account for changed itineraries once landmarks are marked as done or deleted

frontend/lib/modules/current_trip_landmarks_list.dart

@@ -1,3 +1,5 @@
+import 'dart:developer';
+
 import 'package:flutter/material.dart';
 
 import 'package:anyway/structs/landmark.dart';
@@ -24,10 +26,16 @@ List<Widget> landmarksList(Trip trip, {required bool Function(Landmark) selector
         LandmarkCard(landmark, trip),
       );
 
-      if (!landmark.visited && landmark.next != null) {
-        children.add(
-          StepBetweenLandmarks(current: landmark, next: landmark.next!)
-        );
+      if (!landmark.visited) {
+        Landmark? nextLandmark = landmark.next;
+        while (nextLandmark != null && nextLandmark.visited) {
+          nextLandmark = nextLandmark.next;
+        } 
+        if (nextLandmark != null) {
+          children.add(
+            StepBetweenLandmarks(current: landmark, next: nextLandmark!)
+          );
+        }
       }
     }
   }

frontend/lib/modules/current_trip_loading_indicator.dart

@@ -1,4 +1,5 @@
-import 'package:anyway/constants.dart';
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:auto_size_text/auto_size_text.dart';
 
@@ -37,7 +38,10 @@ class _CurrentTripLoadingIndicatorState extends State<CurrentTripLoadingIndicato
       // As a gimmick, and a way to show that the app is still working, show a few loading dots
       const Align(
         alignment: Alignment.bottomCenter,
-        child: StatusText(),
+        child: Padding(
+          padding: EdgeInsets.only(bottom: 12),
+          child: StatusText(),
+        )
       )
     ],
   );
@@ -81,19 +85,19 @@ Widget loadingText(Trip trip) => FutureBuilder(
     Widget greeter;
 
     if (snapshot.hasData) {
-      greeter = AnimatedGradientText(
-        text: 'Creating your trip to ${snapshot.data}...',
+      greeter = AnimatedDotsText(
+        baseText: 'Creating your trip to ${snapshot.data}',
         style: greeterStyle,
       );
     } else if (snapshot.hasError) {
       // the exact error is shown in the central part of the trip overview. No need to show it here
-      greeter = AnimatedGradientText(
-        text: 'Error while loading trip.',
+      greeter = Text(
+        'Error while loading trip.',
         style: greeterStyle,
       );
     } else {
-      greeter = AnimatedGradientText(
-        text: 'Creating your trip...',
+      greeter = AnimatedDotsText(
+        baseText: 'Creating your trip',
         style: greeterStyle,
       );
     }
@@ -101,61 +105,44 @@ Widget loadingText(Trip trip) => FutureBuilder(
   }
 );
 
-class AnimatedGradientText extends StatefulWidget {
-  final String text;
+class AnimatedDotsText extends StatefulWidget {
+  final String baseText;
   final TextStyle style;
 
-  const AnimatedGradientText({
+  const AnimatedDotsText({
     Key? key,
-    required this.text,
+    required this.baseText,
     required this.style,
   }) : super(key: key);
 
   @override
-  _AnimatedGradientTextState createState() => _AnimatedGradientTextState();
+  _AnimatedDotsTextState createState() => _AnimatedDotsTextState();
 }
 
-class _AnimatedGradientTextState extends State<AnimatedGradientText> with SingleTickerProviderStateMixin {
-  late AnimationController _controller;
+class _AnimatedDotsTextState extends State<AnimatedDotsText> {
+  int dotCount = 0;
 
   @override
   void initState() {
     super.initState();
-    _controller = AnimationController(
-      duration: const Duration(seconds: 1),
-      vsync: this,
-    )..repeat();
-  }
-
-  @override
-  void dispose() {
-    _controller.dispose();
-    super.dispose();
+    Timer.periodic(const Duration(seconds: 1), (timer) {
+      if (mounted) {
+        setState(() {
+          dotCount = (dotCount + 1) % 4;
+          // show up to 3 dots
+        });
+      } else {
+        timer.cancel();
+      }
+    });
   }
 
   @override
   Widget build(BuildContext context) {
-    return AnimatedBuilder(
-      animation: _controller,
-      builder: (context, child) {
-        return ShaderMask(
-          shaderCallback: (bounds) {
-            return LinearGradient(
-              colors: [GRADIENT_START, GRADIENT_END, GRADIENT_START],
-              stops: [
-                _controller.value - 1.0,
-                _controller.value,
-                _controller.value + 1.0,
-              ],
-              tileMode: TileMode.mirror,
-            ).createShader(bounds);
-          },
-          child: Text(
-            widget.text,
-            style: widget.style,
-          ),
-        );
-      },
+    String dots = '.' * dotCount;
+    return Text(
+      '${widget.baseText}$dots',
+      style: widget.style,
     );
   }
 }

frontend/lib/modules/landmark_card.dart

@@ -47,32 +47,20 @@ class _LandmarkCardState extends State<LandmarkCard> {
             AspectRatio(
               aspectRatio: 3 / 4,
               child: Column(
+                crossAxisAlignment: CrossAxisAlignment.stretch,
                 children: [
                   if (widget.landmark.imageURL != null && widget.landmark.imageURL!.isNotEmpty)
                     Expanded(
                       child: CachedNetworkImage(
                         imageUrl: widget.landmark.imageURL!,
-                        placeholder: (context, url) => Center(child: CircularProgressIndicator()),
-                        errorWidget: (context, error, stackTrace) => Icon(Icons.question_mark_outlined),
-                        fit: BoxFit.cover,
+                        placeholder: (context, url) => const Center(child: CircularProgressIndicator()),
+                        errorWidget: (context, url, error) => imagePlaceholder(widget.landmark),
+                        fit: BoxFit.cover
                       )
                     )
                   else
-                    Expanded(
-                      child: 
-                      Container(
-                        decoration: BoxDecoration(
-                          gradient: LinearGradient(
-                            begin: Alignment.topLeft,
-                            end: Alignment.bottomRight,
-                            colors: [GRADIENT_START, GRADIENT_END],
-                          ),
-                        ),
-                        child: Center(
-                          child: Icon(widget.landmark.type.icon.icon, size: 50),
-                        ),
-                      ),
-                    ),
+                    imagePlaceholder(widget.landmark),
+
                   if (widget.landmark.type != typeStart && widget.landmark.type != typeFinish)
                     Container(
                       color: PRIMARY_COLOR,
@@ -96,47 +84,54 @@ class _LandmarkCardState extends State<LandmarkCard> {
 
