Remove weird space between column elements - flutter

Question

I have the following layout:
I want to remove the space between the upper box and the buttons, so both appear to be in the same box.
Code:
Column(
children: [
// RAW CONTENT
ConstrainedBox(
constraints: BoxConstraints(
maxWidth: double.infinity,
maxHeight: MediaQuery.of(context).size.height *
_PREVIEW_MAX_HEIGHT_RATIO),
child: Container(
padding: EdgeInsets.only(
left: MARGIN_LAT,
top: MARGIN_TOP,
right: MARGIN_LAT),
child: Container(
decoration: BoxDecoration(
border: Border.all(color: Colors.black38),
borderRadius: BorderRadius.only(
topLeft: _ROUND_BORDER,
topRight: _ROUND_BORDER)),
child: Center(child: Text(_displayValue))),
),
),
// CONTENT BUTTONS
Container(
padding: EdgeInsets.only(
left: MARGIN_LAT, top: 0, right: MARGIN_LAT),
child: Row(
children: [
Expanded(
child: RaisedButton(
padding: EdgeInsets.zero,
child: Text(_static.translate(
context, 'result_contentButton_raw')),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.only(
bottomLeft: _ROUND_BORDER)),
onPressed: () {}),
),
Expanded(
child: RaisedButton(
padding: EdgeInsets.zero,
child: Text(_static.translate(context,
'result_contentButton_displayValue')),
shape: ContinuousRectangleBorder(),
onPressed: () {}),
),
Expanded(
child: RaisedButton(
padding: EdgeInsets.zero,
child: Text(_static.translate(
context, 'result_contentButton_copy')),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.only(
bottomRight: _ROUND_BORDER)),
onPressed: () {}),
)
],
),
),
],
),
Is there any way to do this? Thanks.

Answer 1

The margin you notice is because of the default value for materialTapTargetSize on RaisedButton Widget.
To remove it, change it to MaterialTapTargetSize.shrinkWrap as follows:
Expanded(
child: RaisedButton(
materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
padding: EdgeInsets.zero,
child: Text("This is an other text"),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.only(
bottomLeft: _ROUND_BORDER
)
),
onPressed: () {}
),
)