From 420aa027b305c91380d96d05e39db2767ec1333a Mon Sep 17 00:00:00 2001
From: Jukka Kurkela <jukka.kurkela@gmail.com>
Date: Tue, 16 Mar 2021 14:49:19 +0200
Subject: [PATCH] Exclude base-line from bar size (#8648)

* Exclude base-line from bar size

* lint

* add to types
---
 src/controllers/controller.bar.js             |  12 +++++
 src/core/core.scale.js                        |  15 +++++++
 .../controller.bar/baseLine/bottom.js         |  40 +++++++++++++++++
 .../controller.bar/baseLine/bottom.png        | Bin 0 -> 901 bytes
 test/fixtures/controller.bar/baseLine/left.js |  41 +++++++++++++++++
 .../fixtures/controller.bar/baseLine/left.png | Bin 0 -> 647 bytes
 .../fixtures/controller.bar/baseLine/mid-x.js |  41 +++++++++++++++++
 .../controller.bar/baseLine/mid-x.png         | Bin 0 -> 758 bytes
 .../fixtures/controller.bar/baseLine/mid-y.js |  40 +++++++++++++++++
 .../controller.bar/baseLine/mid-y.png         | Bin 0 -> 930 bytes
 .../fixtures/controller.bar/baseLine/right.js |  42 ++++++++++++++++++
 .../controller.bar/baseLine/right.png         | Bin 0 -> 611 bytes
 test/fixtures/controller.bar/baseLine/top.js  |  41 +++++++++++++++++
 test/fixtures/controller.bar/baseLine/top.png | Bin 0 -> 895 bytes
 .../controller.bar/baseLine/value-x.js        |  42 ++++++++++++++++++
 .../controller.bar/baseLine/value-x.png       | Bin 0 -> 943 bytes
 .../controller.bar/baseLine/value-y.js        |  41 +++++++++++++++++
 .../controller.bar/baseLine/value-y.png       | Bin 0 -> 951 bytes
 test/specs/controller.bar.tests.js            |  10 +++--
 types/index.esm.d.ts                          |   6 +++
 20 files changed, 367 insertions(+), 4 deletions(-)
 create mode 100644 test/fixtures/controller.bar/baseLine/bottom.js
 create mode 100644 test/fixtures/controller.bar/baseLine/bottom.png
 create mode 100644 test/fixtures/controller.bar/baseLine/left.js
 create mode 100644 test/fixtures/controller.bar/baseLine/left.png
 create mode 100644 test/fixtures/controller.bar/baseLine/mid-x.js
 create mode 100644 test/fixtures/controller.bar/baseLine/mid-x.png
 create mode 100644 test/fixtures/controller.bar/baseLine/mid-y.js
 create mode 100644 test/fixtures/controller.bar/baseLine/mid-y.png
 create mode 100644 test/fixtures/controller.bar/baseLine/right.js
 create mode 100644 test/fixtures/controller.bar/baseLine/right.png
 create mode 100644 test/fixtures/controller.bar/baseLine/top.js
 create mode 100644 test/fixtures/controller.bar/baseLine/top.png
 create mode 100644 test/fixtures/controller.bar/baseLine/value-x.js
 create mode 100644 test/fixtures/controller.bar/baseLine/value-x.png
 create mode 100644 test/fixtures/controller.bar/baseLine/value-y.js
 create mode 100644 test/fixtures/controller.bar/baseLine/value-y.png

diff --git a/src/controllers/controller.bar.js b/src/controllers/controller.bar.js
index 0d4176f27..cbac98e51 100644
--- a/src/controllers/controller.bar.js
+++ b/src/controllers/controller.bar.js
@@ -447,6 +447,18 @@ export default class BarController extends DatasetController {
       head = base + size;
     }
 
+    const actualBase = baseValue || 0;
+    if (base === vScale.getPixelForValue(actualBase)) {
+      const halfGrid = vScale.getLineWidthForValue(actualBase) / 2;
+      if (size > 0) {
+        base += halfGrid;
+        size -= halfGrid;
+      } else if (size < 0) {
+        base -= halfGrid;
+        size += halfGrid;
+      }
+    }
+
     return {
       size,
       base,
diff --git a/src/core/core.scale.js b/src/core/core.scale.js
index f62ec10e9..2da297290 100644
--- a/src/core/core.scale.js
+++ b/src/core/core.scale.js
@@ -1606,6 +1606,21 @@ export default class Scale extends Element {
     }
   }
 
