refactor!: consolidate src_base64, src, and src_bytes into unified/intelligent src prop

packages/flet/lib/src/controls/canvas.dart

@@ -193,9 +193,6 @@ class FletCustomPainter extends CustomPainter {
   void paint(Canvas canvas, Size size) {
     onPaintCallback(size);
 
-    debugPrint("paint.size: $size");
-    //debugPrint("paint.shapes: $shapes");
-
     canvas.save();
     canvas.scale(dpr);
     canvas.clipRect(Rect.fromLTWH(0, 0, size.width, size.height));
@@ -541,16 +538,19 @@ Future<void> loadCanvasImage(Control shape) async {
   final completer = Completer();
   shape.properties["_loading"] = completer;
 
-  final src = shape.getString("src");
-  final srcBytes = shape.get("src_bytes") as Uint8List?;
+  final src = shape.getSrc("src");
 
   try {
     Uint8List bytes;
 
-    if (srcBytes != null) {
-      bytes = srcBytes;
-    } else if (src != null) {
-      var assetSrc = shape.backend.getAssetSource(src);
+    if (src.error != null) {
+      throw Exception("Error decoding src: ${src.error}");
+    }
+
+    if (src.hasBytes) {
+      bytes = src.bytes!;
+    } else if (src.hasUri) {
+      var assetSrc = shape.backend.getAssetSource(src.uri!);
       if (assetSrc.isFile) {
         final file = File(assetSrc.path);
         bytes = await file.readAsBytes();
@@ -562,7 +562,7 @@ Future<void> loadCanvasImage(Control shape) async {
         bytes = resp.bodyBytes;
       }
     } else {
-      throw Exception("Missing image source: 'src' or 'src_bytes'");
+      throw Exception("Missing image source: 'src'");
     }
 
     final codec = await ui.instantiateImageCodec(bytes, allowUpscaling: false);
@@ -579,12 +579,15 @@ Future<void> loadCanvasImage(Control shape) async {
   }
 }
 
+/// Produces a fast hash for the `src` so Canvas can tell when it needs to
+/// refetch the image. Inline strings and bytes use FNV to avoid massive hashes.
 int getImageHash(Control shape) {
-  final src = shape.getString("src");
-  final srcBytes = shape.get("src_bytes") as Uint8List?;
-  return src != null
-      ? src.hashCode
-      : srcBytes != null
-          ? fnv1aHash(srcBytes)
-          : 0;
+  final src = shape.getSrc("src");
+  if (src.hasUri) {
+    return src.uri!.hashCode;
+  }
+  if (src.hasBytes) {
+    return fnv1aHash(src.bytes!);
+  }
+  return 0;
 }

packages/flet/lib/src/controls/circle_avatar.dart

@@ -1,11 +1,6 @@
+import 'package:flet/flet.dart';
 import 'package:flutter/material.dart';
 
-import '../extensions/control.dart';
-import '../models/control.dart';
-import '../utils/colors.dart';
-import '../utils/numbers.dart';
-import 'base_controls.dart';
-
 class CircleAvatarControl extends StatelessWidget {
   final Control control;
 
@@ -18,39 +13,10 @@ class CircleAvatarControl extends StatelessWidget {
   Widget build(BuildContext context) {
     debugPrint("CircleAvatar build: ${control.id}");
 
-    var foregroundImageSrc = control.getString("foreground_image_src");
-    var backgroundImageSrc = control.getString("background_image_src");
-    var content = control.buildTextOrWidget("content");
-
-    ImageProvider<Object>? backgroundImage;
-    ImageProvider<Object>? foregroundImage;
-
-    if (foregroundImageSrc != null || backgroundImageSrc != null) {
-      var assetSrc = control.backend
-          .getAssetSource((foregroundImageSrc ?? backgroundImageSrc)!);
-
-      // foregroundImage
-      if (foregroundImageSrc != null) {
-        if (assetSrc.isFile) {
-          // from File
-          foregroundImage = AssetImage(assetSrc.path);
-        } else {
-          // URL
-          foregroundImage = NetworkImage(assetSrc.path);
-        }
-      }
-
-      // backgroundImage
-      if (backgroundImageSrc != null) {
-        if (assetSrc.isFile) {
-          // from File
-          backgroundImage = AssetImage(assetSrc.path);
-        } else {
-          // URL
-          backgroundImage = NetworkImage(assetSrc.path);
-        }
-      }
-    }
+    var foregroundImage =
+        control.getImageProvider("foreground_image_src", context);
+    var backgroundImage =
+        control.getImageProvider("background_image_src", context);
 
     var avatar = CircleAvatar(
         foregroundImage: foregroundImage,
@@ -70,7 +36,7 @@ class CircleAvatarControl extends StatelessWidget {
                 control.triggerEvent("image_error", "foreground");
               }
             : null,
-        child: content);
+        child: control.buildTextOrWidget("content"));
 
     return LayoutControl(control: control, child: avatar);
   }

packages/flet/lib/src/controls/cupertino_switch.dart

@@ -2,9 +2,9 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
 import '../models/control.dart';
-import '../utils/box.dart';
 import '../utils/colors.dart';
 import '../utils/icons.dart';
+import '../utils/images.dart';
 import '../utils/misc.dart';
 import '../utils/numbers.dart';
 import 'base_controls.dart';
@@ -85,18 +85,17 @@ class _CupertinoSwitchControlState extends State<CupertinoSwitchControl> {
 
