Lib: Add setScale function

Author: mdtusz

src/lib/index.js

@@ -483,6 +483,42 @@ lib.setTranslate = function(element, x, y) {
     return transform;
 };
 
+lib.getScale = function(element) {
+
+    var re = /(\bscale\()(\d*\.?\d*)([^\d]*)(\d*\.?\d*)([^\d]*)(.*)/,
+        getter = element.attr ? 'attr' : 'getAttribute',
+        transform = element[getter]('transform') || '';
+
+    var translate = transform.replace(re, function(match, p1, p2, p3, p4) {
+        return [p2, p4].join(' ');
+    })
+    .split(' ');
+
+    return {
+        x: +translate[0] || 1,
+        y: +translate[1] || 1
+    };
+};
+
+lib.setScale = function(element, x, y) {
+
+    var re = /(\bscale\(.*?\);?)/,
+        getter = element.attr ? 'attr' : 'getAttribute',
+        setter = element.attr ? 'attr' : 'setAttribute',
+        transform = element[getter]('transform') || '';
+
+    x = x || 1;
+    y = y || 1;
+
+    transform = transform.replace(re, '').trim();
+    transform += ' scale(' + x + ', ' + y + ')';
+    transform = transform.trim();
+
+    element[setter]('transform', transform);
+
+    return transform;
+};
+
 lib.isIE = function() {
     return typeof window.navigator.msSaveBlob !== 'undefined';
 };

test/jasmine/tests/lib_test.js

@@ -858,9 +858,6 @@ describe('Test lib.js:', function() {
             Lib.setTranslate(el, 10, 20);
             expect(el.getAttribute('transform')).toBe('translate(10, 20)');
 
-            Lib.setTranslate(el, 30, 40);
-            expect(el.getAttribute('transform')).toBe('translate(30, 40)');
-
             Lib.setTranslate(el);
             expect(el.getAttribute('transform')).toBe('translate(0, 0)');
 
@@ -875,9 +872,6 @@ describe('Test lib.js:', function() {
             Lib.setTranslate(el, 5);
             expect(el.attr('transform')).toBe('translate(5, 0)');
 
-            Lib.setTranslate(el, 10, 20);
-            expect(el.attr('transform')).toBe('translate(10, 20)');
-
             Lib.setTranslate(el, 30, 40);
             expect(el.attr('transform')).toBe('translate(30, 40)');
 
@@ -890,6 +884,43 @@ describe('Test lib.js:', function() {
         });
     });
 
+    describe('setScale', function() {
+
+        it('should work with regular DOM elements', function() {
+            var el = document.createElement('div');
+
+            Lib.setScale(el, 5);
+            expect(el.getAttribute('transform')).toBe('scale(5, 1)');
+
+            Lib.setScale(el, 30, 40);
+            expect(el.getAttribute('transform')).toBe('scale(30, 40)');
+
+            Lib.setScale(el);
+            expect(el.getAttribute('transform')).toBe('scale(1, 1)');
+
+            el.setAttribute('transform', 'scale(1, 1); rotate(30)');
+            Lib.setScale(el, 30, 40);
+            expect(el.getAttribute('transform')).toBe('rotate(30) scale(30, 40)');
+        });
+
+        it('should work with d3 elements', function() {
+            var el = d3.select(document.createElement('div'));
+
+            Lib.setScale(el, 5);
+            expect(el.attr('transform')).toBe('scale(5, 1)');
+
+            Lib.setScale(el, 30, 40);
+            expect(el.attr('transform')).toBe('scale(30, 40)');
+
+            Lib.setScale(el);
+            expect(el.attr('transform')).toBe('scale(1, 1)');
+
+            el.attr('transform', 'scale(0, 0); rotate(30)');
+            Lib.setScale(el, 30, 40);
+            expect(el.attr('transform')).toBe('rotate(30) scale(30, 40)');
+        });
+    });
+
     describe('pushUnique', function() {
 
         beforeEach(function() {