+  getLineWidthForValue(value) {
+    const me = this;
+    const grid = me.options.grid;
+    if (!me._isVisible() || !grid.display) {
+      return 0;
+    }
+    const ticks = me.ticks;
+    const index = ticks.findIndex(t => t.value === value);
+    if (index >= 0) {
+      const opts = grid.setContext(me.getContext(index));
+      return opts.lineWidth;
+    }
+    return 0;
+  }
+
   /**
 	 * @protected
 	 */
diff --git a/test/fixtures/controller.bar/baseLine/bottom.js b/test/fixtures/controller.bar/baseLine/bottom.js
new file mode 100644
index 000000000..272b8e99b
--- /dev/null
+++ b/test/fixtures/controller.bar/baseLine/bottom.js
@@ -0,0 +1,40 @@
+module.exports = {
+  config: {
+    type: 'bar',
+    data: {
+      labels: ['a', 'b'],
+      datasets: [{
+        backgroundColor: '#AAFFCC',
+        borderColor: '#0000FF',
+        borderWidth: 1,
+        data: [1, 2]
+      }]
+    },
+    options: {
+      scales: {
+        x: {
+          display: false
+        },
+        y: {
+          ticks: {
+            display: false
+          },
+          grid: {
+            color: function(context) {
+              return context.tick.value === 0 ? 'red' : 'transparent';
+            },
+            lineWidth: 5,
+            tickLength: 0
+          },
+        }
+      },
+      maintainAspectRatio: false
+    }
+  },
+  options: {
+    canvas: {
+      width: 128,
+      height: 128
+    }
+  }
+};
diff --git a/test/fixtures/controller.bar/baseLine/bottom.png b/test/fixtures/controller.bar/baseLine/bottom.png
new file mode 100644
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diff --git a/test/fixtures/controller.bar/baseLine/left.js b/test/fixtures/controller.bar/baseLine/left.js
new file mode 100644
index 000000000..56a68ce54
--- /dev/null
+++ b/test/fixtures/controller.bar/baseLine/left.js
@@ -0,0 +1,41 @@
+module.exports = {
+  config: {
+    type: 'bar',
+    data: {
+      labels: ['a', 'b'],
+      datasets: [{
+        backgroundColor: '#AAFFCC',
+        borderColor: '#0000FF',
+        borderWidth: 1,
+        data: [1, 2]
+      }]
+    },
+    options: {
+      indexAxis: 'y',
+      scales: {
+        y: {
+          display: false
+        },
+        x: {
+          ticks: {
+            display: false
+          },
+          grid: {
+            color: function(context) {
+              return context.tick.value === 0 ? 'red' : 'transparent';
+            },
+            lineWidth: 5,
+            tickLength: 0
+          },
+        }
+      },
+      maintainAspectRatio: false
+    }
+  },
+  options: {
+    canvas: {
+      width: 128,
+      height: 128
+    }
+  }
+};
diff --git a/test/fixtures/controller.bar/baseLine/left.png b/test/fixtures/controller.bar/baseLine/left.png
new file mode 100644
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GIT binary patch
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diff --git a/test/fixtures/controller.bar/baseLine/mid-x.js b/test/fixtures/controller.bar/baseLine/mid-x.js
new file mode 100644
index 000000000..ef6beb5c9
--- /dev/null
+++ b/test/fixtures/controller.bar/baseLine/mid-x.js
@@ -0,0 +1,41 @@
+module.exports = {
+  config: {
+    type: 'bar',
+    data: {
+      labels: ['a', 'b'],
+      datasets: [{
+        backgroundColor: '#AAFFCC',
+        borderColor: '#0000FF',
+        borderWidth: 1,
+        data: [1, -1]
+      }]
+    },
+    options: {
+      indexAxis: 'y',
+      scales: {
+        y: {
+          display: false
+        },
+        x: {
+          ticks: {
+            display: false
+          },
+          grid: {
+            color: function(context) {
+              return context.tick.value === 0 ? 'red' : 'transparent';
+            },
+            lineWidth: 5,
+            tickLength: 0
+          },
+        }
+      },
+      maintainAspectRatio: false
+    }
+  },
+  options: {
+    canvas: {
+      width: 128,
+      height: 128
+    }
+  }
+};
diff --git a/test/fixtures/controller.bar/baseLine/mid-x.png b/test/fixtures/controller.bar/baseLine/mid-x.png
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diff --git a/test/fixtures/controller.bar/baseLine/mid-y.js b/test/fixtures/controller.bar/baseLine/mid-y.js
new file mode 100644
index 000000000..d01c00a12
--- /dev/null
+++ b/test/fixtures/controller.bar/baseLine/mid-y.js
@@ -0,0 +1,40 @@
+module.exports = {
+  config: {
+    type: 'bar',
+    data: {
+      labels: ['a', 'b'],
+      datasets: [{
+        backgroundColor: '#AAFFCC',
+        borderColor: '#0000FF',
+        borderWidth: 1,
+        data: [1, -1]
+      }]
+    },
+    options: {
+      scales: {
+        x: {
+          display: false
+        },
+        y: {
+          ticks: {
+            display: false
+          },
+          grid: {
+            color: function(context) {
+              return context.tick.value === 0 ? 'red' : 'transparent';
+            },
+            lineWidth: 5,
+            tickLength: 0
+          },
+        }
+      },
+      maintainAspectRatio: false
+    }
+  },
+  options: {
+    canvas: {
+      width: 128,
+      height: 128
+    }
+  }
+};
diff --git a/test/fixtures/controller.bar/baseLine/mid-y.png b/test/fixtures/controller.bar/baseLine/mid-y.png
