image: apply layout defaults if an image is present at all

Author: antoinerg

src/plots/cartesian/layout_defaults.js

@@ -41,10 +41,7 @@ module.exports = function supplyLayoutDefaults(layoutIn, layoutOut, fullData) {
     var yaMustDisplay = {};
     var yaMustNotReverse = {};
     var yaMayReverse = {};
-    var yaMustNotScaleanchor = {};
-    var yaMayScaleanchor = {};
-    var yaMustNotConstrainDomain = {};
-    var yaMayConstrainDomain = {};
+    var axHasImage = {};
     var outerTicks = {};
     var noGrids = {};
     var i, j;
@@ -82,20 +79,13 @@ module.exports = function supplyLayoutDefaults(layoutIn, layoutOut, fullData) {
             } else {
                 if(yaName) yaMayHide[yaName] = true;
             }
-            yaMustNotScaleanchor[yaName] = true;
-            yaMustNotConstrainDomain[yaName] = true;
         } else if(trace.type === 'image') {
-            if(yaName) {
-                yaMayReverse[yaName] = true;
-                yaMayScaleanchor[yaName] = true;
-                yaMayConstrainDomain[yaName] = true;
-            }
+            if(yaName) axHasImage[yaName] = true;
+            if(xaName) axHasImage[xaName] = true;
         } else {
             if(yaName) {
                 yaMustDisplay[yaName] = true;
                 yaMustNotReverse[yaName] = true;
-                yaMustNotScaleanchor[yaName] = true;
-                yaMustNotConstrainDomain[yaName] = true;
             }
 
             if(!traceIs(trace, 'carpet') || (trace.type === 'carpet' && !trace._cheater)) {
@@ -206,7 +196,11 @@ module.exports = function supplyLayoutDefaults(layoutIn, layoutOut, fullData) {
             (axLetter === 'y' && !yaMustDisplay[axName] && yaMayHide[axName]);
 
         var reverseDflt =
-            (axLetter === 'y' && !yaMustNotReverse[axName] && yaMayReverse[axName]);
+            (axLetter === 'y' &&
+              (
+                (!yaMustNotReverse[axName] && yaMayReverse[axName]) ||
+                axHasImage[axName]
+              ));
 
         var defaultOptions = {
             letter: axLetter,
@@ -309,16 +303,12 @@ module.exports = function supplyLayoutDefaults(layoutIn, layoutOut, fullData) {
         axLayoutOut = layoutOut[axName];
 
         var scaleanchorDflt = null;
-        if(axLetter === 'y' && !axLayoutIn.hasOwnProperty('scaleanchor') &&
-              !yaMustNotScaleanchor[axName] && yaMayScaleanchor[axName]
-        ) {
+        if(axLetter === 'y' && !axLayoutIn.hasOwnProperty('scaleanchor') && axHasImage[axName]) {
             scaleanchorDflt = axLayoutOut.anchor;
         }
 
         var constrainDflt = null;
-        if(axLetter === 'y' && !axLayoutIn.hasOwnProperty('constrain') &&
-              !yaMustNotConstrainDomain[axName] && yaMayConstrainDomain[axName]
-        ) {
+        if(!axLayoutIn.hasOwnProperty('constrain') && axHasImage[axName]) {
             constrainDflt = 'domain';
         }
         handleConstraintDefaults(axLayoutIn, axLayoutOut, coerce, {

src/traces/image/index.js

@@ -25,11 +25,11 @@ module.exports = {
     meta: {
         description: [
             'Display an image, i.e. data on a 2D regular raster.',
-            'If only images are displayed in a subplot,',
-            'the y axis will be reversed (ie. `autorange: \'reversed\'`)',
-            'and it will have the same scale as the x axis (ie. `scaleanchor: \'x\,`)',
-            'in order for pixels to be rendered as squares and',
-            'the y axis is constrained to the domain (ie. `constrain: \'domain\'`).'
+            'By default, when an image is displayed in a subplot,',
+            'its y axis will be reversed (ie. `autorange: \'reversed\'`),',
+            'constrained to the domain (ie. `constrain: \'domain\'`)',
+            'and it will have the same scale as its x axis (ie. `scaleanchor: \'x\,`)',
+            'in order for pixels to be rendered as squares.'
         ].join(' ')
     }
 };

test/image/baselines/image_axis_type.png

@@ -116,11 +116,11 @@ describe('image smart layout defaults', function() {
         expect(gd._fullLayout.yaxis.autorange).toBe('reversed');
     });
 
-    it('should NOT reverse yaxis if another trace is present', function() {
+    it('should reverse yaxis even if another trace is present', function() {
         gd = {};
         gd.data = [{type: 'image', z: [[[255, 0, 0]]]}, {type: 'scatter', y: [5, 3, 2]}];
         supplyAllDefaults(gd);
-        expect(gd._fullLayout.yaxis.autorange).not.toBe('reversed');
+        expect(gd._fullLayout.yaxis.autorange).toBe('reversed');
     });
 
     it('should NOT reverse yaxis if it\'s already defined', function() {
@@ -138,11 +138,11 @@ describe('image smart layout defaults', function() {
         expect(gd._fullLayout.yaxis.scaleanchor).toBe('x');
     });
 
-    it('should NOT set scaleanchor if another trace is present', function() {
+    it('should set scaleanchor even if another trace is present', function() {
         gd = {};
         gd.data = [{type: 'image', z: [[[255, 0, 0]]]}, {type: 'scatter', y: [5, 3, 2]}];
         supplyAllDefaults(gd);
-        expect(gd._fullLayout.yaxis.scaleanchor).toBe(undefined);
+        expect(gd._fullLayout.yaxis.scaleanchor).toBe('x');
     });
 
     it('should NOT set scaleanchor if it\'s already defined', function() {
@@ -159,11 +159,11 @@ describe('image smart layout defaults', function() {
         expect(gd._fullLayout.yaxis.constrain).toBe('domain');
     });
 
-    it('should NOT constrain axes to domain if another trace is present', function() {
+    it('should constrain axes to domain even if another trace is present', function() {
         gd = {};
         gd.data = [{type: 'image', z: [[[255, 0, 0]]]}, {type: 'scatter', y: [5, 3, 2]}];
         supplyAllDefaults(gd);
-        expect(gd._fullLayout.yaxis.constrain).toBe(undefined);
+        expect(gd._fullLayout.yaxis.constrain).toBe('domain');
     });
 
     it('should NOT constrain axes to domain if it\'s already defined', function() {