paint method

  1. @override
void paint(
  1. PaintingContext context,
  2. Offset offset
)
override

Paint this render object into the given context at the given offset.

Subclasses should override this method to provide a visual appearance for themselves. The render object's local coordinate system is axis-aligned with the coordinate system of the context's canvas and the render object's local origin (i.e, x=0 and y=0) is placed at the given offset in the context's canvas.

Do not call this function directly. If you wish to paint yourself, call markNeedsPaint instead to schedule a call to this function. If you wish to paint one of your children, call PaintingContext.paintChild on the given context.

When painting one of your children (via a paint child function on the given context), the current canvas held by the context might change because draw operations before and after painting children might need to be recorded on separate compositing layers.

Implementation

@override
void paint(PaintingContext context, Offset offset) {
  if (_viewController.textureId == null || _currentTextureSize == null) {
    return;
  }

  // As resizing the Android view happens asynchronously we don't know exactly when is a
  // texture frame with the new size is ready for consumption.
  // TextureLayer is unaware of the texture frame's size and always maps it to the
  // specified rect. If the rect we provide has a different size from the current texture frame's
  // size the texture frame will be scaled.
  // To prevent unwanted scaling artifacts while resizing, clip the texture.
  // This guarantees that the size of the texture frame we're painting is always
  // _currentAndroidTextureSize.
  final bool isTextureLargerThanWidget = _currentTextureSize!.width > size.width ||
                                         _currentTextureSize!.height > size.height;
  if (isTextureLargerThanWidget && clipBehavior != Clip.none) {
    _clipRectLayer.layer = context.pushClipRect(
      true,
      offset,
      offset & size,
      _paintTexture,
      clipBehavior: clipBehavior,
      oldLayer: _clipRectLayer.layer,
    );
    return;
  }
  _clipRectLayer.layer = null;
  _paintTexture(context, offset);
}