Panel: added possibility to group plugins in a panel according to a grid. (#22028)

* POC grid layout of gague.

* added a grid property that can be used to auto size the charts within a panel.

* fill the grid

* fix lint

* change default for stat panel

* avoid empty cells

* Moved to absolute positioning

* Fixed spacing

* Another fix

* Improve layout algorithm

* VizRepeater: Reverted back to so this is auto behavior for some panels

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>
Co-authored-by: Torkel Ödegaard <torkel@grafana.com>

packages/grafana-ui/src/components/BarGauge/BarGauge.tsx

@@ -72,7 +72,7 @@ export class BarGauge extends PureComponent<Props> {
         steps: [],
       },
     },
-    itemSpacing: 10,
+    itemSpacing: 8,
     showUnfilled: true,
   };
 

packages/grafana-ui/src/components/VizRepeater/VizRepeater.tsx

 import React, { PureComponent, CSSProperties } from 'react';
 import { VizOrientation } from '@grafana/data';
+import { calculateGridDimensions } from '../../utils/squares';
 
 interface Props<V, D> {
   /**
@@ -21,6 +22,8 @@ interface Props<V, D> {
   renderCounter: number; // force update of values & render
   orientation: VizOrientation;
   itemSpacing?: number;
+  /** When orientation is set to auto layout items in a grid */
+  autoGrid?: boolean;
 }
 
 export interface VizRepeaterRenderValueProps<V, D = {}> {
@@ -43,7 +46,7 @@ interface State<V> {
 
 export class VizRepeater<V, D = {}> extends PureComponent<Props<V, D>, State<V>> {
   static defaultProps: DefaultProps = {
-    itemSpacing: 10,
+    itemSpacing: 8,
   };
 
   constructor(props: Props<V, D>) {
@@ -75,10 +78,61 @@ export class VizRepeater<V, D = {}> extends PureComponent<Props<V, D>, State<V>>
     return orientation;
   }
 
+  renderGrid() {
+    const { renderValue, height, width, itemSpacing, getAlignmentFactors, orientation } = this
+      .props as PropsWithDefaults<V, D>;
+
+    const { values } = this.state;
+    const grid = calculateGridDimensions(width, height, itemSpacing, values.length);
+    const alignmentFactors = getAlignmentFactors ? getAlignmentFactors(values, grid.width, grid.height) : ({} as D);
+
+    let xGrid = 0;
+    let yGrid = 0;
+    let items: JSX.Element[] = [];
+
+    for (let i = 0; i < values.length; i++) {
+      const value = values[i];
+      const isLastRow = yGrid === grid.yCount - 1;
+
+      const itemWidth = isLastRow ? grid.widthOnLastRow : grid.width;
+      const itemHeight = grid.height;
+
+      const xPos = xGrid * itemWidth + itemSpacing * xGrid;
+      const yPos = yGrid * itemHeight + itemSpacing * yGrid;
+
+      const itemStyles: CSSProperties = {
+        position: 'absolute',
+        left: xPos,
+        top: yPos,
+        width: `${itemWidth}px`,
+        height: `${itemHeight}px`,
+      };
+
+      items.push(
+        <div key={i} style={itemStyles}>
+          {renderValue({ value, width: itemWidth, height: itemHeight, alignmentFactors, orientation })}
+        </div>
+      );
+
+      xGrid++;
+
+      if (xGrid === grid.xCount) {
+        xGrid = 0;
+        yGrid++;
+      }
+    }
+
+    return <div style={{ position: 'relative' }}>{items}</div>;
+  }
+
   render() {
-    const { renderValue, height, width, itemSpacing, getAlignmentFactors } = this.props as PropsWithDefaults<V, D>;
+    const { renderValue, height, width, itemSpacing, getAlignmentFactors, autoGrid, orientation } = this
+      .props as PropsWithDefaults<V, D>;
     const { values } = this.state;
-    const orientation = this.getOrientation();
+
+    if (autoGrid && orientation === VizOrientation.Auto) {
+      return this.renderGrid();
+    }
 
     const itemStyles: React.CSSProperties = {
       display: 'flex',
@@ -91,17 +145,19 @@ export class VizRepeater<V, D = {}> extends PureComponent<Props<V, D>, State<V>>
     let vizHeight = height;
     let vizWidth = width;
 
