adaptive_scrollbar

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Language: English

Adaptive Scrollbar is a library that allows you to create one or more desktop-style scrollbars on a single screen, each of which is bound only to its own object and placed in its own place on the screen.

How to use it

Just wrap with AdaptiveScrollbar your widget that contains your ScrollView object and specify the controller that is attached to this ScrollView object.

AdaptiveScrollbar(
  controller: controller,
  child: Center(
    child: ListView.builder(
      controller: controller,
      itemBuilder: (context, index) { 
        return Text(
            "Line " + index.toString());
      },
      itemCount: 50,
    ))),

pic

Multiple scrollbars

You can add multiple scrollbars to the screen at once. The controller is a required parameter in order to track changes to only one object if there are several ScrollView objects in your widget.

return AdaptiveScrollbar(
  controller: verticalScroll,
  width: width,
  child: AdaptiveScrollbar(
    controller: horizontalScroll,
    width: width,
    position: ScrollbarPosition.bottom,
    bottomPadding: EdgeInsets.only(bottom: verticalWidth),
    child: SingleChildScrollView(
      controller: horizontalScroll,
      scrollDirection: Axis.horizontal,
      child: Container(
        width: 2000,
        child: Container(
          color: Colors.lightBlueAccent,
          child: ListView.builder(
            controller: verticalScroll,
            itemCount: 30,
            itemBuilder: (context, index) {
              return Container(
                height: 30,
                child: Text("Line " + index.toString()));
            }))),
    )));

pic

Customization

You can position your scrollbar on any of the 4 sides of the screen. There is only one thing - if you choose ScrollbarPosition.top or ScrollbarPosition.bottom, your scrollbar will actually be rotated 90 degrees, and the top will be on the right. Do not forget about this if you specify the paddings for bottom and slider. I'll think about how to simplify this.

AdaptiveScrollbar(
  controller: verticalScroll,
  width: verticalWidth,
  child: AdaptiveScrollbar(
    controller: horizontalScroll,
    position: ScrollbarPosition.bottom,
    
    //the horizontal scrollbar will have a padding
    // on the LEFT by the width of the vertical scrollbar
    bottomPadding: EdgeInsets.only(bottom: verticalWidth),
    
    width: horizontalWidth,
    child: ...
),

pic

To set slider width, you can set the horizontal sliderPadding. The vertical sliderPadding will determine the padding of the slider from the start and the end of the bottom. The height of the slider is determined automatically based on the size of the ScrollView object. If ScrollView object has nowhere to scroll, the scrollbar will not be displayed on the screen.

You can set colors for bottom and slider, or completely set the decorations for them.

Slider scroll-to-click speed

You can set your own speed parameters for moving the slider in the direction of the click. scrollToClickDelta is the distance that the slider will move in one move. scrollToClickFirstDelay is the duration of the first delay between the slider moves in the direction of the click, in milliseconds. scrollToClickOtherDelay is the duration of the remaining delays between scrolls in the click direction, in milliseconds.

AdaptiveScrollbar(
  ...
  scrollToClickDelta: 75,
  scrollToClickFirstDelay: 200,
  scrollToClickOtherDelay: 50,
  ...
),

Parameters

ParameterDescriptionTypeDefault value
childWidget that contains your ScrollView.Widgetrequired
controllerController that attached to ScrollView object.ScrollControllerrequired
positionPosition of scrollbar on the screen.ScrollbarPosition (enum)ScrollbarPosition.right
widthWidth of all scrollBar.double16.0
bottomColorBottom color.ColorColors.white
sliderDefaultColorDefault slider color.ColorColors.blueGrey
sliderActiveColorActive slider color.ColorsliderDefaultColor.withRed(10)
bottomDecorationBottom decoration.BoxDecorationBoxDecoration(shape: BoxShape.rectangle, color: bottomColor)
sliderDecorationSlider decoration.BoxDecorationBoxDecoration(shape: BoxShape.rectangle, color: sliderDefaultColor)
scrollToClickDeltaOffset of the slider in the direction of the click.double100.0
scrollToClickFirstDelayDuration of the first delay between scrolls in the click direction, in milliseconds.int400
scrollToClickOtherDelayDuration of the others delays between scrolls in the click direction, in milliseconds.int100
bottomPaddingBottom padding. Don't forget about rotation that depends on position.EdgeInsetsGeometryconst EdgeInsets.all(0.0)
sliderPaddingSlider padding from bottom. Don't forget about rotation that depends on position.EdgeInsetsGeometryconst EdgeInsets.all(2.0)

Libraries

adaptive_scrollbar