fix resize

playbook_snapshot/lib/src/snapshot_support.dart

@@ -7,6 +7,9 @@ import 'package:playbook/playbook.dart';
 import 'snapshot_device.dart';
 
 class SnapshotSupport {
+  static const _maxTryResizeCount = 10;
+  static const _maxSnapshotSize = 50000;
+
   static Future<void> startDevice(
     Widget target,
     WidgetTester tester,
@@ -38,25 +41,43 @@ class SnapshotSupport {
       // We use scrollController.maxScrollExtent to calculate the snapshot size.
       // However, maxScrollExtent may report incorrectly.
       // To solve this, we repeatedly calculate size and update size until we can get a stable value.
-      var lastExtendedSize = device.size;
+      var lastExtendedSize = Size(
+        scenario.layout.compressedResizingTarget.needResizingWidth
+            ? device.size.width
+            : absoluteSize.width,
+        scenario.layout.compressedResizingTarget.needResizingHeight
+            ? device.size.height
+            : absoluteSize.height,
+      );
+      var resize = 0;
       while (true) {
-        final scrollViews = find
-            .byWidgetPredicate((widget) => widget is ScrollView)
+        final scrollables = find
+            .byWidgetPredicate((widget) => widget is Scrollable)
             .evaluate()
-            .map((e) => e.widget as ScrollView);
-        if (scrollViews.isEmpty) break;
+            .map((e) => e.widget as Scrollable);
+        if (scrollables.isEmpty) break;
 
         var extendedSize = device.size;
-        for (final scrollView in scrollViews) {
+        for (final scrollable in scrollables) {
           extendedSize = _extendScrollableSnapshotSize(
-            scrollView: scrollView,
-            extendedSize: extendedSize,
+            scrollable: scrollable,
+            currentExtendedSize: extendedSize,
             originSize: lastExtendedSize,
+            resizingTarget: scenario.layout.compressedResizingTarget,
           );
         }
         if (extendedSize <= lastExtendedSize) break;
         lastExtendedSize = extendedSize;
         await _setSnapshotSize(tester, lastExtendedSize);
+        resize++;
+        if (resize >= _maxTryResizeCount) {
+          throw StateError(
+              'Try resizing too many times. Please try to set your scenario to have a fixed size.');
+        }
+        if (extendedSize.width >= _maxSnapshotSize || extendedSize.height >= _maxSnapshotSize) {
+          throw StateError(
+              'Try resizing too large size ${extendedSize}. Please try to set your scenario to have a fixed size.');
+        }
       }
       snapshotSize = lastExtendedSize;
     } else {
@@ -86,31 +107,47 @@ class SnapshotSupport {
   }
 
   static Size _extendScrollableSnapshotSize({
-    required ScrollView scrollView,
-    required Size extendedSize,
+    required Scrollable scrollable,
+    required Size currentExtendedSize,
     required Size originSize,
+    required _CompressedResizingTarget resizingTarget,
   }) {
-    final controller = scrollView.controller;
-    if (controller == null) {
+    final controller = scrollable.controller;
+    ScrollPosition? position;
+    try {
+      position = controller?.position;
+    } catch (_) {}
+    if (position == null) {
       return Size(
-        max(extendedSize.width, originSize.width),
-        max(extendedSize.height, originSize.height),
+        resizingTarget.needResizingWidth
+            ? max(currentExtendedSize.width, originSize.width)
+            : originSize.width,
+        resizingTarget.needResizingHeight
+            ? max(currentExtendedSize.height, originSize.height)
+            : originSize.height,
       );
     }
 
-    final scrollAxis = controller.position.axis;
-    final maxScrollExtent = controller.position.maxScrollExtent;
+    final scrollAxis = position.axis;
+    final maxScrollExtent = position.maxScrollExtent;
 
+    final Size newExtendedSize;
     switch (scrollAxis) {
       case Axis.horizontal:
-        final height = max(originSize.height, extendedSize.height);
-        final width = max(maxScrollExtent + originSize.width, extendedSize.width);
-        return Size(width, height);
+        final height = max(originSize.height, currentExtendedSize.height);
+        final width = max(maxScrollExtent + originSize.width, currentExtendedSize.width);
+        newExtendedSize = Size(width, height);
+        break;
       case Axis.vertical:
-        final height = max(maxScrollExtent + originSize.height, extendedSize.height);
-        final width = max(originSize.width, extendedSize.width);
-        return Size(width, height);
+        final height = max(maxScrollExtent + originSize.height, currentExtendedSize.height);
+        final width = max(originSize.width, currentExtendedSize.width);
+        newExtendedSize = Size(width, height);
+        break;
     }
+    return Size(
+      resizingTarget.needResizingWidth ? newExtendedSize.width : originSize.width,
+      resizingTarget.needResizingHeight ? newExtendedSize.height : originSize.height,
+    );
   }
 }
 
@@ -123,6 +160,18 @@ extension on ScenarioLayout {
     return v is ScenarioLayoutCompressed || h is ScenarioLayoutCompressed;
   }
 
+  _CompressedResizingTarget get compressedResizingTarget {
+    if (v is ScenarioLayoutCompressed && h is ScenarioLayoutCompressed) {
+      return _CompressedResizingTarget.both;
+    } else if (v is ScenarioLayoutCompressed) {
+      return _CompressedResizingTarget.vertical;
+    } else if (h is ScenarioLayoutCompressed) {
+      return _CompressedResizingTarget.horizontal;
+    } else {
+      throw StateError('No need compressed resizing.');
+    }
+  }
+
   double absoluteWidth(SnapshotDevice device) {
     switch (h.runtimeType) {
       case ScenarioLayoutFixed:
@@ -147,3 +196,17 @@ extension on ScenarioLayout {
     return device.size.height;
   }
 }
+
+enum _CompressedResizingTarget {
+  horizontal,
+  vertical,
+  both,
+}
+
+extension on _CompressedResizingTarget {
+  bool get needResizingWidth =>
+      this == _CompressedResizingTarget.both || this == _CompressedResizingTarget.horizontal;
+
+  bool get needResizingHeight =>
+      this == _CompressedResizingTarget.both || this == _CompressedResizingTarget.vertical;
+}