Position title after legend width calculated

draftlogs/6725_fix.md

@@ -0,0 +1,4 @@
+```
+ - Fix horizontal title alignment [[#6668](https://github.com/plotly/plotly.js/issues/6668)]
+ - Fix single-point histogram when user has provided bin widths [[#6661](https://github.com/plotly/plotly.js/issues/6661)]
+```

src/components/legend/draw.js

@@ -54,6 +54,30 @@ module.exports = function draw(gd, opts) {
     }
 };
 
+// After legend dimensions are calculated the title can be aligned horizontally left, center, right
+function horizontalAlignTitle(titleEl, legendObj, bw) {
+    if((legendObj.title.side !== 'top center') && (legendObj.title.side !== 'top right')) return;
+
+    var font = legendObj.title.font;
+    var lineHeight = font.size * LINE_SPACING;
+    var titleOffset = 0;
+    var textNode = titleEl.node();
+
+    var width = Drawing.bBox(textNode).width;  // width of the title text
+
+    if(legendObj.title.side === 'top center') {
+        titleOffset = 0.5 * (legendObj._width - 2 * bw - 2 * constants.titlePad - width);
+    } else if(legendObj.title.side === 'top right') {
+        titleOffset = legendObj._width - 2 * bw - 2 * constants.titlePad - width;
+    }
+
+    svgTextUtils.positionText(titleEl,
+        bw + constants.titlePad + titleOffset,
+        bw + lineHeight
+    );
+}
+
+
 function drawOne(gd, opts) {
     var legendObj = opts || {};
 
@@ -148,8 +172,9 @@ function drawOne(gd, opts) {
     var title = legendObj.title;
     legendObj._titleWidth = 0;
     legendObj._titleHeight = 0;
+    var titleEl;
     if(title.text) {
-        var titleEl = Lib.ensureSingle(scrollBox, 'text', legendId + 'titletext');
+        titleEl = Lib.ensureSingle(scrollBox, 'text', legendId + 'titletext');
         titleEl.attr('text-anchor', 'start')
             .call(Drawing.font, title.font)
             .text(title.text);
@@ -193,6 +218,11 @@ function drawOne(gd, opts) {
             var isPaperX = legendObj.xref === 'paper';
             var isPaperY = legendObj.yref === 'paper';
 
+            // re-calculate title position after legend width is derived. To allow for horizontal alignment
+            if(title.text) {
+                horizontalAlignTitle(titleEl, legendObj, bw);
+            }
+
             if(!inHover) {
                 var lx, ly;
 
@@ -661,18 +691,13 @@ function computeTextDimensions(g, gd, legendObj, aTitle) {
         // approximation to height offset to center the font
         // to avoid getBoundingClientRect
         if(aTitle === MAIN_TITLE) {
-            var titleOffset = 0;
             if(legendObj.title.side === 'left') {
                 // add extra space between legend title and itmes
                 width += constants.itemGap * 2;
-            } else if(legendObj.title.side === 'top center') {
-                if(legendObj._width) titleOffset = 0.5 * (legendObj._width - 2 * bw - 2 * constants.titlePad - width);
-            } else if(legendObj.title.side === 'top right') {
-                if(legendObj._width) titleOffset = legendObj._width - 2 * bw - 2 * constants.titlePad - width;
             }
 
             svgTextUtils.positionText(textEl,
-                bw + constants.titlePad + titleOffset,
+                bw + constants.titlePad,
                 bw + lineHeight
             );
         } else { // legend item

src/traces/histogram/calc.js

@@ -308,8 +308,10 @@ function calcAllAutoBins(gd, trace, pa, mainData, _overlayEdgeCase) {
 
         // Edge case: single-valued histogram overlaying others
         // Use them all together to calculate the bin size for the single-valued one
+        // Don't re-calculate bin width if user manually specified it (checing in bingroup=='' or xbins is defined)
         if(isOverlay && !Registry.traceIs(trace, '2dMap') && newBinSpec._dataSpan === 0 &&
-            pa.type !== 'category' && pa.type !== 'multicategory') {
+        pa.type !== 'category' && pa.type !== 'multicategory' &&
+        trace.bingroup === '' && (typeof trace.xbins === 'undefined')) {
             // Several single-valued histograms! Stop infinite recursion,
             // just return an extra flag that tells handleSingleValueOverlays
             // to sort out this trace too

test/image/mocks/legend_horizontal_one_row.json

@@ -20,6 +20,7 @@
         }
     ],
     "layout": {
+        "height": 300,
         "title": {"text": "Average Distribution per Month"},
         "legend": { "orientation": "h", "title": { "text": "Legend Title", "side": "top center" }}
     }

test/image/mocks/zz_histogram_overlay-1point-date.json

@@ -0,0 +1,48 @@
+{
+  "data": [
+    {
+      "x": ["2023-05-22 09:29:56.00"],
+      "opacity": 1,
+      "type": "histogram",
+      "name": "Results B",
+      "marker": {
+        "color": "rgba(0, 255, 0, .2)",
+        "line": {
+          "color": "rgba(0, 255, 0, 1)",
+          "width": 2
+        }
+      },
+      "xbins": {
+        "size": "M1",
+        "start": "2023-05-01",
+        "end": "2023-07-01"
+      }
+    },
+    {
+      "x": ["2023-05-21 09:29:56.00", "2023-05-26 09:29:56.00", "2023-06-21 09:29:56.00"],
+      "opacity": 1,
+      "type": "histogram",
+      "name": "Results A",
+      "marker": {
+        "color": "rgba(0, 0, 255, .2)",
+        "line": {
+          "color": "rgba(0, 0, 255, 1)",
+          "width": 2
+        }
+      },
+      "xbins": {
+        "size": "M1",
+        "start": "2023-05-01",
+        "end": "2023-07-01"
+      }
+    }
+  ],
+  "layout": {
+    "barmode": "overlay",
+    "title": { "text": "Sampled Results" },
+    "xaxis": {
+      "title": { "text": "Date" }
+    },
+    "yaxis": { "title": { "text": "Count" } }
+  }
+}