Merge pull request #1371 from jgreywolf/1234-RefactorClassDiagramScaling

1234 refactor class diagram scaling

src/diagrams/class/classRenderer.js

@@ -9,6 +9,7 @@ import svgDraw from './svgDraw';
 parser.yy = classDb;
 
 let idCache = {};
+const padding = 20;
 
 const conf = {
   dividerMargin: 10,
@@ -225,9 +226,22 @@ export const draw = function(text, id) {
     }
   });
 
-  diagram.attr('height', g.graph().height + 40);
-  diagram.attr('width', g.graph().width * 1.5 + 20);
-  diagram.attr('viewBox', '-10 -10 ' + (g.graph().width + 20) + ' ' + (g.graph().height + 20));
+  const svgBounds = diagram.node().getBBox();
+  const width = svgBounds.width + padding * 2;
+  const height = svgBounds.height + padding * 2;
+
+  if (conf.useMaxWidth) {
+    diagram.attr('width', '100%');
+    diagram.attr('style', `max-width: ${width}px;`);
+  } else {
+    diagram.attr('height', height);
+    diagram.attr('width', width);
+  }
+
+  // Ensure the viewBox includes the whole svgBounds area with extra space for padding
+  const vBox = `${svgBounds.x - padding} ${svgBounds.y - padding} ${width} ${height}`;
+  logger.debug(`viewBox ${vBox}`);
+  diagram.attr('viewBox', vBox);
 };
 
 export default {