From 4a92267d1dd073b246d9f2bf201dd0040166b00a Mon Sep 17 00:00:00 2001
From: Sebastian Franco <fransebas@google.com>
Date: Thu, 27 Oct 2022 16:42:24 -0700
Subject: [PATCH] Making code more readable by removing global variable used
 for optimizations

Using the stack was more efficient because it prevented the creation
of new rectangles but it makes the code harder to read and prone to
bugs if the global state of the stack of rectangles gets corrupted
in any way.

When this optimization was written in 2008 it was necessary but now I
don't think it would have a big impact. The stack size is on average
of 30 and the rectangles are only created when doing the reorder which
runs about once per second if the user moves the finger too quickly.

Bug: 188081026
Test: atest ReorderWidgets
Change-Id: I35d8ee8d92f01035e72fe5763a7de47f4b6a73de
---
 src/com/android/launcher3/CellLayout.java | 25 +----------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

diff --git a/src/com/android/launcher3/CellLayout.java b/src/com/android/launcher3/CellLayout.java
index e66d441912..bf63ec0c0a 100644
--- a/src/com/android/launcher3/CellLayout.java
+++ b/src/com/android/launcher3/CellLayout.java
@@ -402,7 +402,6 @@ public class CellLayout extends ViewGroup {
         mCountY = y;
         mOccupied = new GridOccupancy(mCountX, mCountY);
         mTmpOccupied = new GridOccupancy(mCountX, mCountY);
-        mTempRectStack.clear();
         mShortcutsAndWidgets.setCellDimensions(mCellWidth, mCellHeight, mCountX, mCountY,
                 mBorderSpace);
         requestLayout();
@@ -1247,21 +1246,6 @@ public class CellLayout extends ViewGroup {
                 result, resultSpan);
     }
 
-    private final Stack<Rect> mTempRectStack = new Stack<>();
-    private void lazyInitTempRectStack() {
-        if (mTempRectStack.isEmpty()) {
-            for (int i = 0; i < mCountX * mCountY; i++) {
-                mTempRectStack.push(new Rect());
-            }
-        }
-    }
-
-    private void recycleTempRects(Stack<Rect> used) {
-        while (!used.isEmpty()) {
-            mTempRectStack.push(used.pop());
-        }
-    }
-
     /**
      * Find a vacant area that will fit the given bounds nearest the requested
      * cell location. Uses Euclidean distance to score multiple vacant areas.
@@ -1281,8 +1265,6 @@ public class CellLayout extends ViewGroup {
      */
     private int[] findNearestArea(int relativeXPos, int relativeYPos, int minSpanX, int minSpanY,
             int spanX, int spanY, boolean ignoreOccupied, int[] result, int[] resultSpan) {
-        lazyInitTempRectStack();
-
         // For items with a spanX / spanY > 1, the passed in point (relativeXPos, relativeYPos)
         // corresponds to the center of the item, but we are searching based on the top-left cell,
         // so we translate the point over to correspond to the top-left.
@@ -1352,9 +1334,6 @@ public class CellLayout extends ViewGroup {
                         hitMaxY |= ySize >= spanY;
                         incX = !incX;
                     }
-                    incX = true;
-                    hitMaxX = xSize >= spanX;
-                    hitMaxY = ySize >= spanY;
                 }
                 final int[] cellXY = mTmpPoint;
                 cellToCenterPoint(x, y, cellXY);
@@ -1362,8 +1341,7 @@ public class CellLayout extends ViewGroup {
                 // We verify that the current rect is not a sub-rect of any of our previous
                 // candidates. In this case, the current rect is disqualified in favour of the
                 // containing rect.
-                Rect currentRect = mTempRectStack.pop();
-                currentRect.set(x, y, x + xSize, y + ySize);
+                Rect currentRect = new Rect(x, y, x + xSize, y + ySize);
                 boolean contained = false;
                 for (Rect r : validRegions) {
                     if (r.contains(currentRect)) {
@@ -1393,7 +1371,6 @@ public class CellLayout extends ViewGroup {
             bestXY[0] = -1;
             bestXY[1] = -1;
         }
-        recycleTempRects(validRegions);
         return bestXY;
     }