Widgets in this package:
ColumnSuper
RowSuper
FitHorizontally
Box
WrapSuper
TextOneLine
I will slowly but surely add interesting widgets to this package.
Given a list of children widgets, this will arrange them in a column. It can overlap cells, add separators and more.
ColumnSuper({
List<Widget> children,
double outerDistance,
double innerDistance,
bool invert,
Alignment alignment,
Widget separator,
bool separatorOnTop,
});
children
is the list of widgets that represent the column cells, just like in a regular Column
widget. However, the list may contain null
s, which will be ignored.
outerDistance
is the distance in pixels before the first and after the last widget. It can be negative, in which case the cells will overflow the column.
innerDistance
is the distance in pixels between the cells. It can be negative, in which case the cells will overlap.
invert
if true will paint the cells that come later on top of the ones that came before. This is specially useful when cells overlap (negative innerDistance
).
alignment
will align the cells horizontally if they are smaller than the available horizontal space.
separator
is a widget which will be put between each cells. Its height doesn’t matter, since the distance between cells is given by innerDistance
(in other words, separators don’t occupy space). The separator will overflow if its width is larger than the column’s width.
separatorOnTop
if true
(the default) will paint the separator on top of the cells. If false
will paint the separator below the cells.
Note: This is not a substitute for Flutter’s native Column
, it doesn’t try to have a similar API, and it doesn’t do all that Column
does. In special, Expanded
and Flexible
widgets don’t work inside of ColumnSuper
, and it will overflow if the column is not big enough to fit its contents. ColumnSuper
is meant only for certain use cases where Column
won’t work, like when you need overlapping cells.
Try running the ColumnSuper example.
Given a list of children widgets, this will arrange them in a row. It can overlap cells, add separators and more.
RowSuper({
List<Widget> children,
double outerDistance,
double innerDistance,
bool invert,
Alignment alignment,
Widget separator,
bool separatorOnTop,
bool fitHorizontally,
double shrinkLimit,
MainAxisSize mainAxisSize,
});
On contrary to ColumnSuper
and the native Row
(which will overflow if the cells are not big enough to fit their content), RowSuper
will resize its cells, proportionately to the width of the minimum intrinsic width of each cell content.
Try running the RowSuper example.
Most parameters are the same as the ones of ColumnSuper
, except:
fitHorizontally
if true will resize the cells content, horizontally only, until the shrinkLimit
is reached.
shrinkLimit
by default is 67%, which means the cell contents will shrink until 67% of their original width, and then overflow. Make shrinkLimit
equal to 0.0
if you want the cell contents to shrink with no limits. Note, if fitHorizontally
is false, the shrinkLimit
is not used.
mainAxisSize
by default is MainAxisSize.min
, which means the row will occupy no more than its content’s width. Make it MainAxisSize.max
to expand the row to occupy the whole horizontal space.
You can also use a RowSpacer
to add empty space (if available) between cells. For example:
RowSuper(
children: [
widget1,
RowSpacer(),
widget2,
widget3,
]
)
);
Try running the RowSuper with FitHorizontally example.
Note: This is not a substitute for Flutter’s native Row
, it doesn’t try to have a similar API, and it doesn’t do all that Row
does. In special, Expanded
and Flexible
widgets don’t work inside of RowSuper
, since RowSuper
will resize cells proportionately when content doesn’t fit. RowSuper
is meant only for certain use cases where Row
won’t work, like when you need overlapping cells, or when you need to scale the contents of the cells when they don’t fit.
FitHorizontally({
Widget child,
double shrinkLimit,
bool fitsHeight,
AlignmentGeometry alignment,
});
The child
will be asked to define its own intrinsic height. If fitsHeight
is true, the child will be proportionately resized (keeping its aspect ratio) to fit the available height.
Then, if the child doesn’t fit the width, it will be shrinked horizontally only (not keeping its aspect ratio) until it fits, unless shrinkLimit
is larger than zero, in which case it will shrink only until that limit. Note if shrinkLimit
is 1.0 the child will not shrink at all. The default is 0.67 (67%).
This is specially useful for text that is displayed in a single line. When text doesn’t fit the container it will shrink only horizontally, until it reaches the shrink limit. From that point on it will clip, display ellipsis or fade, according to the text’s Text.overflow
property.
Note: FitHorizontally
with shrinkLimit
0.0 is not the same as FittedBox
with BoxFit.fitWidth
, because FitHorizontally
will only scale horizontally, while FittedBox
will maintain the aspect ratio.
