = new BrowserWindow({width: 64 * 16 * zoom, height: 1024 * zoom, x: 5000, y: 5000, zoomFactor: zoom});
+	mainWindow.loadURL('file://' + __dirname + '/index.html');
+	//mainWindow.hide();
+});