Donut

Additional

Language
Kotlin
Version
2.0.0 (May 20, 2020)
Created
Oct 16, 2019
Updated
Oct 13, 2020
Owner
Futured (futuredapp)
Contributors
Lukáš Sztefek (skywall)
Martin Sumera (SumeraMartin)
Ondřej Kalman (okalman)
Matej Semančík (matejsemancik)
Michal Šrůtek (michalsrutek)
Chris Eldon (eldon97)
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Donut

Donut is an Android library which helps you to easily create beautiful doughnut-like charts.

Installation

module/build.gradle:

dependencies {
    implementation("app.futured.donut:library:$version")

    // If you want to use Jetpack Compose version then use only this one dependency
    implementation("app.futured.donut:library-compose:$version")
}

Features

DonutProgressView is a configurable doughnut-like chart view capable of displaying multiple sections with assignable colors. It supports animations and features a gap at the top, which makes it look like a gauge (or tasty bitten-off donut - that's why the name).

The view automatically scales it's sections proportionally to their values once it gets filled up. This allows you to show your users their daily progresses, reached goals, etc.

Usage

Place the view in your layout

<app.futured.donut.DonutProgressView
    android:id="@+id/donut_view"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:donut_bgLineColor="@color/cloud"
    app:donut_gapWidth="20"
    app:donut_gapAngle="270"
    app:donut_strokeWidth="16dp"/>

Submit data to the view

val section1 = DonutSection(
    name = "section_1",
    color = Color.parseColor("#FB1D32"),
    amount = 1f
)

val section2 = DonutSection(
    name = "section_2",
    color = Color.parseColor("#FFB98E"),
    amount = 1f
)

donut_view.cap = 5f
donut_view.submitData(listOf(section1, section2))

You'll get something like this:

About the data cap

Once the sum of all section values exceeds view's cap property, the view starts to scale it's sections proportionally to their amounts along it's length. E.g. if we, in the upper example, set cap to donut_view.cap = 1f (section1.amount + section2.amount > 1f), we would get something like this:

Submitting data

The view accepts list of DonutSection objects that define data to be displayed. Each DonutSection object holds section's unique name (string), it's color (color int) and section's value. (Note: the view uses unique name for each section to resolve it's internal state and animations, and throws IllegalStateException if multiple sections with same name are submitted.)

val waterAmount = DonutSection(
    name = "drink_amount_water",
    color = Color.parseColor("#03BFFA"),
    amount = 1.2f
)

You have to submit new list of sections everytime you want to modify displayed data, as DonutSection object is immutable.

donut_view.submitData(listOf(waterAmount))

Granular controls

The view also provides methods for more granular control over displayed data. You can use addAmount, setAmount and removeAmount methods to add, set or remove specified amounts from displayed sections.

Adding amount
donut_view.addAmount(
    sectionName = "drink_amount_water",
    amount = 0.5f,
    color = Color.parseColor("#03BFFA") // Optional, pass color if you want to create new section
)

The addAmount adds specified amount to section with provided name. What if section does not yet exist? This method has one optional color parameter (default value is null) - when called, and there isn't already displayed any section with provided name and color parameter was specified, the new DonutSection with provided name, amount and color will be automatically created internally for you. If you leave the color param null while trying to add value to non-existent section, nothing happens.

Setting amount
donut_view.setAmount(
    sectionName = "drink_amount_water",
    amount = 2.5f
)

The setAmount methods sets specified amount to section with provided name. If provided amount is equal or less than 0, section and corresponding progress line are automatically removed after animation. If view does not contain specified section, nothing happens.

Removing amount
donut_view.removeAmount(
    sectionName = "drink_amount_water",
    amount = 0.1f
)

The removeAmount simply subtracts specified amount from any displayed section. If resulting amount is equal or less than 0, section and corresponding progress line are automatically removed after animation. If view does not contain specified section, nothing happens.

Get and clear data

If you want to get currently displayed data, call getData() method which returns immutable list of all displayed DonutSection objects. To clear displayed data, call clear() method.

Each call to a data method (submit, add, set, remove, clear) results in view automatically resolving and animating to the new state.

Customization

The view allows you to configure various properties to let you create a unique style that fits your needs. They can be changed either via XML attributes, or at runtime via property access.

XML attributes

Name Default value Description
donut_cap 1.0f View's cap property
donut_strokeWidth 12dp Width of background and section lines in dp
donut_strokeCap round The paint cap used for all lines. Can be either 'round' or 'butt'
donut_bgLineColor #e7e8e9 Color of background line
donut_gapWidth 45° Width of the line gap in degrees
donut_gapAngle 90° Position of the line gap around the view in degrees
donut_direction clockwise Progress lines direction (clockwise or anticlockwise)
donut_animateChanges true Animation enabled flag, if true, the view will animate it's state changes (enabled by default)
donut_animationInterpolator DecelerateInterpolator Interpolator to be used in state change animations
donut_animationDuration 1000 ms Duration of state change animations in ms

In addition to these XML attributes, the view features masterProgress property (0f to 1f) that can be changed programatically. It controls percentual progress of all lines, including the background line, which allows you to get creative with startup animations, etc.

Jetpack Compose version

This library is implemented as a standalone module also for Jetpack Compose. It has the same features as the original implementation, but it supports a wider variety of animations.

@Composable
fun Sample() {
    DonutProgress(
        model = DonutModel(
            cap = 8f,
            masterProgress = 1f,
            gapWidthDegrees = 270f,
            gapAngleDegrees = 90f,
            strokeWidth = 40f,
            backgroundLineColor = Color.LightGray,
            sections = listOf(
                DonutSection(amount = 1f, color = Color.Cyan),
                DonutSection(amount = 1f, color = Color.Red),
                DonutSection(amount = 1f, color = Color.Green),
                DonutSection(amount = 0f, color = Color.Blue)
            )
        ),
        config = DonutConfig(
            isGapAngleAnimationEnabled = true,
            gapAngleAnimationBuilder = TweenBuilder()
            // ...
        )
    )
}

Sample app

The quickest way to explore different styles is to try the sample app, which contains an interactive playground with buttons and sliders to fiddle with.

Contributors

Current maintainer and main contributor for the original version is Matej Semančík and for Jetpack Compose version is Martin Sumera

Licence

Donut is available under MIT license. See LICENSE file for more information.