-    if (orientation === VizOrientation.Horizontal) {
-      repeaterStyle.flexDirection = 'column';
-      itemStyles.marginBottom = `${itemSpacing}px`;
-      vizWidth = width;
-      vizHeight = height / values.length - itemSpacing + itemSpacing / values.length;
-    } else {
-      repeaterStyle.flexDirection = 'row';
-      repeaterStyle.justifyContent = 'space-between';
-      itemStyles.marginRight = `${itemSpacing}px`;
-      vizHeight = height;
-      vizWidth = width / values.length - itemSpacing + itemSpacing / values.length;
+    switch (this.getOrientation()) {
+      case VizOrientation.Horizontal:
+        repeaterStyle.flexDirection = 'column';
+        itemStyles.marginBottom = `${itemSpacing}px`;
+        vizWidth = width;
+        vizHeight = height / values.length - itemSpacing + itemSpacing / values.length;
+        break;
+      case VizOrientation.Vertical:
+        repeaterStyle.flexDirection = 'row';
+        repeaterStyle.justifyContent = 'space-between';
+        itemStyles.marginRight = `${itemSpacing}px`;
+        vizHeight = height;
+        vizWidth = width / values.length - itemSpacing + itemSpacing / values.length;
     }
 
     itemStyles.width = `${vizWidth}px`;

packages/grafana-ui/src/utils/squares.ts

+/**
+ * This function will calculate how many squares we can fit inside a rectangle.
+ * Please have a look at this post for more details about the implementation:
+ * https://math.stackexchange.com/questions/466198/algorithm-to-get-the-maximum-size-of-n-squares-that-fit-into-a-rectangle-with-a
+ *
+ * @param parentWidth width of the parent container
+ * @param parentHeight height of the parent container
+ * @param numberOfChildren number of children that should fit in the parent container
+ */
+export const calculateGridDimensions = (
+  parentWidth: number,
+  parentHeight: number,
+  itemSpacing: number,
+  numberOfChildren: number
+) => {
+  const vertical = calculateSizeOfChild(parentWidth, parentHeight, numberOfChildren);
+  const horizontal = calculateSizeOfChild(parentHeight, parentWidth, numberOfChildren);
+  const square = Math.max(vertical, horizontal);
+  let xCount = Math.floor(parentWidth / square);
+  let yCount = Math.ceil(numberOfChildren / xCount);
+
+  // after yCount update xCount to make split between rows more even
+  xCount = Math.ceil(numberOfChildren / yCount);
+
+  const itemsOnLastRow = xCount - (xCount * yCount - numberOfChildren);
+  const widthOnLastRow = parentWidth / itemsOnLastRow - itemSpacing + itemSpacing / itemsOnLastRow;
+
+  return {
+    width: parentWidth / xCount - itemSpacing + itemSpacing / xCount,
+    height: parentHeight / yCount - itemSpacing + itemSpacing / yCount,
+    widthOnLastRow,
+    xCount,
+    yCount,
+  };
+};
+
+function calculateSizeOfChild(parentWidth: number, parentHeight: number, numberOfChildren: number): number {
+  const parts = Math.ceil(Math.sqrt((numberOfChildren * parentWidth) / parentHeight));
+
+  if (Math.floor((parts * parentHeight) / parentWidth) * parts < numberOfChildren) {
+    return parentHeight / Math.ceil((parts * parentHeight) / parentWidth);
+  }
+
+  return parentWidth / parts;
+}

public/app/plugins/panel/gauge/GaugePanel.tsx

@@ -60,6 +60,7 @@ export class GaugePanel extends PureComponent<PanelProps<GaugeOptions>> {
         width={width}
         height={height}
         source={data}
+        autoGrid={true}
         renderCounter={renderCounter}
         orientation={VizOrientation.Auto}
       />

public/app/plugins/panel/stat/StatPanel.tsx

@@ -22,7 +22,6 @@ import {
   ReducerID,
   getDisplayValueAlignmentFactors,
   DisplayValueAlignmentFactors,
-  VizOrientation,
 } from '@grafana/data';
 
 import { getFieldLinksSupplier } from 'app/features/panel/panellinks/linkSuppliers';
@@ -97,23 +96,9 @@ export class StatPanel extends PureComponent<PanelProps<StatPanelOptions>> {
         height={height}
         source={data}
         renderCounter={renderCounter}
-        orientation={getOrientation(width, height, options.orientation)}
+        autoGrid={true}
+        orientation={options.orientation}
       />
     );
   }
 }
-
-/**
- * Stat panel custom auto orientation
- */
-function getOrientation(width: number, height: number, orientation: VizOrientation): VizOrientation {
-  if (orientation !== VizOrientation.Auto) {
-    return orientation;
-  }
-
-  if (width / height > 2) {
-    return VizOrientation.Vertical;
-  } else {
-    return VizOrientation.Horizontal;
-  }
-}