Progress / Meter

Report task completion with a progress bar, or a measurement within a known range with a meter.

Determinate progress

BitBhProgress renders role="progressbar" with aria-valuenow/min/max and a percentage aria-valuetext. It exposes --bit-bh-progress (a unitless 0–100 number) and data-state="loading|complete"; size the BitBhProgressIndicator with calc(var(--bit-bh-progress) * 1%). Name it with aria-labelledby.

Profile completion 60%

<div class="progress-card">
    <div class="progress-header">
        <span class="progress-label" id="profile-label">Profile completion</span>
        <span class="progress-status">@profile%</span>
    </div>
    <BitBhProgress Value="profile" aria-labelledby="profile-label" class="progress">
        <BitBhProgressIndicator class="progress-indicator" />
    </BitBhProgress>
    <div class="progress-actions">
        <button type="button" class="progress-btn" @onclick="() => profile = Math.Max(0, profile - 20)">− 20%</button>
        <button type="button" class="progress-btn" @onclick="() => profile = Math.Min(100, profile + 20)">+ 20%</button>
    </div>
</div>

@code {
    private double profile = 60;
}

/* All styles are consumer-authored — the library ships zero CSS */
.progress {
    position: relative;
    overflow: hidden;
    width: 100%;
    height: 0.6rem;
    border-radius: 999px;
    background: #e4e4e7;
}

/* --bit-bh-progress is a unitless 0–100 number set inline by BitBhProgress and
   BitBhProgressIndicator; multiply by 1% to size the fill. */
.progress-indicator {
    width: calc(var(--bit-bh-progress, 0) * 1%);
    height: 100%;
    border-radius: inherit;
    background: #2563eb;
    transition: width 250ms ease, background-color 250ms ease;
}

/* data-state="loading | complete | indeterminate" */
.progress-indicator[data-state="complete"] { background: #16a34a; }

/* Labelled card around the bar */
.progress-card {
    display: grid;
    gap: 0.6rem;
    width: 100%;
    max-width: 24rem;
    padding: 1rem;
    border: 1px solid #e4e4e7;
    border-radius: 0.6rem;
    background: #fff;
}

.progress-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 1rem;
    font-size: 0.875rem;
}

.progress-label { font-weight: 600; color: #18181b; }

.progress-status {
    color: #71717a;
    font-size: 0.8rem;
    font-variant-numeric: tabular-nums;
}

.progress-actions { display: flex; gap: 0.5rem; }

.progress-btn {
    all: unset;
    box-sizing: border-box;
    display: inline-flex;
    align-items: center;
    padding: 0.35rem 0.75rem;
    border: 1px solid #e4e4e7;
    border-radius: 0.45rem;
    background: #fff;
    color: #3f3f46;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
}

.progress-btn:hover         { background: #f4f4f5; }
.progress-btn:focus-visible { outline: 2px solid #2563eb; outline-offset: 2px; }
.progress-btn:disabled      { opacity: 0.5; cursor: not-allowed; }

Simulated upload

A timer drives Value in megabytes against Max="8"; ValueText turns it into "2.4 of 8 MB uploaded" for screen readers. The upload starts with Value="null" (indeterminate) while "preparing". Template receives the computed percentage (double?) to draw the label inside the bar. The page implements IDisposable to stop the timer.

quarterly-report.pdf Ready

@implements IDisposable

<div class="progress-card">
    <div class="progress-header">
        <span class="progress-label" id="upload-label">quarterly-report.pdf</span>
        <span class="progress-status">@UploadStatus()</span>
    </div>
    <BitBhProgress Value="uploaded" Max="FileSizeMb"
                ValueText="@((v, max) => $"{v:0.0} of {max:0} MB uploaded")"
                aria-labelledby="upload-label" class="progress progress-lg">
        <Template Context="percent">
            <BitBhProgressIndicator class="progress-indicator" />
            <span class="progress-percent">@(percent is null ? "" : $"{percent:0}%")</span>
        </Template>
    </BitBhProgress>
    <div class="progress-actions">
        <button type="button" class="progress-btn progress-btn-primary"
                disabled="@uploading" @onclick="StartUpload">
            @(uploaded >= FileSizeMb ? "Upload again" : "Start upload")
        </button>
        <button type="button" class="progress-btn"
                disabled="@(!uploading)" @onclick="CancelUpload">Cancel</button>
    </div>
</div>

