fix: eew intensity area

Author: whes1015

lib/app/map/_lib/managers/monitor.dart

@@ -18,6 +18,7 @@ import 'package:dpip/utils/instrumental_intensity_color.dart';
 import 'package:dpip/utils/intensity_color.dart';
 import 'package:dpip/utils/log.dart';
 import 'package:dpip/widgets/map/map.dart';
+import 'package:dpip/widgets/map/intensity_legend.dart';
 import 'package:dpip/widgets/responsive/responsive_container.dart';
 import 'package:dpip/widgets/sheet/morphing_sheet.dart';
 import 'package:flutter/material.dart';
@@ -1633,6 +1634,21 @@ class _MonitorMapLayerSheetState extends State<MonitorMapLayerSheet> {
                 },
               ),
             ),
+            // Intensity legend - positioned at top right, just below buttons
+            // Show RTS mode when no EEW, show EEW mode during EEW
+            // Hide when sheet is expanded
+            if (_isCollapsed)
+              Positioned(
+                top: 80,
+                right: 16,
+                child: SafeArea(
+                  child: IntensityLegend(
+                    mode: activeEew.isNotEmpty
+                        ? IntensityLegendMode.eew
+                        : IntensityLegendMode.rts,
+                  ),
+                ),
+              ),
             Positioned(
               top: 26,
               left: 95,

lib/widgets/map/intensity_legend.dart

@@ -0,0 +1,106 @@
+import 'package:dpip/utils/instrumental_intensity_color.dart';
+import 'package:dpip/utils/intensity_color.dart';
+import 'package:flutter/material.dart';
+
+enum IntensityLegendMode {
+  /// EEW mode: shows intensity 1-9
+  eew,
+
+  /// RTS mode: shows instrumental intensity -3 to 7
+  rts,
+}
+
+class IntensityLegend extends StatelessWidget {
+  final IntensityLegendMode mode;
+
+  const IntensityLegend({super.key, this.mode = IntensityLegendMode.eew});
+
+  List<Color> get _colors => mode == IntensityLegendMode.eew
+      ? List.generate(9, (i) => IntensityColor.intensity(i + 1))
+      : List.generate(11, (i) => InstrumentalIntensityColor.intensity(i - 3));
+
+  List<String> get _labels => mode == IntensityLegendMode.eew
+      ? const ['1', '2', '3', '4', '5⁻', '5⁺', '6⁻', '6⁺', '7']
+      : const ['-3', '-2', '-1', '0', '1', '2', '3', '4', '5', '6', '7'];
+
+  @override
+  Widget build(BuildContext context) {
+    final screenWidth = MediaQuery.of(context).size.width;
+    final width = screenWidth / 2;
+
+    return SizedBox(
+      width: width,
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        crossAxisAlignment: CrossAxisAlignment.end,
+        children: [
+          _buildColorBar(width),
+          const SizedBox(height: 2),
+          _buildLabels(width),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildColorBar(double width) {
+    if (mode == IntensityLegendMode.eew) {
+      // EEW mode: discrete color blocks
+      return ClipRRect(
+        borderRadius: BorderRadius.circular(4),
+        child: SizedBox(
+          height: 8,
+          width: width,
+          child: Row(
+            children: _colors.map((color) {
+              return Expanded(child: Container(color: color));
+            }).toList(),
+          ),
+        ),
+      );
+    } else {
+      // RTS mode: gradient
+      return Container(
+        height: 8,
+        width: width,
+        decoration: BoxDecoration(
+          borderRadius: BorderRadius.circular(4),
+          gradient: LinearGradient(colors: _colors),
+        ),
+      );
+    }
+  }
+
+  Widget _buildLabels(double width) {
+    if (mode == IntensityLegendMode.eew) {
+      // EEW mode: labels centered under each color block
+      return SizedBox(
+        width: width,
+        child: Row(
+          children: _labels.map((label) {
+            return Expanded(
+              child: Text(
+                label,
+                style: const TextStyle(fontSize: 9),
+                textAlign: TextAlign.center,
+              ),
+            );
+          }).toList(),
+        ),
+      );
+    } else {
+      // RTS mode: labels at edges
+      return SizedBox(
+        width: width,
+        child: Row(
+          mainAxisAlignment: MainAxisAlignment.spaceBetween,
+          children: _labels.map((label) {
+            return Text(
+              label,
+              style: const TextStyle(fontSize: 9),
+            );
+          }).toList(),
+        ),
+      );
+    }
+  }
+}