feat(ios): add keep-alive setting prop to list item (experimental)

renderer/native/ios/renderer/component/listview/HippyNextBaseListItemView.h

@@ -26,8 +26,4 @@
 
 @interface HippyNextBaseListItemView : HippyView <ViewAppearStateProtocol>
 
-@property (nonatomic, strong) id type;
-@property (nonatomic, assign) BOOL isSticky;
-
-
 @end

renderer/native/ios/renderer/component/listview/HippyNextBaseListItemViewManager.m

@@ -23,24 +23,27 @@
 #import "HippyNextBaseListItemViewManager.h"
 #import "HippyNextBaseListItemView.h"
 #import "HippyShadowWaterfallItem.h"
+#import "HippyNextShadowListItem.h"
+
 
 @implementation HippyNextBaseListItemViewManager
 
 HIPPY_EXPORT_MODULE(ListViewItem)
 
 HIPPY_EXPORT_VIEW_PROPERTY(type, id)
-HIPPY_EXPORT_VIEW_PROPERTY(isSticky, BOOL)
 HIPPY_EXPORT_VIEW_PROPERTY(onAppear, HippyDirectEventBlock)
 HIPPY_EXPORT_VIEW_PROPERTY(onDisappear, HippyDirectEventBlock)
 HIPPY_EXPORT_VIEW_PROPERTY(onWillAppear, HippyDirectEventBlock)
 HIPPY_EXPORT_VIEW_PROPERTY(onWillDisappear, HippyDirectEventBlock)
+HIPPY_EXPORT_SHADOW_PROPERTY(sticky, BOOL)
+HIPPY_EXPORT_SHADOW_PROPERTY(keepAlive, BOOL)
 
 - (UIView *)view {
     return [[HippyNextBaseListItemView alloc] init];
 }
 
 - (HippyShadowView *)shadowView {
-    return [[HippyShadowWaterfallItem alloc] init];
+    return [[HippyNextShadowListItem alloc] init];
 }
 
 @end

renderer/native/ios/renderer/component/listview/HippyNextBaseListView.mm

@@ -33,6 +33,7 @@
 #import "UIView+Hippy.h"
 #import "UIView+Render.h"
 #import "HippyShadowListView.h"
+#import "HippyNextShadowListItem.h"
 
 static NSString *const kCellIdentifier = @"HippyListCellIdentifier";
 static NSString *const kSupplementaryIdentifier = @"HippySupplementaryIdentifier";
@@ -41,6 +42,7 @@
 @interface HippyNextBaseListView () <HippyRefreshDelegate> {
     BOOL _isInitialListReady;
     NSArray<UICollectionViewCell *> *_previousVisibleCells;
+    NSMutableArray<UIView *> *_keepAliveCellViews; // cellViews that marked keep-Alive
 }
 
 @end
@@ -265,17 +267,28 @@ - (void)collectionView:(UICollectionView *)collectionView
 
 - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
     HippyNextBaseListViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kCellIdentifier forIndexPath:indexPath];
-    HippyShadowView *shadowView = [self.dataSource cellForIndexPath:indexPath];
+    HippyNextShadowListItem *shadowView = (HippyNextShadowListItem *)[self.dataSource cellForIndexPath:indexPath];
 
     UIView *cellView = nil;
     UIView *cachedVisibleCellView = [_cachedWeakCellViews objectForKey:shadowView.hippyTag];
     if (cachedVisibleCellView) {
         cellView = cachedVisibleCellView;
+        // Remove keep-Alive cellView if needed
+        if ([_keepAliveCellViews containsObject:cachedVisibleCellView] && shadowView.keepAlive == NO) {
+            [_keepAliveCellViews removeObject:cachedVisibleCellView];
+        }
         HippyLogTrace(@"%@ 🟢 use cached visible cellView at {%ld - %ld} for %@",
                       self.hippyTag, indexPath.section, indexPath.row, shadowView.hippyTag);
     } else {
         cellView = [self.uiManager createViewForShadowListItem:shadowView];
         [_cachedWeakCellViews setObject:cellView forKey:shadowView.hippyTag];
+        // Add keep-Alive cellView to cache if needed
+        if (shadowView.keepAlive) {
+            if (!_keepAliveCellViews) {
+                _keepAliveCellViews = [NSMutableArray array];
+            }
+            [_keepAliveCellViews addObject:cellView];
+        }
         HippyLogTrace(@"%@ 🟡 create cellView at {%ld - %ld} for %@",
                       self.hippyTag, indexPath.section, indexPath.row, shadowView.hippyTag);
     }

renderer/native/ios/renderer/component/listview/HippyNextBaseListViewDataSource.m

@@ -24,10 +24,9 @@
 #import "HippyNextBaseListViewDataSource.h"
 #import "HippyShadowView.h"
 #import "HippyShadowListView.h"
+#import "HippyNextShadowListItem.h"
 
 
-static NSString * const kStickyCellPropKey = @"sticky";
-
 @interface HippyNextBaseListViewDataSource () {
     NSMutableArray *_shadowHeaderViews;
 }
@@ -42,9 +41,8 @@ - (void)setDataSource:(NSArray<HippyShadowView *> *)dataSource containBannerView
     NSMutableArray<HippyShadowView *> *shadowSectionCell = nil;
     BOOL isFirstIndex = YES;
     for (HippyShadowView *shadowView in dataSource) {
-        if ([self.itemViewName isEqualToString:shadowView.viewName]) {
-            NSNumber *sticky = shadowView.props[kStickyCellPropKey];
-            if ([sticky boolValue]) {
+        if ([shadowView isKindOfClass:HippyNextShadowListItem.class]) {
+            if (((HippyNextShadowListItem *)shadowView).isSticky) {
                 [shadowHeaders addObject:shadowView];
                 if (shadowSectionCell) {
                     [shadowCells addObject:shadowSectionCell];

renderer/native/ios/renderer/component/listview/HippyNextShadowListItem.h

@@ -0,0 +1,39 @@
+/*!
+ * iOS SDK
+ *
+ * Tencent is pleased to support the open source community by making
+ * Hippy available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company.
+ * All rights reserved.
+ *
+ * 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.
+ */
+
+
+#import "HippyShadowWaterfallItem.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/// ListView item's shadow view
+@interface HippyNextShadowListItem : HippyShadowWaterfallItem
+
+/// Whether item is stick to the top
+@property (nonatomic, assign, getter=isSticky) BOOL sticky;
+
+/// Memory management property that sets item to exist for the lifetime of listView
+@property (nonatomic, assign) BOOL keepAlive;
+
+@end
+
+NS_ASSUME_NONNULL_END

renderer/native/ios/renderer/component/listview/HippyNextShadowListItem.m

@@ -0,0 +1,27 @@
+/*!
+ * iOS SDK
+ *
+ * Tencent is pleased to support the open source community by making
+ * Hippy available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company.
+ * All rights reserved.
+ *
+ * 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.
+ */
+
+#import "HippyNextShadowListItem.h"
+
+@implementation HippyNextShadowListItem
+
+@end