Add screenshot demo

jlord · jlord · commit a939582b4ca2 · 2016-04-14T15:47:13.000-07:00
diff --git a/renderer-process/printing/desktop-capturer.js b/renderer-process/printing/desktop-capturer.js
@@ -0,0 +1,37 @@
+const electron = require('electron')
+const desktopCapturer = electron.desktopCapturer
+const electronScreen = electron.screen
+const shell = electron.shell
+
+const fs = require('fs')
+const os = require('os')
+const path = require('path')
+
+const screenshot = document.getElementById('screen-shot')
+
+screenshot.addEventListener('click', function (event) {
+  const thumbSize = determineScreenShotSize()
+  desktopCapturer.getSources({types: ['screen'], thumbnailSize: thumbSize}, function (error, sources) {
+    if (error) return console.log(error)
+
+    sources.forEach(function (source) {
+      if (source.name === "Entire screen") {
+        var screenshotPath = path.join(os.tmpdir(), 'screenshot.png')
+
+        fs.writeFile(screenshotPath, source.thumbnail.toPng(), function (error) {
+          if (error) return console.log(error)
+          shell.openItem(screenshotPath)
+        })
+      }
+    })
+  })
+})
+
+function determineScreenShotSize () {
+  var screenSize = electronScreen.getPrimaryDisplay().workAreaSize
+  var maxDimension = Math.max(screenSize.width, screenSize.height)
+  return {
+    width: maxDimension * window.devicePixelRatio,
+    height: maxDimension * window.devicePixelRatio
+  }
+}
