image: improve layout defaults

src/plots/cartesian/constraints.js

@@ -17,7 +17,11 @@ var concatExtremes = require('./autorange').concatExtremes;
 var ALMOST_EQUAL = require('../../constants/numerical').ALMOST_EQUAL;
 var FROM_BL = require('../../constants/alignment').FROM_BL;
 
-exports.handleConstraintDefaults = function(containerIn, containerOut, coerce, allAxisIds, layoutOut) {
+exports.handleConstraintDefaults = function(containerIn, containerOut, coerce, opts) {
+    var allAxisIds = opts.allAxisIds;
+    var layoutOut = opts.layoutOut;
+    var scaleanchorDflt = opts.scaleanchorDflt;
+    var constrainDflt = opts.constrainDflt;
     var constraintGroups = layoutOut._axisConstraintGroups;
     var matchGroups = layoutOut._axisMatchGroups;
     var axId = containerOut._id;
@@ -28,7 +32,7 @@ exports.handleConstraintDefaults = function(containerIn, containerOut, coerce, a
 
     // coerce the constraint mechanics even if this axis has no scaleanchor
     // because it may be the anchor of another axis.
-    var constrain = coerce('constrain');
+    var constrain = coerce('constrain', constrainDflt);
     Lib.coerce(containerIn, containerOut, {
         constraintoward: {
             valType: 'enumerated',
@@ -53,14 +57,17 @@ exports.handleConstraintDefaults = function(containerIn, containerOut, coerce, a
     // 'matches' wins over 'scaleanchor' (for now)
     var scaleanchor, scaleOpts;
 
-    if(!matches && containerIn.scaleanchor && !(containerOut.fixedrange && constrain !== 'domain')) {
+    if(!matches &&
+       !(containerOut.fixedrange && constrain !== 'domain') &&
+       (containerIn.scaleanchor || scaleanchorDflt)
+     ) {
         scaleOpts = getConstraintOpts(constraintGroups, thisID, allAxisIds, layoutOut, constrain);
         scaleanchor = Lib.coerce(containerIn, containerOut, {
             scaleanchor: {
                 valType: 'enumerated',
                 values: scaleOpts.linkableAxes || []
             }
-        }, 'scaleanchor');
+        }, 'scaleanchor', scaleanchorDflt);
     }
 
     if(matches) {

src/plots/cartesian/layout_defaults.js

@@ -39,8 +39,9 @@ module.exports = function supplyLayoutDefaults(layoutIn, layoutOut, fullData) {
     var yaMayHide = {};
     var xaMustDisplay = {};
     var yaMustDisplay = {};
-    var yaMustForward = {};
-    var yaMayBackward = {};
+    var yaMustNotReverse = {};
+    var yaMayReverse = {};
+    var axHasImage = {};
     var outerTicks = {};
     var noGrids = {};
     var i, j;
@@ -74,24 +75,22 @@ module.exports = function supplyLayoutDefaults(layoutIn, layoutOut, fullData) {
         if(trace.type === 'funnel') {
             if(trace.orientation === 'h') {
                 if(xaName) xaMayHide[xaName] = true;
-                if(yaName) yaMayBackward[yaName] = true;
+                if(yaName) yaMayReverse[yaName] = true;
             } else {
                 if(yaName) yaMayHide[yaName] = true;
             }
+        } else if(trace.type === 'image') {
+            if(yaName) axHasImage[yaName] = true;
+            if(xaName) axHasImage[xaName] = true;
         } else {
             if(yaName) {
                 yaMustDisplay[yaName] = true;
-                yaMustForward[yaName] = true;
+                yaMustNotReverse[yaName] = true;
             }
 
             if(!traceIs(trace, 'carpet') || (trace.type === 'carpet' && !trace._cheater)) {
                 if(xaName) xaMustDisplay[xaName] = true;
             }
-
-            if(trace.type === 'image') {
-                if(yaName) yaMustForward[yaName] = false;
-                if(yaName) yaMayBackward[yaName] = true;
-            }
         }
 
