Reland ProgramExplorer (#3448)

This reverts commit fcaf954.

Author: bkonyi

packages/devtools_app/lib/devtools_app.dart

@@ -12,6 +12,7 @@ export 'src/common_widgets.dart';
 export 'src/connected_app.dart';
 export 'src/console_service.dart';
 export 'src/debugger/debugger_controller.dart';
+export 'src/debugger/program_explorer_controller.dart';
 export 'src/debugger/span_parser.dart';
 export 'src/debugger/syntax_highlighter.dart';
 export 'src/error_badge_manager.dart';

packages/devtools_app/lib/src/common_widgets.dart

@@ -675,6 +675,7 @@ class AreaPaneHeader extends StatelessWidget implements PreferredSizeWidget {
     this.needsLeftBorder = false,
     this.leftActions = const [],
     this.rightActions = const [],
+    this.leftPadding = defaultSpacing,
     this.rightPadding = densePadding,
     this.tall = false,
   }) : super(key: key);
@@ -686,6 +687,7 @@ class AreaPaneHeader extends StatelessWidget implements PreferredSizeWidget {
   final bool needsLeftBorder;
   final List<Widget> leftActions;
   final List<Widget> rightActions;
+  final double leftPadding;
   final double rightPadding;
   final bool tall;
 
@@ -704,7 +706,7 @@ class AreaPaneHeader extends StatelessWidget implements PreferredSizeWidget {
           ),
           color: theme.titleSolidBackgroundColor,
         ),
-        padding: EdgeInsets.only(left: defaultSpacing, right: rightPadding),
+        padding: EdgeInsets.only(left: leftPadding, right: rightPadding),
         alignment: Alignment.centerLeft,
         child: Row(
           children: [

packages/devtools_app/lib/src/debugger/codeview.dart

@@ -42,6 +42,7 @@ class CodeView extends StatefulWidget {
   const CodeView({
     Key key,
     this.controller,
+    this.initialPosition,
     this.scriptRef,
     this.parsedScript,
     this.onSelected,
@@ -57,6 +58,7 @@ class CodeView extends StatefulWidget {
   static double get assumedCharacterWidth => scaleByFontFactor(16.0);
 
   final DebuggerController controller;
+  final ScriptLocation initialPosition;
   final ScriptRef scriptRef;
   final ParsedScript parsedScript;
 
@@ -80,6 +82,10 @@ class _CodeViewState extends State<CodeView>
 
   ParsedScript get parsedScript => widget.parsedScript;
 
+  // Used to ensure we don't update the scroll position when expanding or
+  // collapsing the file explorer.
+  ScriptRef _lastScriptRef;
+
   @override
   void initState() {
     super.initState();
@@ -88,6 +94,16 @@ class _CodeViewState extends State<CodeView>
     gutterController = verticalController.addAndGet();
     textController = verticalController.addAndGet();
     horizontalController = ScrollController();
+    _lastScriptRef = widget.scriptRef;
+
+    if (widget.initialPosition != null) {
+      final location = widget.initialPosition.location;
+      // Lines are 1-indexed. Scrolling to line 1 required a scroll position of
+      // 0.
+      final lineIndex = location.line - 1;
+      final scrollPosition = lineIndex * CodeView.rowHeight;
+      verticalController.jumpTo(scrollPosition);
+    }
 
     addAutoDisposeListener(
       widget.controller.scriptLocation,
@@ -124,12 +140,8 @@ class _CodeViewState extends State<CodeView>
   }
 
   void _updateScrollPosition({bool animate = true}) {
-    if (widget.controller.scriptLocation.value?.scriptRef != scriptRef) {
-      return;
-    }
-
-    final location = widget.controller.scriptLocation.value?.location;
-    if (location?.line == null) {
+    if (widget.controller.scriptLocation.value?.scriptRef?.uri !=
+        scriptRef?.uri) {
       return;
     }
 
@@ -138,17 +150,37 @@ class _CodeViewState extends State<CodeView>
       log('LinkedScrollControllerGroup has no attached controllers');
       return;
     }
+    final location = widget.controller.scriptLocation.value?.location;
+    if (location?.line == null) {
+      // Don't scroll to top if we're just rebuilding the code view for the
+      // same script.
+      if (_lastScriptRef?.uri != scriptRef?.uri) {
+        // Default to scrolling to the top of the script.
+        if (animate) {
+          verticalController.animateTo(
+            0,
+            duration: longDuration,
+            curve: defaultCurve,
+          );
+        } else {
+          verticalController.jumpTo(0);
+        }
+        _lastScriptRef = scriptRef;
+      }
+      return;
+    }
 
     final position = verticalController.position;
     final extent = position.extentInside;
 