             // Main information, useful buttons on the right
             Expanded(
-              child: Padding(
-                padding: const EdgeInsets.all(10),
-                child: Column(
-                  crossAxisAlignment: CrossAxisAlignment.start,
-                  children: [
-                    Text(
-                      widget.landmark.name,
-                      style: Theme.of(context).textTheme.titleMedium,
-                      overflow: TextOverflow.ellipsis,
-                      maxLines: 2,
-                    ),
-                      
-                    if (widget.landmark.nameEN != null)
-                      Text(
-                        widget.landmark.nameEN!,
-                        style: Theme.of(context).textTheme.bodyMedium,
-                        maxLines: 1,
-                        overflow: TextOverflow.ellipsis,
-                      ),
-
-                    // fill the vspace
-                    const Spacer(),
-
-                    SingleChildScrollView(
-                      // allows the buttons to be scrolled
-                      scrollDirection: Axis.horizontal,
-                      child: Wrap(
-                        spacing: 10,
-                        // show the type, the website, and the wikipedia link as buttons/labels in a row
-                        children: [
-                          doneToggleButton(),
-                          if (widget.landmark.websiteURL != null)
-                            websiteButton(),
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  Padding(
+                    padding: const EdgeInsets.all(10),
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        Text(
+                          widget.landmark.name,
+                          style: Theme.of(context).textTheme.titleMedium,
+                          overflow: TextOverflow.ellipsis,
+                          maxLines: 2,
+                        ),
                           
-                          optionsButton()
-                        ],
-                      ),
+                        if (widget.landmark.nameEN != null)
+                          Text(
+                            widget.landmark.nameEN!,
+                            style: Theme.of(context).textTheme.bodyMedium,
+                            maxLines: 1,
+                            overflow: TextOverflow.ellipsis,
+                          ),
+                      ]
                     ),
-                  ],
-                ),
-              ),
+                  ),
+
+                  // fill the vspace
+                  const Spacer(),
+
+                  SingleChildScrollView(
+                    scrollDirection: Axis.horizontal,
+                    padding: EdgeInsets.only(left: 5, right: 5, bottom: 10),
+                    // the scroll view should be flush once the buttons are scrolled to the left
+                    // but initially there should be some padding
+                    child: Wrap(
+                      spacing: 10,
+                      // show the type, the website, and the wikipedia link as buttons/labels in a row
+                      children: [
+                        doneToggleButton(),
+                        if (widget.landmark.websiteURL != null)
+                          websiteButton(),
+                        
+                        optionsButton()
+                      ],
+                    ),
+                  ),
+                ],
+              )
             )
           ],
         )
@@ -195,3 +190,21 @@ class _LandmarkCardState extends State<LandmarkCard> {
     ],
   );
 }
+
+
+
+Widget imagePlaceholder (Landmark landmark) => Expanded(
+  child: 
+  Container(
+    decoration: const BoxDecoration(
+      gradient: LinearGradient(
+        begin: Alignment.topLeft,
+        end: Alignment.bottomRight,
+        colors: [GRADIENT_START, GRADIENT_END],
+      ),
+    ),
+    child: Center(
+      child: Icon(landmark.type.icon.icon, size: 50),
+    ),
+  ),
+);

frontend/lib/modules/step_between_landmarks.dart

@@ -22,6 +22,14 @@ class _StepBetweenLandmarksState extends State<StepBetweenLandmarks> {
   @override
   Widget build(BuildContext context) {
     int? time = widget.current.tripTime?.inMinutes;
+    
+    // since landmarks might have been marked as visited, the next landmark might not be the immediate next in the list
+    // => the precomputed trip time is not valid anymore
+    if (widget.current.next != widget.next) {
+      time = null;
+    }
+    
+    // round 0 travel time to 1 minute
     if (time != null && time < 1) {
       time = 1;
     }

frontend/lib/structs/landmark.dart

@@ -29,9 +29,10 @@ final class Landmark extends LinkedListEntry<Landmark>{
   final Duration? duration;
   bool visited;
 
-  // Next node
+  // Next node is implicitly available through the LinkedListEntry mixin
   // final Landmark? next;
-  final Duration? tripTime;
+  Duration? tripTime;
+  // the trip time depends on the next landmark, so it is not final
 
 
   Landmark({

frontend/lib/structs/trip.dart

@@ -75,8 +75,16 @@ class Trip with ChangeNotifier {
     notifyListeners();
   }
 
-  void removeLandmark(Landmark landmark) {
+  void removeLandmark (Landmark landmark) async {
+    Landmark? previous = landmark.previous;
+    Landmark? next = landmark.next;
     landmarks.remove(landmark);
+    // removing the landmark means we need to recompute the time between the two adjoined landmarks
+    if (previous != null && next != null) {
+      // previous.next = next happens automatically since we are using a LinkedList
+      previous.tripTime = null;
+      // TODO
+    }
     notifyListeners();
   }