new screenshot command for translator ui

daliuge-translator/dlg/dropmake/web/main.js

@@ -78,31 +78,19 @@ function fillOutSettings(){
   }
 
   function makePNG() {
-    //zoomToFit();
-
-    //var svg = myDiagram.makeSvg({
-    var rect_w = myDiagram.viewportBounds.width;
-    var rect_h = myDiagram.viewportBounds.height;
-    var img_w = myDiagram.documentBounds.width;
-    var img_h = myDiagram.documentBounds.height;
-
-    w_ratio = rect_w / img_w;
-    h_ratio = rect_h / img_h;
-
-    var scale_f = Math.min(1.0, Math.min(w_ratio, h_ratio));
-
-    var svg = myDiagram.makeImage({
-        scale: scale_f,
-        background: "White",
-        details: 1.0
-      });
-    svg.style.border = "1px solid black";
-
-    obj = document.getElementById("SVGArea");
-    obj.appendChild(svg);
-    if (obj.children.length > 0) {
-      obj.replaceChild(svg, obj.children[0]);
-    }
+
+    html2canvas(document.querySelector("#main")).then(canvas => {
+      var dataURL = canvas.toDataURL( "image/png" );
+      var data = atob( dataURL.substring( "data:image/png;base64,".length ) ),
+          asArray = new Uint8Array(data.length);
+
+      for( var i = 0, len = data.length; i < len; ++i ) {
+          asArray[i] = data.charCodeAt(i);    
+      }
+
+      var blob = new Blob( [ asArray.buffer ], {type: "image/png"} );
+      saveAs(blob, pgtName+"_Template.png");
+  });
   }
 
   function createZipFilename(graph_name){

daliuge-translator/dlg/dropmake/web/pg_viewer.html

@@ -9,6 +9,8 @@
 
  <script src="/static/src/jquery.min.js"></script>
  <script src="/static/src/bootstrap/js/bootstrap.bundle.min.js"></script>
+ <script src="/static/src/html2canvas.min.js"></script>
+ <script src="/static/src/FileSaver.js"></script>
  <script src="/static/src/require.js"></script>
 
