Decoupling the reorder logic from the CellLayout view

ReorderAlgorithm will now handle all the logic associated with the reorder. Basically all the logic associated with a reorder in CellLayout was copy and pasted into ReorderAlgorithm.java. Test: atest TestReorderAlgorithm Bug: 229292911 Change-Id: Ie096abc346bf705414e47452a42d1dec5be0a041
2022-12-27 14:50:02 -06:00
parent 8fd957e323
commit e4c0345747
4 changed files with 393 additions and 226 deletions
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.celllayout;
+
+import android.view.View;
+
+import com.android.launcher3.CellLayout;
+import com.android.launcher3.MultipageCellLayout;
+import com.android.launcher3.util.GridOccupancy;
+
+import java.util.function.Supplier;
+
+/**
+ * Variant of ReorderAlgorithm which simulates a foldable screen and adds a seam in the middle
+ * to prevent items to be placed in the middle.
+ */
+public class MulticellReorderAlgorithm extends ReorderAlgorithm {
+
+    private final View mSeam;
+
+    public MulticellReorderAlgorithm(CellLayout cellLayout) {
+        super(cellLayout);
+        mSeam = new View(cellLayout.getContext());
+    }
+
+    private CellLayout.ItemConfiguration removeSeamFromSolution(
+            CellLayout.ItemConfiguration solution) {
+        solution.map.forEach((view, cell) -> cell.cellX =
+                cell.cellX > mCellLayout.getCountX() / 2 ? cell.cellX - 1 : cell.cellX);
+        solution.cellX =
+                solution.cellX > mCellLayout.getCountX() / 2 ? solution.cellX - 1 : solution.cellX;
+        return solution;
+    }
+
+    @Override
+    public CellLayout.ItemConfiguration closestEmptySpaceReorder(int pixelX, int pixelY,
+            int minSpanX, int minSpanY,
+            int spanX, int spanY) {
+        return removeSeamFromSolution(simulateSeam(
+                () -> super.closestEmptySpaceReorder(pixelX, pixelY, minSpanX, minSpanY, spanX,
+                        spanY)));
+    }
+
+    @Override
+    public CellLayout.ItemConfiguration findReorderSolution(int pixelX, int pixelY, int minSpanX,
+            int minSpanY, int spanX, int spanY, int[] direction, View dragView, boolean decX,
+            CellLayout.ItemConfiguration solution) {
+        return removeSeamFromSolution(simulateSeam(
+                () -> super.findReorderSolution(pixelX, pixelY, minSpanX, minSpanY, spanX, spanY,
+                        direction, dragView, decX, solution)));
+    }
+
+    @Override
+    public CellLayout.ItemConfiguration dropInPlaceSolution(int pixelX, int pixelY, int spanX,
+            int spanY,
+            View dragView) {
+        return removeSeamFromSolution(simulateSeam(
+                () -> super.dropInPlaceSolution(pixelX, pixelY, spanX, spanY, dragView)));
+    }
+
+    void addSeam() {
+        MultipageCellLayout mcl = (MultipageCellLayout) mCellLayout;
+        mcl.setSeamWasAdded(true);
+        CellLayoutLayoutParams lp = new CellLayoutLayoutParams(mcl.getCountX() / 2, 0, 1,
+                mcl.getCountY());
+        lp.canReorder = false;
+        mcl.setCountX(mcl.getCountX() + 1);
+        mcl.getShortcutsAndWidgets().addViewInLayout(mSeam, lp);
+        mcl.setOccupied(createGridOccupancyWithSeam(mcl.getOccupied()));
+        mcl.mTmpOccupied = new GridOccupancy(mcl.getCountX(), mcl.getCountY());
+    }
+
+    void removeSeam() {
+        MultipageCellLayout mcl = (MultipageCellLayout) mCellLayout;
+        mcl.setCountX(mcl.getCountX() - 1);
+        mcl.getShortcutsAndWidgets().removeViewInLayout(mSeam);
+        mcl.mTmpOccupied = new GridOccupancy(mcl.getCountX(), mcl.getCountY());
+        mcl.setSeamWasAdded(false);
+    }
+
+    /**
+     * The function supplied here will execute while the CellLayout has a simulated seam added.
+     * @param f function to run under simulation
+     * @param <T> return value of the supplied function
+     * @return Value of supplied function
+     */
+    public <T> T simulateSeam(Supplier<T> f) {
+        MultipageCellLayout mcl = (MultipageCellLayout) mCellLayout;
+        if (mcl.isSeamWasAdded()) {
+            return f.get();
+        }
+        GridOccupancy auxGrid = mcl.getOccupied();
+        addSeam();
+        T res = f.get();
+        removeSeam();
+        mcl.setOccupied(auxGrid);
+        return res;
+    }
+
+    GridOccupancy createGridOccupancyWithSeam(GridOccupancy gridOccupancy) {
+        GridOccupancy grid = new GridOccupancy(mCellLayout.getCountX(), mCellLayout.getCountY());
+        for (int x = 0; x < mCellLayout.getCountX(); x++) {
+            for (int y = 0; y < mCellLayout.getCountY(); y++) {
+                int offset = x >= mCellLayout.getCountX() / 2 ? 1 : 0;
+                if (x == mCellLayout.getCountX() / 2) {
+                    grid.cells[x][y] = true;
+                } else {
+                    grid.cells[x][y] = gridOccupancy.cells[x - offset][y];
+                }
+            }
+        }
+        return grid;
+    }
+}