cache ref to tester div and tester ref on drawing module object

- so that Drawing.bBox does not have to query the DOM to fing them on every call.
plotly · etpinard · May 16, 2017 · May 12, 2017 · May 12, 2017 · May 15, 2017
commit 0c62890b6f04e87201c921581d9c9d8abc193f2e
diff --git a/src/components/drawing/index.js b/src/components/drawing/index.js
@@ -579,16 +579,17 @@ drawing.makeTester = function(gd) {
        tester.node()._cache = {};
    }

-    gd._tester = tester;
-    gd._testref = testref;
+    drawing.tester = gd._tester = tester;
+    drawing.testref = gd._testref = testref;
 };

 // use our offscreen tester to get a clientRect for an element,
 // in a reference frame where it isn't translated and its anchor
 // point is at (0,0)
 // always returns a copy of the bbox, so the caller can modify it safely
-var savedBBoxes = [],
-    maxSavedBBoxes = 10000;
+var savedBBoxes = [];
+var maxSavedBBoxes = 10000;
+
 drawing.bBox = function(node) {
    // cache elements we've already measured so we don't have to
    // remeasure the same thing many times
@@ -597,22 +598,24 @@ drawing.bBox = function(node) {
        return Lib.extendFlat({}, savedBBoxes[saveNum.value]);
    }

-    var test3 = d3.select('#js-plotly-tester'),
-        tester = test3.node();
+    var tester3 = drawing.tester;
+    var tester = tester3.node();

    // copy the node to test into the tester
    var testNode = node.cloneNode(true);
    tester.appendChild(testNode);
+
    // standardize its position... do we really want to do this?
    d3.select(testNode).attr({
        x: 0,
        y: 0,
        transform: ''
    });

-    var testRect = testNode.getBoundingClientRect(),
-        refRect = test3.select('.js-reference-point')
-            .node().getBoundingClientRect();
+    var testRect = testNode.getBoundingClientRect();
+    var refRect = drawing.testref
+        .node()
+        .getBoundingClientRect();

    tester.removeChild(testNode);