     // TODO(devoncarew): Adjust this so we don't scroll if we're already in the
     // middle third of the screen.
     if (parsedScript.lineCount * CodeView.rowHeight > extent) {
-      // Scroll to the middle of the screen.
       final lineIndex = location.line - 1;
-      final scrollPosition =
-          lineIndex * CodeView.rowHeight - (extent - CodeView.rowHeight) / 2;
+      final scrollPosition = lineIndex * CodeView.rowHeight -
+          (widget.controller.shouldCenterScrollLocation
+              ? ((extent - CodeView.rowHeight) / 2)
+              : 0);
       if (animate) {
         verticalController.animateTo(
           scrollPosition,
@@ -159,6 +191,7 @@ class _CodeViewState extends State<CodeView>
         verticalController.jumpTo(scrollPosition);
       }
     }
+    _lastScriptRef = scriptRef;
   }
 
   void _onPressed(int line) {
@@ -644,7 +677,7 @@ class _LinesState extends State<Lines> with AutoDisposeMixin {
 
         if (isOutOfViewTop || isOutOfViewBottom) {
           // Scroll this search token to the middle of the view.
-          final targetOffset = math.max(
+          final targetOffset = math.max<double>(
             activeSearch.position.line * CodeView.rowHeight - widget.height / 2,
             0.0,
           );

packages/devtools_app/lib/src/debugger/controls.dart

@@ -12,7 +12,6 @@ import '../common_widgets.dart';
 import '../theme.dart';
 import '../ui/label.dart';
 import 'debugger_controller.dart';
-import 'scripts.dart';
 
 class DebuggingControls extends StatefulWidget {
   const DebuggingControls({Key key}) : super(key: key);
@@ -118,13 +117,14 @@ class _DebuggingControlsState extends State<DebuggingControls>
 
   Widget _librariesButton() {
     return ValueListenableBuilder(
-      valueListenable: controller.librariesVisible,
+      valueListenable: controller.fileExplorerVisible,
       builder: (context, visible, _) {
+        const libraryIcon = Icons.insert_chart;
         return RoundedOutlinedBorder(
           child: Container(
             color: visible ? Theme.of(context).highlightColor : null,
             child: DebuggerButton(
-              title: 'Libraries',
+              title: 'File Explorer',
               icon: libraryIcon,
               onPressed: controller.toggleLibrariesVisible,
             ),

packages/devtools_app/lib/src/debugger/debugger_controller.dart

@@ -19,6 +19,7 @@ import '../ui/search.dart';
 import '../utils.dart';
 import '../vm_service_wrapper.dart';
 import 'debugger_model.dart';
+import 'program_explorer_controller.dart';
 import 'syntax_highlighter.dart';
 
 // TODO(devoncarew): Add some delayed resume value notifiers (to be used to
@@ -33,12 +34,23 @@ class DebuggerController extends DisposableController
   // `initialSwitchToIsolate` can be set to false for tests to skip the logic
   // in `switchToIsolate`.
   DebuggerController({this.initialSwitchToIsolate = true}) {
+    _programExplorerController = ProgramExplorerController(
+      debuggerController: this,
+    );
     autoDispose(serviceManager.onConnectionAvailable
         .listen(_handleConnectionAvailable));
     _scriptHistoryListener = () {
       _showScriptLocation(ScriptLocation(scriptsHistory.current.value));
     };
     scriptsHistory.current.addListener(_scriptHistoryListener);
+    addAutoDisposeListener(currentScriptRef, () {
+      if (!programExplorerController.initialized.value) {
+        programExplorerController.initialize();
+      }
+      if (currentScriptRef.value != null) {
+        programExplorerController.selectScriptNode(currentScriptRef.value);
+      }
+    });
 
     if (_service != null) {
       initialize();
@@ -119,6 +131,10 @@ class DebuggerController extends DisposableController
   Map<LibraryRef, Future<Set<String>>>
       libraryMemberAndImportsAutocompleteCache = {};
 
+  ProgramExplorerController get programExplorerController =>
+      _programExplorerController;
+  ProgramExplorerController _programExplorerController;
+
   final ScriptCache _scriptCache = ScriptCache();
 
   final ScriptsHistory scriptsHistory = ScriptsHistory();
@@ -160,8 +176,11 @@ class DebuggerController extends DisposableController
   final _showFileOpener = ValueNotifier<bool>(false);
 
   /// Jump to the given ScriptRef and optional SourcePosition.
-  void showScriptLocation(ScriptLocation scriptLocation) {
-    _showScriptLocation(scriptLocation);
+  void showScriptLocation(
+    ScriptLocation scriptLocation, {
+    bool centerLocation = true,
+  }) {
+    _showScriptLocation(scriptLocation, centerLocation: centerLocation);
 
