commit 55edfe55f78a702d34c12b2258e2850f7ec8bc4d
author Andras Kloczl <andraskloczl@google.com> Fri May 14 12:21:30 2021 +0200
committer Andras Kloczl <andraskloczl@google.com> Mon May 24 23:22:06 2021 +0200
tree 39aa998501624bf90b86096a72f98092f3639a10
parent f3649f5e9835fb8ae9a4e60cac464e6610c0a172

Add two panel home support for page binding logic

There's a logic which prioritizes the binding for the
current page and defers the other pages' binding.
If two panel home is enabled, we want to bind both pages
together. LauncherPageRestoreHelper has been created to
contain the logic for persisting restoring and calculating
which pages to load immediately.

Test: manual + run LauncherPageRestoreHelperTest robo test
Bug: 174464691
Change-Id: I57ac3f7150303b95b272e922f44bda26f9d5ce2a

src/com/android/launcher3/PagedView.java

diff --git a/src/com/android/launcher3/PagedView.java b/src/com/android/launcher3/PagedView.java
index b26a7ea..123ae6c 100644
--- a/src/com/android/launcher3/PagedView.java
+++ b/src/com/android/launcher3/PagedView.java
@@ -16,6 +16,7 @@
 
 package com.android.launcher3;
 
+import static androidx.annotation.VisibleForTesting.PACKAGE_PRIVATE;
 import static com.android.launcher3.anim.Interpolators.SCROLL;
 import static com.android.launcher3.compat.AccessibilityManagerCompat.isAccessibilityEnabled;
 import static com.android.launcher3.compat.AccessibilityManagerCompat.isObservedEventType;
@@ -48,6 +49,7 @@
 import android.widget.ScrollView;
 
 import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
 
 import com.android.launcher3.compat.AccessibilityManagerCompat;
 import com.android.launcher3.config.FeatureFlags;
@@ -55,6 +57,7 @@
 import com.android.launcher3.touch.PagedOrientationHandler;
 import com.android.launcher3.touch.PagedOrientationHandler.ChildBounds;
 import com.android.launcher3.util.EdgeEffectCompat;
+import com.android.launcher3.util.IntSet;
 import com.android.launcher3.util.Thunk;
 import com.android.launcher3.views.ActivityContext;
 
@@ -282,9 +285,15 @@
         return newPage;
     }
 
-    private int getLeftmostVisiblePageForIndex(int pageIndex) {
+    /**
+     * In most cases where panelCount is 1, this method will just return the page index that was
+     * passed in.
+     * But for example when two panel home is enabled we might need the leftmost visible page index
+     * because that page is the current page.
+     */
+    public int getLeftmostVisiblePageForIndex(int pageIndex) {
         int panelCount = getPanelCount();
-        return (pageIndex / panelCount) * panelCount;
+        return pageIndex - pageIndex % panelCount;
     }
 
     /**
@@ -295,16 +304,34 @@
     }
 
     /**
+     * Returns an IntSet with the indices of the currently visible pages
+     */
+    @VisibleForTesting(otherwise = PACKAGE_PRIVATE)
+    public IntSet getVisiblePageIndices() {
+        IntSet visiblePageIndices = new IntSet();
+        int panelCount = getPanelCount();
+        int pageCount = getPageCount();
+
+        // If a device goes from one panel to two panel (i.e. unfolding a foldable device) while
+        // an odd indexed page is the current page, then the new leftmost visible page will be
+        // different from the old mCurrentPage.
+        int currentPage = getLeftmostVisiblePageForIndex(mCurrentPage);
+        for (int page = currentPage; page < currentPage + panelCount && page < pageCount; page++) {
+            visiblePageIndices.add(page);
+        }
+        return visiblePageIndices;
+    }
+
+    /**
      * Executes the callback against each visible page
      */
     public void forEachVisiblePage(Consumer<View> callback) {
-        int panelCount = getPanelCount();
-        for (int i = mCurrentPage; i < mCurrentPage + panelCount; i++) {
-            View page = getPageAt(i);
+        getVisiblePageIndices().forEach(pageIndex -> {
+            View page = getPageAt(pageIndex);
             if (page != null) {
                 callback.accept(page);
             }
-        }
+        });
     }
 
     /**