Add details to diff. (flutter#4549)

Author: polina-c

.gitignore

@@ -27,3 +27,4 @@ Podfile.lock
 **/build/
 packages/devtools_test/lib/src/mocks/generated.mocks.dart
 **/*.stager_app.dart
+**/test/**/failures/

packages/devtools_app/lib/src/primitives/utils.dart

@@ -1319,6 +1319,15 @@ class ListValueNotifier<T> extends ChangeNotifier
     _rawList.removeRange(start, end);
     _listChanged();
   }
+
+  /// Removes the object at position `index` from this list.
+  ///
+  /// https://api.flutter.dev/flutter/dart-core/List/removeAt.html
+  void removeAt(int index) {
+    _rawList = _rawList.toList();
+    _rawList.removeAt(index);
+    _listChanged();
+  }
 }
 
 /// Wrapper for a list that prevents any modification of the list's content.
@@ -1505,3 +1514,24 @@ bool isPrimativeInstanceKind(String? kind) {
 /// Returns the file name from a URI or path string, by splitting the [uri] at
 /// the directory separators '/', and returning the last element.
 String? fileNameFromUri(String? uri) => uri?.split('/').last;
+
+/// Calculates subtraction of two maps.
+///
+/// Result map keys is union of the imput maps' keys.
+Map<K, R> subtractMaps<K, F, S, R>({
+  required Map<K, S>? substract,
+  required Map<K, F>? from,
+  required R? Function({required S? subtract, required F? from}) subtractor,
+}) {
+  from ??= <K, F>{};
+  substract ??= <K, S>{};
+
+  final result = <K, R>{};
+  final unionOfKeys = from.keys.toSet().union(substract.keys.toSet());
+
+  for (var key in unionOfKeys) {
+    final diff = subtractor(from: from[key], subtract: substract[key]);
+    if (diff != null) result[key] = diff;
+  }
+  return result;
+}

packages/devtools_app/lib/src/screens/memory/memory_heap_tree_view.dart

@@ -440,69 +440,66 @@ class _HeapTreeViewState extends State<HeapTreeView>
       snapshotDisplay = null;
     }
 