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diff --git a/test/fixtures/controller.bar/baseLine/right.js b/test/fixtures/controller.bar/baseLine/right.js
new file mode 100644
index 000000000..1fc069f1f
--- /dev/null
+++ b/test/fixtures/controller.bar/baseLine/right.js
@@ -0,0 +1,42 @@
+module.exports = {
+  config: {
+    type: 'bar',
+    data: {
+      labels: ['a', 'b'],
+      datasets: [{
+        backgroundColor: '#AAFFCC',
+        borderColor: '#0000FF',
+        borderWidth: 1,
+        data: [-1, -2]
+      }]
+    },
+    options: {
+      indexAxis: 'y',
+      scales: {
+        y: {
+          display: false
+        },
+        x: {
+          ticks: {
+            display: false
+          },
+          grid: {
+            color: function(context) {
+              return context.tick.value === 0 ? 'red' : 'transparent';
+            },
+            lineWidth: 5,
+            tickLength: 0,
+            borderWidth: 0
+          },
+        }
+      },
+      maintainAspectRatio: false
+    }
+  },
+  options: {
+    canvas: {
+      width: 128,
+      height: 128
+    }
+  }
+};
diff --git a/test/fixtures/controller.bar/baseLine/right.png b/test/fixtures/controller.bar/baseLine/right.png
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diff --git a/test/fixtures/controller.bar/baseLine/top.js b/test/fixtures/controller.bar/baseLine/top.js
new file mode 100644
index 000000000..86a7a378d
--- /dev/null
+++ b/test/fixtures/controller.bar/baseLine/top.js
@@ -0,0 +1,41 @@
+module.exports = {
+  config: {
+    type: 'bar',
+    data: {
+      labels: ['a', 'b'],
+      datasets: [{
+        backgroundColor: '#AAFFCC',
+        borderColor: '#0000FF',
+        borderWidth: 1,
+        data: [-1, -2]
+      }]
+    },
+    options: {
+      scales: {
+        x: {
+          display: false
+        },
+        y: {
+          ticks: {
+            display: false
+          },
+          grid: {
+            color: function(context) {
+              return context.tick.value === 0 ? 'red' : 'transparent';
+            },
+            borderWidth: 0,
+            lineWidth: 5,
+            tickLength: 0
+          },
+        }
+      },
+      maintainAspectRatio: false
+    }
+  },
+  options: {
+    canvas: {
+      width: 128,
+      height: 128
+    }
+  }
+};
diff --git a/test/fixtures/controller.bar/baseLine/top.png b/test/fixtures/controller.bar/baseLine/top.png
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diff --git a/test/fixtures/controller.bar/baseLine/value-x.js b/test/fixtures/controller.bar/baseLine/value-x.js
new file mode 100644
index 000000000..557a89863
--- /dev/null
+++ b/test/fixtures/controller.bar/baseLine/value-x.js
@@ -0,0 +1,42 @@
+module.exports = {
+  config: {
+    type: 'bar',
+    data: {
+      labels: ['a', 'b'],
+      datasets: [{
+        backgroundColor: '#AAFFCC',
+        borderColor: '#0000FF',
+        borderWidth: 1,
+        data: [1, 3]
+      }]
+    },
+    options: {
+      base: 2,
+      indexAxis: 'y',
+      scales: {
+        y: {
+          display: false
+        },
+        x: {
+          ticks: {
+            display: false
+          },
+          grid: {
+            color: function(context) {
+              return context.tick.value === 2 ? 'red' : 'transparent';
+            },
+            lineWidth: 5,
+            tickLength: 0
+          },
+        }
+      },
+      maintainAspectRatio: false
+    }
+  },
+  options: {
+    canvas: {
+      width: 128,
+      height: 128
+    }
+  }
+};
diff --git a/test/fixtures/controller.bar/baseLine/value-x.png b/test/fixtures/controller.bar/baseLine/value-x.png
new file mode 100644
index 0000000000000000000000000000000000000000..1fd0161a55f50e2850408d52b9af838f45f45e3f
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diff --git a/test/fixtures/controller.bar/baseLine/value-y.js b/test/fixtures/controller.bar/baseLine/value-y.js
new file mode 100644
index 000000000..caee084df
--- /dev/null
+++ b/test/fixtures/controller.bar/baseLine/value-y.js
@@ -0,0 +1,41 @@
+module.exports = {
+  config: {
+    type: 'bar',
+    data: {
+      labels: ['a', 'b'],
+      datasets: [{
+        backgroundColor: '#AAFFCC',
+        borderColor: '#0000FF',
+        borderWidth: 1,
+        data: [1, 3]
+      }]
+    },
+    options: {
+      base: 2,
+      scales: {
+        x: {
+          display: false
+        },
+        y: {
+          ticks: {
+            display: false
+          },
+          grid: {
+            color: function(context) {
+              return context.tick.value === 2 ? 'red' : 'transparent';
+            },
+            lineWidth: 5,
+            tickLength: 0
+          },
+        }
+      },
+      maintainAspectRatio: false
+    }
+  },
+  options: {
+    canvas: {
+      width: 128,
+      height: 128
+    }
+  }
+};
diff --git a/test/fixtures/controller.bar/baseLine/value-y.png b/test/fixtures/controller.bar/baseLine/value-y.png
new file mode 100644
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diff --git a/test/specs/controller.bar.tests.js b/test/specs/controller.bar.tests.js
index 883a9ed58..6be8eb1ed 100644
--- a/test/specs/controller.bar.tests.js
+++ b/test/specs/controller.bar.tests.js
@@ -1528,9 +1528,10 @@ describe('Chart.controllers.bar', function() {
     });
 
