de-null many things

Author: yjbanov

lib/web_ui/lib/src/engine/dom_canvas.dart

@@ -110,8 +110,8 @@ class DomCanvas extends EngineCanvas with SaveElementStackTracking {
       ..transformOrigin = '0 0 0'
       ..transform = effectiveTransform;
 
-    final String? cssColor =
-        paint.color == null ? '#000000' : colorToCssString(paint.color);
+    final String cssColor =
+        paint.color == null ? '#000000' : colorToCssString(paint.color)!;
 
     if (paint.maskFilter != null) {
       style.filter = 'blur(${paint.maskFilter!.webOnlySigma}px)';

lib/web_ui/lib/src/engine/dom_renderer.dart

@@ -172,11 +172,11 @@ class DomRenderer {
     js_util.setProperty(element, name, value);
   }
 
-  void setElementStyle(html.Element? element, String name, String? value) {
+  void setElementStyle(html.Element element, String name, String? value) {
     if (value == null) {
-      element!.style.removeProperty(name);
+      element.style.removeProperty(name);
     } else {
-      element!.style.setProperty(name, value);
+      element.style.setProperty(name, value);
     }
   }
 

lib/web_ui/lib/src/engine/mouse_cursor.dart

@@ -39,7 +39,7 @@ class MouseCursor {
 
   void activateSystemCursor(String? kind) {
     domRenderer.setElementStyle(
-      domRenderer.glassPaneElement,
+      domRenderer.glassPaneElement!,
       'cursor',
       _mapKindToCssValue(kind),
     );

lib/web_ui/lib/src/engine/picture.dart

@@ -10,10 +10,10 @@ class EnginePictureRecorder implements ui.PictureRecorder {
   EnginePictureRecorder();
 
   RecordingCanvas? _canvas;
-  ui.Rect? cullRect;
+  late ui.Rect cullRect;
   bool _isRecording = false;
 
-  RecordingCanvas beginRecording(ui.Rect? bounds) {
+  RecordingCanvas beginRecording(ui.Rect bounds) {
     assert(!_isRecording);
     cullRect = bounds;
     _isRecording = true;

lib/web_ui/lib/src/engine/rrect_renderer.dart

@@ -180,23 +180,23 @@ abstract class _RRectRenderer {
 
 /// Renders RRect to a 2d canvas.
 class _RRectToCanvasRenderer extends _RRectRenderer {
-  final html.CanvasRenderingContext2D? context;
+  final html.CanvasRenderingContext2D context;
   _RRectToCanvasRenderer(this.context);
   void beginPath() {
-    context!.beginPath();
+    context.beginPath();
   }
 
   void moveTo(double x, double y) {
-    context!.moveTo(x, y);
+    context.moveTo(x, y);
   }
 
   void lineTo(double x, double y) {
-    context!.lineTo(x, y);
+    context.lineTo(x, y);
   }
 
   void ellipse(double centerX, double centerY, double radiusX, double radiusY,
       double rotation, double startAngle, double endAngle, bool antiClockwise) {
-    DomRenderer.ellipse(context!, centerX, centerY, radiusX, radiusY, rotation, startAngle,
+    DomRenderer.ellipse(context, centerX, centerY, radiusX, radiusY, rotation, startAngle,
         endAngle, antiClockwise);
   }
 }

lib/web_ui/lib/src/engine/surface/backdrop_filter.dart

@@ -113,10 +113,10 @@ class PersistedBackdropFilter extends PersistedContainerSurface
       // Gaussian blur with standard deviation (normal distribution),
       // the blur will fall within 2 * sigma pixels.
       if (browserEngine == BrowserEngine.webkit) {
-        domRenderer.setElementStyle(_filterElement, '-webkit-backdrop-filter',
+        domRenderer.setElementStyle(_filterElement!, '-webkit-backdrop-filter',
             _imageFilterToCss(filter));
       }
-      domRenderer.setElementStyle(_filterElement, 'backdrop-filter', _imageFilterToCss(filter));
+      domRenderer.setElementStyle(_filterElement!, 'backdrop-filter', _imageFilterToCss(filter));
     }
   }
 

lib/web_ui/lib/src/engine/surface/clip.dart

@@ -297,9 +297,9 @@ class PersistedPhysicalShape extends PersistedContainerSurface
         html.Element.html(svgClipPath, treeSanitizer: _NullTreeSanitizer());
     domRenderer.append(rootElement!, _clipElement!);
     domRenderer.setElementStyle(
-        rootElement, 'clip-path', 'url(#svgClip$_clipIdCounter)');
+        rootElement!, 'clip-path', 'url(#svgClip$_clipIdCounter)');
     domRenderer.setElementStyle(
-        rootElement, '-webkit-clip-path', 'url(#svgClip$_clipIdCounter)');
+        rootElement!, '-webkit-clip-path', 'url(#svgClip$_clipIdCounter)');
     final html.CssStyleDeclaration rootElementStyle = rootElement!.style;
     rootElementStyle
       ..overflow = ''
@@ -325,8 +325,8 @@ class PersistedPhysicalShape extends PersistedContainerSurface
     }
     if (oldSurface.path != path) {
       oldSurface._clipElement?.remove();
-      domRenderer.setElementStyle(rootElement, 'clip-path', '');
-      domRenderer.setElementStyle(rootElement, '-webkit-clip-path', '');
+      domRenderer.setElementStyle(rootElement!, 'clip-path', '');
+      domRenderer.setElementStyle(rootElement!, '-webkit-clip-path', '');
       _applyShape();
     } else {
       _clipElement = oldSurface._clipElement;