Switch to FilterQuality.medium for images (#148799)

flutter/flutter#148253

Author: goderbauer

packages/flutter/lib/src/material/page_transitions_theme.dart

@@ -918,7 +918,7 @@ void _drawImageScaledAndCentered(PaintingContext context, ui.Image image, double
     return;
   }
   final Paint paint = Paint()
-    ..filterQuality = ui.FilterQuality.low
+    ..filterQuality = ui.FilterQuality.medium
     ..color = Color.fromRGBO(0, 0, 0, opacity);
   final double logicalWidth = image.width / pixelRatio;
   final double logicalHeight = image.height / pixelRatio;
@@ -1267,7 +1267,7 @@ class _ZoomEnterTransitionNoCache extends StatelessWidget {
         opacity: fadeTransition,
         child: ScaleTransition(
           scale: scaleTransition,
-          filterQuality: FilterQuality.none,
+          filterQuality: FilterQuality.medium,
           child: child,
         ),
       ),
@@ -1300,7 +1300,7 @@ class _ZoomExitTransitionNoCache extends StatelessWidget {
       opacity: fadeTransition,
       child: ScaleTransition(
         scale: scaleTransition,
-        filterQuality: FilterQuality.none,
+        filterQuality: FilterQuality.medium,
         child: child,
       ),
     );

packages/flutter/lib/src/painting/decoration_image.dart

@@ -51,7 +51,7 @@ class DecorationImage {
     this.matchTextDirection = false,
     this.scale = 1.0,
     this.opacity = 1.0,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
     this.invertColors = false,
     this.isAntiAlias = false,
   });
@@ -148,8 +148,7 @@ class DecorationImage {
 
   /// Used to set the filterQuality of the image.
   ///
-  /// Defaults to [FilterQuality.low] to scale the image, which corresponds to
-  /// bilinear interpolation.
+  /// Defaults to [FilterQuality.medium].
   final FilterQuality filterQuality;
 
   /// Whether the colors of the image are inverted when drawn.
@@ -508,9 +507,7 @@ void debugFlushLastFrameImageSizeInfo() {
 ///    smart invert on iOS.
 ///
 ///  * `filterQuality`: Use this to change the quality when scaling an image.
-///     Use the [FilterQuality.low] quality setting to scale the image, which corresponds to
-///     bilinear interpolation, rather than the default [FilterQuality.none] which corresponds
-///     to nearest-neighbor.
+///     Defaults to [FilterQuality.medium].
 ///
 /// See also:
 ///
@@ -531,7 +528,7 @@ void paintImage({
   ImageRepeat repeat = ImageRepeat.noRepeat,
   bool flipHorizontally = false,
   bool invertColors = false,
-  FilterQuality filterQuality = FilterQuality.low,
+  FilterQuality filterQuality = FilterQuality.medium,
   bool isAntiAlias = false,
   BlendMode blendMode = BlendMode.srcOver,
 }) {

packages/flutter/lib/src/rendering/image.dart

@@ -43,7 +43,7 @@ class RenderImage extends RenderBox {
     TextDirection? textDirection,
     bool invertColors = false,
     bool isAntiAlias = false,
-    FilterQuality filterQuality = FilterQuality.low,
+    FilterQuality filterQuality = FilterQuality.medium,
   }) : _image = image,
        _width = width,
        _height = height,
@@ -188,9 +188,7 @@ class RenderImage extends RenderBox {
 
   /// Used to set the filterQuality of the image.
   ///
-  /// Use the [FilterQuality.low] quality setting to scale the image, which corresponds to
-  /// bilinear interpolation, rather than the default [FilterQuality.none] which corresponds
-  /// to nearest-neighbor.
+  /// Defaults to [FilterQuality.medium].
   FilterQuality get filterQuality => _filterQuality;
   FilterQuality _filterQuality;
   set filterQuality(FilterQuality value) {

packages/flutter/lib/src/widgets/basic.dart

@@ -5959,7 +5959,7 @@ class RawImage extends LeafRenderObjectWidget {
     this.centerSlice,
     this.matchTextDirection = false,
     this.invertColors = false,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
     this.isAntiAlias = false,
   });
 