     var data = chart.getDatasetMeta(0).data;
+    var halfBaseLine = chart.scales.y.getLineWidthForValue(0) / 2;
 
-    expect(data[0].base - minBarLength).toEqual(data[0].y);
-    expect(data[1].base + minBarLength).toEqual(data[1].y);
+    expect(data[0].base - minBarLength + halfBaseLine).toEqual(data[0].y);
+    expect(data[1].base + minBarLength - halfBaseLine).toEqual(data[1].y);
   });
 
   it('minBarLength settings should be used on X axis on horizontal bar chart', function() {
@@ -1547,9 +1548,10 @@ describe('Chart.controllers.bar', function() {
     });
 
     var data = chart.getDatasetMeta(0).data;
+    var halfBaseLine = chart.scales.x.getLineWidthForValue(0) / 2;
 
-    expect(data[0].base + minBarLength).toEqual(data[0].x);
-    expect(data[1].base - minBarLength).toEqual(data[1].x);
+    expect(data[0].base + minBarLength - halfBaseLine).toEqual(data[0].x);
+    expect(data[1].base - minBarLength + halfBaseLine).toEqual(data[1].x);
   });
 
   it('should respect the data visibility settings', function() {
diff --git a/types/index.esm.d.ts b/types/index.esm.d.ts
index 8cdaf9921..0bafe17e6 100644
--- a/types/index.esm.d.ts
+++ b/types/index.esm.d.ts
@@ -1199,6 +1199,12 @@ export interface Scale<O extends CoreScaleOptions = CoreScaleOptions> extends El
    * @return {string}
    */
   getLabelForValue(value: number): string;
+
+  /**
+   * Returns the grid line width at given value
+   */
+  getLineWidthForValue(value: number): number;
+
   /**
    * Returns the location of the given data point. Value can either be an index or a numerical value
    * The coordinate (0, 0) is at the upper-left corner of the canvas
-- 
2.47.3