ValueDecoration class

Draw value of the items on them. Use this only as ChartState.foregroundDecorations in order to be visible at all locations Exact alignment can be set with alignment

Inheritance
Annotations
  • @Deprecated('Use [WidgetItemBuilder] instead if you want to decorate chart items with text')

Constructors

ValueDecoration({TextStyle? textStyle, Alignment alignment = Alignment.topCenter, int listIndex = 0, ValueFromItem valueGenerator = defaultValueForItem, bool hideZeroValues = false, LabelFromItem? labelGenerator})
Constructor for values decoration

Properties

alignment → Alignment
Alignment of the text based on item
final
hashCode → int
The hash code for this object.
no setterinherited
hideZeroValues → bool
final
labelGenerator → LabelFromItem?
Generate a custom label that is used.
final
listIndex → int
Index of list in items, this is used if there are multiple lists in the chart
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
textStyle → TextStyle?
Style for values to use
final
valueGenerator → ValueFromItem
final

Methods

animateTo(DecorationPainter endValue, double t) → DecorationPainter
Animate to next decoration state, each decoration should implement this. This is just regular lerp function, but instead of static function where you pass start and end state, here we start with current state and animate to endValue.
override
applyPaintTransform(ChartState state, Size size) → Offset
override
draw(Canvas canvas, Size size, ChartState state) → void
Draw decoration. Decoration can be foreground or background decoration that will be drawn on the chart decorations can ignore padding and can use whole available canvas to draw.
override
getRenderer(ChartState state) → Widget
inherited
initDecoration(ChartState state) → void
Init decoration is first thing called on decorations, it will pass current ChartState so decoration can easily calculate needed stuff for their layout.
override
isSameType(DecorationPainter other) → bool
Used for animating, we just need to find matching type, don't actually check for equality since we want to animate from one state to other. Some decorations may consider overriding this in case multiples are used
override
layoutSize(BoxConstraints constraints, ChartState state) → Size
override
marginNeeded() → EdgeInsets
Get extra margin (not definable by the user). This makes sure that any decoration that leaves original drawing window is not drawing outside of that window (This is not enforced right now but it's unwanted behaviour)
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
paddingNeeded() → EdgeInsets
Get extra padding (not definable by user, calculated by decoration if needed). This makes sure that decoration will fit with the chart in wanted area.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Methods

makeTextPainter(String value, double width, TextStyle? style, {bool hasMaxWidth = true}) → TextPainter
Get default text painter with set value Helper for _paintText