@code {
    private const double FileSizeMb = 8;
    private double? uploaded = 0;          // null = indeterminate
    private bool uploading;
    private int uploadTicks;
    private System.Threading.Timer? uploadTimer;

    private string UploadStatus()
    {
        if (uploaded is null) return "Preparing…";
        if (uploaded >= FileSizeMb) return "Complete";
        if (!uploading) return "Ready";
        return $"{uploaded:0.0} of {FileSizeMb:0} MB";
    }

    private void StartUpload()
    {
        uploadTimer?.Dispose();
        uploading = true;
        uploaded = null;   // indeterminate while "preparing"
        uploadTicks = 0;
        uploadTimer = new System.Threading.Timer(_ => InvokeAsync(UploadTick), null, 150, 150);
    }

    private void UploadTick()
    {
        if (!uploading) return;
        uploadTicks++;
        if (uploadTicks > 6)   // ~1 s of "preparing" first
        {
            uploaded = Math.Min(FileSizeMb, (uploaded ?? 0) + 0.2);
            if (uploaded >= FileSizeMb) StopTimer();
        }
        StateHasChanged();
    }

    private void CancelUpload()
    {
        StopTimer();
        uploaded = 0;
    }

    private void StopTimer()
    {
        uploading = false;
        uploadTimer?.Dispose();
        uploadTimer = null;
    }

    public void Dispose() => uploadTimer?.Dispose();
}

/* All styles are consumer-authored — the library ships zero CSS */
.progress {
    position: relative;
    overflow: hidden;
    width: 100%;
    height: 0.6rem;
    border-radius: 999px;
    background: #e4e4e7;
}

/* --bit-bh-progress is a unitless 0–100 number set inline by BitBhProgress and
   BitBhProgressIndicator; multiply by 1% to size the fill. */
.progress-indicator {
    width: calc(var(--bit-bh-progress, 0) * 1%);
    height: 100%;
    border-radius: inherit;
    background: #2563eb;
    transition: width 250ms ease, background-color 250ms ease;
}

/* data-state="loading | complete | indeterminate" */
.progress-indicator[data-state="complete"] { background: #16a34a; }

.progress-indicator[data-state="indeterminate"] {
    width: 40%;
    animation: progress-demo-slide 1.2s ease-in-out infinite;
}

@keyframes progress-demo-slide {
    from { transform: translateX(-100%); }
    to   { transform: translateX(250%); }
}

@media (prefers-reduced-motion: reduce) {
    .progress-indicator[data-state="indeterminate"] { animation-duration: 3s; }
}

/* Tall bar with the percentage drawn through BitBhProgress's Template */
.progress-lg { height: 1.25rem; }

.progress-lg .progress-indicator                         { background: #bfdbfe; }
.progress-lg .progress-indicator[data-state="complete"]  { background: #bbf7d0; }

.progress-percent {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding: 0 0.6rem;
    color: #1e3a8a;
    font-size: 0.72rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
}

/* Labelled card around the bar */
.progress-card {
    display: grid;
    gap: 0.6rem;
    width: 100%;
    max-width: 24rem;
    padding: 1rem;
    border: 1px solid #e4e4e7;
    border-radius: 0.6rem;
    background: #fff;
}

.progress-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 1rem;
    font-size: 0.875rem;
}

.progress-label { font-weight: 600; color: #18181b; }

.progress-status {
    color: #71717a;
    font-size: 0.8rem;
    font-variant-numeric: tabular-nums;
}