         // Two things trigger axis visibility:
@@ -197,7 +196,11 @@ module.exports = function supplyLayoutDefaults(layoutIn, layoutOut, fullData) {
             (axLetter === 'y' && !yaMustDisplay[axName] && yaMayHide[axName]);
 
         var reverseDflt =
-            (axLetter === 'y' && !yaMustForward[axName] && yaMayBackward[axName]);
+            (axLetter === 'y' &&
+              (
+                (!yaMustNotReverse[axName] && yaMayReverse[axName]) ||
+                axHasImage[axName]
+              ));
 
         var defaultOptions = {
             letter: axLetter,
@@ -299,7 +302,22 @@ module.exports = function supplyLayoutDefaults(layoutIn, layoutOut, fullData) {
         axLayoutIn = layoutIn[axName];
         axLayoutOut = layoutOut[axName];
 
-        handleConstraintDefaults(axLayoutIn, axLayoutOut, coerce, allAxisIds, layoutOut);
+        var scaleanchorDflt;
+        if(axLetter === 'y' && !axLayoutIn.hasOwnProperty('scaleanchor') && axHasImage[axName]) {
+            scaleanchorDflt = axLayoutOut.anchor;
+        } else {scaleanchorDflt = undefined;}
+
+        var constrainDflt;
+        if(!axLayoutIn.hasOwnProperty('constrain') && axHasImage[axName]) {
+            constrainDflt = 'domain';
+        } else {constrainDflt = undefined;}
+
+        handleConstraintDefaults(axLayoutIn, axLayoutOut, coerce, {
+            allAxisIds: allAxisIds,
+            layoutOut: layoutOut,
+            scaleanchorDflt: scaleanchorDflt,
+            constrainDflt: constrainDflt
+        });
     }
 
     for(i = 0; i < matchGroups.length; i++) {

src/traces/image/index.js

@@ -24,7 +24,12 @@ module.exports = {
     animatable: false,
     meta: {
         description: [
-            'Display an image, i.e. data on a 2D regular raster.'
+            'Display an image, i.e. data on a 2D regular raster.',
+            '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/mocks/image_cat.json

@@ -1,6 +1,6 @@
 {
 "layout": {
-  "width": 400, "height": 400, "yaxis": {"scaleanchor": "x"}, "margin": {"t":25, "b": 25, "r": 25, "l": 40}
+  "width": 400, "height": 400, "yaxis": {"scaleanchor": "x", "autorange": "reversed"}, "margin": {"t":25, "b": 25, "r": 25, "l": 40}
 },
   "data": [
     {"x":[50, 150, 350, 50], "y":[350, 23, 100, 350]},

test/image/mocks/image_colormodel.json

@@ -2,12 +2,14 @@
   "data": [{
     "type": "image",
     "colormodel": "rgb",
-    "dy": 10,
+    "hoverinfo": "all",
+    "dy": 1,
     "dx": 0.5,
     "z": [[[255, 0, 0], [0, 255, 0], [0, 0, 255]]]
   }, {
     "type": "image",
     "colormodel": "hsl",
+    "hoverinfo": "all",
     "z": [
       [[0, 33, 50], [0, 66, 50], [0, 100, 50]],
       [[90, 33, 50], [90, 66, 50], [90, 100, 50]],
@@ -18,7 +20,7 @@
     "yaxis": "y2"
   }],
   "layout": {
-    "grid": {"rows": 2, "columns": 1, "pattern": "independent"},
+    "grid": {"rows": 1, "columns": 2, "pattern": "independent"},
     "width": 600,
     "height": 400
   }

test/jasmine/assets/mock_lists.js

@@ -23,6 +23,7 @@ var svgMockList = [
     ['finance_style', require('@mocks/finance_style.json')],
     ['geo_first', require('@mocks/geo_first.json')],
     ['indicator_bignumber', require('@mocks/indicator_bignumber.json')],
+    ['image_adventurer', require('@mocks/image_adventurer.json')],
     ['layout_image', require('@mocks/layout_image.json')],
     ['layout-colorway', require('@mocks/layout-colorway.json')],
     ['multicategory', require('@mocks/multicategory.json')],

