How to change hitTest area in flutter? - flutter

Question

Somebody knows how to change hitTest area in Flutter?
I have RenderObject and I want to paint child in other place inner my widget.
I changed paint offset and add new hitTest area with help BoxHitTestResult.addWithPaintOffset
But I don't want hitTest to trigger on a child widget with old coordinates 0,0;50,50
Below is an example of my code
class BottomPanel extends SingleChildRenderObjectWidget {
final Widget? child;
BottomPanel([this.child]) : super(child: child);
#override
BottomPanelRenderObject createRenderObject(BuildContext context) =>
BottomPanelRenderObject();
}
class BottomPanelRenderObject extends RenderProxyBoxWithHitTestBehavior {
BottomPanelRenderObject() : super(behavior: HitTestBehavior.translucent);
final newChildOffset = Offset(0, 100);
#override
Rect get paintBounds => Rect.fromLTWH(0, 0, 200, 400);
#override
void layout(Constraints constraints, {bool parentUsesSize = false}) {
super.layout(constraints, parentUsesSize: parentUsesSize);
}
#override
bool hitTest(BoxHitTestResult result, {required Offset position}) {
final hitTestResult = super.hitTest(result, position: position);
print('hitTest: hitTestResult=$hitTestResult BoxHitTestResult=${result}');
if (child != null) {
final childHitTest = result.addWithPaintOffset(
offset: newChildOffset,
position: position,
hitTest: (result, offset) {
return child!.hitTest(result, position: offset);
},
);
print('childHitTest: BoxHitTestResult=${childHitTest}');
}
return hitTestResult;
}
#override
void setupParentData(covariant RenderObject child) {
super.setupParentData(child);
}
#override
void performLayout() {
print('performLayout');
size = paintBounds.size;
child?.layout(constraints, parentUsesSize: true);
}
#override
void performResize() {
print('performResize');
size = paintBounds.size;
}
void paintBox(PaintingContext context, Offset offset) {
context.canvas
..drawRect(
Rect.fromLTWH(0, 150, 100, 100),
Paint()..color = Colors.blueGrey,
);
}
void paintChild(PaintingContext context, Offset offset) {
if (child != null) {
context.paintChild(child!, offset);
}
}
#override
void paint(PaintingContext context, Offset offset) {
context.pushLayer(
OffsetLayer(
offset: newChildOffset,
),
paintChild,
offset,
);
layer = context.pushClipRect(
needsCompositing,
offset,
paintBounds,
paintBox,
clipBehavior: Clip.none,
);
}
}
Screenshot example
Read the flutter docs

Answer 1

That's resolved my problem
#override
bool hitTestChildren(BoxHitTestResult result, {required Offset position}) {
final parentData = child?.parentData as BottomPanelParentData?;
if (parentData != null) {
final childHitTest = result.addWithPaintOffset(
offset: parentData.offset,
position: position,
hitTest: (result, offset) {
return child!.hitTest(result, position: offset);
},
);
return childHitTest;
}
return false;
}