.progress-actions { display: flex; gap: 0.5rem; }

.progress-btn {
    all: unset;
    box-sizing: border-box;
    display: inline-flex;
    align-items: center;
    padding: 0.35rem 0.75rem;
    border: 1px solid #e4e4e7;
    border-radius: 0.45rem;
    background: #fff;
    color: #3f3f46;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
}

.progress-btn:hover         { background: #f4f4f5; }
.progress-btn:focus-visible { outline: 2px solid #2563eb; outline-offset: 2px; }
.progress-btn:disabled      { opacity: 0.5; cursor: not-allowed; }

.progress-btn-primary       { background: #2563eb; border-color: #2563eb; color: #fff; }
.progress-btn-primary:hover { background: #1d4ed8; }

Indeterminate

Leave Value unset (null) when the duration is unknown: aria-valuenow is omitted, data-state="indeterminate" is set and --bit-bh-progress is absent, so CSS can switch to an animation. Honor prefers-reduced-motion.

Syncing mailbox Waiting for the server…

<div class="progress-card">
    <div class="progress-header">
        <span class="progress-label" id="sync-label">Syncing mailbox</span>
        <span class="progress-status">Waiting for the server…</span>
    </div>
    @* No Value: indeterminate *@
    <BitBhProgress aria-labelledby="sync-label" class="progress">
        <BitBhProgressIndicator class="progress-indicator" />
    </BitBhProgress>
</div>

/* All styles are consumer-authored — the library ships zero CSS */
.progress {
    position: relative;
    overflow: hidden;
    width: 100%;
    height: 0.6rem;
    border-radius: 999px;
    background: #e4e4e7;
}

/* --bit-bh-progress is a unitless 0–100 number set inline by BitBhProgress and
   BitBhProgressIndicator; multiply by 1% to size the fill. */
.progress-indicator {
    width: calc(var(--bit-bh-progress, 0) * 1%);
    height: 100%;
    border-radius: inherit;
    background: #2563eb;
    transition: width 250ms ease, background-color 250ms ease;
}

/* data-state="loading | complete | indeterminate" */
.progress-indicator[data-state="complete"] { background: #16a34a; }

.progress-indicator[data-state="indeterminate"] {
    width: 40%;
    animation: progress-demo-slide 1.2s ease-in-out infinite;
}

@keyframes progress-demo-slide {
    from { transform: translateX(-100%); }
    to   { transform: translateX(250%); }
}

@media (prefers-reduced-motion: reduce) {
    .progress-indicator[data-state="indeterminate"] { animation-duration: 3s; }
}

/* Labelled card around the bar */
.progress-card {
    display: grid;
    gap: 0.6rem;
    width: 100%;
    max-width: 24rem;
    padding: 1rem;
    border: 1px solid #e4e4e7;
    border-radius: 0.6rem;
    background: #fff;
}

.progress-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 1rem;
    font-size: 0.875rem;
}

.progress-label { font-weight: 600; color: #18181b; }

.progress-status {
    color: #71717a;
    font-size: 0.8rem;
    font-variant-numeric: tabular-nums;
}

Meter: disk usage

BitBhMeter (role="meter") shows a scalar within a known range — not task progress. Low and High split the range into data-level="low|optimum|high", and --bit-bh-meter (0–100) sizes the fill. ValueText gives a readable value.

System 231 of 256 GB
Projects 118 of 256 GB
Backup 37 of 256 GB

<ul class="meter-list">
    @foreach (var drive in drives)
    {
        <li class="meter-row">
            <div class="progress-header">
                <span class="progress-label" id="@($"drive-{drive.Id}")">@drive.Name</span>
                <span class="progress-status">@drive.Used of 256 GB</span>
            </div>
            <BitBhMeter Value="drive.Used" Max="256" Low="64" High="200"
                     ValueText="@(v => $"{v} of 256 GB used")"
                     aria-labelledby="@($"drive-{drive.Id}")" class="meter">
                <span class="meter-fill"></span>
            </BitBhMeter>
        </li>
    }
</ul>

@code {
    private readonly (string Id, string Name, double Used)[] drives =
        [("system", "System", 231), ("projects", "Projects", 118), ("backup", "Backup", 37)];
}

