BasePainter class abstract

Inheritance
Implementers

Constructors

BasePainter({required double scrollX, required double scale, required double pointSpace, required double pointWidth, double paddingTop = 0, double paddingLeft = 0, double paddingRight = 0, Offset? pressOffset})

Properties

canvasHeight ↔ double
getter/setter pair
canvasWidth ↔ double
getter/setter pair
endIndex ↔ int
getter/setter pair
hashCode → int
The hash code for this object.
no setterinherited
maxValue ↔ double
最大数据
getter/setter pair
minValue ↔ double
最小数据
getter/setter pair
paddingLeft → double
final
paddingRight → double
final
paddingTop → double
final
pointSpace → double
点之间的间距
final
pointWidth → double
final
pressOffset → Offset?
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
scale → double
放大倍数
final
scrollX → double
滚动位置
final
semanticsBuilder → SemanticsBuilderCallback?
Returns a function that builds semantic information for the picture drawn by this painter.
no setterinherited
startIndex ↔ int
getter/setter pair

Methods

addListener(VoidCallback listener) → void
Register a closure to be notified when it is time to repaint.
inherited
bisectionTransformXToIndex(double x, int start, int end) → int
二分查找法
createText({required String text, required TextStyle style}) → TextPainter
创建一个文本TextPainter
dxToTransformX(double dx) → double
X轴坐标值转translate后的坐标值
getValues() → List<double>
获取转换后的数据列表
hitTest(Offset position) → bool?
Called whenever a hit test is being performed on an object that is using this custom paint delegate.
inherited
indexToX(int index) → double
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
onCompute(Size size) → void
获取画布宽度和高度 计算当前屏内相对转换后的X轴位置 根据X轴位置，计算屏内起始和结束展示数据的索引 计算最大值和最小值
onDraw(Canvas canvas) → void
paint(Canvas canvas, Size size) → void
Called whenever the object needs to paint. The given Canvas has its coordinate space configured such that the origin is at the top left of the box. The area of the box is the size of the size argument.
override
removeListener(VoidCallback listener) → void
Remove a previously registered closure from the list of closures that the object notifies when it is time to repaint.
inherited
shouldRebuildSemantics(covariant CustomPainter oldDelegate) → bool
Called whenever a new instance of the custom painter delegate class is provided to the RenderCustomPaint object, or any time that a new CustomPaint object is created with a new instance of the custom painter delegate class (which amounts to the same thing, because the latter is implemented in terms of the former).
inherited
shouldRepaint(covariant CustomPainter oldDelegate) → bool
Called whenever a new instance of the custom painter delegate class is provided to the RenderCustomPaint object, or any time that a new CustomPaint object is created with a new instance of the custom painter delegate class (which amounts to the same thing, because the latter is implemented in terms of the former).
override
toString() → String
A string representation of this object.
inherited
transformValues() → List<double>
transformXToIndex(double translateX) → int
将translate后的坐标值转换成数据索引
valueToY(double value) → double

Operators

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