@@ -6002,8 +6002,7 @@ class RawImage extends LeafRenderObjectWidget {
 
   /// Used to set the filterQuality of the image.
   ///
-  /// Defaults to [FilterQuality.low] to scale the image, which corresponds to
-  /// bilinear interpolation.
+  /// Defaults to [FilterQuality.medium].
   final FilterQuality filterQuality;
 
   /// Used to combine [color] with this image.

packages/flutter/lib/src/widgets/fade_in_image.dart

@@ -92,7 +92,7 @@ class FadeInImage extends StatefulWidget {
     this.height,
     this.fit,
     this.placeholderFit,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
     this.placeholderFilterQuality,
     this.alignment = Alignment.center,
     this.repeat = ImageRepeat.noRepeat,
@@ -149,7 +149,7 @@ class FadeInImage extends StatefulWidget {
     this.placeholderColor,
     this.placeholderColorBlendMode,
     this.placeholderFit,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
     this.placeholderFilterQuality,
     this.alignment = Alignment.center,
     this.repeat = ImageRepeat.noRepeat,
@@ -211,7 +211,7 @@ class FadeInImage extends StatefulWidget {
     this.placeholderColor,
     this.placeholderColorBlendMode,
     this.placeholderFit,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
     this.placeholderFilterQuality,
     this.alignment = Alignment.center,
     this.repeat = ImageRepeat.noRepeat,

packages/flutter/lib/src/widgets/image.dart

@@ -366,7 +366,7 @@ class Image extends StatefulWidget {
     this.matchTextDirection = false,
     this.gaplessPlayback = false,
     this.isAntiAlias = false,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
   });
 
   /// Creates a widget that displays an [ImageStream] obtained from the network.
@@ -414,7 +414,7 @@ class Image extends StatefulWidget {
     this.centerSlice,
     this.matchTextDirection = false,
     this.gaplessPlayback = false,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
     this.isAntiAlias = false,
     Map<String, String>? headers,
     int? cacheWidth,
@@ -471,7 +471,7 @@ class Image extends StatefulWidget {
     this.matchTextDirection = false,
     this.gaplessPlayback = false,
     this.isAntiAlias = false,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
     int? cacheWidth,
     int? cacheHeight,
   }) :
@@ -631,7 +631,7 @@ class Image extends StatefulWidget {
     this.gaplessPlayback = false,
     this.isAntiAlias = false,
     String? package,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
     int? cacheWidth,
     int? cacheHeight,
   }) : image = ResizeImage.resizeIfNeeded(
@@ -693,7 +693,7 @@ class Image extends StatefulWidget {
     this.matchTextDirection = false,
     this.gaplessPlayback = false,
     this.isAntiAlias = false,
-    this.filterQuality = FilterQuality.low,
+    this.filterQuality = FilterQuality.medium,
     int? cacheWidth,
     int? cacheHeight,
   }) : image = ResizeImage.resizeIfNeeded(cacheWidth, cacheHeight, MemoryImage(bytes, scale: scale)),
@@ -873,6 +873,8 @@ class Image extends StatefulWidget {
   /// improve the rendered image quality in this case. Pixels may be misaligned
   /// with the screen pixels as a result of transforms or scaling.
   ///
+  /// Defaults to [FilterQuality.medium].
+  ///
   /// See also:
   ///
   ///  * [FilterQuality], the enum containing all possible filter quality

packages/flutter/lib/src/widgets/overscroll_indicator.dart

@@ -777,7 +777,7 @@ class _StretchingOverscrollIndicatorState extends State<StretchingOverscrollIndi
           final Widget transform = Transform(
             alignment: alignment,
             transform: Matrix4.diagonal3Values(x, y, 1.0),
-            filterQuality: stretch == 0 ? null : FilterQuality.low,
+            filterQuality: stretch == 0 ? null : FilterQuality.medium,
             child: widget.child,
           );
 