test/jasmine/tests/image_test.js

@@ -11,6 +11,7 @@ var failTest = require('../assets/fail_test');
 
 var customAssertions = require('../assets/custom_assertions');
 var assertHoverLabelContent = customAssertions.assertHoverLabelContent;
+var supplyAllDefaults = require('../assets/supply_defaults');
 var Fx = require('@src/components/fx');
 
 describe('image supplyDefaults', function() {
@@ -100,6 +101,82 @@ describe('image supplyDefaults', function() {
     });
 });
 
+describe('image smart layout defaults', function() {
+    var gd;
+    beforeEach(function() {
+        gd = createGraphDiv();
+    });
+
+    afterEach(destroyGraphDiv);
+
+    it('should reverse yaxis if only images are present', function() {
+        gd = {};
+        gd.data = [{type: 'image', z: [[[255, 0, 0]]]}];
+        supplyAllDefaults(gd);
+        expect(gd._fullLayout.yaxis.autorange).toBe('reversed');
+    });
+
+    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).toBe('reversed');
+    });
+
+    it('should NOT reverse yaxis if it\'s already defined', function() {
+        gd = {};
+        gd.data = [{type: 'image', z: [[[255, 0, 0]]]}];
+        gd.layout = {yaxis: {autorange: false}};
+        supplyAllDefaults(gd);
+        expect(gd._fullLayout.yaxis.autorange).toBe(false);
+    });
+
+    it('should set scaleanchor to make square pixels if only images are present', function() {
+        gd = {};
+        gd.data = [{type: 'image', z: [[[255, 0, 0]]]}];
+        supplyAllDefaults(gd);
+        expect(gd._fullLayout.yaxis.scaleanchor).toBe('x');
+    });
+
+    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('x');
+    });
+
+    it('should NOT set scaleanchor if it\'s already defined', function() {
+        gd.data = [{type: 'image', z: [[[255, 0, 0]]]}];
+        gd.layout = {yaxis: {scaleanchor: 'x3'}};
+        supplyAllDefaults(gd);
+        expect(gd._fullLayout.yaxis.scaleanchor).toBe(undefined);
+    });
+
+    it('should constrain axes to domain if only images are present', function() {
+        gd = {};
+        gd.data = [{type: 'image', z: [[[255, 0, 0]]]}];
+        supplyAllDefaults(gd);
+        expect(gd._fullLayout.xaxis.constrain).toBe('domain');
+        expect(gd._fullLayout.yaxis.constrain).toBe('domain');
+    });
+
+    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.xaxis.constrain).toBe('domain');
+        expect(gd._fullLayout.yaxis.constrain).toBe('domain');
+    });
+
+    it('should NOT constrain axes to domain if it\'s already defined', function() {
+        gd.data = [{type: 'image', z: [[[255, 0, 0]]]}];
+        gd.layout = {yaxis: {constrain: false}, xaxis: {constrain: false}};
+        supplyAllDefaults(gd);
+        expect(gd._fullLayout.xaxis.constrain).toBe('range');
+        expect(gd._fullLayout.yaxis.constrain).toBe('range');
+    });
+});
+
 describe('image plot', function() {
     'use strict';
 
@@ -444,10 +521,10 @@ describe('image hover:', function() {
                 zmax: [1, 1, 1],
                 text: [['A', 'B', 'C'], ['D', 'E', 'F']],
                 hovertemplate: '%{text}<extra></extra>'
-            }], layout: {width: 400, height: 400}};
+            }], layout: {width: 400, height: 400, yaxis: {constrain: 'range'}}};
 
             Plotly.newPlot(gd, mockCopy)
-            .then(function() {_hover(140, 200);})
+            .then(function() {_hover(140, 180);})
             .then(function() {
                 assertHoverLabelContent({
                     nums: 'E',