private void paintImageSpan(PaintingContext context, Offset offset)
{
var canvas = context.canvas;
var bounds = offset & size;
canvas.save();
var textOffset = 0;
foreach (var span in text.children)
{
if (span is ImageSpan imageSpan)
{
var offsetForCaret = getOffsetForCaret(
new TextPosition(offset: textOffset),
bounds
);
if (textOffset != 0 &&
offsetForCaret.dx == 0F &&
offsetForCaret.dy == 0F)
{
return;
}
var topLeftOffset = new Offset(
offset.dx + offsetForCaret.dx - (textOffset == 0 ? 0 : 0),
offset.dy + offsetForCaret.dy
);
if (imageSpan.imageResolver.image == null)
{
canvas.drawRect(
rect: Rect.fromLTWH(
topLeftOffset.dx + imageSpan.margin.left,
topLeftOffset.dy + imageSpan.margin.top,
imageSpan.innerWidth,
imageSpan.innerHeight
),
paint: ImagePlaceholderBackgroundPaint);
var textBlobBuilder = new TextBlobBuilder();
var text = $"{(char) Icons.MaterialImage.codePoint}";
var iconSize = imageSpan.innerWidth > imageSpan.innerHeight * 3
? imageSpan.innerHeight * 3 / 4
: imageSpan.innerWidth / 4;
textBlobBuilder.allocRunPos(
style: new TextStyle(
fontFamily: Icons.MaterialImage.fontFamily,
fontSize: iconSize
),
text: text,
offset: 0,
size: text.Length);
var rect = topLeftOffset & new Size(imageSpan.innerWidth, imageSpan.innerHeight);
textBlobBuilder.setBounds(rect.toRect());
canvas.drawTextBlob(
textBlobBuilder.make(),
new Offset(
rect.left + (rect.width - iconSize) / 2,
rect.top + (rect.height + iconSize) / 2),
ImagePlaceholderPaint);
imageSpan.imageResolver.Resolve((imageInfo, synchronousCall) =>
{
if (synchronousCall)
{
ImageUtils.paintImage(
canvas: canvas,
rect: topLeftOffset & new Size(imageSpan.width, imageSpan.height),
image: imageSpan.imageResolver.image,
fit: BoxFit.scaleDown,
alignment: Alignment.center
);
}
else
{
if (owner == null || !owner.debugDoingPaint)
{
markNeedsPaint();
}
}
});
textOffset += imageSpan.toPlainText().Length;
continue;
}
ImageUtils.paintImage(
canvas: canvas,
rect: Rect.fromLTWH(
topLeftOffset.dx + imageSpan.margin.left,
topLeftOffset.dy + imageSpan.margin.top,
imageSpan.innerWidth,
imageSpan.innerHeight
),
image: imageSpan.imageResolver.image,
fit: BoxFit.scaleDown,
alignment: Alignment.center
);
}
textOffset += span.toPlainText().Length;
}
canvas.restore();
}