Try running the FitHorizontally example.
Box
is something between a Container
and a SizedBox
, which is less verbose and can be made const
.
const Box({
bool show,
Color color,
double top,
double right,
double bottom,
double left,
double vertical,
double horizontal,
double width,
double height,
Alignment alignment,
Widget child,
});
Since it can be made const
, it’s good for creating colored boxes, with or without a child and padding:
const Box(color: Colors.red, width: 50, height:30);
The padding is given by top
, right
, bottom
and left
values, but they are only applied if the child is not null. If the child
, width
and height
are all null
, this means the box will occupy no space (will be hidden). Note: This will be extended in the future, so that it ignores horizontal padding when the child has zero width, and ignores vertical padding when the child has zero height.
If top
and bottom
are equal, you can instead provide vertical
:
// This:
const Box(top: 20, bottom:20, child: ...);
// Is the same as this:
const Box(vertical: 20, child: ...);
You can’t provide vertical
and top
or bottom
at the same time.
Similarly, if right
and left
are equal, you can instead provide horizontal
. You can’t provide horizontal
and right
or left
at the same time.
You can also hide the box by making the show
parameter equal to false
.
Box
can be used as a cleaner substitute for Padding
. For example, this code:
return Container(
padding: const EdgeInsets.symmetric(vertical: 8.0, horizontal: 5.0),
color: Colors.green,
child: const Padding(
padding: EdgeInsets.only(top: 12.0, bottom: 12.0, left: 4.0),
child: Text("Hello."),
),
),
);
Is the functional equivalent of this:
return const Box(
vertical: 8.0,
horizontal: 5.0,
color: Colors.green,
child: Box(vertical: 12.0, left: 4.0, child: Text("Hello.")),
);
If need to quickly and temporarily add a color to your box so that you can see it, you can use the constructors Box.r
for red, Box.g
for green, Box.b
for blue, and Box.y
for yellow.
Box(child: myChild);
Box.r(child: myChild);
Box.g(child: myChild);
Box.b(child: myChild);
Box.y(child: myChild);
If you want to see rebuilds, you can use the Box.rand
constructor. It will then change its color to a random one, whenever its build method is called.
Box.rand(child: myChild);
WrapSuper
is similar to the native Wrap
widget with direction = Axis.horizontal
, but it allows you to choose different algorithms for the line-breaks.
WrapSuper
displays its children in lines. It will leave spacing
horizontal space between each child, and it will leave lineSpacing
vertical space between each line. The contents of each line will then be aligned according to the alignment
. The algorithm for the line-breaks is chosen by wrapType
.
WrapSuper({
Key key,
WrapType wrapType,
double spacing,
double lineSpacing,
WrapSuperAlignment alignment,
List<Widget> children,
});
WrapSuper
with WrapType.fit
uses a greedy algorithm for line breaks, which is the same one used by the native Wrap
widget.
However, WrapSuper
with WrapType.balanced
(the default) uses a minimum raggedness algorithm for line breaks. It will position its child widgets in the same number of lines as the greedy algorithm, but these lines will tend to be more similar in width.
For example:
Here is my original StackOverflow question that resulted in this widget.
The algorithm I used was based on this one (Divide and Conquer), which always considers spacing: 1.0
. It was changed (with the help of CodeChef) to allow for other spacings.
Add your thumbs up here if you want native Text
widgets to also allow for better line-breaks.
TextOneLine
is a substitute for Text
when maxLines: 1
, to fix this issue: https://github.com/flutter/flutter/issues/18761 filled by myself a long time ago.
It uses a special fade-with-ellipsis, which is much better than the current buggy and ugly-looking ellipsis-that-cuts-the-whole-word.
For example, this:
Text("This isAVeryLongWordToDemonstrateAProblem", maxLines: 1, softWrap: false);
Will print this in the screen:
This ...
While this:
TextOneLine("This isAVeryLongWordToDemonstrateAProblem");
Will print this:
This isAVeryLongWordToDemonst...
This widget probably only makes sense while that issue is not fixed.
See package align_positioned for widgets AlignPositioned
and its siblings AnimatedAlignPositioned
and AnimChain
. They should be part of this package, but will remain in their own package for historical reasons.
Author: marcglasberg
GitHub: https://github.com/marcglasberg/assorted_layout_widgets
#flutter #dart #programming #mobile-apps