Initial commit: imajViewer Flutter Linux image viewer

lib/widgets/image_canvas.dart

@@ -0,0 +1,125 @@
+import 'dart:io';
+import 'package:flutter/material.dart';
+import 'package:flutter/gestures.dart';
+
+class ImageCanvas extends StatefulWidget {
+  final String filePath;
+
+  const ImageCanvas({super.key, required this.filePath});
+
+  @override
+  State<ImageCanvas> createState() => _ImageCanvasState();
+}
+
+class _ImageCanvasState extends State<ImageCanvas> {
+  late TransformationController _controller;
+  double _currentScale = 1.0;
+
+  @override
+  void initState() {
+    super.initState();
+    _controller = TransformationController();
+    _controller.addListener(_onTransformChanged);
+  }
+
+  @override
+  void didUpdateWidget(ImageCanvas oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.filePath != widget.filePath) {
+      _resetView();
+    }
+  }
+
+  void _resetView() {
+    _controller.value = Matrix4.identity();
+    _currentScale = 1.0;
+  }
+
+  void _onTransformChanged() {
+    _currentScale = _controller.value.getMaxScaleOnAxis();
+  }
+
+  void _handleScroll(PointerScrollEvent event) {
+    final renderBox = context.findRenderObject() as RenderBox?;
+    if (renderBox == null) return;
+
+    final localPosition = renderBox.globalToLocal(event.position);
+
+    final delta = event.scrollDelta.dy;
+    final scaleFactor = delta < 0 ? 1.1 : 1 / 1.1;
+
+    final newScale = (_currentScale * scaleFactor).clamp(0.1, 10.0);
+    if (newScale <= 0.1 || newScale >= 10.0) return;
+
+    final actualScale = newScale / _currentScale;
+
+    // Decompose current matrix: widget_point = scale * child_point + translation
+    // So: child_point = (widget_point - translation) / scale
+    final matrix = _controller.value;
+    final tx = matrix.getTranslation().x;
+    final ty = matrix.getTranslation().y;
+
+    final childX = (localPosition.dx - tx) / _currentScale;
+    final childY = (localPosition.dy - ty) / _currentScale;
+
+    // Build new matrix: zoom around child_point, then re-apply
+    final newMatrix = Matrix4.identity()
+      // ignore: deprecated_member_use
+      ..translate(childX, childY)
+      // ignore: deprecated_member_use
+      ..scale(actualScale)
+      // ignore: deprecated_member_use
+      ..translate(-childX, -childY)
+      ..multiply(_controller.value);
+
+    _controller.value = newMatrix;
+  }
+
+  @override
+  void dispose() {
+    _controller.removeListener(_onTransformChanged);
+    _controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Listener(
+      onPointerSignal: (event) {
+        if (event is PointerScrollEvent) {
+          _handleScroll(event);
+        }
+      },
+      child: InteractiveViewer(
+        transformationController: _controller,
+        boundaryMargin: const EdgeInsets.all(double.infinity),
+        minScale: 0.1,
+        maxScale: 10.0,
+        panEnabled: true,
+        scaleEnabled: false,
+        child: Center(
+          child: Image.file(
+            File(widget.filePath),
+            fit: BoxFit.contain,
+            filterQuality: FilterQuality.high,
+            errorBuilder: (context, error, stackTrace) {
+              return const Center(
+                child: Column(
+                  mainAxisSize: MainAxisSize.min,
+                  children: [
+                    Icon(Icons.broken_image, size: 48, color: Colors.white38),
+                    SizedBox(height: 8),
+                    Text(
+                      'Resim yüklenemedi',
+                      style: TextStyle(color: Colors.white38),
+                    ),
+                  ],
+                ),
+              );
+            },
+          ),
+        ),
+      ),
+    );
+  }
+}