     var materialThumbColor =
         widget.control.getWidgetStateColor("thumb_color", theme);
-    // var materialTrackColor =
-    //     widget.control.getWidgetStateColor("track_color", theme);
-    var activeThumbImage = widget.control.getString("active_thumb_image");
-    var inactiveThumbImage = widget.control.getString("inactive_thumb_image");
+    var activeThumbImage =
+        widget.control.getImageProvider("active_thumb_image_src", context);
+    var inactiveThumbImage =
+        widget.control.getImageProvider("inactive_thumb_image_src", context);
 
     var swtch = CupertinoSwitch(
         autofocus: autofocus,
         focusNode: _focusNode,
         activeTrackColor:
             widget.control.getColor("active_track_color", context),
         thumbColor: materialThumbColor?.resolve({}),
-        //inactiveTrackColor: materialTrackColor?.resolve({}),
         focusColor: widget.control.getColor("focusColor", context),
         inactiveTrackColor:
             widget.control.getColor("inactive_track_color", context),
@@ -107,10 +106,8 @@ class _CupertinoSwitchControlState extends State<CupertinoSwitchControl> {
         trackOutlineWidth:
             widget.control.getWidgetStateDouble("track_outline_width"),
         thumbIcon: widget.control.getWidgetStateIcon("thumb_icon", theme),
-        inactiveThumbImage:
-            getImageProvider(context, inactiveThumbImage, null, null),
-        activeThumbImage:
-            getImageProvider(context, activeThumbImage, null, null),
+        inactiveThumbImage: inactiveThumbImage,
+        activeThumbImage: activeThumbImage,
         onActiveThumbImageError: activeThumbImage == null
             ? null
             : (Object exception, StackTrace? stackTrace) {

packages/flet/lib/src/controls/image.dart

@@ -1,5 +1,3 @@
-import 'dart:typed_data';
-
 import 'package:flutter/material.dart';
 
 import '../extensions/control.dart';
@@ -26,20 +24,14 @@ class ImageControl extends StatelessWidget {
   Widget build(BuildContext context) {
     debugPrint("Image build: ${control.id}");
 
-    var src = control.getString("src", "")!;
-    var srcBase64 = control.getString("src_base64", "")!;
-    var srcBytes = (control.get("src_bytes") as Uint8List?) ?? Uint8List(0);
-    if (src == "" && srcBase64 == "" && srcBytes.isEmpty) {
-      return const ErrorControl(
-          "Image must have either \"src\" or \"src_base64\" or \"src_bytes\" specified.");
+    var rawSrc = control.get("src");
+    if (rawSrc == null) {
+      return const ErrorControl("Image must have \"src\" specified.");
     }
-    var errorContent = control.buildWidget("error_content");
 
     Widget? image = buildImage(
       context: context,
-      src: src,
-      srcBase64: srcBase64,
-      srcBytes: srcBytes,
+      src: rawSrc,
       width: control.getDouble("width"),
       height: control.getDouble("height"),
       cacheWidth: control.getInt("cache_width"),
@@ -55,7 +47,7 @@ class ImageControl extends StatelessWidget {
       filterQuality:
           control.getFilterQuality("filter_quality", FilterQuality.medium)!,
       disabled: control.disabled,
-      errorCtrl: errorContent,
+      errorCtrl: control.buildWidget("error_content"),
     );
     return LayoutControl(
         control: control,

packages/flet/lib/src/controls/markdown.dart

@@ -4,13 +4,11 @@ import 'package:markdown/markdown.dart' as md;
 
 import '../extensions/control.dart';
 import '../models/control.dart';
-import '../utils/box.dart';
 import '../utils/images.dart';
 import '../utils/launch_url.dart';
 import '../utils/markdown.dart';
 import '../utils/numbers.dart';
 import '../utils/uri.dart';
-import '../widgets/error.dart';
 import 'base_controls.dart';
 import 'highlight_view.dart';
 
@@ -51,17 +49,9 @@ class MarkdownControl extends StatelessWidget {
         },
         styleSheet: mdStyleSheet,
         imageBuilder: (Uri uri, String? title, String? alt) {
-          String s = uri.toString();
-          var srcBase64 = isBase64ImageString(s) ? s : null;
-          var src = isUrlOrPath(s) ? s : null;
-          if (src == null && srcBase64 == null) {
-            return ErrorControl("Invalid image URI: $s");
-          }
-
           return buildImage(
               context: context,
-              src: src,
-              srcBase64: srcBase64,
+              src: uri.toString(),
               semanticsLabel: alt,
               disabled: control.disabled,
               errorCtrl: control.buildWidget("image_error_content"));

packages/flet/lib/src/controls/slider.dart

@@ -44,7 +44,7 @@ class _SliderControlState extends State<SliderControl> {
     _value = value;
     var props = {"value": value};
     widget.control.updateProperties(props, notify: true);
-    widget.control.triggerEvent("change");
+    widget.control.triggerEvent("change", value);
   }
 
   @override