     // Update the scripts history (and make sure we don't react to the
     // subsequent event).
@@ -172,7 +191,11 @@ class DebuggerController extends DisposableController
 
   /// Show the given script location (without updating the script navigation
   /// history).
-  void _showScriptLocation(ScriptLocation scriptLocation) {
+  void _showScriptLocation(
+    ScriptLocation scriptLocation, {
+    bool centerLocation = true,
+  }) {
+    _shouldCenterScrollLocation = centerLocation;
     _currentScriptRef.value = scriptLocation?.scriptRef;
 
     _parseCurrentScript();
@@ -281,6 +304,9 @@ class DebuggerController extends DisposableController
   /// Return the sorted list of ScriptRefs active in the current isolate.
   ValueListenable<List<ScriptRef>> get sortedScripts => _sortedScripts;
 
+  bool get shouldCenterScrollLocation => _shouldCenterScrollLocation;
+  bool _shouldCenterScrollLocation = true;
+
   final _breakpoints = ValueNotifier<List<Breakpoint>>([]);
 
   ValueListenable<List<Breakpoint>> get breakpoints => _breakpoints;
@@ -303,7 +329,7 @@ class DebuggerController extends DisposableController
 
   final _librariesVisible = ValueNotifier(false);
 
-  ValueListenable<bool> get librariesVisible => _librariesVisible;
+  ValueListenable<bool> get fileExplorerVisible => _librariesVisible;
 
   /// Make the 'Libraries' view on the right-hand side of the screen visible or
   /// hidden.
@@ -607,7 +633,6 @@ class DebuggerController extends DisposableController
 
   void _handleIsolateEvent(Event event) {
     if (event.isolate.id != isolateRef?.id) return;
-
     switch (event.kind) {
       case EventKind.kIsolateReload:
         _updateAfterIsolateReload(event);
@@ -862,25 +887,12 @@ class DebuggerController extends DisposableController
     _populateScriptAndShowLocation(mainScriptRef);
   }
 
-  SourcePosition calculatePosition(Script script, int tokenPos) {
-    final List<List<int>> table = script.tokenPosTable;
-    if (table == null) {
-      return null;
-    }
-
-    return SourcePosition(
-      line: script.getLineNumberFromTokenPos(tokenPos),
-      column: script.getColumnNumberFromTokenPos(tokenPos),
-      tokenPos: tokenPos,
-    );
-  }
-
   Future<BreakpointAndSourcePosition> _createBreakpointWithLocation(
       Breakpoint breakpoint) async {
     if (breakpoint.resolved) {
       final bp = BreakpointAndSourcePosition.create(breakpoint);
       return getScript(bp.scriptRef).then((Script script) {
-        final pos = calculatePosition(script, bp.tokenPos);
+        final pos = SourcePosition.calculatePosition(script, bp.tokenPos);
         return BreakpointAndSourcePosition.create(breakpoint, pos);
       });
     } else {
@@ -897,7 +909,8 @@ class DebuggerController extends DisposableController
     }
 
     final script = await getScript(location.script);
-    final position = calculatePosition(script, location.tokenPos);
+    final position =
+        SourcePosition.calculatePosition(script, location.tokenPos);
     return StackFrameAndSourcePosition(frame, position: position);
   }
 
@@ -1002,7 +1015,7 @@ class DebuggerController extends DisposableController
     for (SourceReportRange range in report.ranges) {
       if (range.possibleBreakpoints != null) {
         for (int tokenPos in range.possibleBreakpoints) {
-          positions.add(calculatePosition(script, tokenPos));
+          positions.add(SourcePosition.calculatePosition(script, tokenPos));
         }
       }
     }

packages/devtools_app/lib/src/debugger/debugger_model.dart

@@ -93,10 +93,27 @@ class ScriptLocation {
   String toString() => '${scriptRef.uri} $location';
 }
 
-/// A line, column, and an optional tokenPos.
 class SourcePosition {
-  SourcePosition({@required this.line, @required this.column, this.tokenPos});
+  const SourcePosition({
+    @required this.line,
+    @required this.column,
+    this.file,
+    this.tokenPos,
+  });
+
+  factory SourcePosition.calculatePosition(Script script, int tokenPos) {
+    if (script.tokenPosTable == null) {
+      return null;
+    }
+
+    return SourcePosition(
+      line: script.getLineNumberFromTokenPos(tokenPos),
+      column: script.getColumnNumberFromTokenPos(tokenPos),
+      tokenPos: tokenPos,
+    );
+  }
 
+  final String file;
   final int line;
   final int column;
   final int tokenPos;