-    return Padding(
-      padding: const EdgeInsets.only(top: denseRowSpacing),
-      child: Column(
-        children: [
-          const SizedBox(height: defaultSpacing),
-          ValueListenableBuilder<int>(
-            valueListenable: _currentTab,
-            builder: (context, index, _) => Row(
-              mainAxisAlignment: MainAxisAlignment.spaceBetween,
-              children: [
-                TabBar(
-                  labelColor: themeData.textTheme.bodyLarge!.color,
-                  isScrollable: true,
-                  controller: _tabController,
-                  tabs: _tabs,
-                ),
-                if (_searchableTabs.contains(_tabs[index].key))
-                  _buildSearchFilterControls(),
-              ],
-            ),
+    return Column(
+      children: [
+        const SizedBox(height: defaultSpacing),
+        ValueListenableBuilder<int>(
+          valueListenable: _currentTab,
+          builder: (context, index, _) => Row(
+            mainAxisAlignment: MainAxisAlignment.spaceBetween,
+            children: [
+              TabBar(
+                labelColor: themeData.textTheme.bodyLarge!.color,
+                isScrollable: true,
+                controller: _tabController,
+                tabs: _tabs,
+              ),
+              if (_searchableTabs.contains(_tabs[index].key))
+                _buildSearchFilterControls(),
+            ],
           ),
-          const Divider(),
-          Expanded(
-            child: TabBarView(
-              physics: defaultTabBarViewPhysics,
-              controller: _tabController,
-              children: [
-                // Profile Tab
-                KeepAliveWrapper(
-                  child: AllocationProfileTableView(
-                    controller: controller.allocationProfileController,
-                  ),
+        ),
+        const Divider(),
+        Expanded(
+          child: TabBarView(
+            physics: defaultTabBarViewPhysics,
+            controller: _tabController,
+            children: [
+              // Profile Tab
+              KeepAliveWrapper(
+                child: AllocationProfileTableView(
+                  controller: controller.allocationProfileController,
                 ),
-                const KeepAliveWrapper(
-                  child: AllocationProfileTracingView(),
+              ),
+              const KeepAliveWrapper(
+                child: AllocationProfileTracingView(),
+              ),
+              // Analysis Tab
+              KeepAliveWrapper(
+                child: Column(
+                  children: [
+                    _buildSnapshotControls(themeData.textTheme),
+                    const SizedBox(height: denseRowSpacing),
+                    Expanded(
+                      child: buildSnapshotTables(snapshotDisplay),
+                    ),
+                  ],
                 ),
-                // Analysis Tab
+              ),
+              // Diff tab.
+              if (FeatureFlags.memoryDiffing)
                 KeepAliveWrapper(
-                  child: Column(
-                    children: [
-                      _buildSnapshotControls(themeData.textTheme),
-                      const SizedBox(height: denseRowSpacing),
-                      Expanded(
-                        child: buildSnapshotTables(snapshotDisplay),
-                      ),
-                    ],
+                  child: DiffPane(
+                    diffController: controller.diffPaneController,
                   ),
                 ),
-                // Diff tab.
-                if (FeatureFlags.memoryDiffing)
-                  KeepAliveWrapper(
-                    child: DiffPane(
-                      controller: controller.diffPaneController,
-                    ),
-                  ),
-                // Leaks tab.
-                if (controller.shouldShowLeaksTab.value)
-                  const KeepAliveWrapper(child: LeaksPane()),
-              ],
-            ),
+              // Leaks tab.
+              if (controller.shouldShowLeaksTab.value)
+                const KeepAliveWrapper(child: LeaksPane()),
+            ],
           ),
-        ],
-      ),
+        ),
+      ],
     );
   }
 

packages/devtools_app/lib/src/screens/memory/panes/allocation_profile/allocation_profile_table_view.dart

@@ -369,9 +369,8 @@ class _ExportAllocationProfileButton extends StatelessWidget {
     return ValueListenableBuilder<AllocationProfile?>(
       valueListenable: allocationProfileController.currentAllocationProfile,
       builder: (context, currentAllocationProfile, _) {
-        return IconLabelButton(
-          label: 'CSV',
-          icon: Icons.file_download,
+        return ToCsvButton(
+          minScreenWidthForTextBeforeScaling: primaryControlsMinVerboseWidth,
           tooltip: 'Download allocation profile data in CSV format',
           onPressed: currentAllocationProfile == null
               ? null
@@ -380,7 +379,6 @@ class _ExportAllocationProfileButton extends StatelessWidget {
                       .downloadMemoryTableCsv(currentAllocationProfile);
                   notificationService.push(successfulExportMessage(file));
                 },
-          minScreenWidthForTextBeforeScaling: primaryControlsMinVerboseWidth,
         );
       },
     );

packages/devtools_app/lib/src/screens/memory/panes/allocation_tracing/allocation_profile_tracing_view_controller.dart

@@ -126,7 +126,7 @@ class AllocationProfileTracingIsolateState {
 
   void updateClassFilter(String value, {bool force = false}) {
     if (value.isEmpty && _currentFilter.isEmpty && !force) return;
-    final updatedFilter = (value.contains(_currentFilter) && !force
+    final updatedFilteredClassList = (value.contains(_currentFilter) && !force
             ? _filteredClassList.value
             : unfilteredClassList)
         .where(
@@ -135,7 +135,7 @@ class AllocationProfileTracingIsolateState {
         .map((e) => tracedClasses[e.cls.id!]!)
         .toList();
 
-    _filteredClassList.replaceAll(updatedFilter);
+    _filteredClassList.replaceAll(updatedFilteredClassList);
     _currentFilter = value;
   }