added tab switching

Author: Aviral09

src/App.jsx

@@ -30,7 +30,7 @@ const app = () => {
             <Header superState={superState} dispatcher={dispatcher} />
             <section className="body" style={{ display: 'flex', overflow: 'hidden' }}>
                 <div style={{ display: 'flex', overflow: 'auto' }}>
-                    <LocalFileBrowser dispatcher={dispatcher} />
+                    <LocalFileBrowser superState={superState} dispatcher={dispatcher} />
                 </div>
                 <div className="graph" style={{ display: 'flex', overflow: 'hidden' }}>
                     <GraphWorkspace dispatcher={dispatcher} superState={superState} />

src/component/fileBrowser.jsx

@@ -32,9 +32,19 @@ const LocalFileBrowser = ({ superState, dispatcher }) => {
     }, [fileState]);
 
     const handleSelectFile = (data) => {
-        // eslint-disable-next-line max-len
-        if (data.fileObj.name.split('.').pop() === 'graphml') readFile(superState, dispatcher, data.fileObj, data.fileHandle);
-        else {
+        if (data.fileObj.name.split('.').pop() === 'graphml') {
+            let foundi = -1;
+            superState.graphs.forEach((g, i) => {
+                if ((g.fileName === data.fileObj.name)) {
+                    foundi = i;
+                }
+            });
+            if (foundi !== -1) {
+                dispatcher({ type: T.CHANGE_TAB, payload: foundi });
+            } else {
+                readFile(superState, dispatcher, data.fileObj, data.fileHandle);
+            }
+        } else {
             readTextFile(superState, dispatcher, data.fileObj, data.fileHandle);
         }
     };