DRY circular <-> linear onMove zoombox handlers

Author: etpinard

src/plots/polar/polar.js

@@ -688,20 +688,10 @@ proto.updateMainDrag = function(fullLayout, polarLayout) {
         clearSelect(zoomlayer);
     }
 
-    function applyZoomMove(path1, cpath) {
-        zb.attr('d', path1);
-        corners.attr('d', cpath);
-        dragBox.transitionZoombox(zb, corners, dimmed, lum);
-        dimmed = true;
-    }
-
-    function zoomMove(dx, dy) {
-        var x1 = x0 + dx;
-        var y1 = y0 + dy;
-        var rr0 = xy2r(x0, y0);
-        var rr1 = Math.min(xy2r(x1, y1), radius);
-        var a0 = xy2a(x0, y0);
-        var a1 = xy2a(x1, y1);
+    // N.B. this sets scoped 'r0' and 'r1'
+    // return true if 'valid' zoom distance, false otherwise
+    function clampAndSetR0R1(rr0, rr1) {
+        rr1 = Math.min(rr1, radius);
 
         // starting or ending drag near center (outer edge),
         // clamps radial distance at origin (at r=radius)
@@ -710,31 +700,48 @@ proto.updateMainDrag = function(fullLayout, polarLayout) {
         else if(rr1 < OFFEDGE) rr1 = 0;
         else if((radius - rr1) < OFFEDGE) rr1 = radius;
 
-        var path1;
-        var cpath;
-
+        // make sure r0 < r1,
+        // to get correct fill pattern in path1 below
         if(Math.abs(rr1 - rr0) > MINZOOM) {
-            // make sure r0 < r1,
-            // to get correct fill pattern in path1 below
             if(rr0 < rr1) {
                 r0 = rr0;
                 r1 = rr1;
             } else {
                 r0 = rr1;
                 r1 = rr0;
-                a1 = [a0, a0 = a1][0]; // swap a0 and a1
             }
-
-            path1 = path0 + _pathSectorClosed(r1) + _pathSectorClosed(r0);
-            // keep 'starting' angle
-            cpath = pathCorner(r0, a0) + pathCorner(r1, a0);
+            return true;
         } else {
             r0 = null;
             r1 = null;
-            path1 = path0;
-            cpath = 'M0,0Z';
+            return false;
         }
+    }
+
+    function applyZoomMove(path1, cpath) {
+        path1 = path1 || path0;
+        cpath = cpath || 'M0,0Z';
+
+        zb.attr('d', path1);
+        corners.attr('d', cpath);
+        dragBox.transitionZoombox(zb, corners, dimmed, lum);
+        dimmed = true;
+    }
+
+    function zoomMove(dx, dy) {
+        var x1 = x0 + dx;
+        var y1 = y0 + dy;
+        var rr0 = xy2r(x0, y0);
+        var rr1 = Math.min(xy2r(x1, y1), radius);
+        var a0 = xy2a(x0, y0);
+        var path1;
+        var cpath;
 
+        if(clampAndSetR0R1(rr0, rr1)) {
+            path1 = path0 + _pathSectorClosed(r1) + _pathSectorClosed(r0);
+            // keep 'starting' angle
+            cpath = pathCorner(r0, a0) + pathCorner(r1, a0);
+        }
         applyZoomMove(path1, cpath);
     }
 
@@ -762,41 +769,17 @@ proto.updateMainDrag = function(fullLayout, polarLayout) {
         var vangles1 = findEnclosingVertexAngles(a1);
         var rr0 = findPolygonRadius(x0, y0, vangles0[0], vangles0[1]);
         var rr1 = Math.min(findPolygonRadius(x1, y1, vangles1[0], vangles1[1]), radius);
-
-        // starting or ending drag near center (outer edge),
-        // clamps radial distance at origin (at r=radius)
-        if(rr0 < OFFEDGE) rr0 = 0;
-        else if((radius - rr0) < OFFEDGE) rr0 = radius;
-        else if(rr1 < OFFEDGE) rr1 = 0;
-        else if((radius - rr1) < OFFEDGE) rr1 = radius;
-
         var path1;
         var cpath;
 
-        if(Math.abs(rr1 - rr0) > MINZOOM) {
-            // make sure r0 < r1,
-            // to get correct fill pattern in path1 below
-            if(rr0 < rr1) {
-                r0 = rr0;
-                r1 = rr1;
-            } else {
-                r0 = rr1;
-                r1 = rr0;
-            }
-
+        if(clampAndSetR0R1(rr0, rr1)) {
             path1 = path0 + _pathSectorClosed(r1) + _pathSectorClosed(r0);
             // keep 'starting' angle here too
             cpath = [
                 pathCornerForPolygons(r0, vangles0[0], vangles0[1]),
                 pathCornerForPolygons(r1, vangles0[0], vangles0[1])
             ].join(' ');
-        } else {
-            r0 = null;
-            r1 = null;
-            path1 = path0;
-            cpath = 'M0,0Z';
         }
-
         applyZoomMove(path1, cpath);
     }