  <!-- CSS -->

daliuge-translator/dlg/dropmake/web/src/FileSaver.js

@@ -0,0 +1,172 @@
+
+/*
+* FileSaver.js
+* A saveAs() FileSaver implementation.
+*
+* By Eli Grey, http://eligrey.com
+*
+* License : https://github.com/eligrey/FileSaver.js/blob/master/LICENSE.md (MIT)
+* source  : http://purl.eligrey.com/github/FileSaver.js
+*/
+
+// The one and only way of getting global scope in all environments
+// https://stackoverflow.com/q/3277182/1008999
+var _global = typeof window === 'object' && window.window === window
+  ? window : typeof self === 'object' && self.self === self
+  ? self : typeof global === 'object' && global.global === global
+  ? global
+  : this
+
+function bom (blob, opts) {
+  if (typeof opts === 'undefined') opts = { autoBom: false }
+  else if (typeof opts !== 'object') {
+    console.warn('Deprecated: Expected third argument to be a object')
+    opts = { autoBom: !opts }
+  }
+
+  // prepend BOM for UTF-8 XML and text/* types (including HTML)
+  // note: your browser will automatically convert UTF-16 U+FEFF to EF BB BF
+  if (opts.autoBom && /^\s*(?:text\/\S*|application\/xml|\S*\/\S*\+xml)\s*;.*charset\s*=\s*utf-8/i.test(blob.type)) {
+    return new Blob([String.fromCharCode(0xFEFF), blob], { type: blob.type })
+  }
+  return blob
+}
+
+function download (url, name, opts) {
+  var xhr = new XMLHttpRequest()
+  xhr.open('GET', url)
+  xhr.responseType = 'blob'
+  xhr.onload = function () {
+    saveAs(xhr.response, name, opts)
+  }
+  xhr.onerror = function () {
+    console.error('could not download file')
+  }
+  xhr.send()
+}
+
+function corsEnabled (url) {
+  var xhr = new XMLHttpRequest()
+  // use sync to avoid popup blocker
+  xhr.open('HEAD', url, false)
+  try {
+    xhr.send()
+  } catch (e) {}
+  return xhr.status >= 200 && xhr.status <= 299
+}
+
+// `a.click()` doesn't work for all browsers (#465)
+function click (node) {
+  try {
+    node.dispatchEvent(new MouseEvent('click'))
+  } catch (e) {
+    var evt = document.createEvent('MouseEvents')
+    evt.initMouseEvent('click', true, true, window, 0, 0, 0, 80,
+                          20, false, false, false, false, 0, null)
+    node.dispatchEvent(evt)
+  }
+}
+
+// Detect WebView inside a native macOS app by ruling out all browsers
+// We just need to check for 'Safari' because all other browsers (besides Firefox) include that too
+// https://www.whatismybrowser.com/guides/the-latest-user-agent/macos
+var isMacOSWebView = _global.navigator && /Macintosh/.test(navigator.userAgent) && /AppleWebKit/.test(navigator.userAgent) && !/Safari/.test(navigator.userAgent)
+
+var saveAs = _global.saveAs || (
+  // probably in some web worker
+  (typeof window !== 'object' || window !== _global)
+    ? function saveAs () { /* noop */ }
+
+  // Use download attribute first if possible (#193 Lumia mobile) unless this is a macOS WebView
+  : ('download' in HTMLAnchorElement.prototype && !isMacOSWebView)
+  ? function saveAs (blob, name, opts) {
+    var URL = _global.URL || _global.webkitURL
+    var a = document.createElement('a')
+    name = name || blob.name || 'download'
+
+    a.download = name
+    a.rel = 'noopener' // tabnabbing
+
+    // TODO: detect chrome extensions & packaged apps
+    // a.target = '_blank'
+
+    if (typeof blob === 'string') {
+      // Support regular links
+      a.href = blob
+      if (a.origin !== location.origin) {
+        corsEnabled(a.href)
+          ? download(blob, name, opts)
+          : click(a, a.target = '_blank')
+      } else {
+        click(a)
+      }
+    } else {
+      // Support blobs
+      a.href = URL.createObjectURL(blob)
+      setTimeout(function () { URL.revokeObjectURL(a.href) }, 4E4) // 40s
+      setTimeout(function () { click(a) }, 0)
+    }
+  }
+
+  // Use msSaveOrOpenBlob as a second approach
+  : 'msSaveOrOpenBlob' in navigator
+  ? function saveAs (blob, name, opts) {
+    name = name || blob.name || 'download'
+
+    if (typeof blob === 'string') {
+      if (corsEnabled(blob)) {
+        download(blob, name, opts)
+      } else {
+        var a = document.createElement('a')
+        a.href = blob
+        a.target = '_blank'
+        setTimeout(function () { click(a) })
+      }
+    } else {
+      navigator.msSaveOrOpenBlob(bom(blob, opts), name)
+    }
+  }
+
+  // Fallback to using FileReader and a popup
+  : function saveAs (blob, name, opts, popup) {
+    // Open a popup immediately do go around popup blocker
+    // Mostly only available on user interaction and the fileReader is async so...
+    popup = popup || open('', '_blank')
+    if (popup) {
+      popup.document.title =
+      popup.document.body.innerText = 'downloading...'
+    }
+
+    if (typeof blob === 'string') return download(blob, name, opts)
+
+    var force = blob.type === 'application/octet-stream'
+    var isSafari = /constructor/i.test(_global.HTMLElement) || _global.safari
+    var isChromeIOS = /CriOS\/[\d]+/.test(navigator.userAgent)
+
+    if ((isChromeIOS || (force && isSafari) || isMacOSWebView) && typeof FileReader !== 'undefined') {
+      // Safari doesn't allow downloading of blob URLs
+      var reader = new FileReader()
+      reader.onloadend = function () {
+        var url = reader.result
+        url = isChromeIOS ? url : url.replace(/^data:[^;]*;/, 'data:attachment/file;')
+        if (popup) popup.location.href = url
+        else location = url
+        popup = null // reverse-tabnabbing #460
+      }
+      reader.readAsDataURL(blob)
+    } else {
+      var URL = _global.URL || _global.webkitURL
+      var url = URL.createObjectURL(blob)
+      if (popup) popup.location = url
+      else location.href = url
+      popup = null // reverse-tabnabbing #460
+      setTimeout(function () { URL.revokeObjectURL(url) }, 4E4) // 40s
+    }
+  }
+)
+
+_global.saveAs = saveAs.saveAs = saveAs
+
+if (typeof module !== 'undefined') {
+  module.exports = saveAs;
+}