improve the fill area algorithm

silevis · Oct 25, 2024 · b772fd4 · b772fd4
1 parent 6c2c228
commit b772fd4
Showing 1 changed file with 38 additions and 28 deletions.
diff --git a/reactgrid/lib/utils/getFillDirection.ts b/reactgrid/lib/utils/getFillDirection.ts
@@ -20,7 +20,7 @@ export const getFillDirection = (
 
   const currectFocusedCell = store.getCellByIndexes(store.focusedLocation.rowIndex, store.focusedLocation.colIndex);
 
-  if (pointerColIdx === -1) return undefined;
+  if (pointerRowIdx === -1 || pointerColIdx === -1) return undefined;
 
   const selectedArea = store.selectedArea;
 
@@ -35,31 +35,41 @@ export const getFillDirection = (
     cellArea = EMPTY_AREA;
   }
 
-  const differences: { direction: FillDirection; value: number | null }[] = [];
-
-  differences.push({ direction: "", value: null });
-
-  differences.push({
-    direction: "up",
-    value: pointerRowIdx < cellArea.startRowIdx ? pointerRowIdx : null,
-  });
-
-  differences.push({
-    direction: "down",
-    value: pointerRowIdx >= cellArea.endRowIdx ? pointerRowIdx : null,
-  });
-
-  differences.push({
-    direction: "left",
-    value: pointerColIdx < cellArea.startColIdx ? pointerColIdx : null,
-  });
-
-  differences.push({
-    direction: "right",
-    value: pointerColIdx >= cellArea.endColIdx ? pointerColIdx : null,
-  });
-
-  if (differences.every((diff) => diff.value === null)) return differences[0];
-
-  return differences.reduce((prev, current) => (current.value !== null ? current : prev));
+  const bottomDiff = pointerRowIdx >= cellArea.endRowIdx ? Math.abs(pointerRowIdx + 1 - cellArea.endRowIdx) : 0;
+  const topDiff = pointerRowIdx <= cellArea.startRowIdx ? Math.abs(pointerRowIdx - cellArea.startRowIdx) : 0;
+  const rightDiff = pointerColIdx >= cellArea.endColIdx ? Math.abs(pointerColIdx + 1 - cellArea.endColIdx) : 0;
+  const leftDiff = pointerColIdx <= cellArea.startColIdx ? Math.abs(pointerColIdx - cellArea.startColIdx) : 0;
+
+  if (pointerRowIdx >= cellArea.endRowIdx) {
+    if (bottomDiff >= rightDiff && bottomDiff >= leftDiff) {
+      return {
+        direction: "down",
+        value: pointerRowIdx,
+      };
+    }
+  }
+  if (pointerRowIdx <= cellArea.startRowIdx) {
+    if (topDiff >= rightDiff && topDiff >= leftDiff) {
+      return {
+        direction: "up",
+        value: pointerRowIdx,
+      };
+    }
+  }
+  if (pointerColIdx >= cellArea.endColIdx) {
+    if (rightDiff > topDiff && rightDiff > bottomDiff) {
+      return {
+        direction: "right",
+        value: pointerColIdx,
+      };
+    }
+  }
+  if (pointerColIdx <= cellArea.startColIdx) {
+    if (leftDiff > topDiff && leftDiff > bottomDiff) {
+      return {
+        direction: "left",
+        value: pointerColIdx,
+      };
+    }
+  }
 };