launcher: use scalable grid in 4x4

Many changes are required to make scalable displays work correctly on
foldables. This first one is making sure that the correct number of
columns is used when calculating the used width for scalable grid. The
spaces around the workspace are not final yet.

Bug: 191879424
Test: manual
Change-Id: Idc41ed004580f1f86d8f9595d005abc72301b1e3

src/com/android/launcher3/DeviceProfile.java

@@ -33,6 +33,7 @@ import android.graphics.Point;
 import android.graphics.PointF;
 import android.graphics.Rect;
 import android.util.DisplayMetrics;
+import android.util.Pair;
 import android.view.Surface;
 
 import com.android.launcher3.CellLayout.ContainerType;
@@ -576,8 +577,9 @@ public class DeviceProfile {
             // We scale to fit the cellWidth and cellHeight in the available space.
             // The benefit of scalable grids is that we can get consistent aspect ratios between
             // devices.
-            float usedWidth = (cellWidthPx * inv.numColumns)
-                    + (cellLayoutBorderSpacingPx * (inv.numColumns - 1))
+            int numColumns = isTwoPanels ? inv.numColumns * 2 : inv.numColumns;
+            float usedWidth = (cellWidthPx * numColumns)
+                    + (cellLayoutBorderSpacingPx * (numColumns - 1))
                     + (desiredWorkspaceLeftRightMarginPx * 2);
             // We do not subtract padding here, as we also scale the workspace padding if needed.
             scaleX = availableWidthPx / usedWidth;
@@ -638,8 +640,9 @@ public class DeviceProfile {
         setCellLayoutBorderSpacing((int) (cellLayoutBorderSpacingOriginalPx * scale));
 
         if (isScalableGrid) {
-            cellWidthPx = pxFromDp(inv.minCellWidth, mMetrics, scale);
-            cellHeightPx = pxFromDp(inv.minCellHeight, mMetrics, scale);
+            PointF minCellHeightAndWidth = getMinCellHeightAndWidth();
+            cellWidthPx = pxFromDp(minCellHeightAndWidth.x, mMetrics, scale);
+            cellHeightPx = pxFromDp(minCellHeightAndWidth.y, mMetrics, scale);
             int cellContentHeight = iconSizePx + iconDrawablePaddingPx
                     + Utilities.calculateTextHeight(iconTextSizePx);
             cellYPaddingPx = Math.max(0, cellHeightPx - cellContentHeight) / 2;
@@ -698,6 +701,28 @@ public class DeviceProfile {
         folderIconOffsetYPx = (iconSizePx - folderIconSizePx) / 2;
     }
 
+    /**
+     * Returns the minimum cell height and width as a pair.
+     */
+    private PointF getMinCellHeightAndWidth() {
+        PointF result = new PointF();
+
+        if (isTwoPanels) {
+            if (isLandscape) {
+                result.x = inv.twoPanelLandscapeMinCellWidthDps;
+                result.y = inv.twoPanelLandscapeMinCellHeightDps;
+            } else {
+                result.x = inv.twoPanelPortraitMinCellWidthDps;
+                result.y = inv.twoPanelPortraitMinCellHeightDps;
+            }
+        } else {
+            result.x = inv.minCellWidth;
+            result.y = inv.minCellHeight;
+        }
+
+        return result;
+    }
+
     private void updateAvailableFolderCellDimensions(Resources res) {
         updateFolderCellSize(1f, res);
 
@@ -781,17 +806,14 @@ public class DeviceProfile {
         if (result == null) {
             result = new Point();
         }
+
         // Since we are only concerned with the overall padding, layout direction does
         // not matter.
         Point padding = getTotalWorkspacePadding();
-        // availableWidthPx is the screen width of the device. In 2 panels mode, each panel should
-        // only have half of the screen width. In addition, there is only cellLayoutPadding in the
-        // left side of the left most panel and the right most side of the right panel. There is no
-        // cellLayoutPadding in the middle.
-        int screenWidthPx = isTwoPanels
-                ? availableWidthPx / 2 - padding.x - cellLayoutPaddingLeftRightPx
-                : availableWidthPx - padding.x - cellLayoutPaddingLeftRightPx * 2;
-        result.x = calculateCellWidth(screenWidthPx, cellLayoutBorderSpacingPx, inv.numColumns);
+
+        int numColumns = isTwoPanels ? inv.numColumns * 2 : inv.numColumns;
+        int screenWidthPx = availableWidthPx - padding.x;
+        result.x = calculateCellWidth(screenWidthPx, cellLayoutBorderSpacingPx, numColumns);
         result.y = calculateCellHeight(availableHeightPx - padding.y
                 - cellLayoutBottomPaddingPx, cellLayoutBorderSpacingPx, inv.numRows);
         return result;
@@ -1038,6 +1060,14 @@ public class DeviceProfile {
 
         writer.println(prefix + "\tinv.minCellWidth:" + inv.minCellWidth + "dp");
         writer.println(prefix + "\tinv.minCellHeight:" + inv.minCellHeight + "dp");
+        writer.println(prefix + "\tinv.twoPanelPortraitMinCellHeightDps:"
+                + inv.twoPanelPortraitMinCellHeightDps + "dp");
+        writer.println(prefix + "\tinv.twoPanelPortraitMinCellWidthDps:"
+                + inv.twoPanelPortraitMinCellWidthDps + "dp");
+        writer.println(prefix + "\tinv.twoPanelLandscapeMinCellHeightDps:"
+                + inv.twoPanelLandscapeMinCellHeightDps + "dp");
+        writer.println(prefix + "\tinv.twoPanelLandscapeMinCellWidthDps:"
+                + inv.twoPanelLandscapeMinCellWidthDps + "dp");
 
         writer.println(prefix + "\tinv.numColumns:" + inv.numColumns);
         writer.println(prefix + "\tinv.numRows:" + inv.numRows);