ENH: alert when sheet is completely valid

Fixes #57.

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Features
 * Valid cells (i.e., those without any errors or warnings) are no longer colored green as this information wasn't important to display. The green coloring could actually detract from the ease of locating invalid cells. [#58](https://github.com/biocore/Keemei/issues/58)
+* Users are notified when a sheet is completely valid (i.e., no cells have errors or warnings) via a pop-up box. [#57](https://github.com/biocore/Keemei/issues/57)
 
 ## Version 2
 Initial alpha release.

src/Base.gs

@@ -43,6 +43,11 @@ function validate() {
   validateColumns_(sheet, state);
 
   setStatus_(range, state);
+
+  if (isValidState_(state)) {
+    var ui = SpreadsheetApp.getUi();
+    ui.alert("Valid spreadsheet", "All's well! Your spreadsheet is valid.", ui.ButtonSet.OK);
+  }
 };
 
 function clear() {

src/State.gs

@@ -3,6 +3,20 @@ function setStatus_(range, state) {
   range.setNotes(state.notes);
 };
 
+function isValidState_(state) {
+  var valid = true;
+  for (var i = 0; i < state.colors.length; i++) {
+    for (var j = 0; j < state.colors[i].length; j++) {
+      var color = state.colors[i][j];
+      if (color == Status.ERROR || color == Status.WARNING) {
+        valid = false;
+        break;
+      }
+    }
+  }
+  return valid;
+};
+
 function initializeState_(range) {
   colors = initializeGrid_(range, Status.RESET);
   notes = initializeGrid_(range, "");