From 45107bc480ae52e5bb9b08dc88166da49a1211a3 Mon Sep 17 00:00:00 2001
From: Maja Grubic <maja.grubic@elastic.co>
Date: Fri, 5 Jun 2020 14:21:17 +0100
Subject: [PATCH] [Dashboard] Improve duplicate panel positioning (#67461)

* [Dashboard] Clone panel position

* Fixing inconsistencies in previous commit; removing readonly property of a grid

* Change sorting algorithm so that it sorts by the ending coordinates

* Always place panel to the bottom

* Fixing declaration error

* Add more comments

* Make GridData readonly
---
 .../panel/dashboard_panel_placement.ts        | 58 +++++++++++++++----
 1 file changed, 47 insertions(+), 11 deletions(-)

diff --git a/src/plugins/dashboard/public/application/embeddable/panel/dashboard_panel_placement.ts b/src/plugins/dashboard/public/application/embeddable/panel/dashboard_panel_placement.ts
index 62a39ee898d3a..1b060c186db97 100644
--- a/src/plugins/dashboard/public/application/embeddable/panel/dashboard_panel_placement.ts
+++ b/src/plugins/dashboard/public/application/embeddable/panel/dashboard_panel_placement.ts
@@ -108,16 +108,32 @@ interface IplacementDirection {
   fits: boolean;
 }
 
+/**
+ * Compare grid data by an ending y coordinate. Grid data with a smaller ending y coordinate
+ * comes first.
+ * @param a
+ * @param b
+ */
+function comparePanels(a: GridData, b: GridData): number {
+  if (a.y + a.h < b.y + b.h) {
+    return -1;
+  }
+  if (a.y + a.h > b.y + b.h) {
+    return 1;
+  }
+  // a.y === b.y
+  if (a.x + a.w <= b.x + b.w) {
+    return -1;
+  }
+  return 1;
+}
+
 export function placePanelBeside({
   width,
   height,
   currentPanels,
   placeBesideId,
 }: IPanelPlacementBesideArgs): Omit<GridData, 'i'> {
-  // const clonedPanels = _.cloneDeep(currentPanels);
-  if (!placeBesideId) {
-    throw new Error('Place beside method called without placeBesideId');
-  }
   const panelToPlaceBeside = currentPanels[placeBesideId];
   if (!panelToPlaceBeside) {
     throw new PanelNotFoundError();
@@ -130,10 +146,11 @@ export function placePanelBeside({
 
   const possiblePlacementDirections: IplacementDirection[] = [
     { grid: { x: beside.x + beside.w, y: beside.y, w: width, h: height }, fits: true }, // right
-    { grid: { x: beside.x - width, y: beside.y, w: width, h: height }, fits: true }, // left
+    { grid: { x: 0, y: beside.y + beside.h, w: width, h: height }, fits: true }, // left side of next row
     { grid: { x: beside.x, y: beside.y + beside.h, w: width, h: height }, fits: true }, // bottom
   ];
 
+  // first, we check if there is place around the current panel
   for (const direction of possiblePlacementDirections) {
     if (
       direction.grid.x >= 0 &&
@@ -156,13 +173,32 @@ export function placePanelBeside({
     }
   }
   // if we get here that means there is no blank space around the panel we are placing beside. This means it's time to mess up the dashboard's groove. Fun!
-  const [, , bottomPlacement] = possiblePlacementDirections;
-  for (const currentPanelGrid of otherPanels) {
-    if (bottomPlacement.grid.y <= currentPanelGrid.y) {
-      const movedPanel = _.cloneDeep(currentPanels[currentPanelGrid.i]);
-      movedPanel.gridData.y = movedPanel.gridData.y + bottomPlacement.grid.h;
-      currentPanels[currentPanelGrid.i] = movedPanel;
+  /**
+   * 1. sort the panels in the grid
+   * 2. place the cloned panel to the bottom
+   * 3. reposition the panels after the cloned panel in the grid
+   */
+  const grid = otherPanels.sort(comparePanels);
+
+  let position = 0;
+  for (position; position < grid.length; position++) {
+    if (beside.i === grid[position].i) {
+      break;
     }
   }
+  const bottomPlacement = possiblePlacementDirections[2];
+  // place to the bottom and move all other panels
+  let originalPositionInTheGrid = grid[position + 1].i;
+  const diff =
+    bottomPlacement.grid.y +
+    bottomPlacement.grid.h -
+    currentPanels[originalPositionInTheGrid].gridData.y;
+
+  for (let j = position + 1; j < grid.length; j++) {
+    originalPositionInTheGrid = grid[j].i;
+    const movedPanel = _.cloneDeep(currentPanels[originalPositionInTheGrid]);
+    movedPanel.gridData.y = movedPanel.gridData.y + diff;
+    currentPanels[originalPositionInTheGrid] = movedPanel;
+  }
   return bottomPlacement.grid;
 }