packages/flutter/lib/src/widgets/snapshot_widget.dart

@@ -381,7 +381,7 @@ class _RenderSnapshotWidget extends RenderProxyBox {
 ///   final Rect src = Rect.fromLTWH(0, 0, image.width.toDouble(), image.height.toDouble());
 ///   final Rect dst = Rect.fromLTWH(offset.dx, offset.dy, size.width, size.height);
 ///   final Paint paint = Paint()
-///     ..filterQuality = FilterQuality.low;
+///     ..filterQuality = FilterQuality.medium;
 ///   context.canvas.drawImageRect(image, src, dst, paint);
 /// }
 /// ```
@@ -414,7 +414,7 @@ abstract class SnapshotPainter extends ChangeNotifier {
   ///   final Rect src = Rect.fromLTWH(0, 0, sourceSize.width, sourceSize.height);
   ///   final Rect dst = Rect.fromLTWH(offset.dx, offset.dy, size.width, size.height);
   ///   final Paint paint = Paint()
-  ///     ..filterQuality = FilterQuality.low;
+  ///     ..filterQuality = FilterQuality.medium;
   ///   context.canvas.drawImageRect(image, src, dst, paint);
   /// }
   /// ```
@@ -482,7 +482,7 @@ class _DefaultSnapshotPainter implements SnapshotPainter {
     final Rect src = Rect.fromLTWH(0, 0, sourceSize.width, sourceSize.height);
     final Rect dst = Rect.fromLTWH(offset.dx, offset.dy, size.width, size.height);
     final Paint paint = Paint()
-      ..filterQuality = FilterQuality.low;
+      ..filterQuality = FilterQuality.medium;
     context.canvas.drawImageRect(image, src, dst, paint);
   }
 

packages/flutter/test/painting/decoration_test.dart

@@ -341,7 +341,7 @@ void main() {
         opacity: 0.99,
         scale: 2.01,
       ).toString(),
-      'DecorationImage(SynchronousTestImageProvider(), Alignment.center, scale 2.0, opacity 1.0, FilterQuality.low)',
+      'DecorationImage(SynchronousTestImageProvider(), Alignment.center, scale 2.0, opacity 1.0, FilterQuality.medium)',
     );
   });
 
@@ -389,7 +389,7 @@ void main() {
       '     BoxFit.contain, Alignment.center, centerSlice:\n'
       '     Rect.fromLTRB(10.0, 20.0, 40.0, 60.0), ImageRepeat.repeatY,\n'
       '     match text direction, scale 0.5, opacity 0.5,\n'
-      '     FilterQuality.low, invert colors, use anti-aliasing)\n'
+      '     FilterQuality.medium, invert colors, use anti-aliasing)\n'
       '   The ImageConfiguration was:\n'
       '     ImageConfiguration(size: Size(100.0, 100.0))\n',
     );

packages/flutter/test/rendering/image_test.dart

@@ -40,7 +40,7 @@ Future<void> main() async {
         '   image: $squareImage\n'
         '   alignment: Alignment.center\n'
         '   invertColors: false\n'
-        '   filterQuality: low\n',
+        '   filterQuality: medium\n',
       ),
     );
 

packages/flutter/test/widgets/basic_test.dart

@@ -47,7 +47,7 @@ void main() {
       expect(renderObject.centerSlice, null);
       expect(renderObject.matchTextDirection, false);
       expect(renderObject.invertColors, false);
-      expect(renderObject.filterQuality, FilterQuality.low);
+      expect(renderObject.filterQuality, FilterQuality.medium);
       expect(renderObject.isAntiAlias, false);
 
       final ui.Image image2 = (await tester.runAsync<ui.Image>(() => createTestImage(width: 2, height: 2)))!;

packages/flutter/test/widgets/fade_in_image_test.dart

@@ -590,7 +590,6 @@ void main() {
         await tester.pumpWidget(FadeInImage(
           placeholder: placeholderProvider,
           image: imageProvider,
-          filterQuality: FilterQuality.medium,
         ));
 
         expect(findFadeInImage(tester).placeholder!.filterQuality, equals(findFadeInImage(tester).target.filterQuality));
@@ -604,7 +603,6 @@ void main() {
         await tester.pumpWidget(FadeInImage(
           placeholder: placeholderProvider,
           image: imageProvider,
-          filterQuality: FilterQuality.medium,
           placeholderFilterQuality: FilterQuality.high,
         ));