/* All styles are consumer-authored — the library ships zero CSS */
.meter {
    position: relative;
    overflow: hidden;
    width: 100%;
    height: 0.5rem;
    border-radius: 999px;
    background: #e4e4e7;
}

/* --bit-bh-meter (0–100) is set inline on the meter and inherited by the fill. */
.meter-fill {
    display: block;
    width: calc(var(--bit-bh-meter) * 1%);
    height: 100%;
    border-radius: inherit;
    background: #2563eb;
    transition: width 250ms ease, background-color 250ms ease;
}

/* data-level="low | optimum | high" (below Low / between / above High) */
.meter[data-level="low"]  .meter-fill { background: #16a34a; }
.meter[data-level="high"] .meter-fill { background: #dc2626; }

.meter-list {
    display: grid;
    gap: 1rem;
    width: 100%;
    max-width: 24rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.meter-row { display: grid; gap: 0.4rem; }

.progress-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 1rem;
    font-size: 0.875rem;
}

.progress-label  { font-weight: 600; color: #18181b; }
.progress-status { color: #71717a; font-size: 0.8rem; font-variant-numeric: tabular-nums; }

Meter: password strength

A 0–4 score with Low="2" and High="3": weak scores are low, fair ones optimum, a full score high. BitBhMeter's Template receives the percentage, used here to fill four segments.

Choose a password

Strength: Very weak

<div class="strength">
    <label for="pw" class="progress-label">Choose a password</label>
    <input id="pw" type="password" class="strength-input" autocomplete="new-password"
           @bind="password" @bind:event="oninput" aria-describedby="pw-strength" />
    <BitBhMeter Value="Score()" Max="4" Low="2" High="3"
             ValueText="@(v => StrengthLabels[(int)v])"
             aria-label="Password strength" class="strength-meter">
        <Template Context="percent">
            @for (var i = 1; i <= 4; i++)
            {
                <span class="strength-segment" data-filled="@(percent >= i * 25)"></span>
            }
        </Template>
    </BitBhMeter>
    <span class="progress-status" id="pw-strength">Strength: <strong>@(StrengthLabels[Score()])</strong></span>
</div>

@code {
    private string password = "";
    private static readonly string[] StrengthLabels = ["Very weak", "Weak", "Fair", "Good", "Strong"];

    private int Score()
    {
        if (password.Length == 0) return 0;
        var score = 0;
        if (password.Length >= 8) score++;
        if (password.Any(char.IsUpper) && password.Any(char.IsLower)) score++;
        if (password.Any(char.IsDigit)) score++;
        if (password.Any(c => !char.IsLetterOrDigit(c))) score++;
        return score;
    }
}

/* All styles are consumer-authored — the library ships zero CSS */
.strength {
    display: grid;
    gap: 0.5rem;
    width: 100%;
    max-width: 20rem;
}

.strength-input {
    padding: 0.5rem 0.75rem;
    border: 1px solid #d4d4d8;
    border-radius: 0.45rem;
    background: #fff;
    font: inherit;
    font-size: 0.9rem;
}

.strength-input:focus-visible { outline: 2px solid #2563eb; outline-offset: 1px; }

/* BitBhMeter root laid out as four segments */
.strength-meter {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.3rem;
}

.strength-segment {
    height: 0.375rem;
    border-radius: 999px;
    background: #e4e4e7;
    transition: background-color 200ms ease;
}

/* data-level from Low="2" / High="3"; data-filled from the Template */
.strength-meter[data-level="low"]     .strength-segment[data-filled] { background: #dc2626; }
.strength-meter[data-level="optimum"] .strength-segment[data-filled] { background: #d97706; }
.strength-meter[data-level="high"]    .strength-segment[data-filled] { background: #16a34a; }

.progress-label  { font-weight: 600; color: #18181b; }
.progress-status { color: #71717a; font-size: 0.8rem; font-variant-numeric: tabular-nums; }